Gitweb:
http://git.exim.org/exim.git/commitdiff/44bbabb570db6e700a31469a0faf2ac27bf3bfe0
Commit: 44bbabb570db6e700a31469a0faf2ac27bf3bfe0
Parent: 8ebb1c9ea93eb27500756a578640d890b53264d3
Author: Phil Pennock <pdp@???>
AuthorDate: Sun Feb 5 19:13:32 2012 -0500
Committer: Phil Pennock <pdp@???>
CommitDate: Sun Feb 5 19:13:32 2012 -0500
Implemented gsasl driver for authentication.
Missing: documentation; tests.
Tested: PLAIN auth.
Status: probably buggy
---
src/scripts/MakeLinks | 2 +
src/src/EDITME | 4 +-
src/src/auths/Makefile | 4 +-
src/src/auths/check_serv_cond.c | 43 +++-
src/src/auths/cyrus_sasl.c | 2 +-
src/src/auths/cyrus_sasl.h | 1 +
src/src/auths/get_no64_data.c | 4 +-
src/src/auths/gsasl_exim.c | 587 +++++++++++++++++++++++++++++++++++++++
src/src/auths/gsasl_exim.h | 42 +++
src/src/config.h.defaults | 1 +
src/src/drtables.c | 35 ++-
src/src/exim.c | 13 +-
src/src/exim.h | 8 -
src/src/functions.h | 2 +
src/src/globals.h | 5 +
src/src/structs.h | 2 +
src/src/tls-gnu.c | 20 ++-
src/src/tls.c | 1 +
18 files changed, 748 insertions(+), 28 deletions(-)
diff --git a/src/scripts/MakeLinks b/src/scripts/MakeLinks
index 082659c..f7d0003 100755
--- a/src/scripts/MakeLinks
+++ b/src/scripts/MakeLinks
@@ -123,6 +123,8 @@ ln -s ../../src/auths/call_radius.c call_radius.c
ln -s ../../src/auths/check_serv_cond.c check_serv_cond.c
ln -s ../../src/auths/cyrus_sasl.c cyrus_sasl.c
ln -s ../../src/auths/cyrus_sasl.h cyrus_sasl.h
+ln -s ../../src/auths/gsasl_exim.c gsasl_exim.c
+ln -s ../../src/auths/gsasl_exim.h gsasl_exim.h
ln -s ../../src/auths/get_data.c get_data.c
ln -s ../../src/auths/get_no64_data.c get_no64_data.c
ln -s ../../src/auths/md5.c md5.c
diff --git a/src/src/EDITME b/src/src/EDITME
index a180cd5..7e426ea 100644
--- a/src/src/EDITME
+++ b/src/src/EDITME
@@ -553,6 +553,7 @@ FIXED_NEVER_USERS=root
# AUTH_CRAM_MD5=yes
# AUTH_CYRUS_SASL=yes
# AUTH_DOVECOT=yes
+# AUTH_GSASL=yes
# AUTH_PLAINTEXT=yes
# AUTH_SPA=yes
@@ -560,9 +561,10 @@ FIXED_NEVER_USERS=root
#------------------------------------------------------------------------------
# If you specified AUTH_CYRUS_SASL above, you should ensure that you have the
# Cyrus SASL library installed before trying to build Exim, and you probably
-# want to uncomment the following line:
+# want to uncomment the first line below. Similarly for GNU SASL.
# AUTH_LIBS=-lsasl2
+# AUTH_LIBS=-lgsasl
#------------------------------------------------------------------------------
diff --git a/src/src/auths/Makefile b/src/src/auths/Makefile
index 3e0e1a2..1354c8c 100644
--- a/src/src/auths/Makefile
+++ b/src/src/auths/Makefile
@@ -7,7 +7,8 @@
OBJ = auth-spa.o b64decode.o b64encode.o call_pam.o call_pwcheck.o \
call_radius.o check_serv_cond.o cram_md5.o cyrus_sasl.o dovecot.o \
- get_data.o get_no64_data.o md5.o plaintext.o pwcheck.o sha1.o \
+ get_data.o get_no64_data.o gsasl_exim.o \
+ md5.o plaintext.o pwcheck.o sha1.o \
spa.o xtextdecode.o xtextencode.o
auths.a: $(OBJ)
@@ -38,6 +39,7 @@ xtextencode.o: $(HDRS) xtextencode.c
cram_md5.o: $(HDRS) cram_md5.c cram_md5.h
cyrus_sasl.o: $(HDRS) cyrus_sasl.c cyrus_sasl.h
dovecot.o: $(HDRS) dovecot.c dovecot.h
+gsasl_exim.o: $(HDRS) gsasl_exim.c gsasl_exim.h
plaintext.o: $(HDRS) plaintext.c plaintext.h
spa.o: $(HDRS) spa.c spa.h
diff --git a/src/src/auths/check_serv_cond.c b/src/src/auths/check_serv_cond.c
index 476d112..c10ff1b 100644
--- a/src/src/auths/check_serv_cond.c
+++ b/src/src/auths/check_serv_cond.c
@@ -16,8 +16,8 @@ by all authenticators. */
*************************************************/
/* This function is called from the server code of all authenticators. For
-plaintext, it is always called: the argument cannot be empty, because for
-plaintext, setting server_condition is what enables it as a server
+plaintext and gsasl, it is always called: the argument cannot be empty, because
+for those, setting server_condition is what enables it as a server
authenticator. For all the other authenticators, this function is called after
they have authenticated, to enable additional authorization to be done.
@@ -32,12 +32,40 @@ Returns:
int
auth_check_serv_cond(auth_instance *ablock)
{
+ return auth_check_some_cond(ablock,
+ US"server_condition", ablock->server_condition, OK);
+}
+
+
+/*************************************************
+* Check some server condition *
+*************************************************/
+
+/* This underlies server_condition, but is also used for some more generic
+ checks.
+
+Arguments:
+ ablock the authenticator's instance block
+ label debugging label naming the string checked
+ condition the condition string to be expanded and checked
+ unset value to return on NULL condition
+
+Returns:
+ OK success (or unset=OK)
+ DEFER couldn't complete the check
+ FAIL authentication failed
+*/
+
+int
+auth_check_some_cond(auth_instance *ablock,
+ uschar *label, uschar *condition, int unset)
+{
uschar *cond;
HDEBUG(D_auth)
{
int i;
- debug_printf("%s authenticator:\n", ablock->name);
+ debug_printf("%s authenticator %s:\n", ablock->name, label);
for (i = 0; i < AUTH_VARS; i++)
{
if (auth_vars[i] != NULL)
@@ -51,8 +79,13 @@ HDEBUG(D_auth)
/* For the plaintext authenticator, server_condition is never NULL. For the
rest, an unset condition lets everything through. */
-if (ablock->server_condition == NULL) return OK;
-cond = expand_string(ablock->server_condition);
+/* For server_condition, an unset condition lets everything through.
+For plaintext/gsasl authenticators, it will have been pre-checked to prevent
+this. We return the unset scenario value given to us, which for
+server_condition will be OK and otherwise will typically be FAIL. */
+
+if (condition == NULL) return unset;
+cond = expand_string(condition);
HDEBUG(D_auth)
{
diff --git a/src/src/auths/cyrus_sasl.c b/src/src/auths/cyrus_sasl.c
index fea1def..df7abc9 100644
--- a/src/src/auths/cyrus_sasl.c
+++ b/src/src/auths/cyrus_sasl.c
@@ -113,7 +113,7 @@ if(ob->server_mech == NULL)
* authenticator of type whatever mechanism we're using
*/
-cbs[0].proc = &mysasl_config;
+cbs[0].proc = (int(*)(void))&mysasl_config;
cbs[0].context = ob->server_mech;
rc=sasl_server_init(cbs, "exim");
diff --git a/src/src/auths/cyrus_sasl.h b/src/src/auths/cyrus_sasl.h
index 7e62e63..031e783 100644
--- a/src/src/auths/cyrus_sasl.h
+++ b/src/src/auths/cyrus_sasl.h
@@ -31,5 +31,6 @@ extern void auth_cyrus_sasl_init(auth_instance *);
extern int auth_cyrus_sasl_server(auth_instance *, uschar *);
extern int auth_cyrus_sasl_client(auth_instance *, smtp_inblock *,
smtp_outblock *, int, uschar *, int);
+extern void auth_cyrus_sasl_version_report(FILE *f);
/* End of cyrus_sasl.h */
diff --git a/src/src/auths/get_no64_data.c b/src/src/auths/get_no64_data.c
index 4055c04..ea5fd6f 100644
--- a/src/src/auths/get_no64_data.c
+++ b/src/src/auths/get_no64_data.c
@@ -14,8 +14,8 @@
/* This function is used by authentication drivers to output a challenge
to the SMTP client and read the response line. This version does not use base
-64 encoding for the text on the 334 line. It is used by the SPA and dovecot
-authenticators.
+64 encoding for the text on the 334 line. It is used by the SPA, dovecot
+and gsasl authenticators.
Arguments:
aptr set to point to the response (which is in big_buffer)
diff --git a/src/src/auths/gsasl_exim.c b/src/src/auths/gsasl_exim.c
new file mode 100644
index 0000000..e88bd25
--- /dev/null
+++ b/src/src/auths/gsasl_exim.c
@@ -0,0 +1,587 @@
+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+/* Copyright (c) Twitter Inc 2012 */
+
+/* Interface to GNU SASL library for generic authentication. */
+
+/* Trade-offs:
+
+GNU SASL does not provide authentication data itself, so we have to expose
+that decision to configuration. For some mechanisms, we need to act much
+like plaintext. For others, we only need to be able to provide some
+evaluated data on demand. There's no abstracted way (ie, without hardcoding
+knowledge of authenticators here) to know which need what properties; we
+can't query a session or the library for "we will need these for mechanism X".
+
+So: we always require server_condition, even if sometimes it will just be
+set as "yes". We do provide a number of other hooks, which might not make
+sense in all contexts. For some, we can do checks at init time.
+*/
+
+#include "../exim.h"
+
+#ifndef AUTH_GSASL
+/* dummy function to satisfy compilers when we link in an "empty" file. */
+static void dummy(int x) { dummy(x-1); }
+#else
+
+#include <gsasl.h>
+#include "gsasl_exim.h"
+
+/* Authenticator-specific options. */
+/* I did have server_*_condition options for various mechanisms, but since
+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. */
+optionlist auth_gsasl_options[] = {
+ { "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)) }
+};
+/* 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);
+
+/* Defaults for the authenticator-specific options. */
+auth_gsasl_options_block auth_gsasl_option_defaults = {
+ US"smtp", /* server_service */
+ US"$primary_hostname", /* server_hostname */
+ NULL, /* server_realm */
+ NULL, /* server_mech */
+ NULL, /* server_password */
+ NULL, /* server_scram_iter */
+ NULL, /* server_scram_salt */
+ FALSE /* server_channelbinding */
+};
+
+/* "Globals" for managing the gsasl interface. */
+
+static Gsasl *gsasl_ctx = NULL;
+static int
+ main_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop);
+static int
+ server_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop, auth_instance *ablock);
+static int
+ client_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop, auth_instance *ablock);
+
+static BOOL sasl_error_should_defer = FALSE;
+static Gsasl_property callback_loop = 0;
+static BOOL checked_server_condition = FALSE;
+
+enum { CURRENTLY_SERVER = 1, CURRENTLY_CLIENT = 2 };
+
+struct callback_exim_state {
+ auth_instance *ablock;
+ int currently;
+};
+
+
+/*************************************************
+* Initialization entry point *
+*************************************************/
+
+/* Called for each instance, after its options have been read, to
+enable consistency checks to be done, or anything else that needs
+to be set up. */
+
+void
+auth_gsasl_init(auth_instance *ablock)
+{
+ char *p;
+ int rc, supported;
+ auth_gsasl_options_block *ob =
+ (auth_gsasl_options_block *)(ablock->options_block);
+
+ /* As per existing Cyrus glue, use the authenticator's public name as
+ the default for the mechanism name; we don't handle multiple mechanisms
+ in one authenticator, but the same driver can be used multiple times. */
+
+ if (ob->server_mech == NULL)
+ ob->server_mech = string_copy(ablock->public_name);
+
+ /* Can get multiple session contexts from one library context, so just
+ initialise the once. */
+ if (gsasl_ctx == NULL) {
+ rc = gsasl_init(&gsasl_ctx);
+ if (rc != GSASL_OK) {
+ log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
+ "couldn't initialise GNU SASL library: %s (%s)",
+ ablock->name, gsasl_strerror_name(rc), gsasl_strerror(rc));
+ }
+ gsasl_callback_set(gsasl_ctx, main_callback);
+ }
+
+ /* We don't need this except to log it for debugging. */
+ rc = gsasl_server_mechlist(gsasl_ctx, &p);
+ if (rc != GSASL_OK)
+ log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
+ "failed to retrieve list of mechanisms: %s (%s)",
+ ablock->name, gsasl_strerror_name(rc), gsasl_strerror(rc));
+ HDEBUG(D_auth) debug_printf("GNU SASL supports: %s\n", p);
+
+ supported = gsasl_client_support_p(gsasl_ctx, (const char *)ob->server_mech);
+ if (!supported)
+ log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
+ "GNU SASL does not support mechanism \"%s\"",
+ ablock->name, ob->server_mech);
+
+ if ((ablock->server_condition == NULL) &&
+ (strcmpic(ob->server_mech, US"EXTERNAL") ||
+ strcmpic(ob->server_mech, US"ANONYMOUS") ||
+ strcmpic(ob->server_mech, US"PLAIN") ||
+ strcmpic(ob->server_mech, US"LOGIN")))
+ log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
+ "Need server_condition for %s mechanism",
+ ablock->name, ob->server_mech);
+
+ /* At present, for mechanisms we don't panic on absence of server_condition;
+ need to figure out the most generically correct approach to deciding when
+ it's critical and when it isn't. Eg, for simple validation (PLAIN mechanism,
+ etc) it clearly is critical.
+
+ So don't activate without server_condition, this might be relaxed in the future.
+ */
+ if (ablock->server_condition != NULL) ablock->server = TRUE;
+ ablock->client = FALSE;
+}
+
+
+/* GNU SASL uses one top-level callback, registered at library level.
+We dispatch to client and server functions instead. */
+
+static int
+main_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop)
+{
+ int rc = 0;
+ struct callback_exim_state *cb_state =
+ (struct callback_exim_state *)gsasl_session_hook_get(sctx);
+
+ HDEBUG(D_auth) debug_printf("Callback entered, prop=%d (loop prop=%d)\n",
+ prop, callback_loop);
+
+ if (cb_state == NULL) {
+ HDEBUG(D_auth) debug_printf(" not from our server/client processing.\n");
+ return GSASL_NO_CALLBACK;
+ }
+
+ if (callback_loop > 0) {
+ /* Most likely is that we were asked for property foo, and to
+ expand the string we asked for property bar to put into an auth
+ variable, but property bar is not supplied for this mechanism. */
+ HDEBUG(D_auth)
+ debug_printf("Loop, asked for property %d while handling property %d\n",
+ prop, callback_loop);
+ return GSASL_NO_CALLBACK;
+ }
+ callback_loop = prop;
+
+ if (cb_state->currently == CURRENTLY_CLIENT)
+ rc = client_callback(ctx, sctx, prop, cb_state->ablock);
+ else if (cb_state->currently == CURRENTLY_SERVER)
+ rc = server_callback(ctx, sctx, prop, cb_state->ablock);
+ else {
+ log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
+ "unhandled callback state, bug in Exim", cb_state->ablock->name);
+ /* NOTREACHED */
+ }
+
+ callback_loop = 0;
+ return rc;
+}
+
+
+/*************************************************
+* Server entry point *
+*************************************************/
+
+/* For interface, see auths/README */
+
+int
+auth_gsasl_server(auth_instance *ablock, uschar *initial_data)
+{
+ char *tmps;
+ char *to_send, *received;
+ Gsasl_session *sctx = NULL;
+ auth_gsasl_options_block *ob =
+ (auth_gsasl_options_block *)(ablock->options_block);
+ struct callback_exim_state cb_state;
+ int rc, auth_result, exim_error, exim_error_override;
+
+ HDEBUG(D_auth)
+ debug_printf("GNU SASL: initialising session for %s, mechanism %s.\n",
+ ablock->name, ob->server_mech);
+
+ rc = gsasl_server_start(gsasl_ctx, (const char *)ob->server_mech, &sctx);
+ if (rc != GSASL_OK) {
+ auth_defer_msg = string_sprintf("GNU SASL: session start failure: %s (%s)",
+ gsasl_strerror_name(rc), gsasl_strerror(rc));
+ HDEBUG(D_auth) debug_printf("%s\n", auth_defer_msg);
+ return DEFER;
+ }
+ /* Hereafter: gsasl_finish(sctx) please */
+
+ gsasl_session_hook_set(sctx, (void *)ablock);
+ cb_state.ablock = ablock;
+ cb_state.currently = CURRENTLY_SERVER;
+ gsasl_session_hook_set(sctx, (void *)&cb_state);
+
+ tmps = CS expand_string(ob->server_service);
+ gsasl_property_set(sctx, GSASL_SERVICE, tmps);
+ tmps = CS expand_string(ob->server_hostname);
+ gsasl_property_set(sctx, GSASL_HOSTNAME, tmps);
+ if (ob->server_realm) {
+ tmps = CS expand_string(ob->server_realm);
+ if (tmps && *tmps) {
+ gsasl_property_set(sctx, GSASL_REALM, tmps);
+ }
+ }
+ /* We don't support protection layers. */
+ gsasl_property_set(sctx, GSASL_QOPS, "qop-auth");
+#ifdef SUPPORT_TLS
+ if (tls_channelbinding_b64) {
+ /* Some auth mechanisms can ensure that both sides are talking withing the
+ same security context; for TLS, this means that even if a bad certificate
+ has been accepted, they remain MitM-proof because both sides must be within
+ the same negotiated session; if someone is terminating one sesson and
+ proxying data on within a second, authentication will fail.
+
+ We might not have this available, depending upon TLS implementation,
+ ciphersuite, phase of moon ...
+
+ If we do, it results in extra SASL mechanisms being available; here,
+ Exim's one-mechanism-per-authenticator potentially causes problems.
+ It depends upon how GNU SASL will implement the PLUS variants of GS2
+ and whether it automatically mandates a switch to the bound PLUS
+ if the data is available. Since default-on, despite being more secure,
+ 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*
+ */
+ if (ob->server_channelbinding) {
+ HDEBUG(D_auth) debug_printf("Auth %s: Enabling channel-binding\n",
+ ablock->name);
+ gsasl_property_set(sctx, GSASL_CB_TLS_UNIQUE,
+ (const char *) tls_channelbinding_b64);
+ } else {
+ HDEBUG(D_auth)
+ debug_printf("Auth %s: Not enabling channel-binding (data available)\n",
+ ablock->name);
+ }
+ } else {
+ HDEBUG(D_auth)
+ debug_printf("Auth %s: no channel-binding data available\n",
+ ablock->name);
+ }
+#endif
+
+ checked_server_condition = FALSE;
+
+ received = CS initial_data;
+ to_send = NULL;
+ exim_error = exim_error_override = OK;
+
+ do {
+ rc = gsasl_step64(sctx, received, &to_send);
+
+ switch (rc) {
+ case GSASL_OK:
+ goto STOP_INTERACTION;
+
+ case GSASL_NEEDS_MORE:
+ break;
+
+ case GSASL_AUTHENTICATION_ERROR:
+ case GSASL_INTEGRITY_ERROR:
+ case GSASL_NO_AUTHID:
+ case GSASL_NO_ANONYMOUS_TOKEN:
+ case GSASL_NO_AUTHZID:
+ case GSASL_NO_PASSWORD:
+ case GSASL_NO_PASSCODE:
+ case GSASL_NO_PIN:
+ case GSASL_BASE64_ERROR:
+ HDEBUG(D_auth) debug_printf("GNU SASL permanent error: %s (%s)\n",
+ gsasl_strerror_name(rc), gsasl_strerror(rc));
+ log_write(0, LOG_REJECT, "%s authenticator (%s):\n "
+ "GNU SASL permanent failure: %s (%s)",
+ ablock->name, ob->server_mech,
+ gsasl_strerror_name(rc), gsasl_strerror(rc));
+ if (rc == GSASL_BASE64_ERROR)
+ exim_error_override = BAD64;
+ goto STOP_INTERACTION;
+
+ default:
+ auth_defer_msg = string_sprintf("GNU SASL temporary error: %s (%s)",
+ gsasl_strerror_name(rc), gsasl_strerror(rc));
+ HDEBUG(D_auth) debug_printf("%s\n", auth_defer_msg);
+ exim_error_override = DEFER;
+ goto STOP_INTERACTION;
+ }
+
+ exim_error =
+ auth_get_no64_data((uschar **)&received, (uschar *)to_send);
+ if (exim_error)
+ break; /* handles * cancelled check */
+
+ } while (rc == GSASL_NEEDS_MORE);
+
+STOP_INTERACTION:
+ auth_result = rc;
+
+ gsasl_finish(sctx);
+
+ /* Can return: OK DEFER FAIL CANCELLED BAD64 UNEXPECTED */
+
+ if (exim_error != OK)
+ return exim_error;
+
+ if (auth_result != GSASL_OK) {
+ HDEBUG(D_auth) debug_printf("authentication returned %s (%s)\n",
+ gsasl_strerror_name(auth_result), gsasl_strerror(auth_result));
+ if (exim_error_override != OK)
+ return exim_error_override; /* might be DEFER */
+ if (sasl_error_should_defer) /* overriding auth failure SASL error */
+ return DEFER;
+ return FAIL;
+ }
+
+ /* Auth succeeded, check server_condition unless already done in callback */
+ return checked_server_condition ? OK : auth_check_serv_cond(ablock);
+}
+
+/* returns the GSASL status of expanding the Exim string given */
+static int
+condition_check(auth_instance *ablock, uschar *label, uschar *condition_string)
+{
+ int exim_rc;
+
+ exim_rc = auth_check_some_cond(ablock, label, condition_string, FAIL);
+
+ if (exim_rc == OK) {
+ return GSASL_OK;
+ } else if (exim_rc == DEFER) {
+ sasl_error_should_defer = TRUE;
+ return GSASL_AUTHENTICATION_ERROR;
+ } else if (exim_rc == FAIL) {
+ return GSASL_AUTHENTICATION_ERROR;
+ }
+
+ log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
+ "Unhandled return from checking %s: %d",
+ ablock->name, label, exim_rc);
+ /* NOTREACHED */
+ return GSASL_AUTHENTICATION_ERROR;
+}
+
+static int
+server_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop, auth_instance *ablock)
+{
+ char *tmps;
+ uschar *propval;
+ int cbrc = GSASL_NO_CALLBACK;
+ int i;
+ 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);
+
+ for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL;
+ expand_nmax = 0;
+
+ switch (prop) {
+ case GSASL_VALIDATE_SIMPLE:
+ /* GSASL_AUTHID, GSASL_AUTHZID, and GSASL_PASSWORD */
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_AUTHID);
+ auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_AUTHZID);
+ auth_vars[1] = expand_nstring[2] = propval ? propval : US"";
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_PASSWORD);
+ auth_vars[2] = expand_nstring[3] = propval ? propval : US"";
+ expand_nmax = 3;
+ for (i = 1; i <= 3; ++i)
+ expand_nlength[i] = Ustrlen(expand_nstring[i]);
+
+ cbrc = condition_check(ablock, US"server_condition", ablock->server_condition);
+ checked_server_condition = TRUE;
+ break;
+
+ case GSASL_VALIDATE_EXTERNAL:
+ if (ablock->server_condition == NULL) {
+ HDEBUG(D_auth) debug_printf("No server_condition supplied, to validate EXTERNAL.\n");
+ cbrc = GSASL_AUTHENTICATION_ERROR;
+ break;
+ }
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_AUTHZID);
+ /* We always set $auth1, even if only to empty string. */
+ auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
+ expand_nlength[1] = Ustrlen(expand_nstring[1]);
+ expand_nmax = 1;
+
+ cbrc = condition_check(ablock,
+ US"server_condition (EXTERNAL)", ablock->server_condition);
+ checked_server_condition = TRUE;
+ break;
+
+ case GSASL_VALIDATE_ANONYMOUS:
+ if (ablock->server_condition == NULL) {
+ HDEBUG(D_auth) debug_printf("No server_condition supplied, to validate ANONYMOUS.\n");
+ cbrc = GSASL_AUTHENTICATION_ERROR;
+ break;
+ }
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_ANONYMOUS_TOKEN);
+ /* We always set $auth1, even if only to empty string. */
+ auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
+ expand_nlength[1] = Ustrlen(expand_nstring[1]);
+ expand_nmax = 1;
+
+ cbrc = condition_check(ablock,
+ US"server_condition (ANONYMOUS)", ablock->server_condition);
+ checked_server_condition = TRUE;
+ break;
+
+ case GSASL_VALIDATE_GSSAPI:
+ /* GSASL_AUTHZID and GSASL_GSSAPI_DISPLAY_NAME */
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_AUTHZID);
+ auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_GSSAPI_DISPLAY_NAME);
+ auth_vars[1] = expand_nstring[2] = propval ? propval : US"";
+ expand_nmax = 2;
+ for (i = 1; i <= 2; ++i)
+ expand_nlength[i] = Ustrlen(expand_nstring[i]);
+
+ /* In this one case, it perhaps makes sense to default back open?
+ But for consistency, let's just mandate server_condition here too. */
+ cbrc = condition_check(ablock,
+ US"server_condition (GSSAPI family)", ablock->server_condition);
+ checked_server_condition = TRUE;
+ break;
+
+ case GSASL_PASSWORD:
+ /* DIGEST-MD5: GSASL_AUTHID, GSASL_AUTHZID and GSASL_REALM
+ CRAM-MD5: GSASL_AUTHID
+ PLAIN: GSASL_AUTHID and GSASL_AUTHZID
+ LOGIN: GSASL_AUTHID
+ */
+ if (ob->server_scram_iter) {
+ tmps = CS expand_string(ob->server_scram_iter);
+ gsasl_property_set(sctx, GSASL_SCRAM_ITER, tmps);
+ }
+ if (ob->server_scram_salt) {
+ tmps = CS expand_string(ob->server_scram_salt);
+ gsasl_property_set(sctx, GSASL_SCRAM_SALT, tmps);
+ }
+ /* Asking for GSASL_AUTHZID will probably call back into us.
+ Do we really want to hardcode limits per mechanism? What happens when
+ a new mechanism is added to the library. It *shouldn't* result in us
+ needing to add more glue, since avoiding that is a large part of the
+ point of SASL. */
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_AUTHID);
+ auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_AUTHZID);
+ auth_vars[1] = expand_nstring[2] = propval ? propval : US"";
+ propval = (uschar *) gsasl_property_get(sctx, GSASL_REALM);
+ auth_vars[2] = expand_nstring[3] = propval ? propval : US"";
+ expand_nmax = 3;
+ for (i = 1; i <= 3; ++i)
+ expand_nlength[i] = Ustrlen(expand_nstring[i]);
+
+ tmps = CS expand_string(ob->server_password);
+ if (tmps == NULL) {
+ sasl_error_should_defer = expand_string_forcedfail ? FALSE : TRUE;
+ HDEBUG(D_auth) debug_printf("server_password expansion failed, so "
+ "can't tell GNU SASL library the password for %s\n", auth_vars[0]);
+ return GSASL_AUTHENTICATION_ERROR;
+ }
+ gsasl_property_set(sctx, GSASL_PASSWORD, tmps);
+ /* This is inadequate; don't think Exim's store stacks are geared
+ 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));
+ cbrc = GSASL_OK;
+ break;
+
+ default:
+ HDEBUG(D_auth) debug_printf("Unrecognised callback: %d\n", prop);
+ cbrc = GSASL_NO_CALLBACK;
+ }
+
+ HDEBUG(D_auth) debug_printf("Returning %s (%s)\n",
+ gsasl_strerror_name(cbrc), gsasl_strerror(cbrc));
+
+ return cbrc;
+}
+
+
+/*************************************************
+* Client entry point *
+*************************************************/
+
+/* For interface, see auths/README */
+
+int
+auth_gsasl_client(
+ auth_instance *ablock, /* authenticator block */
+ smtp_inblock *inblock, /* connection inblock */
+ smtp_outblock *outblock, /* connection outblock */
+ int timeout, /* command timeout */
+ uschar *buffer, /* buffer for reading response */
+ int buffsize) /* size of buffer */
+{
+ HDEBUG(D_auth)
+ debug_printf("Client side NOT IMPLEMENTED: you should not see this!\n");
+ /* NOT IMPLEMENTED */
+ return FAIL;
+}
+
+static int
+client_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop, auth_instance *ablock)
+{
+ int cbrc = GSASL_NO_CALLBACK;
+ 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("Client side NOT IMPLEMENTED: you should not see this!\n");
+
+ return cbrc;
+}
+
+/*************************************************
+* Diagnostic API *
+*************************************************/
+
+void
+auth_gsasl_version_report(FILE *f)
+{
+ const char *runtime;
+ runtime = gsasl_check_version(NULL);
+ fprintf(f, "Library version: GNU SASL: Compile: %s\n"
+ " Runtime: %s\n",
+ GSASL_VERSION, runtime);
+}
+
+#endif /* AUTH_GSASL */
+
+/* End of gsasl_exim.c */
diff --git a/src/src/auths/gsasl_exim.h b/src/src/auths/gsasl_exim.h
new file mode 100644
index 0000000..785b853
--- /dev/null
+++ b/src/src/auths/gsasl_exim.h
@@ -0,0 +1,42 @@
+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+/* Copyright (c) Twitter Inc 2012 */
+
+/* Interface to GNU SASL library for generic authentication. */
+
+/* Authenticator-specific options. */
+
+typedef struct {
+ uschar *server_service;
+ uschar *server_hostname;
+ uschar *server_realm;
+ uschar *server_mech;
+ uschar *server_password;
+ uschar *server_scram_iter;
+ uschar *server_scram_salt;
+ BOOL server_channelbinding;
+} auth_gsasl_options_block;
+
+/* Data for reading the authenticator-specific options. */
+
+extern optionlist auth_gsasl_options[];
+extern int auth_gsasl_options_count;
+
+/* Defaults for the authenticator-specific options. */
+
+extern auth_gsasl_options_block auth_gsasl_option_defaults;
+
+/* The entry points for the mechanism */
+
+extern void auth_gsasl_init(auth_instance *);
+extern int auth_gsasl_server(auth_instance *, uschar *);
+extern int auth_gsasl_client(auth_instance *, smtp_inblock *,
+ smtp_outblock *, int, uschar *, int);
+extern void auth_gsasl_version_report(FILE *f);
+
+/* End of gsasl_exim.h */
diff --git a/src/src/config.h.defaults b/src/src/config.h.defaults
index bc983c4..c562ee9 100644
--- a/src/src/config.h.defaults
+++ b/src/src/config.h.defaults
@@ -20,6 +20,7 @@ it's a default value. */
#define AUTH_CRAM_MD5
#define AUTH_CYRUS_SASL
#define AUTH_DOVECOT
+#define AUTH_GSASL
#define AUTH_PLAINTEXT
#define AUTH_SPA
diff --git a/src/src/drtables.c b/src/src/drtables.c
index 37ecf4f..6e42ef9 100644
--- a/src/src/drtables.c
+++ b/src/src/drtables.c
@@ -37,6 +37,10 @@ set to NULL for those that are not compiled into the binary. */
#include "auths/dovecot.h"
#endif
+#ifdef AUTH_GSASL
+#include "auths/gsasl_exim.h"
+#endif
+
#ifdef AUTH_PLAINTEXT
#include "auths/plaintext.h"
#endif
@@ -58,7 +62,8 @@ auth_info auths_available[] = {
sizeof(auth_cram_md5_options_block),
auth_cram_md5_init, /* init function */
auth_cram_md5_server, /* server function */
- auth_cram_md5_client /* client function */
+ auth_cram_md5_client, /* client function */
+ NULL /* diagnostic function */
},
#endif
@@ -71,7 +76,8 @@ auth_info auths_available[] = {
sizeof(auth_cyrus_sasl_options_block),
auth_cyrus_sasl_init, /* init function */
auth_cyrus_sasl_server, /* server function */
- NULL /* client function */
+ NULL, /* client function */
+ auth_cyrus_sasl_version_report /* diagnostic function */
},
#endif
@@ -84,7 +90,22 @@ auth_info auths_available[] = {
sizeof(auth_dovecot_options_block),
auth_dovecot_init, /* init function */
auth_dovecot_server, /* server function */
- NULL /* client function */
+ NULL, /* client function */
+ NULL /* diagnostic function */
+ },
+#endif
+
+#ifdef AUTH_GSASL
+ {
+ US"gsasl", /* lookup name */
+ auth_gsasl_options,
+ &auth_gsasl_options_count,
+ &auth_gsasl_option_defaults,
+ sizeof(auth_gsasl_options_block),
+ auth_gsasl_init, /* init function */
+ auth_gsasl_server, /* server function */
+ NULL, /* client function */
+ auth_gsasl_version_report /* diagnostic function */
},
#endif
@@ -97,7 +118,8 @@ auth_info auths_available[] = {
sizeof(auth_plaintext_options_block),
auth_plaintext_init, /* init function */
auth_plaintext_server, /* server function */
- auth_plaintext_client /* client function */
+ auth_plaintext_client, /* client function */
+ NULL /* diagnostic function */
},
#endif
@@ -110,11 +132,12 @@ auth_info auths_available[] = {
sizeof(auth_spa_options_block),
auth_spa_init, /* init function */
auth_spa_server, /* server function */
- auth_spa_client /* client function */
+ auth_spa_client, /* client function */
+ NULL /* diagnostic function */
},
#endif
-{ US"", NULL, NULL, NULL, 0, NULL, NULL, NULL }
+{ US"", NULL, NULL, NULL, 0, NULL, NULL, NULL, NULL }
};
diff --git a/src/src/exim.c b/src/src/exim.c
index a6c0d78..b4ea01d 100644
--- a/src/src/exim.c
+++ b/src/src/exim.c
@@ -725,6 +725,8 @@ Returns: nothing
static void
show_whats_supported(FILE *f)
{
+ auth_info *authi;
+
#ifdef DB_VERSION_STRING
fprintf(f, "Berkeley DB: %s\n", DB_VERSION_STRING);
#elif defined(BTREEVERSION) && defined(HASHVERSION)
@@ -867,6 +869,9 @@ fprintf(f, "Authenticators:");
#ifdef AUTH_DOVECOT
fprintf(f, " dovecot");
#endif
+#ifdef AUTH_GSASL
+ fprintf(f, " gsasl");
+#endif
#ifdef AUTH_PLAINTEXT
fprintf(f, " plaintext");
#endif
@@ -962,9 +967,11 @@ DEBUG(D_any) do {
tls_version_report(f);
#endif
-#ifdef AUTH_CYRUS_SASL
- auth_cyrus_sasl_version_report(f);
-#endif
+ for (authi = auths_available; *authi->driver_name != '\0'; ++authi) {
+ if (authi->version_report) {
+ (*authi->version_report)(f);
+ }
+ }
fprintf(f, "Library version: PCRE: Compile: %d.%d%s\n"
" Runtime: %s\n",
diff --git a/src/src/exim.h b/src/src/exim.h
index a45ea0b..626d33d 100644
--- a/src/src/exim.h
+++ b/src/src/exim.h
@@ -538,12 +538,4 @@ default to EDQUOT if it exists, otherwise ENOSPC. */
#endif
#endif
-/* These are for reporting version information from various componenents, to
-figure out what's actually happening. They need to be available to the main
-function, so we declare them here. Unfortunate. */
-
-#ifdef AUTH_CYRUS_SASL
-extern void auth_cyrus_sasl_version_report(FILE *);
-#endif
-
/* End of exim.h */
diff --git a/src/src/functions.h b/src/src/functions.h
index 5efcbbb..d257594 100644
--- a/src/src/functions.h
+++ b/src/src/functions.h
@@ -54,6 +54,8 @@ extern int auth_call_radius(uschar *, uschar **);
extern int auth_call_saslauthd(uschar *, uschar *, uschar *, uschar *,
uschar **);
extern int auth_check_serv_cond(auth_instance *);
+extern int auth_check_some_cond(auth_instance *, uschar *, uschar *, int);
+
extern int auth_get_data(uschar **, uschar *, int);
extern int auth_get_no64_data(uschar **, uschar *);
extern uschar *auth_xtextencode(uschar *, int);
diff --git a/src/src/globals.h b/src/src/globals.h
index 4ed3950..1066306 100644
--- a/src/src/globals.h
+++ b/src/src/globals.h
@@ -90,6 +90,7 @@ extern uschar *openssl_options; /* OpenSSL compatibility options */
extern const pcre *regex_STARTTLS; /* For recognizing STARTTLS settings */
extern uschar *tls_advertise_hosts; /* host for which TLS is advertised */
extern uschar *tls_certificate; /* Certificate file */
+extern uschar *tls_channelbinding_b64; /* string of base64 channel binding */
extern uschar *tls_crl; /* CRL File */
extern uschar *tls_dhparam; /* DH param file */
extern BOOL tls_offered; /* Server offered TLS */
@@ -101,6 +102,10 @@ extern uschar *tls_verify_certificates;/* Path for certificates to check */
extern uschar *tls_verify_hosts; /* Mandatory client verification */
#endif
+#ifdef USE_GNUTLS
+extern
+#endif
+
/* Input-reading functions for messages, so we can use special ones for
incoming TCP/IP. */
diff --git a/src/src/structs.h b/src/src/structs.h
index 3790c7f..9b51d0b 100644
--- a/src/src/structs.h
+++ b/src/src/structs.h
@@ -367,6 +367,8 @@ typedef struct auth_info {
int, /* command timeout */
uschar *, /* buffer for reading response */
int); /* sizeof buffer */
+ void (*version_report)( /* diagnostic version reporting */
+ FILE *); /* I/O stream to print to */
} auth_info;
diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c
index f77768f..2d1a327 100644
--- a/src/src/tls-gnu.c
+++ b/src/src/tls-gnu.c
@@ -854,7 +854,10 @@ construct_cipher_name(gnutls_session session)
{
static uschar cipherbuf[256];
uschar *ver;
-int bits, c, kx, mac;
+int bits, c, kx, mac, rc;
+#ifdef GNUTLS_CB_TLS_UNIQUE
+gnutls_datum_t channel;
+#endif
ver = string_copy(
US gnutls_protocol_get_name(gnutls_protocol_get_version(session)));
@@ -871,6 +874,21 @@ string_format(cipherbuf, sizeof(cipherbuf), "%s:%s:%u", ver,
tls_cipher = cipherbuf;
DEBUG(D_tls) debug_printf("cipher: %s\n", cipherbuf);
+
+if (tls_channelbinding_b64)
+ free(tls_channelbinding_b64);
+tls_channelbinding_b64 = NULL;
+
+#ifdef GNUTLS_CB_TLS_UNIQUE
+channel = { NULL, 0 };
+rc = gnutls_session_channel_binding(session, GNUTLS_CB_TLS_UNIQUE, &channel);
+if (rc) {
+ DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc));
+} else {
+ tls_channelbinding_b64 = auth_b64encode(channel.data, (int)channel.size);
+ DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage.\n");
+}
+#endif
}
diff --git a/src/src/tls.c b/src/src/tls.c
index 7cb1550..d975a2c 100644
--- a/src/src/tls.c
+++ b/src/src/tls.c
@@ -40,6 +40,7 @@ static int ssl_xfer_buffer_hwm = 0;
static int ssl_xfer_eof = 0;
static int ssl_xfer_error = 0;
+uschar *tls_channelbinding_b64 = NULL;
/*************************************************
