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SUSE:SLE-15-SP2:GA
openssh.18131
openssh-7.6p1-gssapi_key_exchange.patch
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File openssh-7.6p1-gssapi_key_exchange.patch of Package openssh.18131
# HG changeset patch # Parent cecae3493b46b71dc33441caf0804cf5225d834e Index: openssh-7.6p1/Makefile.in =================================================================== --- openssh-7.6p1.orig/Makefile.in 2019-03-11 22:12:16.456130058 +0100 +++ openssh-7.6p1/Makefile.in 2019-03-11 22:12:25.872179597 +0100 @@ -100,6 +100,8 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \ LIBSSH_OBJS += fips.o +LIBSSH_OBJS += kexgssc.o kexgsss.o + SSHOBJS= ssh.o readconf.o clientloop.o sshtty.o \ sshconnect.o sshconnect2.o mux.o Index: openssh-7.6p1/auth-krb5.c =================================================================== --- openssh-7.6p1.orig/auth-krb5.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/auth-krb5.c 2019-03-11 22:12:16.544130519 +0100 @@ -182,8 +182,13 @@ auth_krb5_password(Authctxt *authctxt, c len = strlen(authctxt->krb5_ticket_file) + 6; authctxt->krb5_ccname = xmalloc(len); +#ifdef USE_CCAPI + snprintf(authctxt->krb5_ccname, len, "API:%s", + authctxt->krb5_ticket_file); +#else snprintf(authctxt->krb5_ccname, len, "FILE:%s", authctxt->krb5_ticket_file); +#endif #ifdef USE_PAM if (options.use_pam) @@ -243,12 +248,18 @@ ssh_krb5_cc_gen(krb5_context ctx, krb5_c int tmpfd, ret, oerrno; char ccname[40]; mode_t old_umask; +#ifdef USE_CCAPI + char cctemplate[] = "API:krb5cc_%d"; +#else + char cctemplate[] = "FILE:/tmp/krb5cc_%d_XXXXXXXXXX"; +#endif ret = snprintf(ccname, sizeof(ccname), - "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid()); + cctemplate, geteuid()); if (ret < 0 || (size_t)ret >= sizeof(ccname)) return ENOMEM; +#ifndef USE_CCAPI old_umask = umask(0177); tmpfd = mkstemp(ccname + strlen("FILE:")); oerrno = errno; @@ -265,6 +276,7 @@ ssh_krb5_cc_gen(krb5_context ctx, krb5_c return oerrno; } close(tmpfd); +#endif return (krb5_cc_resolve(ctx, ccname, ccache)); } Index: openssh-7.6p1/auth.c =================================================================== --- openssh-7.6p1.orig/auth.c 2019-03-11 22:12:16.316129321 +0100 +++ openssh-7.6p1/auth.c 2019-03-11 22:12:25.872179597 +0100 @@ -395,6 +395,7 @@ auth_root_allowed(const char *method) case PERMIT_NO_PASSWD: if (strcmp(method, "publickey") == 0 || strcmp(method, "hostbased") == 0 || + strcmp(method, "gssapi-keyex") == 0 || strcmp(method, "gssapi-with-mic") == 0) return 1; break; Index: openssh-7.6p1/auth2-gss.c =================================================================== --- openssh-7.6p1.orig/auth2-gss.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/auth2-gss.c 2019-03-11 22:12:24.852174230 +0100 @@ -1,7 +1,7 @@ /* $OpenBSD: auth2-gss.c,v 1.26 2017/06/24 06:34:38 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -31,6 +31,7 @@ #include <sys/types.h> #include <stdarg.h> +#include <string.h> #include "xmalloc.h" #include "key.h" @@ -53,6 +54,41 @@ static int input_gssapi_mic(int type, u_ static int input_gssapi_exchange_complete(int type, u_int32_t plen, struct ssh *ssh); static int input_gssapi_errtok(int, u_int32_t, struct ssh *); +/* + * The 'gssapi_keyex' userauth mechanism. + */ +static int +userauth_gsskeyex(struct ssh *ssh) +{ + Authctxt *authctxt = ssh->authctxt; + int authenticated = 0; + Buffer b; + gss_buffer_desc mic, gssbuf; + u_int len; + + mic.value = packet_get_string(&len); + mic.length = len; + + packet_check_eom(); + + ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service, + "gssapi-keyex"); + + gssbuf.value = buffer_ptr(&b); + gssbuf.length = buffer_len(&b); + + /* gss_kex_context is NULL with privsep, so we can't check it here */ + if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, + &gssbuf, &mic)))) + authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user, + authctxt->pw)); + + buffer_free(&b); + free(mic.value); + + return (authenticated); +} + /* * We only support those mechanisms that we know about (ie ones that we know * how to check local user kuserok and the like) @@ -240,7 +276,8 @@ input_gssapi_exchange_complete(int type, packet_check_eom(); - authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); + authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user, + authctxt->pw)); if ((!use_privsep || mm_is_monitor()) && (displayname = ssh_gssapi_displayname()) != NULL) @@ -281,7 +318,8 @@ input_gssapi_mic(int type, u_int32_t ple gssbuf.length = buffer_len(&b); if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic)))) - authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); + authenticated = + PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw)); else logit("GSSAPI MIC check failed"); @@ -301,6 +339,12 @@ input_gssapi_mic(int type, u_int32_t ple return 0; } +Authmethod method_gsskeyex = { + "gssapi-keyex", + userauth_gsskeyex, + &options.gss_authentication +}; + Authmethod method_gssapi = { "gssapi-with-mic", userauth_gssapi, Index: openssh-7.6p1/auth2.c =================================================================== --- openssh-7.6p1.orig/auth2.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/auth2.c 2019-03-11 22:12:25.872179597 +0100 @@ -72,6 +72,7 @@ extern Authmethod method_passwd; extern Authmethod method_kbdint; extern Authmethod method_hostbased; #ifdef GSSAPI +extern Authmethod method_gsskeyex; extern Authmethod method_gssapi; #endif @@ -79,6 +80,7 @@ Authmethod *authmethods[] = { &method_none, &method_pubkey, #ifdef GSSAPI + &method_gsskeyex, &method_gssapi, #endif &method_passwd, Index: openssh-7.6p1/clientloop.c =================================================================== --- openssh-7.6p1.orig/clientloop.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/clientloop.c 2019-03-11 22:12:16.544130519 +0100 @@ -112,6 +112,10 @@ #include "ssherr.h" #include "hostfile.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* import options */ extern Options options; @@ -1349,9 +1353,18 @@ client_loop(struct ssh *ssh, int have_pt break; /* Do channel operations unless rekeying in progress. */ - if (!ssh_packet_is_rekeying(ssh)) + if (!ssh_packet_is_rekeying(ssh)) { channel_after_select(ssh, readset, writeset); +#ifdef GSSAPI + if (options.gss_renewal_rekey && + ssh_gssapi_credentials_updated((Gssctxt *)NULL)) { + debug("credentials updated - forcing rekey"); + need_rekeying = 1; + } +#endif + } + /* Buffer input from the connection. */ client_process_net_input(readset); Index: openssh-7.6p1/configure.ac =================================================================== --- openssh-7.6p1.orig/configure.ac 2019-03-11 22:12:16.528130435 +0100 +++ openssh-7.6p1/configure.ac 2019-03-11 22:12:25.688178629 +0100 @@ -621,6 +621,30 @@ main() { if (NSVersionOfRunTimeLibrary(" [Use tunnel device compatibility to OpenBSD]) AC_DEFINE([SSH_TUN_PREPEND_AF], [1], [Prepend the address family to IP tunnel traffic]) + AC_MSG_CHECKING(if we have the Security Authorization Session API) + AC_TRY_COMPILE([#include <Security/AuthSession.h>], + [SessionCreate(0, 0);], + [ac_cv_use_security_session_api="yes" + AC_DEFINE(USE_SECURITY_SESSION_API, 1, + [platform has the Security Authorization Session API]) + LIBS="$LIBS -framework Security" + AC_MSG_RESULT(yes)], + [ac_cv_use_security_session_api="no" + AC_MSG_RESULT(no)]) + AC_MSG_CHECKING(if we have an in-memory credentials cache) + AC_TRY_COMPILE( + [#include <Kerberos/Kerberos.h>], + [cc_context_t c; + (void) cc_initialize (&c, 0, NULL, NULL);], + [AC_DEFINE(USE_CCAPI, 1, + [platform uses an in-memory credentials cache]) + LIBS="$LIBS -framework Security" + AC_MSG_RESULT(yes) + if test "x$ac_cv_use_security_session_api" = "xno"; then + AC_MSG_ERROR(*** Need a security framework to use the credentials cache API ***) + fi], + [AC_MSG_RESULT(no)] + ) m4_pattern_allow([AU_IPv]) AC_CHECK_DECL([AU_IPv4], [], AC_DEFINE([AU_IPv4], [0], [System only supports IPv4 audit records]) Index: openssh-7.6p1/gss-genr.c =================================================================== --- openssh-7.6p1.orig/gss-genr.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/gss-genr.c 2019-03-11 22:12:25.688178629 +0100 @@ -1,7 +1,7 @@ /* $OpenBSD: gss-genr.c,v 1.24 2016/09/12 01:22:38 deraadt Exp $ */ /* - * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -40,12 +40,167 @@ #include "buffer.h" #include "log.h" #include "ssh2.h" +#include "cipher.h" +#include "key.h" +#include "kex.h" +#include <openssl/evp.h> #include "ssh-gss.h" extern u_char *session_id2; extern u_int session_id2_len; +typedef struct { + char *encoded; + gss_OID oid; +} ssh_gss_kex_mapping; + +/* + * XXX - It would be nice to find a more elegant way of handling the + * XXX passing of the key exchange context to the userauth routines + */ + +Gssctxt *gss_kex_context = NULL; + +static ssh_gss_kex_mapping *gss_enc2oid = NULL; + +int +ssh_gssapi_oid_table_ok() { + return (gss_enc2oid != NULL); +} + +/* + * Return a list of the gss-group1-sha1 mechanisms supported by this program + * + * We test mechanisms to ensure that we can use them, to avoid starting + * a key exchange with a bad mechanism + */ + +char * +ssh_gssapi_client_mechanisms(const char *host, const char *client) { + gss_OID_set gss_supported; + OM_uint32 min_status; + + if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported))) + return NULL; + + return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism, + host, client)); +} + +char * +ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check, + const char *host, const char *client) { + Buffer buf; + size_t i; + int oidpos, enclen; + char *mechs, *encoded; + u_char digest[EVP_MAX_MD_SIZE]; + char deroid[2]; + const EVP_MD *evp_md = EVP_md5(); + EVP_MD_CTX md; + + if (gss_enc2oid != NULL) { + for (i = 0; gss_enc2oid[i].encoded != NULL; i++) + free(gss_enc2oid[i].encoded); + free(gss_enc2oid); + } + + gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) * + (gss_supported->count + 1)); + + buffer_init(&buf); + + oidpos = 0; + for (i = 0; i < gss_supported->count; i++) { + if (gss_supported->elements[i].length < 128 && + (*check)(NULL, &(gss_supported->elements[i]), host, client)) { + + deroid[0] = SSH_GSS_OIDTYPE; + deroid[1] = gss_supported->elements[i].length; + + EVP_DigestInit(&md, evp_md); + EVP_DigestUpdate(&md, deroid, 2); + EVP_DigestUpdate(&md, + gss_supported->elements[i].elements, + gss_supported->elements[i].length); + EVP_DigestFinal(&md, digest, NULL); + + encoded = xmalloc(EVP_MD_size(evp_md) * 2); + enclen = __b64_ntop(digest, EVP_MD_size(evp_md), + encoded, EVP_MD_size(evp_md) * 2); + + if (oidpos != 0) + buffer_put_char(&buf, ','); + + buffer_append(&buf, KEX_GSS_GEX_SHA1_ID, + sizeof(KEX_GSS_GEX_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + buffer_put_char(&buf, ','); + buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID, + sizeof(KEX_GSS_GRP1_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + buffer_put_char(&buf, ','); + buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID, + sizeof(KEX_GSS_GRP14_SHA1_ID) - 1); + buffer_append(&buf, encoded, enclen); + + gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]); + gss_enc2oid[oidpos].encoded = encoded; + oidpos++; + } + } + gss_enc2oid[oidpos].oid = NULL; + gss_enc2oid[oidpos].encoded = NULL; + + buffer_put_char(&buf, '\0'); + + mechs = xmalloc(buffer_len(&buf)); + buffer_get(&buf, mechs, buffer_len(&buf)); + buffer_free(&buf); + + if (strlen(mechs) == 0) { + free(mechs); + mechs = NULL; + } + + return (mechs); +} + +gss_OID +ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) { + int i = 0; + + switch (kex_type) { + case KEX_GSS_GRP1_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GRP1_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1; + break; + case KEX_GSS_GRP14_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GRP14_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1; + break; + case KEX_GSS_GEX_SHA1: + if (strlen(name) < sizeof(KEX_GSS_GEX_SHA1_ID)) + return GSS_C_NO_OID; + name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1; + break; + default: + return GSS_C_NO_OID; + } + + while (gss_enc2oid[i].encoded != NULL && + strcmp(name, gss_enc2oid[i].encoded) != 0) + i++; + + if (gss_enc2oid[i].oid != NULL && ctx != NULL) + ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid); + + return gss_enc2oid[i].oid; +} + /* Check that the OID in a data stream matches that in the context */ int ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len) @@ -198,7 +353,7 @@ ssh_gssapi_init_ctx(Gssctxt *ctx, int de } ctx->major = gss_init_sec_context(&ctx->minor, - GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid, + ctx->client_creds, &ctx->context, ctx->name, ctx->oid, GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag, 0, NULL, recv_tok, NULL, send_tok, flags, NULL); @@ -228,8 +383,42 @@ ssh_gssapi_import_name(Gssctxt *ctx, con } OM_uint32 +ssh_gssapi_client_identity(Gssctxt *ctx, const char *name) +{ + gss_buffer_desc gssbuf; + gss_name_t gssname; + OM_uint32 status; + gss_OID_set oidset; + + gssbuf.value = (void *) name; + gssbuf.length = strlen(gssbuf.value); + + gss_create_empty_oid_set(&status, &oidset); + gss_add_oid_set_member(&status, ctx->oid, &oidset); + + ctx->major = gss_import_name(&ctx->minor, &gssbuf, + GSS_C_NT_USER_NAME, &gssname); + + if (!ctx->major) + ctx->major = gss_acquire_cred(&ctx->minor, + gssname, 0, oidset, GSS_C_INITIATE, + &ctx->client_creds, NULL, NULL); + + gss_release_name(&status, &gssname); + gss_release_oid_set(&status, &oidset); + + if (ctx->major) + ssh_gssapi_error(ctx); + + return(ctx->major); +} + +OM_uint32 ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash) { + if (ctx == NULL) + return -1; + if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context, GSS_C_QOP_DEFAULT, buffer, hash))) ssh_gssapi_error(ctx); @@ -237,6 +426,19 @@ ssh_gssapi_sign(Gssctxt *ctx, gss_buffer return (ctx->major); } +/* Priviledged when used by server */ +OM_uint32 +ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) +{ + if (ctx == NULL) + return -1; + + ctx->major = gss_verify_mic(&ctx->minor, ctx->context, + gssbuf, gssmic, NULL); + + return (ctx->major); +} + void ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service, const char *context) @@ -250,11 +452,16 @@ ssh_gssapi_buildmic(Buffer *b, const cha } int -ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host) +ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host, + const char *client) { gss_buffer_desc token = GSS_C_EMPTY_BUFFER; OM_uint32 major, minor; gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"}; + Gssctxt *intctx = NULL; + + if (ctx == NULL) + ctx = &intctx; /* RFC 4462 says we MUST NOT do SPNEGO */ if (oid->length == spnego_oid.length && @@ -264,6 +471,10 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx ssh_gssapi_build_ctx(ctx); ssh_gssapi_set_oid(*ctx, oid); major = ssh_gssapi_import_name(*ctx, host); + + if (!GSS_ERROR(major) && client) + major = ssh_gssapi_client_identity(*ctx, client); + if (!GSS_ERROR(major)) { major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token, NULL); @@ -273,10 +484,66 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx GSS_C_NO_BUFFER); } - if (GSS_ERROR(major)) + if (GSS_ERROR(major) || intctx != NULL) ssh_gssapi_delete_ctx(ctx); return (!GSS_ERROR(major)); } +int +ssh_gssapi_credentials_updated(Gssctxt *ctxt) { + static gss_name_t saved_name = GSS_C_NO_NAME; + static OM_uint32 saved_lifetime = 0; + static gss_OID saved_mech = GSS_C_NO_OID; + static gss_name_t name; + static OM_uint32 last_call = 0; + OM_uint32 lifetime, now, major, minor; + int equal; + + now = time(NULL); + + if (ctxt) { + debug("Rekey has happened - updating saved versions"); + + if (saved_name != GSS_C_NO_NAME) + gss_release_name(&minor, &saved_name); + + major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL, + &saved_name, &saved_lifetime, NULL, NULL); + + if (!GSS_ERROR(major)) { + saved_mech = ctxt->oid; + saved_lifetime+= now; + } else { + /* Handle the error */ + } + return 0; + } + + if (now - last_call < 10) + return 0; + + last_call = now; + + if (saved_mech == GSS_C_NO_OID) + return 0; + + major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL, + &name, &lifetime, NULL, NULL); + if (major == GSS_S_CREDENTIALS_EXPIRED) + return 0; + else if (GSS_ERROR(major)) + return 0; + + major = gss_compare_name(&minor, saved_name, name, &equal); + gss_release_name(&minor, &name); + if (GSS_ERROR(major)) + return 0; + + if (equal && (saved_lifetime < lifetime + now - 10)) + return 1; + + return 0; +} + #endif /* GSSAPI */ Index: openssh-7.6p1/gss-serv-krb5.c =================================================================== --- openssh-7.6p1.orig/gss-serv-krb5.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/gss-serv-krb5.c 2019-03-11 22:12:16.544130519 +0100 @@ -121,7 +121,7 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl krb5_error_code problem; krb5_principal princ; OM_uint32 maj_status, min_status; - int len; + const char *new_ccname, *new_cctype; const char *errmsg; if (client->creds == NULL) { @@ -181,11 +181,26 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl return; } - client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache)); + new_cctype = krb5_cc_get_type(krb_context, ccache); + new_ccname = krb5_cc_get_name(krb_context, ccache); + client->store.envvar = "KRB5CCNAME"; - len = strlen(client->store.filename) + 6; - client->store.envval = xmalloc(len); - snprintf(client->store.envval, len, "FILE:%s", client->store.filename); +#ifdef USE_CCAPI + xasprintf(&client->store.envval, "API:%s", new_ccname); + client->store.filename = NULL; +#else + if (new_ccname[0] == ':') + new_ccname++; + xasprintf(&client->store.envval, "%s:%s", new_cctype, new_ccname); + if (strcmp(new_cctype, "DIR") == 0) { + char *p; + p = strrchr(client->store.envval, '/'); + if (p) + *p = '\0'; + } + if ((strcmp(new_cctype, "FILE") == 0) || (strcmp(new_cctype, "DIR") == 0)) + client->store.filename = xstrdup(new_ccname); +#endif #ifdef USE_PAM if (options.use_pam) @@ -194,9 +209,76 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_cl krb5_cc_close(krb_context, ccache); + client->store.data = krb_context; + return; } +int +ssh_gssapi_krb5_updatecreds(ssh_gssapi_ccache *store, + ssh_gssapi_client *client) +{ + krb5_ccache ccache = NULL; + krb5_principal principal = NULL; + char *name = NULL; + krb5_error_code problem; + OM_uint32 maj_status, min_status; + + if ((problem = krb5_cc_resolve(krb_context, store->envval, &ccache))) { + logit("krb5_cc_resolve(): %.100s", + krb5_get_err_text(krb_context, problem)); + return 0; + } + + /* Find out who the principal in this cache is */ + if ((problem = krb5_cc_get_principal(krb_context, ccache, + &principal))) { + logit("krb5_cc_get_principal(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_cc_close(krb_context, ccache); + return 0; + } + + if ((problem = krb5_unparse_name(krb_context, principal, &name))) { + logit("krb5_unparse_name(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + return 0; + } + + + if (strcmp(name,client->exportedname.value)!=0) { + debug("Name in local credentials cache differs. Not storing"); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + krb5_free_unparsed_name(krb_context, name); + return 0; + } + krb5_free_unparsed_name(krb_context, name); + + /* Name matches, so lets get on with it! */ + + if ((problem = krb5_cc_initialize(krb_context, ccache, principal))) { + logit("krb5_cc_initialize(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_free_principal(krb_context, principal); + krb5_cc_close(krb_context, ccache); + return 0; + } + + krb5_free_principal(krb_context, principal); + + if ((maj_status = gss_krb5_copy_ccache(&min_status, client->creds, + ccache))) { + logit("gss_krb5_copy_ccache() failed. Sorry!"); + krb5_cc_close(krb_context, ccache); + return 0; + } + + return 1; +} + ssh_gssapi_mech gssapi_kerberos_mech = { "toWM5Slw5Ew8Mqkay+al2g==", "Kerberos", @@ -204,7 +286,8 @@ ssh_gssapi_mech gssapi_kerberos_mech = { NULL, &ssh_gssapi_krb5_userok, NULL, - &ssh_gssapi_krb5_storecreds + &ssh_gssapi_krb5_storecreds, + &ssh_gssapi_krb5_updatecreds }; #endif /* KRB5 */ Index: openssh-7.6p1/gss-serv.c =================================================================== --- openssh-7.6p1.orig/gss-serv.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/gss-serv.c 2019-03-11 22:12:16.544130519 +0100 @@ -1,7 +1,7 @@ /* $OpenBSD: gss-serv.c,v 1.30 2017/06/24 06:34:38 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -45,17 +45,19 @@ #include "session.h" #include "misc.h" #include "servconf.h" +#include "uidswap.h" #include "ssh-gss.h" +#include "monitor_wrap.h" extern ServerOptions options; static ssh_gssapi_client gssapi_client = { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER, - GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL, NULL}}; + GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, NULL, {NULL, NULL, NULL, NULL, NULL}, 0, 0}; ssh_gssapi_mech gssapi_null_mech = - { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL}; + { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL}; #ifdef KRB5 extern ssh_gssapi_mech gssapi_kerberos_mech; @@ -142,6 +144,28 @@ ssh_gssapi_server_ctx(Gssctxt **ctx, gss } /* Unprivileged */ +char * +ssh_gssapi_server_mechanisms() { + if (supported_oids == NULL) + ssh_gssapi_prepare_supported_oids(); + return (ssh_gssapi_kex_mechs(supported_oids, + &ssh_gssapi_server_check_mech, NULL, NULL)); +} + +/* Unprivileged */ +int +ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data, + const char *dummy) { + Gssctxt *ctx = NULL; + int res; + + res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid))); + ssh_gssapi_delete_ctx(&ctx); + + return (res); +} + +/* Unprivileged */ void ssh_gssapi_supported_oids(gss_OID_set *oidset) { @@ -151,7 +175,9 @@ ssh_gssapi_supported_oids(gss_OID_set *o gss_OID_set supported; gss_create_empty_oid_set(&min_status, oidset); - gss_indicate_mechs(&min_status, &supported); + + if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported))) + return; while (supported_mechs[i]->name != NULL) { if (GSS_ERROR(gss_test_oid_set_member(&min_status, @@ -277,8 +303,48 @@ OM_uint32 ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) { int i = 0; + int equal = 0; + gss_name_t new_name = GSS_C_NO_NAME; + gss_buffer_desc ename = GSS_C_EMPTY_BUFFER; + + if (options.gss_store_rekey && client->used && ctx->client_creds) { + if (client->mech->oid.length != ctx->oid->length || + (memcmp(client->mech->oid.elements, + ctx->oid->elements, ctx->oid->length) !=0)) { + debug("Rekeyed credentials have different mechanism"); + return GSS_S_COMPLETE; + } + + if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor, + ctx->client_creds, ctx->oid, &new_name, + NULL, NULL, NULL))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + + ctx->major = gss_compare_name(&ctx->minor, client->name, + new_name, &equal); + + if (GSS_ERROR(ctx->major)) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + + if (!equal) { + debug("Rekeyed credentials have different name"); + return GSS_S_COMPLETE; + } + + debug("Marking rekeyed credentials for export"); - gss_buffer_desc ename; + gss_release_name(&ctx->minor, &client->name); + gss_release_cred(&ctx->minor, &client->creds); + client->name = new_name; + client->creds = ctx->client_creds; + ctx->client_creds = GSS_C_NO_CREDENTIAL; + client->updated = 1; + return GSS_S_COMPLETE; + } client->mech = NULL; @@ -293,6 +359,13 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_g if (client->mech == NULL) return GSS_S_FAILURE; + if (ctx->client_creds && + (ctx->major = gss_inquire_cred_by_mech(&ctx->minor, + ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + if ((ctx->major = gss_display_name(&ctx->minor, ctx->client, &client->displayname, NULL))) { ssh_gssapi_error(ctx); @@ -310,6 +383,8 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_g return (ctx->major); } + gss_release_buffer(&ctx->minor, &ename); + /* We can't copy this structure, so we just move the pointer to it */ client->creds = ctx->client_creds; ctx->client_creds = GSS_C_NO_CREDENTIAL; @@ -320,11 +395,21 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_g void ssh_gssapi_cleanup_creds(void) { - if (gssapi_client.store.filename != NULL) { - /* Unlink probably isn't sufficient */ - debug("removing gssapi cred file\"%s\"", - gssapi_client.store.filename); - unlink(gssapi_client.store.filename); + /* TODO */ + krb5_ccache ccache = NULL; + krb5_error_code problem; + + if (gssapi_client.store.data != NULL) { + if ((problem = krb5_cc_resolve(gssapi_client.store.data, gssapi_client.store.envval, &ccache))) { + debug("%s: krb5_cc_resolve(): %.100s", __func__, + krb5_get_err_text(gssapi_client.store.data, problem)); + } else if ((problem = krb5_cc_destroy(gssapi_client.store.data, ccache))) { + debug("%s: krb5_cc_resolve(): %.100s", __func__, + krb5_get_err_text(gssapi_client.store.data, problem)); + } else { + krb5_free_context(gssapi_client.store.data); + gssapi_client.store.data = NULL; + } } } @@ -357,7 +442,7 @@ ssh_gssapi_do_child(char ***envp, u_int /* Privileged */ int -ssh_gssapi_userok(char *user) +ssh_gssapi_userok(char *user, struct passwd *pw) { OM_uint32 lmin; @@ -367,9 +452,11 @@ ssh_gssapi_userok(char *user) return 0; } if (gssapi_client.mech && gssapi_client.mech->userok) - if ((*gssapi_client.mech->userok)(&gssapi_client, user)) + if ((*gssapi_client.mech->userok)(&gssapi_client, user)) { + gssapi_client.used = 1; + gssapi_client.store.owner = pw; return 1; - else { + } else { /* Destroy delegated credentials if userok fails */ gss_release_buffer(&lmin, &gssapi_client.displayname); gss_release_buffer(&lmin, &gssapi_client.exportedname); @@ -383,14 +470,90 @@ ssh_gssapi_userok(char *user) return (0); } -/* Privileged */ -OM_uint32 -ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) +/* These bits are only used for rekeying. The unpriviledged child is running + * as the user, the monitor is root. + * + * In the child, we want to : + * *) Ask the monitor to store our credentials into the store we specify + * *) If it succeeds, maybe do a PAM update + */ + +/* Stuff for PAM */ + +#ifdef USE_PAM +static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg, + struct pam_response **resp, void *data) { - ctx->major = gss_verify_mic(&ctx->minor, ctx->context, - gssbuf, gssmic, NULL); + return (PAM_CONV_ERR); +} +#endif - return (ctx->major); +void +ssh_gssapi_rekey_creds() { + int ok; + int ret; +#ifdef USE_PAM + pam_handle_t *pamh = NULL; + struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL}; + char *envstr; +#endif + + if (gssapi_client.store.filename == NULL && + gssapi_client.store.envval == NULL && + gssapi_client.store.envvar == NULL) + return; + + ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store)); + + if (!ok) + return; + + debug("Rekeyed credentials stored successfully"); + + /* Actually managing to play with the ssh pam stack from here will + * be next to impossible. In any case, we may want different options + * for rekeying. So, use our own :) + */ +#ifdef USE_PAM + if (!use_privsep) { + debug("Not even going to try and do PAM with privsep disabled"); + return; + } + + ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name, + &pamconv, &pamh); + if (ret) + return; + + xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar, + gssapi_client.store.envval); + + ret = pam_putenv(pamh, envstr); + if (!ret) + pam_setcred(pamh, PAM_REINITIALIZE_CRED); + pam_end(pamh, PAM_SUCCESS); +#endif +} + +int +ssh_gssapi_update_creds(ssh_gssapi_ccache *store) { + int ok = 0; + + /* Check we've got credentials to store */ + if (!gssapi_client.updated) + return 0; + + gssapi_client.updated = 0; + + temporarily_use_uid(gssapi_client.store.owner); + if (gssapi_client.mech && gssapi_client.mech->updatecreds) + ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client); + else + debug("No update function for this mechanism"); + + restore_uid(); + + return ok; } /* Privileged */ Index: openssh-7.6p1/kex.c =================================================================== --- openssh-7.6p1.orig/kex.c 2019-03-11 22:12:16.420129867 +0100 +++ openssh-7.6p1/kex.c 2019-03-11 22:12:25.872179597 +0100 @@ -56,6 +56,10 @@ #include "fips.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* prototype */ static int kex_choose_conf(struct ssh *); static int kex_input_newkeys(int, u_int32_t, struct ssh *); @@ -105,6 +109,11 @@ static const struct kexalg kexalgs_all[] { KEX_CURVE25519_SHA256, KEX_C25519_SHA256, 0, SSH_DIGEST_SHA256 }, { KEX_CURVE25519_SHA256_OLD, KEX_C25519_SHA256, 0, SSH_DIGEST_SHA256 }, #endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */ +#ifdef GSSAPI + { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 }, + { KEX_GSS_GRP1_SHA1_ID, KEX_GSS_GRP1_SHA1, 0, SSH_DIGEST_SHA1 }, + { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 }, +#endif { NULL, -1, -1, -1}, }; @@ -129,6 +138,10 @@ static const struct kexalg kexalgs_fips1 # endif /* OPENSSL_HAS_NISTP521 */ #endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ +#ifdef GSSAPI + { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 }, + { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 }, +#endif { NULL, -1, -1, -1}, }; @@ -179,6 +192,12 @@ kex_alg_by_name(const char *name) for (k = fips_select_kexalgs(); k->name != NULL; k++) { if (strcmp(k->name, name) == 0) return k; +#ifdef GSSAPI + if (strncmp(name, "gss-", 4) == 0) { + if (strncmp(k->name, name, strlen(k->name)) == 0) + return k; + } +#endif } return NULL; } Index: openssh-7.6p1/kex.h =================================================================== --- openssh-7.6p1.orig/kex.h 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/kex.h 2019-03-11 22:12:25.872179597 +0100 @@ -99,6 +99,11 @@ enum kex_exchange { KEX_DH_GEX_SHA256, KEX_ECDH_SHA2, KEX_C25519_SHA256, +#ifdef GSSAPI + KEX_GSS_GRP1_SHA1, + KEX_GSS_GRP14_SHA1, + KEX_GSS_GEX_SHA1, +#endif KEX_MAX }; @@ -147,6 +152,12 @@ struct kex { u_int flags; int hash_alg; int ec_nid; +#ifdef GSSAPI + int gss_deleg_creds; + int gss_trust_dns; + char *gss_host; + char *gss_client; +#endif char *client_version_string; char *server_version_string; char *failed_choice; @@ -196,6 +207,10 @@ int kexecdh_client(struct ssh *); int kexecdh_server(struct ssh *); int kexc25519_client(struct ssh *); int kexc25519_server(struct ssh *); +#ifdef GSSAPI +int kexgss_client(struct ssh *); +int kexgss_server(struct ssh *); +#endif int kex_dh_hash(int, const char *, const char *, const u_char *, size_t, const u_char *, size_t, const u_char *, size_t, Index: openssh-7.6p1/kexgssc.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ openssh-7.6p1/kexgssc.c 2019-03-11 22:15:41.125206910 +0100 @@ -0,0 +1,353 @@ +/* + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef GSSAPI + +#include "includes.h" + +#include <openssl/crypto.h> +#include <openssl/bn.h> + +#include <string.h> + +#include "xmalloc.h" +#include "buffer.h" +#include "ssh2.h" +#include "key.h" +#include "cipher.h" +#include "digest.h" +#include "kex.h" +#include "log.h" +#include "packet.h" +#include "dh.h" + +#include "ssh-gss.h" + +#include "fips.h" + +int +kexgss_client(struct ssh *ssh) +{ + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + gss_buffer_desc recv_tok, gssbuf, msg_tok, *token_ptr; + Gssctxt *ctxt; + OM_uint32 maj_status, min_status, ret_flags; + u_int klen, kout, slen = 0, strlen; + DH *dh; + BIGNUM *dh_server_pub = NULL; + BIGNUM *shared_secret = NULL; + BIGNUM *p = NULL; + BIGNUM *g = NULL; + u_char *kbuf; + u_char *serverhostkey = NULL; + u_char *empty = ""; + char *msg; + /* TODO + char *lang; + */ + int type = 0; + int first = 1; + int nbits = 0, min = DH_GRP_MIN, max = DH_GRP_MAX; + int p_bitlen; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t hashlen; + + /* Initialise our GSSAPI world */ + ssh_gssapi_build_ctx(&ctxt); + if (ssh_gssapi_id_kex(ctxt, ssh->kex->name, ssh->kex->kex_type) + == GSS_C_NO_OID) + fatal("Couldn't identify host exchange"); + + if (ssh_gssapi_import_name(ctxt, ssh->kex->gss_host)) + fatal("Couldn't import hostname"); + + if (ssh->kex->gss_client && + ssh_gssapi_client_identity(ctxt, ssh->kex->gss_client)) + fatal("Couldn't acquire client credentials"); + + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + dh = dh_new_group1(); + explicit_bzero(kbuf, klen); + break; + case KEX_GSS_GRP14_SHA1: + dh = dh_new_group14(); + break; + case KEX_GSS_GEX_SHA1: + debug("Doing group exchange\n"); + nbits = dh_estimate(ssh->kex->we_need * 8); + packet_start(SSH2_MSG_KEXGSS_GROUPREQ); + packet_put_int(min); + packet_put_int(nbits); + packet_put_int(max); + + packet_send(); + + packet_read_expect(SSH2_MSG_KEXGSS_GROUP); + + if ((p = BN_new()) == NULL) + fatal("BN_new() failed"); + packet_get_bignum2(p); + p_bitlen = BN_num_bits(p); + if ((g = BN_new()) == NULL) + fatal("BN_new() failed"); + packet_get_bignum2(g); + packet_check_eom(); + + if (p_bitlen < min || p_bitlen > max) { + fatal("GSSGRP_GEX group out of range: %d !< %d !< %d", + min, p_bitlen, max); + } + + dh = dh_new_group(g, p); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + /* Step 1 - e is dh->pub_key */ + dh_gen_key(dh, ssh->kex->we_need * 8); + + /* This is f, we initialise it now to make life easier */ + dh_server_pub = BN_new(); + if (dh_server_pub == NULL) + fatal("dh_server_pub == NULL"); + + token_ptr = GSS_C_NO_BUFFER; + + do { + debug("Calling gss_init_sec_context"); + + maj_status = ssh_gssapi_init_ctx(ctxt, + ssh->kex->gss_deleg_creds, token_ptr, &send_tok, + &ret_flags); + + if (GSS_ERROR(maj_status)) { + if (send_tok.length != 0) { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, + send_tok.length); + } + fatal("gss_init_context failed"); + } + + /* If we've got an old receive buffer get rid of it */ + if (token_ptr != GSS_C_NO_BUFFER) + free(recv_tok.value); + + if (maj_status == GSS_S_COMPLETE) { + /* If mutual state flag is not true, kex fails */ + if (!(ret_flags & GSS_C_MUTUAL_FLAG)) + fatal("Mutual authentication failed"); + + /* If integ avail flag is not true kex fails */ + if (!(ret_flags & GSS_C_INTEG_FLAG)) + fatal("Integrity check failed"); + } + + /* + * If we have data to send, then the last message that we + * received cannot have been a 'complete'. + */ + if (send_tok.length != 0) { + if (first) { + packet_start(SSH2_MSG_KEXGSS_INIT); + packet_put_string(send_tok.value, + send_tok.length); + packet_put_bignum2(dh->pub_key); + first = 0; + } else { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, + send_tok.length); + } + packet_send(); + gss_release_buffer(&min_status, &send_tok); + + /* If we've sent them data, they should reply */ + do { + type = packet_read(); + if (type == SSH2_MSG_KEXGSS_HOSTKEY) { + debug("Received KEXGSS_HOSTKEY"); + if (serverhostkey) + fatal("Server host key received more than once"); + serverhostkey = + packet_get_string(&slen); + } + } while (type == SSH2_MSG_KEXGSS_HOSTKEY); + + switch (type) { + case SSH2_MSG_KEXGSS_CONTINUE: + debug("Received GSSAPI_CONTINUE"); + if (maj_status == GSS_S_COMPLETE) + fatal("GSSAPI Continue received from server when complete"); + recv_tok.value = packet_get_string(&strlen); + recv_tok.length = strlen; + break; + case SSH2_MSG_KEXGSS_COMPLETE: + debug("Received GSSAPI_COMPLETE"); + packet_get_bignum2(dh_server_pub); + msg_tok.value = packet_get_string(&strlen); + msg_tok.length = strlen; + + /* Is there a token included? */ + if (packet_get_char()) { + recv_tok.value= + packet_get_string(&strlen); + recv_tok.length = strlen; + /* If we're already complete - protocol error */ + if (maj_status == GSS_S_COMPLETE) + packet_disconnect("Protocol error: received token when complete"); + } else { + /* No token included */ + if (maj_status != GSS_S_COMPLETE) + packet_disconnect("Protocol error: did not receive final token"); + } + break; + case SSH2_MSG_KEXGSS_ERROR: + debug("Received Error"); + maj_status = packet_get_int(); + min_status = packet_get_int(); + msg = packet_get_string(NULL); + /* TODO + lang = packet_get_string(NULL); + */ + fatal("GSSAPI Error: \n%.400s",msg); + default: + packet_disconnect("Protocol error: didn't expect packet type %d", + type); + } + token_ptr = &recv_tok; + } else { + /* No data, and not complete */ + if (maj_status != GSS_S_COMPLETE) + fatal("Not complete, and no token output"); + } + } while (maj_status & GSS_S_CONTINUE_NEEDED); + + /* + * We _must_ have received a COMPLETE message in reply from the + * server, which will have set dh_server_pub and msg_tok + */ + + if (type != SSH2_MSG_KEXGSS_COMPLETE) + fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it"); + + /* Check f in range [1, p-1] */ + if (!dh_pub_is_valid(dh, dh_server_pub)) + packet_disconnect("bad server public DH value"); + + /* compute K=f^x mod p */ + klen = DH_size(dh); + kbuf = xmalloc(klen); + kout = DH_compute_key(kbuf, dh_server_pub, dh); + if ((int)kout < 0) + fatal("DH_compute_key: failed"); + + shared_secret = BN_new(); + if (shared_secret == NULL) + fatal("kexgss_client: BN_new failed"); + + if (BN_bin2bn(kbuf, kout, shared_secret) == NULL) + fatal("kexdh_client: BN_bin2bn failed"); + + explicit_bzero(kbuf, klen); + free(kbuf); + + hashlen = sizeof(hash); + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + case KEX_GSS_GRP14_SHA1: + kex_dh_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, + ssh->kex->server_version_string, + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + (serverhostkey ? serverhostkey : empty), slen, + dh->pub_key, /* e */ + dh_server_pub, /* f */ + shared_secret, /* K */ + hash, &hashlen + ); + break; + case KEX_GSS_GEX_SHA1: + kexgex_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, + ssh->kex->server_version_string, + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + (serverhostkey ? serverhostkey : empty), slen, + min, nbits, max, + dh->p, dh->g, + dh->pub_key, + dh_server_pub, + shared_secret, + hash, &hashlen + ); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + gssbuf.value = hash; + gssbuf.length = hashlen; + + /* Verify that the hash matches the MIC we just got. */ + if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok))) + packet_disconnect("Hash's MIC didn't verify"); + + free(msg_tok.value); + + DH_free(dh); + if (serverhostkey) + free(serverhostkey); + BN_clear_free(dh_server_pub); + + /* save session id */ + if (ssh->kex->session_id == NULL) { + ssh->kex->session_id_len = hashlen; + ssh->kex->session_id = xmalloc(ssh->kex->session_id_len); + memcpy(ssh->kex->session_id, hash, ssh->kex->session_id_len); + } + + if (ssh->kex->gss_deleg_creds) + ssh_gssapi_credentials_updated(ctxt); + + if (gss_kex_context == NULL) + gss_kex_context = ctxt; + else + ssh_gssapi_delete_ctx(&ctxt); + + /* TODO: check kex_derive_keys_bn return value */ + kex_derive_keys_bn(ssh, hash, hashlen, shared_secret); + BN_clear_free(shared_secret); + explicit_bzero(hash, sizeof(hash)); + return kex_send_newkeys(ssh); +} + +#endif /* GSSAPI */ Index: openssh-7.6p1/kexgsss.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ openssh-7.6p1/kexgsss.c 2019-03-11 22:16:09.189354576 +0100 @@ -0,0 +1,303 @@ +/* + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef GSSAPI + +#include <string.h> + +#include <openssl/crypto.h> +#include <openssl/bn.h> + +#include "xmalloc.h" +#include "buffer.h" +#include "ssh2.h" +#include "key.h" +#include "cipher.h" +#include "kex.h" +#include "log.h" +#include "packet.h" +#include "dh.h" +#include "ssh-gss.h" +#include "monitor_wrap.h" +#include "misc.h" /* servconf.h needs misc.h for struct ForwardOptions */ +#include "servconf.h" +#include "ssh-gss.h" +#include "digest.h" + +#include "fips.h" + +extern ServerOptions options; + +int +kexgss_server(struct ssh *ssh) +{ + OM_uint32 maj_status, min_status; + + /* + * Some GSSAPI implementations use the input value of ret_flags (an + * output variable) as a means of triggering mechanism specific + * features. Initializing it to zero avoids inadvertently + * activating this non-standard behaviour. + */ + + OM_uint32 ret_flags = 0; + gss_buffer_desc gssbuf, recv_tok, msg_tok; + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + Gssctxt *ctxt = NULL; + u_int slen, klen, kout; + u_char *kbuf; + DH *dh; + int min = -1, max = -1, nbits = -1; + int cmin = -1, cmax = -1; /* client proposal */ + BIGNUM *shared_secret = NULL; + BIGNUM *dh_client_pub = NULL; + int type = 0; + gss_OID oid; + char *mechs; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t hashlen; + + /* Initialise GSSAPI */ + + /* If we're rekeying, privsep means that some of the private structures + * in the GSSAPI code are no longer available. This kludges them back + * into life + */ + if (!ssh_gssapi_oid_table_ok()) + if ((mechs = ssh_gssapi_server_mechanisms())) + free(mechs); + + debug2("%s: Identifying %s", __func__, ssh->kex->name); + oid = ssh_gssapi_id_kex(NULL, ssh->kex->name, ssh->kex->kex_type); + if (oid == GSS_C_NO_OID) + fatal("Unknown gssapi mechanism"); + + debug2("%s: Acquiring credentials", __func__); + + if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid)))) + fatal("Unable to acquire credentials for the server"); + + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + dh = dh_new_group1(); + break; + case KEX_GSS_GRP14_SHA1: + dh = dh_new_group14(); + break; + case KEX_GSS_GEX_SHA1: + debug("Doing group exchange"); + packet_read_expect(SSH2_MSG_KEXGSS_GROUPREQ); + /* store client proposal to provide valid signature */ + cmin = packet_get_int(); + nbits = packet_get_int(); + cmax = packet_get_int(); + min = MAX(DH_GRP_MIN, cmin); + max = MIN(DH_GRP_MAX, cmax); + packet_check_eom(); + if (max < min || nbits < min || max < nbits) { + fatal("GSS_GEX, bad parameters: %d !< %d !< %d", + min, nbits, max); + } + dh = PRIVSEP(choose_dh(min, nbits, max)); + if (dh == NULL) + packet_disconnect("Protocol error: no matching group found"); + + packet_start(SSH2_MSG_KEXGSS_GROUP); + packet_put_bignum2(dh->p); + packet_put_bignum2(dh->g); + packet_send(); + + packet_write_wait(); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + dh_gen_key(dh, ssh->kex->we_need * 8); + + do { + debug("Wait SSH2_MSG_GSSAPI_INIT"); + type = packet_read(); + switch(type) { + case SSH2_MSG_KEXGSS_INIT: + if (dh_client_pub != NULL) + fatal("Received KEXGSS_INIT after initialising"); + recv_tok.value = packet_get_string(&slen); + recv_tok.length = slen; + + if ((dh_client_pub = BN_new()) == NULL) + fatal("dh_client_pub == NULL"); + + packet_get_bignum2(dh_client_pub); + + /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */ + break; + case SSH2_MSG_KEXGSS_CONTINUE: + recv_tok.value = packet_get_string(&slen); + recv_tok.length = slen; + break; + default: + packet_disconnect( + "Protocol error: didn't expect packet type %d", + type); + } + + maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok, + &send_tok, &ret_flags)); + + free(recv_tok.value); + + if (maj_status != GSS_S_COMPLETE && send_tok.length == 0) + fatal("Zero length token output when incomplete"); + + if (dh_client_pub == NULL) + fatal("No client public key"); + + if (maj_status & GSS_S_CONTINUE_NEEDED) { + debug("Sending GSSAPI_CONTINUE"); + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + gss_release_buffer(&min_status, &send_tok); + } + } while (maj_status & GSS_S_CONTINUE_NEEDED); + + if (GSS_ERROR(maj_status)) { + if (send_tok.length > 0) { + packet_start(SSH2_MSG_KEXGSS_CONTINUE); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + } + fatal("accept_ctx died"); + } + + if (!(ret_flags & GSS_C_MUTUAL_FLAG)) + fatal("Mutual Authentication flag wasn't set"); + + if (!(ret_flags & GSS_C_INTEG_FLAG)) + fatal("Integrity flag wasn't set"); + + if (!dh_pub_is_valid(dh, dh_client_pub)) + packet_disconnect("bad client public DH value"); + + klen = DH_size(dh); + kbuf = xmalloc(klen); + kout = DH_compute_key(kbuf, dh_client_pub, dh); + if ((int)kout < 0) + fatal("DH_compute_key: failed"); + + shared_secret = BN_new(); + if (shared_secret == NULL) + fatal("kexgss_server: BN_new failed"); + + if (BN_bin2bn(kbuf, kout, shared_secret) == NULL) + fatal("kexgss_server: BN_bin2bn failed"); + + explicit_bzero(kbuf, klen); + free(kbuf); + + hashlen = sizeof(hash); + switch (ssh->kex->kex_type) { + case KEX_GSS_GRP1_SHA1: + case KEX_GSS_GRP14_SHA1: + kex_dh_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, ssh->kex->server_version_string, + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + NULL, 0, /* Change this if we start sending host keys */ + dh_client_pub, dh->pub_key, shared_secret, + hash, &hashlen + ); + break; + case KEX_GSS_GEX_SHA1: + kexgex_hash( + ssh->kex->hash_alg, + ssh->kex->client_version_string, ssh->kex->server_version_string, + buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer), + buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my), + NULL, 0, + cmin, nbits, cmax, + dh->p, dh->g, + dh_client_pub, + dh->pub_key, + shared_secret, + hash, &hashlen + ); + break; + default: + fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type); + } + + BN_clear_free(dh_client_pub); + + if (ssh->kex->session_id == NULL) { + ssh->kex->session_id_len = hashlen; + ssh->kex->session_id = xmalloc(ssh->kex->session_id_len); + memcpy(ssh->kex->session_id, hash, ssh->kex->session_id_len); + } + + gssbuf.value = hash; + gssbuf.length = hashlen; + + if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt,&gssbuf,&msg_tok)))) + fatal("Couldn't get MIC"); + + packet_start(SSH2_MSG_KEXGSS_COMPLETE); + packet_put_bignum2(dh->pub_key); + packet_put_string(msg_tok.value,msg_tok.length); + + if (send_tok.length != 0) { + packet_put_char(1); /* true */ + packet_put_string(send_tok.value, send_tok.length); + } else { + packet_put_char(0); /* false */ + } + packet_send(); + + gss_release_buffer(&min_status, &send_tok); + gss_release_buffer(&min_status, &msg_tok); + + if (gss_kex_context == NULL) + gss_kex_context = ctxt; + else + ssh_gssapi_delete_ctx(&ctxt); + + DH_free(dh); + + /* TODO: check kex_derive_keys_bn return value */ + kex_derive_keys_bn(ssh, hash, hashlen, shared_secret); + BN_clear_free(shared_secret); + explicit_bzero(hash, sizeof(hash)); + kex_send_newkeys(ssh); + + /* If this was a rekey, then save out any delegated credentials we + * just exchanged. */ + if (options.gss_store_rekey) + ssh_gssapi_rekey_creds(); + return 0; +} +#endif /* GSSAPI */ Index: openssh-7.6p1/monitor.c =================================================================== --- openssh-7.6p1.orig/monitor.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/monitor.c 2019-03-11 22:12:25.872179597 +0100 @@ -157,6 +157,8 @@ int mm_answer_gss_setup_ctx(int, Buffer int mm_answer_gss_accept_ctx(int, Buffer *); int mm_answer_gss_userok(int, Buffer *); int mm_answer_gss_checkmic(int, Buffer *); +int mm_answer_gss_sign(int, Buffer *); +int mm_answer_gss_updatecreds(int, Buffer *); #endif #ifdef SSH_AUDIT_EVENTS @@ -230,6 +232,7 @@ struct mon_table mon_dispatch_proto20[] {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx}, {MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok}, {MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic}, + {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign}, #endif {0, 0, NULL} }; @@ -246,6 +249,12 @@ struct mon_table mon_dispatch_postauth20 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, #endif +#ifdef GSSAPI + {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx}, + {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx}, + {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign}, + {MONITOR_REQ_GSSUPCREDS, 0, mm_answer_gss_updatecreds}, +#endif {0, 0, NULL} }; @@ -302,6 +311,10 @@ monitor_child_preauth(Authctxt *_authctx /* Permit requests for moduli and signatures */ monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); +#ifdef GSSAPI + /* and for the GSSAPI key exchange */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1); +#endif /* The first few requests do not require asynchronous access */ while (!authenticated) { @@ -408,6 +421,10 @@ monitor_child_postauth(struct monitor *p monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); +#ifdef GSSAPI + /* and for the GSSAPI key exchange */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1); +#endif if (!no_pty_flag) { monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); @@ -1626,6 +1643,13 @@ monitor_apply_keystate(struct monitor *p # endif #endif /* WITH_OPENSSL */ kex->kex[KEX_C25519_SHA256] = kexc25519_server; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server; + } +#endif kex->load_host_public_key=&get_hostkey_public_by_type; kex->load_host_private_key=&get_hostkey_private_by_type; kex->host_key_index=&get_hostkey_index; @@ -1714,7 +1738,8 @@ mm_answer_gss_setup_ctx(int sock, Buffer OM_uint32 major; u_int len; - if (!options.gss_authentication) + /* TODO */ + if (!options.gss_authentication && !options.gss_keyex) fatal("%s: GSSAPI authentication not enabled", __func__); goid.elements = buffer_get_string(m, &len); @@ -1744,7 +1769,8 @@ mm_answer_gss_accept_ctx(int sock, Buffe OM_uint32 flags = 0; /* GSI needs this */ u_int len; - if (!options.gss_authentication) + /* TODO */ + if (!options.gss_authentication && !options.gss_keyex) fatal("%s: GSSAPI authentication not enabled", __func__); in.value = buffer_get_string(m, &len); @@ -1764,6 +1790,7 @@ mm_answer_gss_accept_ctx(int sock, Buffe monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN, 1); } return (0); } @@ -1775,7 +1802,8 @@ mm_answer_gss_checkmic(int sock, Buffer OM_uint32 ret; u_int len; - if (!options.gss_authentication) + /* TODO */ + if (!options.gss_authentication && !options.gss_keyex) fatal("%s: GSSAPI authentication not enabled", __func__); gssbuf.value = buffer_get_string(m, &len); @@ -1805,10 +1833,12 @@ mm_answer_gss_userok(int sock, Buffer *m int authenticated; const char *displayname; - if (!options.gss_authentication) + /* TODO */ + if (!options.gss_authentication && !options.gss_keyex) fatal("%s: GSSAPI authentication not enabled", __func__); - authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); + authenticated = authctxt->valid && + ssh_gssapi_userok(authctxt->user, authctxt->pw); buffer_clear(m); buffer_put_int(m, authenticated); @@ -1824,5 +1854,73 @@ mm_answer_gss_userok(int sock, Buffer *m /* Monitor loop will terminate if authenticated */ return (authenticated); } + +int +mm_answer_gss_sign(int socket, Buffer *m) +{ + gss_buffer_desc data; + gss_buffer_desc hash = GSS_C_EMPTY_BUFFER; + OM_uint32 major, minor; + u_int len; + + if (!options.gss_authentication && !options.gss_keyex) + fatal("In GSSAPI monitor when GSSAPI is disabled"); + + data.value = buffer_get_string(m, &len); + data.length = len; + if (data.length != 20) + fatal("%s: data length incorrect: %d", __func__, + (int) data.length); + + /* Save the session ID on the first time around */ + if (session_id2_len == 0) { + session_id2_len = data.length; + session_id2 = xmalloc(session_id2_len); + memcpy(session_id2, data.value, session_id2_len); + } + major = ssh_gssapi_sign(gsscontext, &data, &hash); + + free(data.value); + + buffer_clear(m); + buffer_put_int(m, major); + buffer_put_string(m, hash.value, hash.length); + + mm_request_send(socket, MONITOR_ANS_GSSSIGN, m); + + gss_release_buffer(&minor, &hash); + + /* Turn on getpwnam permissions */ + monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); + + /* And credential updating, for when rekeying */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSUPCREDS, 1); + + return (0); +} + +int +mm_answer_gss_updatecreds(int socket, Buffer *m) { + ssh_gssapi_ccache store; + int ok; + + store.filename = buffer_get_string(m, NULL); + store.envvar = buffer_get_string(m, NULL); + store.envval = buffer_get_string(m, NULL); + + ok = ssh_gssapi_update_creds(&store); + + free(store.filename); + free(store.envvar); + free(store.envval); + + buffer_clear(m); + buffer_put_int(m, ok); + + mm_request_send(socket, MONITOR_ANS_GSSUPCREDS, m); + + return(0); +} + #endif /* GSSAPI */ Index: openssh-7.6p1/monitor.h =================================================================== --- openssh-7.6p1.orig/monitor.h 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/monitor.h 2019-03-11 22:12:25.872179597 +0100 @@ -65,6 +65,9 @@ enum monitor_reqtype { MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111, MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113, + MONITOR_REQ_GSSSIGN = 201, MONITOR_ANS_GSSSIGN = 202, + MONITOR_REQ_GSSUPCREDS = 203, MONITOR_ANS_GSSUPCREDS = 204, + }; struct monitor { Index: openssh-7.6p1/monitor_wrap.c =================================================================== --- openssh-7.6p1.orig/monitor_wrap.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/monitor_wrap.c 2019-03-11 22:12:25.872179597 +0100 @@ -937,7 +937,7 @@ mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss } int -mm_ssh_gssapi_userok(char *user) +mm_ssh_gssapi_userok(char *user, struct passwd *pw) { Buffer m; int authenticated = 0; @@ -954,5 +954,50 @@ mm_ssh_gssapi_userok(char *user) debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); return (authenticated); } + +OM_uint32 +mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash) +{ + Buffer m; + OM_uint32 major; + u_int len; + + buffer_init(&m); + buffer_put_string(&m, data->value, data->length); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, &m); + + major = buffer_get_int(&m); + hash->value = buffer_get_string(&m, &len); + hash->length = len; + + buffer_free(&m); + + return(major); +} + +int +mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store) +{ + Buffer m; + int ok; + + buffer_init(&m); + + buffer_put_cstring(&m, store->filename ? store->filename : ""); + buffer_put_cstring(&m, store->envvar ? store->envvar : ""); + buffer_put_cstring(&m, store->envval ? store->envval : ""); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, &m); + + ok = buffer_get_int(&m); + + buffer_free(&m); + + return (ok); +} + #endif /* GSSAPI */ Index: openssh-7.6p1/monitor_wrap.h =================================================================== --- openssh-7.6p1.orig/monitor_wrap.h 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/monitor_wrap.h 2019-03-11 22:12:25.872179597 +0100 @@ -57,8 +57,10 @@ int mm_sshkey_verify(const struct sshkey OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID); OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *, gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *); -int mm_ssh_gssapi_userok(char *user); +int mm_ssh_gssapi_userok(char *user, struct passwd *); OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t); +OM_uint32 mm_ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t); +int mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *); #endif #ifdef USE_PAM Index: openssh-7.6p1/readconf.c =================================================================== --- openssh-7.6p1.orig/readconf.c 2019-03-11 22:12:16.420129867 +0100 +++ openssh-7.6p1/readconf.c 2019-03-11 22:12:16.548130542 +0100 @@ -161,6 +161,8 @@ typedef enum { oClearAllForwardings, oNoHostAuthenticationForLocalhost, oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout, oAddressFamily, oGssAuthentication, oGssDelegateCreds, + oGssTrustDns, oGssKeyEx, oGssClientIdentity, oGssRenewalRekey, + oGssServerIdentity, oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly, oSendEnv, oControlPath, oControlMaster, oControlPersist, oHashKnownHosts, @@ -200,10 +202,20 @@ static struct { /* Sometimes-unsupported options */ #if defined(GSSAPI) { "gssapiauthentication", oGssAuthentication }, + { "gssapikeyexchange", oGssKeyEx }, { "gssapidelegatecredentials", oGssDelegateCreds }, + { "gssapitrustdns", oGssTrustDns }, + { "gssapiclientidentity", oGssClientIdentity }, + { "gssapiserveridentity", oGssServerIdentity }, + { "gssapirenewalforcesrekey", oGssRenewalRekey }, # else { "gssapiauthentication", oUnsupported }, + { "gssapikeyexchange", oUnsupported }, { "gssapidelegatecredentials", oUnsupported }, + { "gssapitrustdns", oUnsupported }, + { "gssapiclientidentity", oUnsupported }, + { "gssapiserveridentity", oUnsupported }, + { "gssapirenewalforcesrekey", oUnsupported }, #endif #ifdef ENABLE_PKCS11 { "smartcarddevice", oPKCS11Provider }, @@ -977,10 +989,30 @@ parse_time: intptr = &options->gss_authentication; goto parse_flag; + case oGssKeyEx: + intptr = &options->gss_keyex; + goto parse_flag; + case oGssDelegateCreds: intptr = &options->gss_deleg_creds; goto parse_flag; + case oGssTrustDns: + intptr = &options->gss_trust_dns; + goto parse_flag; + + case oGssClientIdentity: + charptr = &options->gss_client_identity; + goto parse_string; + + case oGssServerIdentity: + charptr = &options->gss_server_identity; + goto parse_string; + + case oGssRenewalRekey: + intptr = &options->gss_renewal_rekey; + goto parse_flag; + case oBatchMode: intptr = &options->batch_mode; goto parse_flag; @@ -1808,7 +1840,12 @@ initialize_options(Options * options) options->pubkey_authentication = -1; options->challenge_response_authentication = -1; options->gss_authentication = -1; + options->gss_keyex = -1; options->gss_deleg_creds = -1; + options->gss_trust_dns = -1; + options->gss_renewal_rekey = -1; + options->gss_client_identity = NULL; + options->gss_server_identity = NULL; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->kbd_interactive_devices = NULL; @@ -1948,8 +1985,14 @@ fill_default_options(Options * options) options->challenge_response_authentication = 1; if (options->gss_authentication == -1) options->gss_authentication = 0; + if (options->gss_keyex == -1) + options->gss_keyex = 0; if (options->gss_deleg_creds == -1) options->gss_deleg_creds = 0; + if (options->gss_trust_dns == -1) + options->gss_trust_dns = 0; + if (options->gss_renewal_rekey == -1) + options->gss_renewal_rekey = 0; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) Index: openssh-7.6p1/readconf.h =================================================================== --- openssh-7.6p1.orig/readconf.h 2019-03-11 22:12:16.420129867 +0100 +++ openssh-7.6p1/readconf.h 2019-03-11 22:12:16.548130542 +0100 @@ -42,7 +42,12 @@ typedef struct { int challenge_response_authentication; /* Try S/Key or TIS, authentication. */ int gss_authentication; /* Try GSS authentication */ + int gss_keyex; /* Try GSS key exchange */ int gss_deleg_creds; /* Delegate GSS credentials */ + int gss_trust_dns; /* Trust DNS for GSS canonicalization */ + int gss_renewal_rekey; /* Credential renewal forces rekey */ + char *gss_client_identity; /* Principal to initiate GSSAPI with */ + char *gss_server_identity; /* GSSAPI target principal */ int password_authentication; /* Try password * authentication. */ int kbd_interactive_authentication; /* Try keyboard-interactive auth. */ Index: openssh-7.6p1/regress/cert-hostkey.sh =================================================================== --- openssh-7.6p1.orig/regress/cert-hostkey.sh 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/regress/cert-hostkey.sh 2019-03-11 22:12:16.548130542 +0100 @@ -59,7 +59,7 @@ touch $OBJ/host_revoked_plain touch $OBJ/host_revoked_cert cat $OBJ/host_ca_key.pub $OBJ/host_ca_key2.pub > $OBJ/host_revoked_ca -PLAIN_TYPES=`$SSH -Q key-plain | sed 's/^ssh-dss/ssh-dsa/g;s/^ssh-//'` +PLAIN_TYPES=`$SSH -Q key-plain | grep -v null | sed 's/^ssh-dss/ssh-dsa/g;s/^ssh-//'` if echo "$PLAIN_TYPES" | grep '^rsa$' >/dev/null 2>&1 ; then PLAIN_TYPES="$PLAIN_TYPES rsa-sha2-256 rsa-sha2-512" Index: openssh-7.6p1/regress/cert-userkey.sh =================================================================== --- openssh-7.6p1.orig/regress/cert-userkey.sh 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/regress/cert-userkey.sh 2019-03-11 22:12:16.548130542 +0100 @@ -7,7 +7,7 @@ rm -f $OBJ/authorized_keys_$USER $OBJ/us cp $OBJ/sshd_proxy $OBJ/sshd_proxy_bak cp $OBJ/ssh_proxy $OBJ/ssh_proxy_bak -PLAIN_TYPES=`$SSH -Q key-plain | sed 's/^ssh-dss/ssh-dsa/;s/^ssh-//'` +PLAIN_TYPES=`$SSH -Q key-plain | grep -v null | sed 's/^ssh-dss/ssh-dsa/;s/^ssh-//'` if echo "$PLAIN_TYPES" | grep '^rsa$' >/dev/null 2>&1 ; then PLAIN_TYPES="$PLAIN_TYPES rsa-sha2-256 rsa-sha2-512" Index: openssh-7.6p1/regress/kextype.sh =================================================================== --- openssh-7.6p1.orig/regress/kextype.sh 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/regress/kextype.sh 2019-03-11 22:12:16.548130542 +0100 @@ -14,6 +14,9 @@ echo "KexAlgorithms=$KEXOPT" >> $OBJ/ssh tries="1 2 3 4" for k in `${SSH} -Q kex`; do + if [ $k = "gss-gex-sha1-" -o $k = "gss-group1-sha1-" -o $k = "gss-group14-sha1-" ]; then + continue + fi verbose "kex $k" for i in $tries; do ${SSH} -F $OBJ/ssh_proxy -o KexAlgorithms=$k x true Index: openssh-7.6p1/regress/rekey.sh =================================================================== --- openssh-7.6p1.orig/regress/rekey.sh 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/regress/rekey.sh 2019-03-11 22:12:16.548130542 +0100 @@ -38,6 +38,9 @@ increase_datafile_size 300 opts="" for i in `${SSH} -Q kex`; do + if [ $i = "gss-gex-sha1-" -o $i = "gss-group1-sha1-" -o $i = "gss-group14-sha1-" ]; then + continue + fi opts="$opts KexAlgorithms=$i" done for i in `${SSH} -Q cipher`; do @@ -56,6 +59,9 @@ done if ${SSH} -Q cipher-auth | grep '^.*$' >/dev/null 2>&1 ; then for c in `${SSH} -Q cipher-auth`; do for kex in `${SSH} -Q kex`; do + if [ $kex = "gss-gex-sha1-" -o $kex = "gss-group1-sha1-" -o $kex = "gss-group14-sha1-" ]; then + continue + fi verbose "client rekey $c $kex" ssh_data_rekeying "KexAlgorithms=$kex" -oRekeyLimit=256k -oCiphers=$c done Index: openssh-7.6p1/servconf.c =================================================================== --- openssh-7.6p1.orig/servconf.c 2019-03-11 22:12:16.420129867 +0100 +++ openssh-7.6p1/servconf.c 2019-03-11 22:12:16.548130542 +0100 @@ -115,8 +115,10 @@ initialize_server_options(ServerOptions options->kerberos_ticket_cleanup = -1; options->kerberos_get_afs_token = -1; options->gss_authentication=-1; + options->gss_keyex = -1; options->gss_cleanup_creds = -1; options->gss_strict_acceptor = -1; + options->gss_store_rekey = -1; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->challenge_response_authentication = -1; @@ -291,10 +293,14 @@ fill_default_server_options(ServerOption options->kerberos_get_afs_token = 0; if (options->gss_authentication == -1) options->gss_authentication = 0; + if (options->gss_keyex == -1) + options->gss_keyex = 0; if (options->gss_cleanup_creds == -1) options->gss_cleanup_creds = 1; if (options->gss_strict_acceptor == -1) options->gss_strict_acceptor = 1; + if (options->gss_store_rekey == -1) + options->gss_store_rekey = 0; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) @@ -435,6 +441,7 @@ typedef enum { sHostKeyAlgorithms, sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile, sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor, + sGssKeyEx, sGssStoreRekey, sAcceptEnv, sPermitTunnel, sMatch, sPermitOpen, sForceCommand, sChrootDirectory, sUsePrivilegeSeparation, sAllowAgentForwarding, @@ -512,11 +519,17 @@ static struct { { "gssapiauthentication", sGssAuthentication, SSHCFG_ALL }, { "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL }, { "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL }, + { "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL }, + { "gssapistorecredentialsonrekey", sGssStoreRekey, SSHCFG_GLOBAL }, #else { "gssapiauthentication", sUnsupported, SSHCFG_ALL }, { "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL }, { "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL }, + { "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL }, + { "gssapistorecredentialsonrekey", sUnsupported, SSHCFG_GLOBAL }, #endif + { "gssusesessionccache", sUnsupported, SSHCFG_GLOBAL }, + { "gssapiusesessioncredcache", sUnsupported, SSHCFG_GLOBAL }, { "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL }, { "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL }, { "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, @@ -1283,6 +1296,10 @@ process_server_config_line(ServerOptions intptr = &options->gss_authentication; goto parse_flag; + case sGssKeyEx: + intptr = &options->gss_keyex; + goto parse_flag; + case sGssCleanupCreds: intptr = &options->gss_cleanup_creds; goto parse_flag; @@ -1291,6 +1308,10 @@ process_server_config_line(ServerOptions intptr = &options->gss_strict_acceptor; goto parse_flag; + case sGssStoreRekey: + intptr = &options->gss_store_rekey; + goto parse_flag; + case sPasswordAuthentication: intptr = &options->password_authentication; goto parse_flag; @@ -2039,6 +2060,10 @@ copy_set_server_options(ServerOptions *d M_CP_INTOPT(password_authentication); M_CP_INTOPT(gss_authentication); + M_CP_INTOPT(gss_keyex); + M_CP_INTOPT(gss_cleanup_creds); + M_CP_INTOPT(gss_strict_acceptor); + M_CP_INTOPT(gss_store_rekey); M_CP_INTOPT(pubkey_authentication); M_CP_INTOPT(kerberos_authentication); M_CP_INTOPT(hostbased_authentication); @@ -2331,7 +2356,10 @@ dump_config(ServerOptions *o) #endif #ifdef GSSAPI dump_cfg_fmtint(sGssAuthentication, o->gss_authentication); + dump_cfg_fmtint(sGssKeyEx, o->gss_keyex); dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds); + dump_cfg_fmtint(sGssStrictAcceptor, o->gss_strict_acceptor); + dump_cfg_fmtint(sGssStoreRekey, o->gss_store_rekey); #endif dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication); dump_cfg_fmtint(sKbdInteractiveAuthentication, Index: openssh-7.6p1/servconf.h =================================================================== --- openssh-7.6p1.orig/servconf.h 2019-03-11 22:12:16.316129321 +0100 +++ openssh-7.6p1/servconf.h 2019-03-11 22:12:16.548130542 +0100 @@ -16,6 +16,8 @@ #ifndef SERVCONF_H #define SERVCONF_H +#include "misc.h" + #define MAX_PORTS 256 /* Max # ports. */ #define MAX_ALLOW_USERS 256 /* Max # users on allow list. */ @@ -119,8 +121,10 @@ typedef struct { int kerberos_get_afs_token; /* If true, try to get AFS token if * authenticated with Kerberos. */ int gss_authentication; /* If true, permit GSSAPI authentication */ + int gss_keyex; /* If true, permit GSSAPI key exchange */ int gss_cleanup_creds; /* If true, destroy cred cache on logout */ int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ + int gss_store_rekey; int password_authentication; /* If true, permit password * authentication. */ int kbd_interactive_authentication; /* If true, permit */ Index: openssh-7.6p1/ssh-gss.h =================================================================== --- openssh-7.6p1.orig/ssh-gss.h 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/ssh-gss.h 2019-03-11 22:12:16.548130542 +0100 @@ -1,6 +1,6 @@ /* $OpenBSD: ssh-gss.h,v 1.12 2017/06/24 06:34:38 djm Exp $ */ /* - * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -61,10 +61,22 @@ #define SSH_GSS_OIDTYPE 0x06 +#define SSH2_MSG_KEXGSS_INIT 30 +#define SSH2_MSG_KEXGSS_CONTINUE 31 +#define SSH2_MSG_KEXGSS_COMPLETE 32 +#define SSH2_MSG_KEXGSS_HOSTKEY 33 +#define SSH2_MSG_KEXGSS_ERROR 34 +#define SSH2_MSG_KEXGSS_GROUPREQ 40 +#define SSH2_MSG_KEXGSS_GROUP 41 +#define KEX_GSS_GRP1_SHA1_ID "gss-group1-sha1-" +#define KEX_GSS_GRP14_SHA1_ID "gss-group14-sha1-" +#define KEX_GSS_GEX_SHA1_ID "gss-gex-sha1-" + typedef struct { char *filename; char *envvar; char *envval; + struct passwd *owner; void *data; } ssh_gssapi_ccache; @@ -72,8 +84,11 @@ typedef struct { gss_buffer_desc displayname; gss_buffer_desc exportedname; gss_cred_id_t creds; + gss_name_t name; struct ssh_gssapi_mech_struct *mech; ssh_gssapi_ccache store; + int used; + int updated; } ssh_gssapi_client; typedef struct ssh_gssapi_mech_struct { @@ -84,6 +99,7 @@ typedef struct ssh_gssapi_mech_struct { int (*userok) (ssh_gssapi_client *, char *); int (*localname) (ssh_gssapi_client *, char **); void (*storecreds) (ssh_gssapi_client *); + int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *); } ssh_gssapi_mech; typedef struct { @@ -94,10 +110,11 @@ typedef struct { gss_OID oid; /* client */ gss_cred_id_t creds; /* server */ gss_name_t client; /* server */ - gss_cred_id_t client_creds; /* server */ + gss_cred_id_t client_creds; /* both */ } Gssctxt; extern ssh_gssapi_mech *supported_mechs[]; +extern Gssctxt *gss_kex_context; int ssh_gssapi_check_oid(Gssctxt *, void *, size_t); void ssh_gssapi_set_oid_data(Gssctxt *, void *, size_t); @@ -119,17 +136,33 @@ void ssh_gssapi_build_ctx(Gssctxt **); void ssh_gssapi_delete_ctx(Gssctxt **); OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t); void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *); -int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *); +int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *, const char *); +OM_uint32 ssh_gssapi_client_identity(Gssctxt *, const char *); +int ssh_gssapi_credentials_updated(Gssctxt *); /* In the server */ +typedef int ssh_gssapi_check_fn(Gssctxt **, gss_OID, const char *, + const char *); +char *ssh_gssapi_client_mechanisms(const char *, const char *); +char *ssh_gssapi_kex_mechs(gss_OID_set, ssh_gssapi_check_fn *, const char *, + const char *); +gss_OID ssh_gssapi_id_kex(Gssctxt *, char *, int); +int ssh_gssapi_server_check_mech(Gssctxt **,gss_OID, const char *, + const char *); OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID); -int ssh_gssapi_userok(char *name); +int ssh_gssapi_userok(char *name, struct passwd *); OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t); void ssh_gssapi_do_child(char ***, u_int *); void ssh_gssapi_cleanup_creds(void); void ssh_gssapi_storecreds(void); const char *ssh_gssapi_displayname(void); +char *ssh_gssapi_server_mechanisms(void); +int ssh_gssapi_oid_table_ok(); + +int ssh_gssapi_update_creds(ssh_gssapi_ccache *store); + +void ssh_gssapi_rekey_creds(void); #endif /* GSSAPI */ #endif /* _SSH_GSS_H */ Index: openssh-7.6p1/ssh_config =================================================================== --- openssh-7.6p1.orig/ssh_config 2019-03-11 22:12:16.248128963 +0100 +++ openssh-7.6p1/ssh_config 2019-03-11 22:12:16.548130542 +0100 @@ -40,6 +40,8 @@ Host * # HostbasedAuthentication no # GSSAPIAuthentication no # GSSAPIDelegateCredentials no +# GSSAPIKeyExchange no +# GSSAPITrustDNS no # BatchMode no # CheckHostIP yes # AddressFamily any Index: openssh-7.6p1/ssh_config.0 =================================================================== --- openssh-7.6p1.orig/ssh_config.0 2019-03-11 22:12:16.420129867 +0100 +++ openssh-7.6p1/ssh_config.0 2019-03-11 22:12:16.548130542 +0100 @@ -408,9 +408,40 @@ DESCRIPTION Specifies whether user authentication based on GSSAPI is allowed. The default is no. + GSSAPIKeyExchange + Specifies whether key exchange based on GSSAPI may be used. When + using GSSAPI key exchange the server need not have a host key. + The default is no. + Note that this option applies to protocol version 2 only. + + GSSAPIClientIdentity + If set, specifies the GSSAPI client identity that ssh should use + when connecting to the server. The default is unset, which means + that the default identity will be used. + + GSSAPIServerIdentity + If set, specifies the GSSAPI server identity that ssh should expect + when connecting to the server. The default is unset, which means + that the expected GSSAPI server identity will be determined from + the target hostname. + GSSAPIDelegateCredentials Forward (delegate) credentials to the server. The default is no. + GSSAPIRenewalForcesRekey + If set to yes then renewal of the client's GSSAPI credentials will + force the rekeying of the ssh connection. With a compatible server, + this can delegate the renewed credentials to a session on the + server. The default is no. + + GSSAPITrustDns + Set to yes to indicate that the DNS is trusted to securely + canonicalize the name of the host being connected to. If no, the + hostname entered on the command line will be passed untouched to + the GSSAPI library. The default is no. + This option only applies to protocol version 2 connections using + GSSAPI. + HashKnownHosts Indicates that ssh(1) should hash host names and addresses when they are added to ~/.ssh/known_hosts. These hashed names may be Index: openssh-7.6p1/ssh_config.5 =================================================================== --- openssh-7.6p1.orig/ssh_config.5 2019-03-11 22:12:16.420129867 +0100 +++ openssh-7.6p1/ssh_config.5 2019-03-11 22:12:16.548130542 +0100 @@ -722,10 +722,40 @@ The default is Specifies whether user authentication based on GSSAPI is allowed. The default is .Cm no . +.It Cm GSSAPIClientIdentity +If set, specifies the GSSAPI client identity that ssh should use when +connecting to the server. The default is unset, which means that the default +identity will be used. .It Cm GSSAPIDelegateCredentials Forward (delegate) credentials to the server. The default is .Cm no . +.It Cm GSSAPIKeyExchange +Specifies whether key exchange based on GSSAPI may be used. When using +GSSAPI key exchange the server need not have a host key. +The default is +.Dq no . +.It Cm GSSAPIRenewalForcesRekey +If set to +.Dq yes +then renewal of the client's GSSAPI credentials will force the rekeying of the +ssh connection. With a compatible server, this can delegate the renewed +credentials to a session on the server. +The default is +.Dq no . +.It Cm GSSAPIServerIdentity +If set, specifies the GSSAPI server identity that ssh should expect when +connecting to the server. The default is unset, which means that the +expected GSSAPI server identity will be determined from the target +hostname. +.It Cm GSSAPITrustDns +Set to +.Dq yes to indicate that the DNS is trusted to securely canonicalize +the name of the host being connected to. If +.Dq no, the hostname entered on the +command line will be passed untouched to the GSSAPI library. +The default is +.Dq no . .It Cm HashKnownHosts Indicates that .Xr ssh 1 Index: openssh-7.6p1/sshconnect2.c =================================================================== --- openssh-7.6p1.orig/sshconnect2.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/sshconnect2.c 2019-03-11 22:12:25.688178629 +0100 @@ -82,6 +82,124 @@ extern char *client_version_string; extern char *server_version_string; extern Options options; +/* XXX from auth.h -- refactoring move these useful functions away of client context*/ + +/* + * Returns the remote DNS hostname as a string. The returned string must not + * be freed. NB. this will usually trigger a DNS query the first time it is + * called. + * This function does additional checks on the hostname to mitigate some + * attacks on legacy rhosts-style authentication. + * XXX is RhostsRSAAuthentication vulnerable to these? + * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?) + */ + +static char * +remote_hostname(struct ssh *ssh) +{ + struct sockaddr_storage from; + socklen_t fromlen; + struct addrinfo hints, *ai, *aitop; + char name[NI_MAXHOST], ntop2[NI_MAXHOST]; + const char *ntop = ssh_remote_ipaddr(ssh); + + /* Get IP address of client. */ + fromlen = sizeof(from); + memset(&from, 0, sizeof(from)); + if (getpeername(ssh_packet_get_connection_in(ssh), + (struct sockaddr *)&from, &fromlen) < 0) { + debug("getpeername failed: %.100s", strerror(errno)); + return strdup(ntop); + } + + ipv64_normalise_mapped(&from, &fromlen); + if (from.ss_family == AF_INET6) + fromlen = sizeof(struct sockaddr_in6); + + debug3("Trying to reverse map address %.100s.", ntop); + /* Map the IP address to a host name. */ + if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name), + NULL, 0, NI_NAMEREQD) != 0) { + /* Host name not found. Use ip address. */ + return strdup(ntop); + } + + /* + * if reverse lookup result looks like a numeric hostname, + * someone is trying to trick us by PTR record like following: + * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5 + */ + memset(&hints, 0, sizeof(hints)); + hints.ai_socktype = SOCK_DGRAM; /*dummy*/ + hints.ai_flags = AI_NUMERICHOST; + if (getaddrinfo(name, NULL, &hints, &ai) == 0) { + logit("Nasty PTR record \"%s\" is set up for %s, ignoring", + name, ntop); + freeaddrinfo(ai); + return strdup(ntop); + } + + /* Names are stored in lowercase. */ + lowercase(name); + + /* + * Map it back to an IP address and check that the given + * address actually is an address of this host. This is + * necessary because anyone with access to a name server can + * define arbitrary names for an IP address. Mapping from + * name to IP address can be trusted better (but can still be + * fooled if the intruder has access to the name server of + * the domain). + */ + memset(&hints, 0, sizeof(hints)); + hints.ai_family = from.ss_family; + hints.ai_socktype = SOCK_STREAM; + if (getaddrinfo(name, NULL, &hints, &aitop) != 0) { + logit("reverse mapping checking getaddrinfo for %.700s " + "[%s] failed.", name, ntop); + return strdup(ntop); + } + /* Look for the address from the list of addresses. */ + for (ai = aitop; ai; ai = ai->ai_next) { + if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2, + sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 && + (strcmp(ntop, ntop2) == 0)) + break; + } + freeaddrinfo(aitop); + /* If we reached the end of the list, the address was not there. */ + if (ai == NULL) { + /* Address not found for the host name. */ + logit("Address %.100s maps to %.600s, but this does not " + "map back to the address.", ntop, name); + return strdup(ntop); + } + return strdup(name); +} + +/* + * Return the canonical name of the host in the other side of the current + * connection. The host name is cached, so it is efficient to call this + * several times. + */ + +const char * +get_canonical_hostname(struct ssh *ssh, int use_dns) +{ + static char *dnsname; + + if (!use_dns) + return ssh_remote_ipaddr(ssh); + else if (dnsname != NULL) + return dnsname; + else { + dnsname = remote_hostname(ssh); + return dnsname; + } +} + + + /* * SSH2 key exchange */ @@ -162,9 +280,36 @@ ssh_kex2(char *host, struct sockaddr *ho struct kex *kex; int r; +#ifdef GSSAPI + char *orig = NULL, *gss = NULL; + char *gss_host = NULL; +#endif + xxx_host = host; xxx_hostaddr = hostaddr; +#ifdef GSSAPI + /* TODO: should we use myproposal[PROPOSAL_KEX_ALGS] + * instead of options.kex_algorithms? */ + if (options.gss_keyex) { + /* Add the GSSAPI mechanisms currently supported on this + * client to the key exchange algorithm proposal */ + orig = options.kex_algorithms; + + if (options.gss_trust_dns) + gss_host = (char *)get_canonical_hostname(active_state, 1); + else + gss_host = host; + + gss = ssh_gssapi_client_mechanisms(gss_host, options.gss_client_identity); + if (gss) { + debug("Offering GSSAPI proposal: %s", gss); + xasprintf(&options.kex_algorithms, + "%s,%s", gss, orig); + } + } +#endif + if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL) fatal("%s: kex_names_cat", __func__); myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s); @@ -192,6 +337,17 @@ ssh_kex2(char *host, struct sockaddr *ho order_hostkeyalgs(host, hostaddr, port)); } +#ifdef GSSAPI + /* If we've got GSSAPI algorithms, then we also support the + * 'null' hostkey, as a last resort */ + if (options.gss_keyex && gss) { + orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; + xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], + "%s,null", orig); + free(gss); + } +#endif + if (options.rekey_limit || options.rekey_interval) packet_set_rekey_limits(options.rekey_limit, options.rekey_interval); @@ -213,10 +369,30 @@ ssh_kex2(char *host, struct sockaddr *ho # endif #endif kex->kex[KEX_C25519_SHA256] = kexc25519_client; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; + } +#endif kex->client_version_string=client_version_string; kex->server_version_string=server_version_string; kex->verify_host_key=&verify_host_key_callback; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->gss_deleg_creds = options.gss_deleg_creds; + kex->gss_trust_dns = options.gss_trust_dns; + kex->gss_client = options.gss_client_identity; + if (options.gss_server_identity) { + kex->gss_host = options.gss_server_identity; + } else { + kex->gss_host = gss_host; + } + } +#endif + ssh_dispatch_run_fatal(active_state, DISPATCH_BLOCK, &kex->done); /* remove ext-info from the KEX proposals for rekeying */ @@ -311,6 +487,7 @@ int input_gssapi_token(int type, u_int32 int input_gssapi_hash(int type, u_int32_t, struct ssh *); int input_gssapi_error(int, u_int32_t, struct ssh *); int input_gssapi_errtok(int, u_int32_t, struct ssh *); +int userauth_gsskeyex(Authctxt *authctxt); #endif void userauth(Authctxt *, char *); @@ -327,6 +504,11 @@ static char *authmethods_get(void); Authmethod authmethods[] = { #ifdef GSSAPI + {"gssapi-keyex", + userauth_gsskeyex, + NULL, + &options.gss_authentication, + NULL}, {"gssapi-with-mic", userauth_gssapi, NULL, @@ -654,19 +836,31 @@ userauth_gssapi(Authctxt *authctxt) static u_int mech = 0; OM_uint32 min; int ok = 0; + const char *gss_host; + + if (options.gss_server_identity) + gss_host = options.gss_server_identity; + else if (options.gss_trust_dns) + gss_host = get_canonical_hostname(active_state, 1); + else + gss_host = authctxt->host; /* Try one GSSAPI method at a time, rather than sending them all at * once. */ if (gss_supported == NULL) - gss_indicate_mechs(&min, &gss_supported); + if (GSS_ERROR(gss_indicate_mechs(&min, &gss_supported))) { + gss_supported = NULL; + return 0; + } /* Check to see if the mechanism is usable before we offer it */ while (mech < gss_supported->count && !ok) { /* My DER encoding requires length<128 */ if (gss_supported->elements[mech].length < 128 && ssh_gssapi_check_mechanism(&gssctxt, - &gss_supported->elements[mech], authctxt->host)) { + &gss_supported->elements[mech], gss_host, + options.gss_client_identity)) { ok = 1; /* Mechanism works */ } else { mech++; @@ -763,8 +957,8 @@ input_gssapi_response(int type, u_int32_ { Authctxt *authctxt = ssh->authctxt; Gssctxt *gssctxt; - int oidlen; - char *oidv; + u_int oidlen; + u_char *oidv; if (authctxt == NULL) fatal("input_gssapi_response: no authentication context"); @@ -877,6 +1071,48 @@ input_gssapi_error(int type, u_int32_t p free(lang); return 0; } + +int +userauth_gsskeyex(Authctxt *authctxt) +{ + Buffer b; + gss_buffer_desc gssbuf; + gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; + OM_uint32 ms; + + static int attempt = 0; + if (attempt++ >= 1) + return (0); + + if (gss_kex_context == NULL) { + debug("No valid Key exchange context"); + return (0); + } + + ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, + "gssapi-keyex"); + + gssbuf.value = buffer_ptr(&b); + gssbuf.length = buffer_len(&b); + + if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { + buffer_free(&b); + return (0); + } + + packet_start(SSH2_MSG_USERAUTH_REQUEST); + packet_put_cstring(authctxt->server_user); + packet_put_cstring(authctxt->service); + packet_put_cstring(authctxt->method->name); + packet_put_string(mic.value, mic.length); + packet_send(); + + buffer_free(&b); + gss_release_buffer(&ms, &mic); + + return (1); +} + #endif /* GSSAPI */ int Index: openssh-7.6p1/sshd.c =================================================================== --- openssh-7.6p1.orig/sshd.c 2019-03-11 22:12:16.528130435 +0100 +++ openssh-7.6p1/sshd.c 2019-03-11 22:12:25.872179597 +0100 @@ -128,6 +128,10 @@ #include "version.h" #include "ssherr.h" +#ifdef USE_SECURITY_SESSION_API +#include <Security/AuthSession.h> +#endif + /* Re-exec fds */ #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1) #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2) @@ -546,7 +550,7 @@ privsep_preauth_child(void) #ifdef GSSAPI /* Cache supported mechanism OIDs for later use */ - if (options.gss_authentication) + if (options.gss_authentication || options.gss_keyex) ssh_gssapi_prepare_supported_oids(); #endif @@ -880,8 +884,9 @@ notify_hostkeys(struct ssh *ssh) } debug3("%s: sent %d hostkeys", __func__, nkeys); if (nkeys == 0) - fatal("%s: no hostkeys", __func__); - packet_send(); + debug3("%s: no hostkeys", __func__); + else + packet_send(); sshbuf_free(buf); } @@ -1733,7 +1738,12 @@ main(int ac, char **av) key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp); free(fp); } +#ifndef GSSAPI if (!sensitive_data.have_ssh2_key) { +#else + /* The GSSAPI key exchange can run without a host key */ + if (!sensitive_data.have_ssh2_key && !options.gss_keyex) { +#endif logit("sshd: no hostkeys available -- exiting."); exit(1); } @@ -1904,6 +1914,60 @@ main(int ac, char **av) /* This is the child processing a new connection. */ setproctitle("%s", "[accepted]"); +#ifdef USE_SECURITY_SESSION_API + /* + * Create a new security session for use by the new user login if + * the current session is the root session or we are not launched + * by inetd (eg: debugging mode or server mode). We do not + * necessarily need to create a session if we are launched from + * inetd because Panther xinetd will create a session for us. + * + * The only case where this logic will fail is if there is an + * inetd running in a non-root session which is not creating + * new sessions for us. Then all the users will end up in the + * same session (bad). + * + * When the client exits, the session will be destroyed for us + * automatically. + * + * We must create the session before any credentials are stored + * (including AFS pags, which happens a few lines below). + */ + { + OSStatus err = 0; + SecuritySessionId sid = 0; + SessionAttributeBits sattrs = 0; + + err = SessionGetInfo(callerSecuritySession, &sid, &sattrs); + if (err) + error("SessionGetInfo() failed with error %.8X", + (unsigned) err); + else + debug("Current Session ID is %.8X / Session Attributes are %.8X", + (unsigned) sid, (unsigned) sattrs); + + if (inetd_flag && !(sattrs & sessionIsRoot)) + debug("Running in inetd mode in a non-root session... " + "assuming inetd created the session for us."); + else { + debug("Creating new security session..."); + err = SessionCreate(0, sessionHasTTY | sessionIsRemote); + if (err) + error("SessionCreate() failed with error %.8X", + (unsigned) err); + + err = SessionGetInfo(callerSecuritySession, &sid, + &sattrs); + if (err) + error("SessionGetInfo() failed with error %.8X", + (unsigned) err); + else + debug("New Session ID is %.8X / Session Attributes are %.8X", + (unsigned) sid, (unsigned) sattrs); + } + } +#endif + /* * Create a new session and process group since the 4.4BSD * setlogin() affects the entire process group. We don't @@ -2017,6 +2081,60 @@ main(int ac, char **av) remote_ip, remote_port, laddr, ssh_local_port(ssh)); free(laddr); +#ifdef USE_SECURITY_SESSION_API + /* + * Create a new security session for use by the new user login if + * the current session is the root session or we are not launched + * by inetd (eg: debugging mode or server mode). We do not + * necessarily need to create a session if we are launched from + * inetd because Panther xinetd will create a session for us. + * + * The only case where this logic will fail is if there is an + * inetd running in a non-root session which is not creating + * new sessions for us. Then all the users will end up in the + * same session (bad). + * + * When the client exits, the session will be destroyed for us + * automatically. + * + * We must create the session before any credentials are stored + * (including AFS pags, which happens a few lines below). + */ + { + OSStatus err = 0; + SecuritySessionId sid = 0; + SessionAttributeBits sattrs = 0; + + err = SessionGetInfo(callerSecuritySession, &sid, &sattrs); + if (err) + error("SessionGetInfo() failed with error %.8X", + (unsigned) err); + else + debug("Current Session ID is %.8X / Session Attributes are %.8X", + (unsigned) sid, (unsigned) sattrs); + + if (inetd_flag && !(sattrs & sessionIsRoot)) + debug("Running in inetd mode in a non-root session... " + "assuming inetd created the session for us."); + else { + debug("Creating new security session..."); + err = SessionCreate(0, sessionHasTTY | sessionIsRemote); + if (err) + error("SessionCreate() failed with error %.8X", + (unsigned) err); + + err = SessionGetInfo(callerSecuritySession, &sid, + &sattrs); + if (err) + error("SessionGetInfo() failed with error %.8X", + (unsigned) err); + else + debug("New Session ID is %.8X / Session Attributes are %.8X", + (unsigned) sid, (unsigned) sattrs); + } + } +#endif + /* * We don't want to listen forever unless the other side * successfully authenticates itself. So we set up an alarm which is @@ -2200,6 +2318,48 @@ do_ssh2_kex(void) myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal( list_hostkey_types()); +#ifdef GSSAPI + { + char *orig; + char *gss = NULL; + char *newstr = NULL; + orig = myproposal[PROPOSAL_KEX_ALGS]; + + /* + * If we don't have a host key, then there's no point advertising + * the other key exchange algorithms + */ + + if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0) + orig = NULL; + + if (options.gss_keyex) + gss = ssh_gssapi_server_mechanisms(); + else + gss = NULL; + + if (gss && orig) + xasprintf(&newstr, "%s,%s", gss, orig); + else if (gss) + newstr = gss; + else if (orig) + newstr = orig; + + /* + * If we've got GSSAPI mechanisms, then we've got the 'null' host + * key alg, but we can't tell people about it unless its the only + * host key algorithm we support + */ + if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0) + myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null"; + + if (newstr) + myproposal[PROPOSAL_KEX_ALGS] = newstr; + else + fatal("No supported key exchange algorithms"); + } +#endif + /* start key exchange */ if ((r = kex_setup(active_state, myproposal)) != 0) fatal("kex_setup: %s", ssh_err(r)); @@ -2217,6 +2377,13 @@ do_ssh2_kex(void) # endif #endif kex->kex[KEX_C25519_SHA256] = kexc25519_server; +#ifdef GSSAPI + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server; + } +#endif kex->server = 1; kex->client_version_string=client_version_string; kex->server_version_string=server_version_string; Index: openssh-7.6p1/sshd_config =================================================================== --- openssh-7.6p1.orig/sshd_config 2019-03-11 22:12:16.248128963 +0100 +++ openssh-7.6p1/sshd_config 2019-03-11 22:12:16.548130542 +0100 @@ -70,6 +70,8 @@ AuthorizedKeysFile .ssh/authorized_keys # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes +#GSSAPIStrictAcceptorCheck yes +#GSSAPIKeyExchange no # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will Index: openssh-7.6p1/sshd_config.0 =================================================================== --- openssh-7.6p1.orig/sshd_config.0 2019-03-11 22:12:16.424129889 +0100 +++ openssh-7.6p1/sshd_config.0 2019-03-11 22:12:16.548130542 +0100 @@ -369,6 +369,12 @@ DESCRIPTION Specifies whether user authentication based on GSSAPI is allowed. The default is no. + GSSAPIKeyExchange + Specifies whether key exchange based on GSSAPI is allowed. GSSAPI + key exchange doesn't rely on ssh keys to verify host identity. The + default is no. + Note that this option applies to protocol version 2 only. + GSSAPICleanupCredentials Specifies whether to automatically destroy the user's credentials cache on logout. The default is yes. @@ -382,6 +388,12 @@ DESCRIPTION facility is provided to assist with operation on multi homed machines. The default is yes. + GSSAPIStoreCredentialsOnRekey + Controls whether the user's GSSAPI credentials should be updated + following a successful connection rekeying. This option can be used + to accepted renewed or updated credentials from a compatible + client. The default is no. + HostbasedAcceptedKeyTypes Specifies the key types that will be accepted for hostbased authentication as a comma-separated pattern list. Alternately if Index: openssh-7.6p1/sshd_config.5 =================================================================== --- openssh-7.6p1.orig/sshd_config.5 2019-03-11 22:12:16.424129889 +0100 +++ openssh-7.6p1/sshd_config.5 2019-03-11 22:12:16.552130562 +0100 @@ -642,6 +642,11 @@ Specifies whether to automatically destr on logout. The default is .Cm yes . +.It Cm GSSAPIKeyExchange +Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange +doesn't rely on ssh keys to verify host identity. +The default is +.Dq no . .It Cm GSSAPIStrictAcceptorCheck Determines whether to be strict about the identity of the GSSAPI acceptor a client authenticates against. @@ -656,6 +661,11 @@ machine's default store. This facility is provided to assist with operation on multi homed machines. The default is .Cm yes . +.It Cm GSSAPIStoreCredentialsOnRekey +Controls whether the user's GSSAPI credentials should be updated following a +successful connection rekeying. This option can be used to accepted renewed +or updated credentials from a compatible client. The default is +.Dq no . .It Cm HostbasedAcceptedKeyTypes Specifies the key types that will be accepted for hostbased authentication as a comma-separated pattern list. Index: openssh-7.6p1/sshkey.c =================================================================== --- openssh-7.6p1.orig/sshkey.c 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/sshkey.c 2019-03-11 22:12:25.872179597 +0100 @@ -112,6 +112,7 @@ static const struct keytype keytypes[] = # endif /* OPENSSL_HAS_NISTP521 */ # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ + { "null", "null", KEY_NULL, 0, 0, 1 }, { NULL, NULL, -1, -1, 0, 0 } }; Index: openssh-7.6p1/sshkey.h =================================================================== --- openssh-7.6p1.orig/sshkey.h 2017-10-02 21:34:26.000000000 +0200 +++ openssh-7.6p1/sshkey.h 2019-03-11 22:12:25.872179597 +0100 @@ -61,6 +61,7 @@ enum sshkey_types { KEY_DSA_CERT, KEY_ECDSA_CERT, KEY_ED25519_CERT, + KEY_NULL, KEY_UNSPEC };
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