* Exim - an Internet mail transport agent *
*************************************************/
+/* Copyright (c) The Exim Maintainers 2019 */
/* Copyright (c) University of Cambridge 1995 - 2018 */
/* See the file NOTICE for conditions of use and distribution. */
*/
#include "../exim.h"
+#define CHANNELBIND_HACK
#ifndef AUTH_GSASL
/* dummy function to satisfy compilers when we link in an "empty" file. */
#include <gsasl.h>
#include "gsasl_exim.h"
+
+#if GSASL_VERSION_MINOR >= 9
+# define EXIM_GSASL_HAVE_SCRAM_SHA_256
+#endif
+
+
/* 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[] = {
+ { "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,
/* Defaults for the authenticator-specific options. */
auth_gsasl_options_block auth_gsasl_option_defaults = {
- US"smtp", /* server_service */
- US"$primary_hostname", /* server_hostname */
- NULL, /* server_realm */
- NULL, /* server_mech */
- NULL, /* server_password */
- NULL, /* server_scram_iter */
- NULL, /* server_scram_salt */
- FALSE /* server_channelbinding */
+ .server_service = US"smtp",
+ .server_hostname = US"$primary_hostname",
+ .server_scram_iter = US"4096",
+ /* all others zero/null */
};
/* Dummy values */
void auth_gsasl_init(auth_instance *ablock) {}
int auth_gsasl_server(auth_instance *ablock, uschar *data) {return 0;}
-int auth_gsasl_client(auth_instance *ablock, smtp_inblock * sx,
+int auth_gsasl_client(auth_instance *ablock, void * sx,
int timeout, uschar *buffer, int buffsize) {return 0;}
void auth_gsasl_version_report(FILE *f) {}
+void
+auth_gsasl_macros(void)
+{
+# ifdef EXIM_GSASL_HAVE_SCRAM_SHA_256
+ builtin_macro_create(US"_HAVE_AUTH_GSASL_SCRAM_SHA_256");
+# endif
+}
+
#else /*!MACRO_PREDEF*/
void
auth_gsasl_init(auth_instance *ablock)
{
-char *p;
-int rc, supported;
+static char * once = NULL;
+int rc;
auth_gsasl_options_block *ob =
(auth_gsasl_options_block *)(ablock->options_block);
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)
+if (!ob->server_mech)
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) {
+
+if (!gsasl_ctx)
+ {
+ if ((rc = gsasl_init(&gsasl_ctx)) != 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, CCS ob->server_mech);
-if (!supported)
+HDEBUG(D_auth) if (!once)
+ {
+ if ((rc = gsasl_server_mechlist(gsasl_ctx, &once)) != 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));
+
+ debug_printf("GNU SASL supports: %s\n", once);
+ }
+
+if (!gsasl_client_support_p(gsasl_ctx, CCS ob->server_mech))
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) &&
- (streqic(ob->server_mech, US"EXTERNAL") ||
- streqic(ob->server_mech, US"ANONYMOUS") ||
- streqic(ob->server_mech, US"PLAIN") ||
- streqic(ob->server_mech, US"LOGIN")))
- log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
- "Need server_condition for %s mechanism",
+ablock->server = TRUE;
+
+if ( !ablock->server_condition
+ && ( streqic(ob->server_mech, US"EXTERNAL")
+ || streqic(ob->server_mech, US"ANONYMOUS")
+ || streqic(ob->server_mech, US"PLAIN")
+ || streqic(ob->server_mech, US"LOGIN")
+ ) )
+ {
+ ablock->server = FALSE;
+ HDEBUG(D_auth) debug_printf("%s authenticator: "
+ "Need server_condition for %s mechanism\n",
ablock->name, ob->server_mech);
+ }
/* This does *not* scale to new SASL mechanisms. Need a better way to ask
which properties will be needed. */
-if ((ob->server_realm == NULL) &&
- streqic(ob->server_mech, US"DIGEST-MD5"))
- log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
- "Need server_realm for %s mechanism",
+
+if ( !ob->server_realm
+ && streqic(ob->server_mech, US"DIGEST-MD5"))
+ {
+ ablock->server = FALSE;
+ HDEBUG(D_auth) debug_printf("%s authenticator: "
+ "Need server_realm for %s mechanism\n",
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;
+
+ablock->client = ob->client_username && ob->client_password;
}
struct callback_exim_state *cb_state =
(struct callback_exim_state *)gsasl_session_hook_get(sctx);
-HDEBUG(D_auth)
- debug_printf("GNU SASL Callback entered, prop=%d (loop prop=%d)\n",
- prop, callback_loop);
-
-if (cb_state == NULL)
+if (!cb_state)
{
- HDEBUG(D_auth) debug_printf(" not from our server/client processing.\n");
+ HDEBUG(D_auth) debug_printf("gsasl callback (%d) not from our server/client processing\n", prop);
+#ifdef CHANNELBIND_HACK
+ if (prop == GSASL_CB_TLS_UNIQUE)
+ {
+ uschar * s;
+ if ((s = gsasl_callback_hook_get(ctx)))
+ {
+ HDEBUG(D_auth) debug_printf("GSASL_CB_TLS_UNIQUE from ctx hook\n");
+ gsasl_property_set(sctx, GSASL_CB_TLS_UNIQUE, CS s);
+ }
+ else
+ {
+ HDEBUG(D_auth) debug_printf("GSASL_CB_TLS_UNIQUE! dummy for now\n");
+ gsasl_property_set(sctx, GSASL_CB_TLS_UNIQUE, "");
+ }
+ return GSASL_OK;
+ }
+#endif
return GSASL_NO_CALLBACK;
}
+HDEBUG(D_auth)
+ debug_printf("GNU SASL Callback entered, prop=%d (loop prop=%d)\n",
+ prop, callback_loop);
+
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. */
+ /* 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);
int rc, auth_result, exim_error, exim_error_override;
HDEBUG(D_auth)
- debug_printf("GNU SASL: initialising session for %s, mechanism %s.\n",
+ debug_printf("GNU SASL: initialising session for %s, mechanism %s\n",
ablock->name, ob->server_mech);
-rc = gsasl_server_start(gsasl_ctx, CCS ob->server_mech, &sctx);
-if (rc != GSASL_OK)
+#ifndef DISABLE_TLS
+if (tls_in.channelbinding && ob->server_channelbinding)
+ {
+# ifdef EXPERIMENTAL_TLS_RESUME
+ if (!tls_in.ext_master_secret && tls_in.resumption == RESUME_USED)
+ { /* per RFC 7677 section 4 */
+ HDEBUG(D_auth) debug_printf(
+ "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. */
+
+ gsasl_callback_hook_set(gsasl_ctx, tls_in.channelbinding);
+# endif
+ }
+#endif
+
+if ((rc = gsasl_server_start(gsasl_ctx, CCS ob->server_mech, &sctx)) != GSASL_OK)
{
auth_defer_msg = string_sprintf("GNU SASL: session start failure: %s (%s)",
gsasl_strerror_name(rc), gsasl_strerror(rc));
}
/* 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);
+gsasl_session_hook_set(sctx, &cb_state);
tmps = CS expand_string(ob->server_service);
gsasl_property_set(sctx, GSASL_SERVICE, tmps);
}
/* We don't support protection layers. */
gsasl_property_set(sctx, GSASL_QOPS, "qop-auth");
-#ifdef SUPPORT_TLS
-if (tls_channelbinding_b64)
+
+#ifndef DISABLE_TLS
+if (tls_in.channelbinding)
{
/* 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
{
HDEBUG(D_auth) debug_printf("Auth %s: Enabling channel-binding\n",
ablock->name);
- gsasl_property_set(sctx, GSASL_CB_TLS_UNIQUE,
- CCS tls_channelbinding_b64);
+# ifndef CHANNELBIND_HACK
+ gsasl_property_set(sctx, GSASL_CB_TLS_UNIQUE, CCS tls_in.channelbinding);
+# endif
}
else
- {
HDEBUG(D_auth)
debug_printf("Auth %s: Not enabling channel-binding (data available)\n",
ablock->name);
- }
}
else
HDEBUG(D_auth)
exim_error = exim_error_override = OK;
do {
- rc = gsasl_step64(sctx, received, &to_send);
-
- switch (rc)
+ switch (rc = gsasl_step64(sctx, received, &to_send))
{
case GSASL_OK:
if (!to_send)
goto STOP_INTERACTION;
}
- if ((rc == GSASL_NEEDS_MORE) ||
- (to_send && *to_send))
- exim_error =
- auth_get_no64_data((uschar **)&received, US to_send);
+ if ((rc == GSASL_NEEDS_MORE) || (to_send && *to_send))
+ exim_error = auth_get_no64_data(USS &received, US to_send);
if (to_send)
{
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)
+int exim_rc = auth_check_some_cond(ablock, label, condition_string, FAIL);
+switch (exim_rc)
{
- sasl_error_should_defer = TRUE;
- return GSASL_AUTHENTICATION_ERROR;
+ case OK: return GSASL_OK;
+ case DEFER: sasl_error_should_defer = TRUE;
+ return GSASL_AUTHENTICATION_ERROR;
+ case FAIL: return GSASL_AUTHENTICATION_ERROR;
+ default: log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator: "
+ "Unhandled return from checking %s: %d",
+ ablock->name, label, exim_rc);
}
-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)
+server_callback(Gsasl *ctx, Gsasl_session *sctx, Gsasl_property prop,
+ auth_instance *ablock)
{
char *tmps;
uschar *propval;
switch (prop)
{
case GSASL_VALIDATE_SIMPLE:
+ HDEBUG(D_auth) debug_printf(" VALIDATE_SIMPLE\n");
/* GSASL_AUTHID, GSASL_AUTHZID, and GSASL_PASSWORD */
- propval = US gsasl_property_fast(sctx, GSASL_AUTHID);
- auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
- propval = US gsasl_property_fast(sctx, GSASL_AUTHZID);
- auth_vars[1] = expand_nstring[2] = propval ? propval : US"";
- propval = US gsasl_property_fast(sctx, GSASL_PASSWORD);
- auth_vars[2] = expand_nstring[3] = propval ? propval : US"";
+ propval = US gsasl_property_fast(sctx, GSASL_AUTHID);
+ auth_vars[0] = expand_nstring[1] = propval ? string_copy(propval) : US"";
+ propval = US gsasl_property_fast(sctx, GSASL_AUTHZID);
+ auth_vars[1] = expand_nstring[2] = propval ? string_copy(propval) : US"";
+ propval = US gsasl_property_fast(sctx, GSASL_PASSWORD);
+ auth_vars[2] = expand_nstring[3] = propval ? string_copy(propval) : US"";
expand_nmax = 3;
for (int i = 1; i <= 3; ++i)
expand_nlength[i] = Ustrlen(expand_nstring[i]);
break;
case GSASL_VALIDATE_EXTERNAL:
- if (ablock->server_condition == NULL)
+ 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");
+ HDEBUG(D_auth) debug_printf("No server_condition supplied, to validate EXTERNAL\n");
cbrc = GSASL_AUTHENTICATION_ERROR;
break;
}
- propval = US gsasl_property_fast(sctx, GSASL_AUTHZID);
+ propval = US gsasl_property_fast(sctx, GSASL_AUTHZID);
+
/* We always set $auth1, even if only to empty string. */
- auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
+ auth_vars[0] = expand_nstring[1] = propval ? string_copy(propval) : US"";
expand_nlength[1] = Ustrlen(expand_nstring[1]);
expand_nmax = 1;
break;
case GSASL_VALIDATE_ANONYMOUS:
- if (ablock->server_condition == NULL)
+ 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");
+ HDEBUG(D_auth) debug_printf("No server_condition supplied, to validate ANONYMOUS\n");
cbrc = GSASL_AUTHENTICATION_ERROR;
break;
}
- propval = US gsasl_property_fast(sctx, GSASL_ANONYMOUS_TOKEN);
+ propval = US gsasl_property_fast(sctx, GSASL_ANONYMOUS_TOKEN);
+
/* We always set $auth1, even if only to empty string. */
- auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
+
+ auth_vars[0] = expand_nstring[1] = propval ? string_copy(propval) : US"";
expand_nlength[1] = Ustrlen(expand_nstring[1]);
expand_nmax = 1;
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
(if the SASL mechanism supports that, which Kerberos does) but is
unverified, same as normal for other mechanisms.
-
- First coding, we had these values swapped, but for consistency and prior
+ First coding, we had these values swapped, but for consistency and prior
to the first release of Exim with this authenticator, they've been
switched to match the ordering of GSASL_VALIDATE_SIMPLE. */
- propval = US gsasl_property_fast(sctx, GSASL_GSSAPI_DISPLAY_NAME);
- auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
- propval = US gsasl_property_fast(sctx, GSASL_AUTHZID);
- auth_vars[1] = expand_nstring[2] = propval ? propval : US"";
+
+ propval = US gsasl_property_fast(sctx, GSASL_GSSAPI_DISPLAY_NAME);
+ auth_vars[0] = expand_nstring[1] = propval ? string_copy(propval) : US"";
+ propval = US gsasl_property_fast(sctx, GSASL_AUTHZID);
+ auth_vars[1] = expand_nstring[2] = propval ? string_copy(propval) : US"";
expand_nmax = 2;
for (int 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_SCRAM_ITER:
+ HDEBUG(D_auth) debug_printf(" SCRAM_ITER\n");
+ if (ob->server_scram_iter)
+ {
+ tmps = CS expand_string(ob->server_scram_iter);
+ gsasl_property_set(sctx, GSASL_SCRAM_ITER, tmps);
+ cbrc = GSASL_OK;
+ }
+ break;
+
+ case GSASL_SCRAM_SALT:
+ HDEBUG(D_auth) debug_printf(" SCRAM_SALT\n");
+ if (ob->server_scram_iter)
+ {
+ tmps = CS expand_string(ob->server_scram_salt);
+ gsasl_property_set(sctx, GSASL_SCRAM_SALT, tmps);
+ cbrc = GSASL_OK;
+ }
+ break;
+
case GSASL_PASSWORD:
+ HDEBUG(D_auth) debug_printf(" PASSWORD\n");
/* DIGEST-MD5: GSASL_AUTHID, GSASL_AUTHZID and GSASL_REALM
CRAM-MD5: GSASL_AUTHID
PLAIN: GSASL_AUTHID and GSASL_AUTHZID
tmps = CS expand_string(ob->server_scram_salt);
gsasl_property_set(sctx, GSASL_SCRAM_SALT, tmps);
}
+
/* Asking for GSASL_AUTHZID calls back into us if we use
gsasl_property_get(), thus the use of gsasl_property_fast().
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 = US gsasl_property_fast(sctx, GSASL_AUTHID);
- auth_vars[0] = expand_nstring[1] = propval ? propval : US"";
- propval = US gsasl_property_fast(sctx, GSASL_AUTHZID);
- auth_vars[1] = expand_nstring[2] = propval ? propval : US"";
- propval = US gsasl_property_fast(sctx, GSASL_REALM);
- auth_vars[2] = expand_nstring[3] = propval ? propval : US"";
+
+ propval = US gsasl_property_fast(sctx, GSASL_AUTHID);
+ auth_vars[0] = expand_nstring[1] = propval ? string_copy(propval) : US"";
+ propval = US gsasl_property_fast(sctx, GSASL_AUTHZID);
+ auth_vars[1] = expand_nstring[2] = propval ? string_copy(propval) : US"";
+ propval = US gsasl_property_fast(sctx, GSASL_REALM);
+ auth_vars[2] = expand_nstring[3] = propval ? string_copy(propval) : US"";
expand_nmax = 3;
for (int i = 1; i <= 3; ++i)
expand_nlength[i] = Ustrlen(expand_nstring[i]);
- tmps = CS expand_string(ob->server_password);
- if (tmps == NULL)
+ if (!ob->server_password)
+ break;
+ if (!(tmps = CS expand_string(ob->server_password)))
{
sasl_error_should_defer = f.expand_string_forcedfail ? FALSE : TRUE;
HDEBUG(D_auth) debug_printf("server_password expansion failed, so "
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);
+ HDEBUG(D_auth) debug_printf(" Unrecognised callback: %d\n", prop);
cbrc = GSASL_NO_CALLBACK;
}
}
+/******************************************************************************/
+
+#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)
+{
+uschar * s;
+int rc;
+
+if (flags & PROP_OPTIONAL && !val) return TRUE;
+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);
+return TRUE;
+}
+
/*************************************************
* Client entry point *
*************************************************/
int
auth_gsasl_client(
auth_instance *ablock, /* authenticator block */
- smtp_inblock * sx, /* connection */
+ void * sx, /* connection */
int timeout, /* command timeout */
uschar *buffer, /* buffer for reading response */
int buffsize) /* size of buffer */
{
+auth_gsasl_options_block *ob =
+ (auth_gsasl_options_block *)(ablock->options_block);
+Gsasl_session * sctx = NULL;
+struct callback_exim_state cb_state;
+uschar * s;
+BOOL initial = TRUE;
+int rc, yield = FAIL;
+
HDEBUG(D_auth)
- debug_printf("Client side NOT IMPLEMENTED: you should not see this!\n");
-/* NOT IMPLEMENTED */
-return FAIL;
+ debug_printf("GNU SASL: initialising session for %s, mechanism %s\n",
+ ablock->name, ob->server_mech);
+
+*buffer = 0;
+
+#ifndef DISABLE_TLS
+if (tls_out.channelbinding && ob->client_channelbinding)
+ {
+# ifdef EXPERIMENTAL_TLS_RESUME
+ if (!tls_out.ext_master_secret && tls_out.resumption == RESUME_USED)
+ { /* per RFC 7677 section 4 */
+ 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. */
+
+ gsasl_callback_hook_set(gsasl_ctx, tls_out.channelbinding);
+# endif
+ }
+#endif
+
+if ((rc = gsasl_client_start(gsasl_ctx, CCS ob->server_mech, &sctx)) != GSASL_OK)
+ {
+ string_format(buffer, buffsize, "GNU SASL: session start failure: %s (%s)",
+ gsasl_strerror_name(rc), gsasl_strerror(rc));
+ HDEBUG(D_auth) debug_printf("%s\n", buffer);
+ return ERROR;
+ }
+
+cb_state.ablock = ablock;
+cb_state.currently = CURRENTLY_CLIENT;
+gsasl_session_hook_set(sctx, &cb_state);
+
+/* Set properties */
+
+if ( !client_prop(sctx, GSASL_PASSWORD, ob->client_password, US"password",
+ 0, buffer, buffsize)
+ || !client_prop(sctx, GSASL_AUTHID, ob->client_username, US"username",
+ 0, buffer, buffsize)
+ || !client_prop(sctx, GSASL_AUTHZID, ob->client_authz, US"authz",
+ PROP_OPTIONAL, buffer, buffsize)
+ )
+ return ERROR;
+
+#ifndef DISABLE_TLS
+if (tls_out.channelbinding)
+ if (ob->client_channelbinding)
+ {
+ HDEBUG(D_auth) debug_printf("Auth %s: Enabling channel-binding\n",
+ ablock->name);
+# ifndef CHANNELBIND_HACK
+ gsasl_property_set(sctx, GSASL_CB_TLS_UNIQUE, CCS tls_out.channelbinding);
+# endif
+ }
+ else
+ HDEBUG(D_auth)
+ debug_printf("Auth %s: Not enabling channel-binding (data available)\n",
+ ablock->name);
+#endif
+
+/* Run the SASL conversation with the server */
+
+for(s = NULL; ;)
+ {
+ uschar * outstr;
+ BOOL fail;
+
+ rc = gsasl_step64(sctx, CS s, CSS &outstr);
+
+ fail = initial
+ ? smtp_write_command(sx, SCMD_FLUSH,
+ outstr ? "AUTH %s %s\r\n" : "AUTH %s\r\n",
+ ablock->public_name, outstr) <= 0
+ : outstr
+ ? smtp_write_command(sx, SCMD_FLUSH, "%s\r\n", outstr) <= 0
+ : FALSE;
+ if (outstr && *outstr) free(outstr);
+ if (fail)
+ {
+ yield = FAIL_SEND;
+ goto done;
+ }
+ initial = FALSE;
+
+ if (rc != GSASL_NEEDS_MORE)
+ {
+ if (rc != GSASL_OK)
+ {
+ string_format(buffer, buffsize, "gsasl: %s", gsasl_strerror(rc));
+ break;
+ }
+
+ /* expecting a final 2xx from the server, accepting the AUTH */
+
+ if (smtp_read_response(sx, buffer, buffsize, '2', timeout))
+ yield = OK;
+ break; /* from SASL sequence loop */
+ }
+
+ /* 2xx or 3xx response is acceptable. If 2xx, no further input */
+
+ if (!smtp_read_response(sx, buffer, buffsize, '3', timeout))
+ if (errno == 0 && buffer[0] == '2')
+ buffer[4] = '\0';
+ else
+ {
+ yield = FAIL;
+ goto done;
+ }
+ s = buffer + 4;
+ }
+
+done:
+gsasl_finish(sctx);
+return yield;
}
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;
+HDEBUG(D_auth) debug_printf("GNU SASL callback %d for %s/%s as client\n",
+ prop, ablock->name, ablock->public_name);
+switch (prop)
+ {
+ case GSASL_AUTHZID:
+ HDEBUG(D_auth) debug_printf(" inquired for AUTHZID; not providing one\n");
+ break;
+ case GSASL_SCRAM_SALTED_PASSWORD:
+ HDEBUG(D_auth)
+ debug_printf(" inquired for SCRAM_SALTED_PASSWORD; not providing one\n");
+ break;
+ case GSASL_CB_TLS_UNIQUE:
+ 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);
+ break;
+ }
+return GSASL_NO_CALLBACK;
}
/*************************************************
GSASL_VERSION, runtime);
}
+
+
+/* Dummy */
+void auth_gsasl_macros(void) {}
+
#endif /*!MACRO_PREDEF*/
#endif /* AUTH_GSASL */
projects / exim.git / blobdiff