X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fsrc%2Fauths%2Fgsasl_exim.c;h=479d01a29daa1a9a4cd0996f528ad3240e2cc877;hb=753739fdef6d9753ee4a7e89afd959a4034d2ad9;hp=80ae354f9ef9dd3a3ab99ec8e07bef1d37cc4d96;hpb=2b615f22d0ce78ba28a6d758d6a2a5c8cb33e10a;p=user%2Fhenk%2Fcode%2Fexim.git diff --git a/src/src/auths/gsasl_exim.c b/src/src/auths/gsasl_exim.c index 80ae354f9..479d01a29 100644 --- a/src/src/auths/gsasl_exim.c +++ b/src/src/auths/gsasl_exim.c @@ -2,7 +2,7 @@ * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) The Exim Maintainers 2019 */ +/* Copyright (c) The Exim Maintainers 2019-2020 */ /* Copyright (c) University of Cambridge 1995 - 2018 */ /* See the file NOTICE for conditions of use and distribution. */ @@ -27,7 +27,6 @@ sense in all contexts. For some, we can do checks at init time. */ #include "../exim.h" -#define CHANNELBIND_HACK #ifndef AUTH_GSASL /* dummy function to satisfy compilers when we link in an "empty" file. */ @@ -40,8 +39,22 @@ static void dummy(int x) { dummy2(x-1); } #include "gsasl_exim.h" -#if GSASL_VERSION_MINOR >= 9 +#if GSASL_VERSION_MINOR >= 10 # define EXIM_GSASL_HAVE_SCRAM_SHA_256 +# define EXIM_GSASL_SCRAM_S_KEY + +#elif GSASL_VERSION_MINOR == 9 +# define EXIM_GSASL_HAVE_SCRAM_SHA_256 + +# if GSASL_VERSION_PATCH >= 1 +# define EXIM_GSASL_SCRAM_S_KEY +# endif +# if GSASL_VERSION_PATCH < 2 +# define CHANNELBIND_HACK +# endif + +#else +# define CHANNELBIND_HACK #endif @@ -50,35 +63,30 @@ static void dummy(int x) { dummy2(x-1); } we only ever handle one mechanism at a time, I didn't see the point in keeping that. In case someone sees a point, I've left the condition_check() API alone. */ +#define LOFF(field) OPT_OFF(auth_gsasl_options_block, field) + optionlist auth_gsasl_options[] = { - { "client_authz", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, client_authz)) }, - { "client_channelbinding", opt_bool, - (void *)(offsetof(auth_gsasl_options_block, client_channelbinding)) }, - { "client_password", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, client_password)) }, - { "client_username", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, client_username)) }, - - { "server_channelbinding", opt_bool, - (void *)(offsetof(auth_gsasl_options_block, server_channelbinding)) }, - { "server_hostname", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, server_hostname)) }, - { "server_mech", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, server_mech)) }, - { "server_password", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, server_password)) }, - { "server_realm", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, server_realm)) }, - { "server_scram_iter", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, server_scram_iter)) }, - { "server_scram_salt", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, server_scram_salt)) }, - { "server_service", opt_stringptr, - (void *)(offsetof(auth_gsasl_options_block, server_service)) } + { "client_authz", opt_stringptr, LOFF(client_authz) }, + { "client_channelbinding", opt_bool, LOFF(client_channelbinding) }, + { "client_password", opt_stringptr, LOFF(client_password) }, + { "client_spassword", opt_stringptr, LOFF(client_spassword) }, + { "client_username", opt_stringptr, LOFF(client_username) }, + + { "server_channelbinding", opt_bool, LOFF(server_channelbinding) }, + { "server_hostname", opt_stringptr, LOFF(server_hostname) }, +#ifdef EXIM_GSASL_SCRAM_S_KEY + { "server_key", opt_stringptr, LOFF(server_key) }, +#endif + { "server_mech", opt_stringptr, LOFF(server_mech) }, + { "server_password", opt_stringptr, LOFF(server_password) }, + { "server_realm", opt_stringptr, LOFF(server_realm) }, + { "server_scram_iter", opt_stringptr, LOFF(server_scram_iter) }, + { "server_scram_salt", opt_stringptr, LOFF(server_scram_salt) }, +#ifdef EXIM_GSASL_SCRAM_S_KEY + { "server_skey", opt_stringptr, LOFF(server_s_key) }, +#endif + { "server_service", opt_stringptr, LOFF(server_service) } }; -/* GSASL_SCRAM_SALTED_PASSWORD documented only for client, so not implementing -hooks to avoid cleartext passwords in the Exim server. */ int auth_gsasl_options_count = sizeof(auth_gsasl_options)/sizeof(optionlist); @@ -93,6 +101,7 @@ auth_gsasl_options_block auth_gsasl_option_defaults = { #ifdef MACRO_PREDEF +# include "../macro_predef.h" /* Dummy values */ void auth_gsasl_init(auth_instance *ablock) {} @@ -107,6 +116,9 @@ auth_gsasl_macros(void) # ifdef EXIM_GSASL_HAVE_SCRAM_SHA_256 builtin_macro_create(US"_HAVE_AUTH_GSASL_SCRAM_SHA_256"); # endif +# ifdef EXIM_GSASL_SCRAM_S_KEY + builtin_macro_create(US"_HAVE_AUTH_GSASL_SCRAM_S_KEY"); +# endif } #else /*!MACRO_PREDEF*/ @@ -288,6 +300,53 @@ return rc; } +/************************************************* +* Debug service function * +*************************************************/ +static const uschar * +gsasl_prop_code_to_name(Gsasl_property prop) +{ +switch (prop) + { + case GSASL_AUTHID: return US"AUTHID"; + case GSASL_AUTHZID: return US"AUTHZID"; + case GSASL_PASSWORD: return US"PASSWORD"; + case GSASL_ANONYMOUS_TOKEN: return US"ANONYMOUS_TOKEN"; + case GSASL_SERVICE: return US"SERVICE"; + case GSASL_HOSTNAME: return US"HOSTNAME"; + case GSASL_GSSAPI_DISPLAY_NAME: return US"GSSAPI_DISPLAY_NAME"; + case GSASL_PASSCODE: return US"PASSCODE"; + case GSASL_SUGGESTED_PIN: return US"SUGGESTED_PIN"; + case GSASL_PIN: return US"PIN"; + case GSASL_REALM: return US"REALM"; + case GSASL_DIGEST_MD5_HASHED_PASSWORD: return US"DIGEST_MD5_HASHED_PASSWORD"; + case GSASL_QOPS: return US"QOPS"; + case GSASL_QOP: return US"QOP"; + case GSASL_SCRAM_ITER: return US"SCRAM_ITER"; + case GSASL_SCRAM_SALT: return US"SCRAM_SALT"; + case GSASL_SCRAM_SALTED_PASSWORD: return US"SCRAM_SALTED_PASSWORD"; +#ifdef EXIM_GSASL_SCRAM_S_KEY + case GSASL_SCRAM_STOREDKEY: return US"SCRAM_STOREDKEY"; + case GSASL_SCRAM_SERVERKEY: return US"SCRAM_SERVERKEY"; +#endif + case GSASL_CB_TLS_UNIQUE: return US"CB_TLS_UNIQUE"; + case GSASL_SAML20_IDP_IDENTIFIER: return US"SAML20_IDP_IDENTIFIER"; + case GSASL_SAML20_REDIRECT_URL: return US"SAML20_REDIRECT_URL"; + case GSASL_OPENID20_REDIRECT_URL: return US"OPENID20_REDIRECT_URL"; + case GSASL_OPENID20_OUTCOME_DATA: return US"OPENID20_OUTCOME_DATA"; + case GSASL_SAML20_AUTHENTICATE_IN_BROWSER: return US"SAML20_AUTHENTICATE_IN_BROWSER"; + case GSASL_OPENID20_AUTHENTICATE_IN_BROWSER: return US"OPENID20_AUTHENTICATE_IN_BROWSER"; + case GSASL_VALIDATE_SIMPLE: return US"VALIDATE_SIMPLE"; + case GSASL_VALIDATE_EXTERNAL: return US"VALIDATE_EXTERNAL"; + case GSASL_VALIDATE_ANONYMOUS: return US"VALIDATE_ANONYMOUS"; + case GSASL_VALIDATE_GSSAPI: return US"VALIDATE_GSSAPI"; + case GSASL_VALIDATE_SECURID: return US"VALIDATE_SECURID"; + case GSASL_VALIDATE_SAML20: return US"VALIDATE_SAML20"; + case GSASL_VALIDATE_OPENID20: return US"VALIDATE_OPENID20"; + } +return CUS string_sprintf("(unknown prop: %d)", (int)prop); +} + /************************************************* * Server entry point * *************************************************/ @@ -312,7 +371,7 @@ HDEBUG(D_auth) #ifndef DISABLE_TLS if (tls_in.channelbinding && ob->server_channelbinding) { -# ifdef EXPERIMENTAL_TLS_RESUME +# ifndef DISABLE_TLS_RESUME if (!tls_in.ext_master_secret && tls_in.resumption == RESUME_USED) { /* per RFC 7677 section 4 */ HDEBUG(D_auth) debug_printf( @@ -321,9 +380,9 @@ if (tls_in.channelbinding && ob->server_channelbinding) } # endif # ifdef CHANNELBIND_HACK -/* This is a gross hack to get around the library a) requiring that -c-b was already set, at the _start() call, and b) caching a b64'd -version of the binding then which it never updates. */ +/* This is a gross hack to get around the library before 1.9.2 +a) requiring that c-b was already set, at the _start() call, and +b) caching a b64'd version of the binding then which it never updates. */ gsasl_callback_hook_set(gsasl_ctx, tls_in.channelbinding); # endif @@ -376,6 +435,12 @@ if (tls_in.channelbinding) would then result in mechanism name changes on a library update, we have little choice but to default it off and let the admin choose to enable it. *sigh* + + Earlier library versions need this set early, during the _start() call, + so we had to misuse gsasl_callback_hook_set/get() as a data transfer + mech for the callback done at that time to get the bind-data. More recently + the callback is done (if needed) during the first gsasl_stop(). We know + the bind-data here so can set it (and should not get a callback). */ if (ob->server_channelbinding) { @@ -440,6 +505,7 @@ do { goto STOP_INTERACTION; } + /*XXX having our caller send the final smtp "235" is unfortunate; wastes a roundtrip */ if ((rc == GSASL_NEEDS_MORE) || (to_send && *to_send)) exim_error = auth_get_no64_data(USS &received, US to_send); @@ -457,6 +523,21 @@ do { STOP_INTERACTION: auth_result = rc; +HDEBUG(D_auth) + { + const uschar * s; + if ((s = CUS gsasl_property_fast(sctx, GSASL_SCRAM_ITER))) + debug_printf(" - itercnt: '%s'\n", s); + if ((s = CUS gsasl_property_fast(sctx, GSASL_SCRAM_SALT))) + debug_printf(" - salt: '%s'\n", s); +#ifdef EXIM_GSASL_SCRAM_S_KEY + if ((s = CUS gsasl_property_fast(sctx, GSASL_SCRAM_SERVERKEY))) + debug_printf(" - ServerKey: '%s'\n", s); + if ((s = CUS gsasl_property_fast(sctx, GSASL_SCRAM_STOREDKEY))) + debug_printf(" - StoredKey: '%s'\n", s); +#endif + } + gsasl_finish(sctx); /* Can return: OK DEFER FAIL CANCELLED BAD64 UNEXPECTED */ @@ -501,14 +582,19 @@ return GSASL_AUTHENTICATION_ERROR; } +/* Set the "next" $auth[n] and increment expand_nmax */ + static void set_exim_authvar_from_prop(Gsasl_session * sctx, Gsasl_property prop) { uschar * propval = US gsasl_property_fast(sctx, prop); int i = expand_nmax, j = i + 1; propval = propval ? string_copy(propval) : US""; -auth_vars[i] = expand_nstring[j] = propval; +HDEBUG(D_auth) debug_printf("auth[%d] <= %s'%s'\n", + j, gsasl_prop_code_to_name(prop), propval); +expand_nstring[j] = propval; expand_nlength[j] = Ustrlen(propval); +if (i < AUTH_VARS) auth_vars[i] = propval; expand_nmax = j; } @@ -530,19 +616,36 @@ set_exim_authvar_from_prop(sctx, GSASL_REALM); } +static int +prop_from_option(Gsasl_session * sctx, Gsasl_property prop, + const uschar * option) +{ +HDEBUG(D_auth) debug_printf(" %s\n", gsasl_prop_code_to_name(prop)); +if (option) + { + set_exim_authvars_from_a_az_r_props(sctx); + option = expand_cstring(option); + HDEBUG(D_auth) debug_printf(" '%s'\n", option); + if (*option) + gsasl_property_set(sctx, prop, CCS option); + return GSASL_OK; + } +HDEBUG(D_auth) debug_printf(" option not set\n"); +return GSASL_NO_CALLBACK; +} + static int server_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop, auth_instance *ablock) { char *tmps; -uschar *propval; +uschar *s, *propval; int cbrc = GSASL_NO_CALLBACK; auth_gsasl_options_block *ob = (auth_gsasl_options_block *)(ablock->options_block); -HDEBUG(D_auth) - debug_printf("GNU SASL callback %d for %s/%s as server\n", - prop, ablock->name, ablock->public_name); +HDEBUG(D_auth) debug_printf("GNU SASL callback %s for %s/%s as server\n", + gsasl_prop_code_to_name(prop), ablock->name, ablock->public_name); for (int i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; expand_nmax = 0; @@ -550,7 +653,6 @@ expand_nmax = 0; switch (prop) { case GSASL_VALIDATE_SIMPLE: - HDEBUG(D_auth) debug_printf(" VALIDATE_SIMPLE\n"); /* GSASL_AUTHID, GSASL_AUTHZID, and GSASL_PASSWORD */ set_exim_authvar_from_prop(sctx, GSASL_AUTHID); set_exim_authvar_from_prop(sctx, GSASL_AUTHZID); @@ -561,7 +663,6 @@ switch (prop) break; case GSASL_VALIDATE_EXTERNAL: - HDEBUG(D_auth) debug_printf(" VALIDATE_EXTERNAL\n"); if (!ablock->server_condition) { HDEBUG(D_auth) debug_printf("No server_condition supplied, to validate EXTERNAL\n"); @@ -576,7 +677,6 @@ switch (prop) break; case GSASL_VALIDATE_ANONYMOUS: - HDEBUG(D_auth) debug_printf(" VALIDATE_ANONYMOUS\n"); if (!ablock->server_condition) { HDEBUG(D_auth) debug_printf("No server_condition supplied, to validate ANONYMOUS\n"); @@ -591,7 +691,6 @@ switch (prop) break; case GSASL_VALIDATE_GSSAPI: - HDEBUG(D_auth) debug_printf(" VALIDATE_GSSAPI\n"); /* GSASL_AUTHZID and GSASL_GSSAPI_DISPLAY_NAME The display-name is authenticated as part of GSS, the authzid is claimed by the SASL integration after authentication; protected against tampering @@ -613,37 +712,25 @@ switch (prop) break; case GSASL_SCRAM_ITER: - HDEBUG(D_auth) debug_printf(" SCRAM_ITER\n"); - if (ob->server_scram_iter) - { - set_exim_authvars_from_a_az_r_props(sctx); - tmps = CS expand_string(ob->server_scram_iter); - HDEBUG(D_auth) debug_printf(" '%s'\n", tmps); - gsasl_property_set(sctx, GSASL_SCRAM_ITER, tmps); - cbrc = GSASL_OK; - } - else - HDEBUG(D_auth) debug_printf(" option not set\n"); + cbrc = prop_from_option(sctx, prop, ob->server_scram_iter); break; case GSASL_SCRAM_SALT: - HDEBUG(D_auth) debug_printf(" SCRAM_SALT\n"); - if (ob->server_scram_salt) - { - set_exim_authvars_from_a_az_r_props(sctx); - tmps = CS expand_string(ob->server_scram_salt); - HDEBUG(D_auth) debug_printf(" '%s'\n", tmps); - if (*tmps) - gsasl_property_set(sctx, GSASL_SCRAM_SALT, tmps); - cbrc = GSASL_OK; - } - else - HDEBUG(D_auth) debug_printf(" option not set\n"); + cbrc = prop_from_option(sctx, prop, ob->server_scram_salt); + break; + +#ifdef EXIM_GSASL_SCRAM_S_KEY + case GSASL_SCRAM_STOREDKEY: + cbrc = prop_from_option(sctx, prop, ob->server_s_key); break; + case GSASL_SCRAM_SERVERKEY: + cbrc = prop_from_option(sctx, prop, ob->server_key); + break; +#endif + case GSASL_PASSWORD: - HDEBUG(D_auth) debug_printf(" PASSWORD\n"); - /* SCRAM-SHA-1: GSASL_AUTHID, GSASL_AUTHZID and GSASL_REALM + /* SCRAM-*: GSASL_AUTHID, GSASL_AUTHZID and GSASL_REALM DIGEST-MD5: GSASL_AUTHID, GSASL_AUTHZID and GSASL_REALM CRAM-MD5: GSASL_AUTHID PLAIN: GSASL_AUTHID and GSASL_AUTHZID @@ -651,12 +738,12 @@ switch (prop) */ set_exim_authvars_from_a_az_r_props(sctx); - if (!ob->server_password) + if (!(s = ob->server_password)) { HDEBUG(D_auth) debug_printf("option not set\n"); break; } - if (!(tmps = CS expand_string(ob->server_password))) + if (!(tmps = CS expand_string(s))) { sasl_error_should_defer = !f.expand_string_forcedfail; HDEBUG(D_auth) debug_printf("server_password expansion failed, so " @@ -670,7 +757,7 @@ switch (prop) for memory wiping, so expanding strings will leave stuff laying around. But no need to compound the problem, so get rid of the one we can. */ - memset(tmps, '\0', strlen(tmps)); + if (US tmps != s) memset(tmps, '\0', strlen(tmps)); cbrc = GSASL_OK; break; @@ -691,19 +778,25 @@ return cbrc; #define PROP_OPTIONAL BIT(0) static BOOL -client_prop(Gsasl_session * sctx, Gsasl_property propnum, uschar * val, - const uschar * why, unsigned flags, uschar * buffer, int buffsize) +set_client_prop(Gsasl_session * sctx, Gsasl_property prop, uschar * val, + unsigned flags, uschar * buffer, int buffsize) { uschar * s; int rc; -if (flags & PROP_OPTIONAL && !val) return TRUE; +if (!val) return !!(flags & PROP_OPTIONAL); if (!(s = expand_string(val)) || !(flags & PROP_OPTIONAL) && !*s) { string_format(buffer, buffsize, "%s", expand_string_message); return FALSE; } -if (*s) gsasl_property_set(sctx, propnum, CS s); +if (*s) + { + HDEBUG(D_auth) debug_printf("%s: set %s = '%s'\n", __FUNCTION__, + gsasl_prop_code_to_name(prop), s); + gsasl_property_set(sctx, prop, CS s); + } + return TRUE; } @@ -738,18 +831,19 @@ HDEBUG(D_auth) #ifndef DISABLE_TLS if (tls_out.channelbinding && ob->client_channelbinding) { -# ifdef EXPERIMENTAL_TLS_RESUME +# ifndef DISABLE_TLS_RESUME if (!tls_out.ext_master_secret && tls_out.resumption == RESUME_USED) - { /* per RFC 7677 section 4 */ + { /* Per RFC 7677 section 4. See also RFC 7627, "Triple Handshake" + vulnerability, and https://www.mitls.org/pages/attacks/3SHAKE */ string_format(buffer, buffsize, "%s", "channel binding not usable on resumed TLS without extended-master-secret"); return FAIL; } # endif # ifdef CHANNELBIND_HACK - /* This is a gross hack to get around the library a) requiring that - c-b was already set, at the _start() call, and b) caching a b64'd - version of the binding then which it never updates. */ + /* This is a gross hack to get around the library before 1.9.2 + a) requiring that c-b was already set, at the _start() call, and + b) caching a b64'd version of the binding then which it never updates. */ gsasl_callback_hook_set(gsasl_ctx, tls_out.channelbinding); # endif @@ -770,11 +864,11 @@ gsasl_session_hook_set(sctx, &cb_state); /* Set properties */ -if ( !client_prop(sctx, GSASL_PASSWORD, ob->client_password, US"password", +if ( !set_client_prop(sctx, GSASL_PASSWORD, ob->client_password, 0, buffer, buffsize) - || !client_prop(sctx, GSASL_AUTHID, ob->client_username, US"username", + || !set_client_prop(sctx, GSASL_AUTHID, ob->client_username, 0, buffer, buffsize) - || !client_prop(sctx, GSASL_AUTHZID, ob->client_authz, US"authz", + || !set_client_prop(sctx, GSASL_AUTHZID, ob->client_authz, PROP_OPTIONAL, buffer, buffsize) ) return ERROR; @@ -848,6 +942,15 @@ for(s = NULL; ;) } done: +if (yield == OK) + { + expand_nmax = 0; + set_exim_authvar_from_prop(sctx, GSASL_AUTHID); + set_exim_authvar_from_prop(sctx, GSASL_SCRAM_ITER); + set_exim_authvar_from_prop(sctx, GSASL_SCRAM_SALT); + set_exim_authvar_from_prop(sctx, GSASL_SCRAM_SALTED_PASSWORD); + } + gsasl_finish(sctx); return yield; } @@ -855,21 +958,38 @@ return yield; static int client_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop, auth_instance *ablock) { -HDEBUG(D_auth) debug_printf("GNU SASL callback %d for %s/%s as client\n", - prop, ablock->name, ablock->public_name); +HDEBUG(D_auth) debug_printf("GNU SASL callback %s for %s/%s as client\n", + gsasl_prop_code_to_name(prop), ablock->name, ablock->public_name); switch (prop) { - case GSASL_AUTHZID: - HDEBUG(D_auth) debug_printf(" inquired for AUTHZID; not providing one\n"); + case GSASL_CB_TLS_UNIQUE: /*XXX should never get called for this */ + HDEBUG(D_auth) + debug_printf(" filling in\n"); + gsasl_property_set(sctx, GSASL_CB_TLS_UNIQUE, CCS tls_out.channelbinding); break; case GSASL_SCRAM_SALTED_PASSWORD: - HDEBUG(D_auth) - debug_printf(" inquired for SCRAM_SALTED_PASSWORD; not providing one\n"); + { + uschar * client_spassword = + ((auth_gsasl_options_block *) ablock->options_block)->client_spassword; + uschar dummy[4]; + HDEBUG(D_auth) if (!client_spassword) + debug_printf(" client_spassword option unset\n"); + if (client_spassword) + { + expand_nmax = 0; + set_exim_authvar_from_prop(sctx, GSASL_AUTHID); + set_exim_authvar_from_prop(sctx, GSASL_SCRAM_ITER); + set_exim_authvar_from_prop(sctx, GSASL_SCRAM_SALT); + set_client_prop(sctx, GSASL_SCRAM_SALTED_PASSWORD, client_spassword, + 0, dummy, sizeof(dummy)); + for (int i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; + expand_nmax = 0; + } break; - case GSASL_CB_TLS_UNIQUE: + } + default: HDEBUG(D_auth) - debug_printf(" inquired for CB_TLS_UNIQUE, filling in\n"); - gsasl_property_set(sctx, GSASL_CB_TLS_UNIQUE, CCS tls_out.channelbinding); + debug_printf(" not providing one\n"); break; } return GSASL_NO_CALLBACK;