* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2014 */
+/* Copyright (c) University of Cambridge 1995 - 2015 */
/* See the file NOTICE for conditions of use and distribution. */
/* Copyright (c) Phil Pennock 2012 */
The code herein is a revamp of GnuTLS integration using the current APIs; the
original tls-gnu.c was based on a patch which was contributed by Nikos
-Mavroyanopoulos. The revamp is partially a rewrite, partially cut&paste as
+Mavrogiannopoulos. The revamp is partially a rewrite, partially cut&paste as
appropriate.
APIs current as of GnuTLS 2.12.18; note that the GnuTLS manual is for GnuTLS 3,
/* needed to disable PKCS11 autoload unless requested */
#if GNUTLS_VERSION_NUMBER >= 0x020c00
# include <gnutls/pkcs11.h>
+# define SUPPORT_PARAM_TO_PK_BITS
+#endif
+#if GNUTLS_VERSION_NUMBER < 0x030103 && !defined(DISABLE_OCSP)
+# warning "GnuTLS library version too old; define DISABLE_OCSP in Makefile"
+# define DISABLE_OCSP
+#endif
+#if GNUTLS_VERSION_NUMBER < 0x020a00 && !defined(DISABLE_EVENT)
+# warning "GnuTLS library version too old; tls:cert event unsupported"
+# define DISABLE_EVENT
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030306
+# define SUPPORT_CA_DIR
+#else
+# undef SUPPORT_CA_DIR
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030014
+# define SUPPORT_SYSDEFAULT_CABUNDLE
+#endif
+
+#ifndef DISABLE_OCSP
+# include <gnutls/ocsp.h>
#endif
/* GnuTLS 2 vs 3
/* Values for verify_requirement */
-enum peer_verify_requirement { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED };
+enum peer_verify_requirement
+ { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED };
/* This holds most state for server or client; with this, we can set up an
outbound TLS-enabled connection in an ACL callout, while not stomping all
*/
typedef struct exim_gnutls_state {
- gnutls_session_t session;
+ gnutls_session_t session;
gnutls_certificate_credentials_t x509_cred;
- gnutls_priority_t priority_cache;
+ gnutls_priority_t priority_cache;
enum peer_verify_requirement verify_requirement;
- int fd_in;
- int fd_out;
- BOOL peer_cert_verified;
- BOOL trigger_sni_changes;
- BOOL have_set_peerdn;
+ int fd_in;
+ int fd_out;
+ BOOL peer_cert_verified;
+ BOOL trigger_sni_changes;
+ BOOL have_set_peerdn;
const struct host_item *host;
- uschar *peerdn;
- uschar *ciphersuite;
- uschar *received_sni;
+ gnutls_x509_crt_t peercert;
+ uschar *peerdn;
+ uschar *ciphersuite;
+ uschar *received_sni;
const uschar *tls_certificate;
const uschar *tls_privatekey;
const uschar *tls_verify_certificates;
const uschar *tls_crl;
const uschar *tls_require_ciphers;
+
uschar *exp_tls_certificate;
uschar *exp_tls_privatekey;
- uschar *exp_tls_sni;
uschar *exp_tls_verify_certificates;
uschar *exp_tls_crl;
uschar *exp_tls_require_ciphers;
+ uschar *exp_tls_ocsp_file;
+ const uschar *exp_tls_verify_cert_hostnames;
+#ifndef DISABLE_EVENT
+ uschar *event_action;
+#endif
tls_support *tlsp; /* set in tls_init() */
NULL, NULL, NULL, VERIFY_NONE, -1, -1, FALSE, FALSE, FALSE,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL, NULL, NULL,
- NULL, NULL, NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+ NULL,
+#ifndef DISABLE_EVENT
+ NULL,
+#endif
NULL,
NULL, 0, 0, 0, 0,
};
single-threaded to keep from processing data on an inbound TLS connection while
talking to another TLS connection for an outbound check. This does mean that
there's no way for heart-beats to be responded to, for the duration of the
-second connection. */
+second connection.
+XXX But see gnutls_session_get_ptr()
+*/
static exim_gnutls_state_st state_server, state_client;
static BOOL exim_gnutls_base_init_done = FALSE;
+#ifndef DISABLE_OCSP
+static BOOL gnutls_buggy_ocsp = FALSE;
+#endif
+
/* ------------------------------------------------------------------------ */
/* macros */
the library logging; a value less than 0 disables the calls to set up logging
callbacks. */
#ifndef EXIM_GNUTLS_LIBRARY_LOG_LEVEL
-#define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1
+# define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1
#endif
#ifndef EXIM_CLIENT_DH_MIN_BITS
-#define EXIM_CLIENT_DH_MIN_BITS 1024
+# define EXIM_CLIENT_DH_MIN_BITS 1024
#endif
/* With GnuTLS 2.12.x+ we have gnutls_sec_param_to_pk_bits() with which we
can ask for a bit-strength. Without that, we stick to the constant we had
before, for now. */
#ifndef EXIM_SERVER_DH_BITS_PRE2_12
-#define EXIM_SERVER_DH_BITS_PRE2_12 1024
+# define EXIM_SERVER_DH_BITS_PRE2_12 1024
#endif
#define exim_gnutls_err_check(Label) do { \
- if (rc != GNUTLS_E_SUCCESS) { return tls_error((Label), gnutls_strerror(rc), host); } } while (0)
+ if (rc != GNUTLS_E_SUCCESS) \
+ return tls_error((Label), gnutls_strerror(rc), host, errstr); \
+ } while (0)
-#define expand_check_tlsvar(Varname) expand_check(state->Varname, US #Varname, &state->exp_##Varname)
+#define expand_check_tlsvar(Varname, errstr) \
+ expand_check(state->Varname, US #Varname, &state->exp_##Varname, errstr)
#if GNUTLS_VERSION_NUMBER >= 0x020c00
-#define HAVE_GNUTLS_SESSION_CHANNEL_BINDING
-#define HAVE_GNUTLS_SEC_PARAM_CONSTANTS
-#define HAVE_GNUTLS_RND
+# define HAVE_GNUTLS_SESSION_CHANNEL_BINDING
+# define HAVE_GNUTLS_SEC_PARAM_CONSTANTS
+# define HAVE_GNUTLS_RND
/* The security fix we provide with the gnutls_allow_auto_pkcs11 option
* (4.82 PP/09) introduces a compatibility regression. The symbol simply
* isn't available sometimes, so this needs to become a conditional
* compilation; the sanest way to deal with this being a problem on
* older OSes is to block it in the Local/Makefile with this compiler
* definition */
-#ifndef AVOID_GNUTLS_PKCS11
-#define HAVE_GNUTLS_PKCS11
-#endif /* AVOID_GNUTLS_PKCS11 */
+# ifndef AVOID_GNUTLS_PKCS11
+# define HAVE_GNUTLS_PKCS11
+# endif /* AVOID_GNUTLS_PKCS11 */
#endif
static int exim_sni_handling_cb(gnutls_session_t session);
+#ifndef DISABLE_OCSP
+static int server_ocsp_stapling_cb(gnutls_session_t session, void * ptr,
+ gnutls_datum_t * ocsp_response);
+#endif
usually obtained from gnutls_strerror()
host NULL if setting up a server;
the connected host if setting up a client
+ errstr pointer to returned error string
Returns: OK/DEFER/FAIL
*/
static int
-tls_error(const uschar *prefix, const char *msg, const host_item *host)
+tls_error(const uschar *prefix, const char *msg, const host_item *host,
+ uschar ** errstr)
{
-if (host)
- {
- log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s)%s%s",
- host->name, host->address, prefix, msg ? ": " : "", msg ? msg : "");
- return FAIL;
- }
-else
- {
- uschar *conn_info = smtp_get_connection_info();
- if (Ustrncmp(conn_info, US"SMTP ", 5) == 0)
- conn_info += 5;
- log_write(0, LOG_MAIN, "TLS error on %s (%s)%s%s",
- conn_info, prefix, msg ? ": " : "", msg ? msg : "");
- return DEFER;
- }
+if (errstr)
+ *errstr = string_sprintf("(%s)%s%s", prefix, msg ? ": " : "", msg ? msg : "");
+return host ? FAIL : DEFER;
}
static void
record_io_error(exim_gnutls_state_st *state, int rc, uschar *when, uschar *text)
{
-const char *msg;
+const char * msg;
+uschar * errstr;
if (rc == GNUTLS_E_FATAL_ALERT_RECEIVED)
msg = CS string_sprintf("%s: %s", US gnutls_strerror(rc),
else
msg = gnutls_strerror(rc);
-tls_error(when, msg, state->host);
+(void) tls_error(when, msg, state->host, &errstr);
+
+if (state->host)
+ log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection %s",
+ state->host->name, state->host->address, errstr);
+else
+ {
+ uschar * conn_info = smtp_get_connection_info();
+ if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
+ /* I'd like to get separated H= here, but too hard for now */
+ log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
+ }
}
* Set various Exim expansion vars *
*************************************************/
+#define exim_gnutls_cert_err(Label) \
+ do \
+ { \
+ if (rc != GNUTLS_E_SUCCESS) \
+ { \
+ DEBUG(D_tls) debug_printf("TLS: cert problem: %s: %s\n", \
+ (Label), gnutls_strerror(rc)); \
+ return rc; \
+ } \
+ } while (0)
+
+static int
+import_cert(const gnutls_datum_t * cert, gnutls_x509_crt_t * crtp)
+{
+int rc;
+
+rc = gnutls_x509_crt_init(crtp);
+exim_gnutls_cert_err(US"gnutls_x509_crt_init (crt)");
+
+rc = gnutls_x509_crt_import(*crtp, cert, GNUTLS_X509_FMT_DER);
+exim_gnutls_cert_err(US"failed to import certificate [gnutls_x509_crt_import(cert)]");
+
+return rc;
+}
+
+#undef exim_gnutls_cert_err
+
+
/* We set various Exim global variables from the state, once a session has
been established. With TLS callouts, may need to change this to stack
variables, or just re-call it with the server state after client callout
has finished.
-Make sure anything set here is inset in tls_getc().
+Make sure anything set here is unset in tls_getc().
Sets:
tls_active fd
tls_certificate_verified bool indicator
tls_channelbinding_b64 for some SASL mechanisms
tls_cipher a string
+ tls_peercert pointer to library internal
tls_peerdn a string
tls_sni a (UTF-8) string
+ tls_ourcert pointer to library internal
Argument:
state the relevant exim_gnutls_state_st *
*/
static void
-extract_exim_vars_from_tls_state(exim_gnutls_state_st *state, BOOL is_server)
+extract_exim_vars_from_tls_state(exim_gnutls_state_st * state)
{
gnutls_cipher_algorithm_t cipher;
#ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING
int rc;
gnutls_datum_t channel;
#endif
+tls_support * tlsp = state->tlsp;
-state->tlsp->active = state->fd_out;
+tlsp->active = state->fd_out;
cipher = gnutls_cipher_get(state->session);
/* returns size in "bytes" */
-state->tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8;
+tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8;
-state->tlsp->cipher = state->ciphersuite;
+tlsp->cipher = state->ciphersuite;
DEBUG(D_tls) debug_printf("cipher: %s\n", state->ciphersuite);
-state->tlsp->certificate_verified = state->peer_cert_verified;
+tlsp->certificate_verified = state->peer_cert_verified;
/* note that tls_channelbinding_b64 is not saved to the spool file, since it's
only available for use for authenticators while this TLS session is running. */
} else {
old_pool = store_pool;
store_pool = POOL_PERM;
- tls_channelbinding_b64 = auth_b64encode(channel.data, (int)channel.size);
+ tls_channelbinding_b64 = b64encode(channel.data, (int)channel.size);
store_pool = old_pool;
DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage.\n");
}
#endif
-state->tlsp->peerdn = state->peerdn;
-state->tlsp->sni = state->received_sni;
+/* peercert is set in peer_status() */
+tlsp->peerdn = state->peerdn;
+tlsp->sni = state->received_sni;
+
+/* record our certificate */
+ {
+ const gnutls_datum_t * cert = gnutls_certificate_get_ours(state->session);
+ gnutls_x509_crt_t crt;
+
+ tlsp->ourcert = cert && import_cert(cert, &crt)==0 ? crt : NULL;
+ }
}
*/
static int
-init_server_dh(void)
+init_server_dh(uschar ** errstr)
{
int fd, rc;
unsigned int dh_bits;
-gnutls_datum m;
+gnutls_datum_t m;
uschar filename_buf[PATH_MAX];
uschar *filename = NULL;
size_t sz;
m.data = NULL;
m.size = 0;
-if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam))
+if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam, errstr))
return DEFER;
if (!exp_tls_dhparam)
}
else if (exp_tls_dhparam[0] != '/')
{
- m.data = US std_dh_prime_named(exp_tls_dhparam);
- if (m.data == NULL)
- return tls_error(US"No standard prime named", CS exp_tls_dhparam, NULL);
+ if (!(m.data = US std_dh_prime_named(exp_tls_dhparam)))
+ return tls_error(US"No standard prime named", CS exp_tls_dhparam, NULL, errstr);
m.size = Ustrlen(m.data);
}
else
different filename and ensure we have sufficient bits. */
dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL);
if (!dh_bits)
- return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL);
+ return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL, errstr);
DEBUG(D_tls)
debug_printf("GnuTLS tells us that for D-H PK, NORMAL is %d bits.\n",
dh_bits);
{
if (!string_format(filename_buf, sizeof(filename_buf),
"%s/gnutls-params-%d", spool_directory, dh_bits))
- return tls_error(US"overlong filename", NULL, NULL);
+ return tls_error(US"overlong filename", NULL, NULL, errstr);
filename = filename_buf;
}
/* Open the cache file for reading and if successful, read it and set up the
parameters. */
-fd = Uopen(filename, O_RDONLY, 0);
-if (fd >= 0)
+if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0)
{
struct stat statbuf;
FILE *fp;
{
saved_errno = errno;
(void)close(fd);
- return tls_error(US"TLS cache stat failed", strerror(saved_errno), NULL);
+ return tls_error(US"TLS cache stat failed", strerror(saved_errno), NULL, errstr);
}
if (!S_ISREG(statbuf.st_mode))
{
(void)close(fd);
- return tls_error(US"TLS cache not a file", NULL, NULL);
+ return tls_error(US"TLS cache not a file", NULL, NULL, errstr);
}
- fp = fdopen(fd, "rb");
- if (!fp)
+ if (!(fp = fdopen(fd, "rb")))
{
saved_errno = errno;
(void)close(fd);
return tls_error(US"fdopen(TLS cache stat fd) failed",
- strerror(saved_errno), NULL);
+ strerror(saved_errno), NULL, errstr);
}
m.size = statbuf.st_size;
- m.data = malloc(m.size);
- if (m.data == NULL)
+ if (!(m.data = malloc(m.size)))
{
fclose(fp);
- return tls_error(US"malloc failed", strerror(errno), NULL);
+ return tls_error(US"malloc failed", strerror(errno), NULL, errstr);
}
- sz = fread(m.data, m.size, 1, fp);
- if (!sz)
+ if (!(sz = fread(m.data, m.size, 1, fp)))
{
saved_errno = errno;
fclose(fp);
free(m.data);
- return tls_error(US"fread failed", strerror(saved_errno), NULL);
+ return tls_error(US"fread failed", strerror(saved_errno), NULL, errstr);
}
fclose(fp);
}
else
return tls_error(string_open_failed(errno, "\"%s\" for reading", filename),
- NULL, NULL);
+ NULL, NULL, errstr);
/* If ret < 0, either the cache file does not exist, or the data it contains
is not useful. One particular case of this is when upgrading from an older
if ((PATH_MAX - Ustrlen(filename)) < 10)
return tls_error(US"Filename too long to generate replacement",
- CS filename, NULL);
+ CS filename, NULL, errstr);
temp_fn = string_copy(US "%s.XXXXXXX");
- fd = mkstemp(CS temp_fn); /* modifies temp_fn */
- if (fd < 0)
- return tls_error(US"Unable to open temp file", strerror(errno), NULL);
+ if ((fd = mkstemp(CS temp_fn)) < 0) /* modifies temp_fn */
+ return tls_error(US"Unable to open temp file", strerror(errno), NULL, errstr);
(void)fchown(fd, exim_uid, exim_gid); /* Probably not necessary */
/* GnuTLS overshoots!
if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER)
exim_gnutls_err_check(US"gnutls_dh_params_export_pkcs3(NULL) sizing");
m.size = sz;
- m.data = malloc(m.size);
- if (m.data == NULL)
- return tls_error(US"memory allocation failed", strerror(errno), NULL);
+ if (!(m.data = malloc(m.size)))
+ return tls_error(US"memory allocation failed", strerror(errno), NULL, errstr);
+
/* this will return a size 1 less than the allocation size above */
rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM,
m.data, &sz);
}
m.size = sz; /* shrink by 1, probably */
- sz = write_to_fd_buf(fd, m.data, (size_t) m.size);
- if (sz != m.size)
+ if ((sz = write_to_fd_buf(fd, m.data, (size_t) m.size)) != m.size)
{
free(m.data);
return tls_error(US"TLS cache write D-H params failed",
- strerror(errno), NULL);
+ strerror(errno), NULL, errstr);
}
free(m.data);
- sz = write_to_fd_buf(fd, US"\n", 1);
- if (sz != 1)
+ if ((sz = write_to_fd_buf(fd, US"\n", 1)) != 1)
return tls_error(US"TLS cache write D-H params final newline failed",
- strerror(errno), NULL);
+ strerror(errno), NULL, errstr);
- rc = close(fd);
- if (rc)
- return tls_error(US"TLS cache write close() failed",
- strerror(errno), NULL);
+ if ((rc = close(fd)))
+ return tls_error(US"TLS cache write close() failed", strerror(errno), NULL, errstr);
if (Urename(temp_fn, filename) < 0)
return tls_error(string_sprintf("failed to rename \"%s\" as \"%s\"",
- temp_fn, filename), strerror(errno), NULL);
+ temp_fn, filename), strerror(errno), NULL, errstr);
DEBUG(D_tls) debug_printf("wrote D-H parameters to file \"%s\"\n", filename);
}
+/* Create and install a selfsigned certificate, for use in server mode */
+
+static int
+tls_install_selfsign(exim_gnutls_state_st * state, uschar ** errstr)
+{
+gnutls_x509_crt_t cert = NULL;
+time_t now;
+gnutls_x509_privkey_t pkey = NULL;
+const uschar * where;
+int rc;
+
+where = US"initialising pkey";
+if ((rc = gnutls_x509_privkey_init(&pkey))) goto err;
+
+where = US"initialising cert";
+if ((rc = gnutls_x509_crt_init(&cert))) goto err;
+
+where = US"generating pkey";
+if ((rc = gnutls_x509_privkey_generate(pkey, GNUTLS_PK_RSA,
+#ifdef SUPPORT_PARAM_TO_PK_BITS
+ gnutls_sec_param_to_pk_bits(GNUTLS_PK_RSA, GNUTLS_SEC_PARAM_LOW),
+#else
+ 1024,
+#endif
+ 0)))
+ goto err;
+
+where = US"configuring cert";
+now = 0;
+if ( (rc = gnutls_x509_crt_set_version(cert, 3))
+ || (rc = gnutls_x509_crt_set_serial(cert, &now, sizeof(now)))
+ || (rc = gnutls_x509_crt_set_activation_time(cert, now = time(NULL)))
+ || (rc = gnutls_x509_crt_set_expiration_time(cert, now + 60 * 60)) /* 1 hr */
+ || (rc = gnutls_x509_crt_set_key(cert, pkey))
+
+ || (rc = gnutls_x509_crt_set_dn_by_oid(cert,
+ GNUTLS_OID_X520_COUNTRY_NAME, 0, "UK", 2))
+ || (rc = gnutls_x509_crt_set_dn_by_oid(cert,
+ GNUTLS_OID_X520_ORGANIZATION_NAME, 0, "Exim Developers", 15))
+ || (rc = gnutls_x509_crt_set_dn_by_oid(cert,
+ GNUTLS_OID_X520_COMMON_NAME, 0,
+ smtp_active_hostname, Ustrlen(smtp_active_hostname)))
+ )
+ goto err;
+
+where = US"signing cert";
+if ((rc = gnutls_x509_crt_sign(cert, cert, pkey))) goto err;
+
+where = US"installing selfsign cert";
+ /* Since: 2.4.0 */
+if ((rc = gnutls_certificate_set_x509_key(state->x509_cred, &cert, 1, pkey)))
+ goto err;
+
+rc = OK;
+
+out:
+ if (cert) gnutls_x509_crt_deinit(cert);
+ if (pkey) gnutls_x509_privkey_deinit(pkey);
+ return rc;
+
+err:
+ rc = tls_error(where, gnutls_strerror(rc), NULL, errstr);
+ goto out;
+}
+
+
+
+
/*************************************************
* Variables re-expanded post-SNI *
*************************************************/
Arguments:
state exim_gnutls_state_st *
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
-tls_expand_session_files(exim_gnutls_state_st *state)
+tls_expand_session_files(exim_gnutls_state_st *state, uschar ** errstr)
{
struct stat statbuf;
int rc;
int cert_count;
/* We check for tls_sni *before* expansion. */
-if (!state->host)
- {
+if (!host) /* server */
if (!state->received_sni)
{
if (state->tls_certificate &&
saved_tls_verify_certificates = state->exp_tls_verify_certificates;
saved_tls_crl = state->exp_tls_crl;
}
- }
rc = gnutls_certificate_allocate_credentials(&state->x509_cred);
exim_gnutls_err_check(US"gnutls_certificate_allocate_credentials");
/* check if we at least have a certificate, before doing expensive
D-H generation. */
-if (!expand_check_tlsvar(tls_certificate))
+if (!expand_check_tlsvar(tls_certificate, errstr))
return DEFER;
/* certificate is mandatory in server, optional in client */
-if ((state->exp_tls_certificate == NULL) ||
- (*state->exp_tls_certificate == '\0'))
- {
- if (state->host == NULL)
- return tls_error(US"no TLS server certificate is specified", NULL, NULL);
+if ( !state->exp_tls_certificate
+ || !*state->exp_tls_certificate
+ )
+ if (!host)
+ return tls_install_selfsign(state, errstr);
else
DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n");
- }
-if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey))
+if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey, errstr))
return DEFER;
/* tls_privatekey is optional, defaulting to same file as certificate */
state->exp_tls_certificate, state->exp_tls_privatekey);
if (state->received_sni)
- {
- if ((Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0) &&
- (Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0))
+ if ( Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0
+ && Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0
+ )
{
DEBUG(D_tls) debug_printf("TLS SNI: cert and key unchanged\n");
}
{
DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair.\n");
}
- }
rc = gnutls_certificate_set_x509_key_file(state->x509_cred,
CS state->exp_tls_certificate, CS state->exp_tls_privatekey,
DEBUG(D_tls) debug_printf("TLS: cert/key registered\n");
} /* tls_certificate */
+
+/* Set the OCSP stapling server info */
+
+#ifndef DISABLE_OCSP
+if ( !host /* server */
+ && tls_ocsp_file
+ )
+ {
+ if (gnutls_buggy_ocsp)
+ {
+ DEBUG(D_tls) debug_printf("GnuTLS library is buggy for OCSP; avoiding\n");
+ }
+ else
+ {
+ if (!expand_check(tls_ocsp_file, US"tls_ocsp_file",
+ &state->exp_tls_ocsp_file, errstr))
+ return DEFER;
+
+ /* Use the full callback method for stapling just to get observability.
+ More efficient would be to read the file once only, if it never changed
+ (due to SNI). Would need restart on file update, or watch datestamp. */
+
+ gnutls_certificate_set_ocsp_status_request_function(state->x509_cred,
+ server_ocsp_stapling_cb, state->exp_tls_ocsp_file);
+
+ DEBUG(D_tls) debug_printf("OCSP response file = %s\n", state->exp_tls_ocsp_file);
+ }
+ }
+#endif
+
+
/* Set the trusted CAs file if one is provided, and then add the CRL if one is
provided. Experiment shows that, if the certificate file is empty, an unhelpful
error message is provided. However, if we just refrain from setting anything up
if (state->tls_verify_certificates && *state->tls_verify_certificates)
{
- if (!expand_check_tlsvar(tls_verify_certificates))
+ if (!expand_check_tlsvar(tls_verify_certificates, errstr))
return DEFER;
+#ifndef SUPPORT_SYSDEFAULT_CABUNDLE
+ if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0)
+ state->exp_tls_verify_certificates = NULL;
+#endif
if (state->tls_crl && *state->tls_crl)
- if (!expand_check_tlsvar(tls_crl))
+ if (!expand_check_tlsvar(tls_crl, errstr))
return DEFER;
if (!(state->exp_tls_verify_certificates &&
return OK;
}
-if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0)
+#ifdef SUPPORT_SYSDEFAULT_CABUNDLE
+if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0)
+ cert_count = gnutls_certificate_set_x509_system_trust(state->x509_cred);
+else
+#endif
{
- log_write(0, LOG_MAIN|LOG_PANIC, "could not stat %s "
- "(tls_verify_certificates): %s", state->exp_tls_verify_certificates,
- strerror(errno));
- return DEFER;
- }
+ if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "could not stat %s "
+ "(tls_verify_certificates): %s", state->exp_tls_verify_certificates,
+ strerror(errno));
+ return DEFER;
+ }
-/* The test suite passes in /dev/null; we could check for that path explicitly,
-but who knows if someone has some weird FIFO which always dumps some certs, or
-other weirdness. The thing we really want to check is that it's not a
-directory, since while OpenSSL supports that, GnuTLS does not.
-So s/!S_ISREG/S_ISDIR/ and change some messsaging ... */
-if (S_ISDIR(statbuf.st_mode))
- {
- DEBUG(D_tls)
- debug_printf("verify certificates path is a dir: \"%s\"\n",
- state->exp_tls_verify_certificates);
- log_write(0, LOG_MAIN|LOG_PANIC,
- "tls_verify_certificates \"%s\" is a directory",
- state->exp_tls_verify_certificates);
- return DEFER;
- }
+#ifndef SUPPORT_CA_DIR
+ /* The test suite passes in /dev/null; we could check for that path explicitly,
+ but who knows if someone has some weird FIFO which always dumps some certs, or
+ other weirdness. The thing we really want to check is that it's not a
+ directory, since while OpenSSL supports that, GnuTLS does not.
+ So s/!S_ISREG/S_ISDIR/ and change some messaging ... */
+ if (S_ISDIR(statbuf.st_mode))
+ {
+ DEBUG(D_tls)
+ debug_printf("verify certificates path is a dir: \"%s\"\n",
+ state->exp_tls_verify_certificates);
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "tls_verify_certificates \"%s\" is a directory",
+ state->exp_tls_verify_certificates);
+ return DEFER;
+ }
+#endif
-DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n",
- state->exp_tls_verify_certificates, statbuf.st_size);
+ DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n",
+ state->exp_tls_verify_certificates, statbuf.st_size);
-if (statbuf.st_size == 0)
- {
- DEBUG(D_tls)
- debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n");
- return OK;
+ if (statbuf.st_size == 0)
+ {
+ DEBUG(D_tls)
+ debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n");
+ return OK;
+ }
+
+ cert_count =
+
+#ifdef SUPPORT_CA_DIR
+ (statbuf.st_mode & S_IFMT) == S_IFDIR
+ ?
+ gnutls_certificate_set_x509_trust_dir(state->x509_cred,
+ CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM)
+ :
+#endif
+ gnutls_certificate_set_x509_trust_file(state->x509_cred,
+ CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM);
}
-cert_count = gnutls_certificate_set_x509_trust_file(state->x509_cred,
- CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM);
if (cert_count < 0)
{
rc = cert_count;
- exim_gnutls_err_check(US"gnutls_certificate_set_x509_trust_file");
+ exim_gnutls_err_check(US"setting certificate trust");
}
DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", cert_count);
Arguments:
state exim_gnutls_state_st *
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
-tls_set_remaining_x509(exim_gnutls_state_st *state)
+tls_set_remaining_x509(exim_gnutls_state_st *state, uschar ** errstr)
{
int rc;
const host_item *host = state->host; /* macro should be reconsidered? */
{
if (!dh_server_params)
{
- rc = init_server_dh();
+ rc = init_server_dh(errstr);
if (rc != OK) return rc;
}
gnutls_certificate_set_dh_params(state->x509_cred, dh_server_params);
* Initialize for GnuTLS *
*************************************************/
+
+#ifndef DISABLE_OCSP
+
+static BOOL
+tls_is_buggy_ocsp(void)
+{
+const uschar * s;
+uschar maj, mid, mic;
+
+s = CUS gnutls_check_version(NULL);
+maj = atoi(CCS s);
+if (maj == 3)
+ {
+ while (*s && *s != '.') s++;
+ mid = atoi(CCS ++s);
+ if (mid <= 2)
+ return TRUE;
+ else if (mid >= 5)
+ return FALSE;
+ else
+ {
+ while (*s && *s != '.') s++;
+ mic = atoi(CCS ++s);
+ return mic <= (mid == 3 ? 16 : 3);
+ }
+ }
+return FALSE;
+}
+
+#endif
+
+
/* Called from both server and client code. In the case of a server, errors
before actual TLS negotiation return DEFER.
crl CRL file
require_ciphers tls_require_ciphers setting
caller_state returned state-info structure
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
const uschar *cas,
const uschar *crl,
const uschar *require_ciphers,
- exim_gnutls_state_st **caller_state)
+ exim_gnutls_state_st **caller_state,
+ uschar ** errstr)
{
exim_gnutls_state_st *state;
int rc;
}
#endif
+#ifndef DISABLE_OCSP
+ if (tls_ocsp_file && (gnutls_buggy_ocsp = tls_is_buggy_ocsp()))
+ log_write(0, LOG_MAIN, "OCSP unusable with this GnuTLS library version");
+#endif
+
exim_gnutls_base_init_done = TRUE;
}
DEBUG(D_tls)
debug_printf("Expanding various TLS configuration options for session credentials.\n");
-rc = tls_expand_session_files(state);
-if (rc != OK) return rc;
+if ((rc = tls_expand_session_files(state, errstr)) != OK) return rc;
/* These are all other parts of the x509_cred handling, since SNI in GnuTLS
requires a new structure afterwards. */
-rc = tls_set_remaining_x509(state);
-if (rc != OK) return rc;
+if ((rc = tls_set_remaining_x509(state, errstr)) != OK) return rc;
/* set SNI in client, only */
if (host)
{
- if (!expand_check(state->tlsp->sni, US"tls_out_sni", &state->exp_tls_sni))
+ if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni, errstr))
return DEFER;
- if (state->exp_tls_sni && *state->exp_tls_sni)
+ if (state->tlsp->sni && *state->tlsp->sni)
{
DEBUG(D_tls)
- debug_printf("Setting TLS client SNI to \"%s\"\n", state->exp_tls_sni);
- sz = Ustrlen(state->exp_tls_sni);
+ debug_printf("Setting TLS client SNI to \"%s\"\n", state->tlsp->sni);
+ sz = Ustrlen(state->tlsp->sni);
rc = gnutls_server_name_set(state->session,
- GNUTLS_NAME_DNS, state->exp_tls_sni, sz);
+ GNUTLS_NAME_DNS, state->tlsp->sni, sz);
exim_gnutls_err_check(US"gnutls_server_name_set");
}
}
if (state->tls_require_ciphers && *state->tls_require_ciphers)
{
- if (!expand_check_tlsvar(tls_require_ciphers))
+ if (!expand_check_tlsvar(tls_require_ciphers, errstr))
return DEFER;
if (state->exp_tls_require_ciphers && *state->exp_tls_require_ciphers)
{
-
/*************************************************
* Extract peer information *
*************************************************/
Arguments:
state exim_gnutls_state_st *
+ errstr pointer to error string
Returns: OK/DEFER/FAIL
*/
static int
-peer_status(exim_gnutls_state_st *state)
+peer_status(exim_gnutls_state_st *state, uschar ** errstr)
{
uschar cipherbuf[256];
-const gnutls_datum *cert_list;
+const gnutls_datum_t *cert_list;
int old_pool, rc;
unsigned int cert_list_size = 0;
gnutls_protocol_t protocol;
{
DEBUG(D_tls) debug_printf("TLS: no certificate from peer (%p & %d)\n",
cert_list, cert_list_size);
- if (state->verify_requirement == VERIFY_REQUIRED)
+ if (state->verify_requirement >= VERIFY_REQUIRED)
return tls_error(US"certificate verification failed",
- "no certificate received from peer", state->host);
+ "no certificate received from peer", state->host, errstr);
return OK;
}
const char *ctn = gnutls_certificate_type_get_name(ct);
DEBUG(D_tls)
debug_printf("TLS: peer cert not X.509 but instead \"%s\"\n", ctn);
- if (state->verify_requirement == VERIFY_REQUIRED)
+ if (state->verify_requirement >= VERIFY_REQUIRED)
return tls_error(US"certificate verification not possible, unhandled type",
- ctn, state->host);
+ ctn, state->host, errstr);
return OK;
}
-#define exim_gnutls_peer_err(Label) do { \
- if (rc != GNUTLS_E_SUCCESS) { \
- DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", (Label), gnutls_strerror(rc)); \
- if (state->verify_requirement == VERIFY_REQUIRED) { return tls_error((Label), gnutls_strerror(rc), state->host); } \
- return OK; } } while (0)
+#define exim_gnutls_peer_err(Label) \
+ do { \
+ if (rc != GNUTLS_E_SUCCESS) \
+ { \
+ DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", \
+ (Label), gnutls_strerror(rc)); \
+ if (state->verify_requirement >= VERIFY_REQUIRED) \
+ return tls_error((Label), gnutls_strerror(rc), state->host, errstr); \
+ return OK; \
+ } \
+ } while (0)
+
+rc = import_cert(&cert_list[0], &crt);
+exim_gnutls_peer_err(US"cert 0");
-rc = gnutls_x509_crt_init(&crt);
-exim_gnutls_peer_err(US"gnutls_x509_crt_init (crt)");
+state->tlsp->peercert = state->peercert = crt;
-rc = gnutls_x509_crt_import(crt, &cert_list[0], GNUTLS_X509_FMT_DER);
-exim_gnutls_peer_err(US"failed to import certificate [gnutls_x509_crt_import(cert 0)]");
sz = 0;
rc = gnutls_x509_crt_get_dn(crt, NULL, &sz);
if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER)
dn_buf = store_get_perm(sz);
rc = gnutls_x509_crt_get_dn(crt, CS dn_buf, &sz);
exim_gnutls_peer_err(US"failed to extract certificate DN [gnutls_x509_crt_get_dn(cert 0)]");
+
state->peerdn = dn_buf;
return OK;
Arguments:
state exim_gnutls_state_st *
- error where to put an error message
+ errstr where to put an error message
Returns:
FALSE if the session should be rejected
*/
static BOOL
-verify_certificate(exim_gnutls_state_st *state, const char **error)
+verify_certificate(exim_gnutls_state_st *state, uschar ** errstr)
{
int rc;
unsigned int verify;
-*error = NULL;
+*errstr = NULL;
-if ((rc = peer_status(state)) != OK)
+if ((rc = peer_status(state, errstr)) != OK)
{
verify = GNUTLS_CERT_INVALID;
- *error = "certificate not supplied";
+ *errstr = US"certificate not supplied";
}
else
rc = gnutls_certificate_verify_peers2(state->session, &verify);
/* Handle the result of verification. INVALID seems to be set as well
as REVOKED, but leave the test for both. */
-if (rc < 0 || verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED))
+if (rc < 0 ||
+ verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED)
+ )
{
state->peer_cert_verified = FALSE;
- if (!*error)
- *error = verify & GNUTLS_CERT_REVOKED
- ? "certificate revoked" : "certificate invalid";
+ if (!*errstr)
+ *errstr = verify & GNUTLS_CERT_REVOKED
+ ? US"certificate revoked" : US"certificate invalid";
DEBUG(D_tls)
- debug_printf("TLS certificate verification failed (%s): peerdn=%s\n",
- *error, state->peerdn ? state->peerdn : US"<unset>");
+ debug_printf("TLS certificate verification failed (%s): peerdn=\"%s\"\n",
+ *errstr, state->peerdn ? state->peerdn : US"<unset>");
- if (state->verify_requirement == VERIFY_REQUIRED)
+ if (state->verify_requirement >= VERIFY_REQUIRED)
{
- gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE);
+ gnutls_alert_send(state->session,
+ GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE);
return FALSE;
}
DEBUG(D_tls)
debug_printf("TLS verify failure overridden (host in tls_try_verify_hosts)\n");
}
+
else
{
+ if (state->exp_tls_verify_cert_hostnames)
+ {
+ int sep = 0;
+ const uschar * list = state->exp_tls_verify_cert_hostnames;
+ uschar * name;
+ while ((name = string_nextinlist(&list, &sep, NULL, 0)))
+ if (gnutls_x509_crt_check_hostname(state->tlsp->peercert, CS name))
+ break;
+ if (!name)
+ {
+ DEBUG(D_tls)
+ debug_printf("TLS certificate verification failed: cert name mismatch\n");
+ if (state->verify_requirement >= VERIFY_REQUIRED)
+ {
+ gnutls_alert_send(state->session,
+ GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE);
+ return FALSE;
+ }
+ return TRUE;
+ }
+ }
state->peer_cert_verified = TRUE;
- DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=%s\n",
+ DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=\"%s\"\n",
state->peerdn ? state->peerdn : US"<unset>");
}
exim_gnutls_state_st *state = &state_server;
unsigned int sni_type;
int rc, old_pool;
+uschar * dummy_errstr;
rc = gnutls_server_name_get(session, sni_name, &data_len, &sni_type, 0);
if (rc != GNUTLS_E_SUCCESS)
else
debug_printf("TLS failure: gnutls_server_name_get(): %s [%d]\n",
gnutls_strerror(rc), rc);
- };
+ }
return 0;
}
if (!state->trigger_sni_changes)
return 0;
-rc = tls_expand_session_files(state);
-if (rc != OK)
+if ((rc = tls_expand_session_files(state, &dummy_errstr)) != OK)
{
/* If the setup of certs/etc failed before handshake, TLS would not have
been offered. The best we can do now is abort. */
return GNUTLS_E_APPLICATION_ERROR_MIN;
}
-rc = tls_set_remaining_x509(state);
+rc = tls_set_remaining_x509(state, &dummy_errstr);
if (rc != OK) return GNUTLS_E_APPLICATION_ERROR_MIN;
return 0;
+#ifndef DISABLE_OCSP
+
+static int
+server_ocsp_stapling_cb(gnutls_session_t session, void * ptr,
+ gnutls_datum_t * ocsp_response)
+{
+int ret;
+
+if ((ret = gnutls_load_file(ptr, ocsp_response)) < 0)
+ {
+ DEBUG(D_tls) debug_printf("Failed to load ocsp stapling file %s\n",
+ (char *)ptr);
+ tls_in.ocsp = OCSP_NOT_RESP;
+ return GNUTLS_E_NO_CERTIFICATE_STATUS;
+ }
+
+tls_in.ocsp = OCSP_VFY_NOT_TRIED;
+return 0;
+}
+
+#endif
+
+
+#ifndef DISABLE_EVENT
+/*
+We use this callback to get observability and detail-level control
+for an exim TLS connection (either direction), raising a tls:cert event
+for each cert in the chain presented by the peer. Any event
+can deny verification.
+
+Return 0 for the handshake to continue or non-zero to terminate.
+*/
+
+static int
+verify_cb(gnutls_session_t session)
+{
+const gnutls_datum_t * cert_list;
+unsigned int cert_list_size = 0;
+gnutls_x509_crt_t crt;
+int rc;
+uschar * yield;
+exim_gnutls_state_st * state = gnutls_session_get_ptr(session);
+
+cert_list = gnutls_certificate_get_peers(session, &cert_list_size);
+if (cert_list)
+ while (cert_list_size--)
+ {
+ rc = import_cert(&cert_list[cert_list_size], &crt);
+ if (rc != GNUTLS_E_SUCCESS)
+ {
+ DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n",
+ cert_list_size, gnutls_strerror(rc));
+ break;
+ }
+
+ state->tlsp->peercert = crt;
+ if ((yield = event_raise(state->event_action,
+ US"tls:cert", string_sprintf("%d", cert_list_size))))
+ {
+ log_write(0, LOG_MAIN,
+ "SSL verify denied by event-action: depth=%d: %s",
+ cert_list_size, yield);
+ return 1; /* reject */
+ }
+ state->tlsp->peercert = NULL;
+ }
+
+return 0;
+}
+
+#endif
+
+
/* ------------------------------------------------------------------------ */
/* Exported functions */
Arguments:
require_ciphers list of allowed ciphers or NULL
+ errstr pointer to error string
Returns: OK on success
DEFER for errors before the start of the negotiation
- FAIL for errors during the negotation; the server can't
+ FAIL for errors during the negotiation; the server can't
continue running.
*/
int
-tls_server_start(const uschar *require_ciphers)
+tls_server_start(const uschar * require_ciphers, uschar ** errstr)
{
int rc;
-const char *error;
-exim_gnutls_state_st *state = NULL;
+exim_gnutls_state_st * state = NULL;
/* Check for previous activation */
if (tls_in.active >= 0)
{
- tls_error(US"STARTTLS received after TLS started", "", NULL);
+ tls_error(US"STARTTLS received after TLS started", "", NULL, errstr);
smtp_printf("554 Already in TLS\r\n");
return FAIL;
}
DEBUG(D_tls) debug_printf("initialising GnuTLS as a server\n");
-rc = tls_init(NULL, tls_certificate, tls_privatekey,
+if ((rc = tls_init(NULL, tls_certificate, tls_privatekey,
NULL, tls_verify_certificates, tls_crl,
- require_ciphers, &state);
-if (rc != OK) return rc;
+ require_ciphers, &state, errstr)) != OK) return rc;
/* If this is a host for which certificate verification is mandatory or
optional, set up appropriately. */
if (verify_check_host(&tls_verify_hosts) == OK)
{
- DEBUG(D_tls) debug_printf("TLS: a client certificate will be required.\n");
+ DEBUG(D_tls)
+ debug_printf("TLS: a client certificate will be required.\n");
state->verify_requirement = VERIFY_REQUIRED;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE);
}
else if (verify_check_host(&tls_try_verify_hosts) == OK)
{
- DEBUG(D_tls) debug_printf("TLS: a client certificate will be requested but not required.\n");
+ DEBUG(D_tls)
+ debug_printf("TLS: a client certificate will be requested but not required.\n");
state->verify_requirement = VERIFY_OPTIONAL;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST);
}
else
{
- DEBUG(D_tls) debug_printf("TLS: a client certificate will not be requested.\n");
+ DEBUG(D_tls)
+ debug_printf("TLS: a client certificate will not be requested.\n");
state->verify_requirement = VERIFY_NONE;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE);
}
+#ifndef DISABLE_EVENT
+if (event_action)
+ {
+ state->event_action = event_action;
+ gnutls_session_set_ptr(state->session, state);
+ gnutls_certificate_set_verify_function(state->x509_cred, verify_cb);
+ }
+#endif
+
/* Register SNI handling; always, even if not in tls_certificate, so that the
expansion variable $tls_sni is always available. */
if (!state->tlsp->on_connect)
{
smtp_printf("220 TLS go ahead\r\n");
- fflush(smtp_out); /*XXX JGH */
+ fflush(smtp_out);
}
/* Now negotiate the TLS session. We put our own timer on it, since it seems
that the GnuTLS library doesn't. */
gnutls_transport_set_ptr2(state->session,
- (gnutls_transport_ptr)fileno(smtp_in),
- (gnutls_transport_ptr)fileno(smtp_out));
+ (gnutls_transport_ptr_t)(long) fileno(smtp_in),
+ (gnutls_transport_ptr_t)(long) fileno(smtp_out));
state->fd_in = fileno(smtp_in);
state->fd_out = fileno(smtp_out);
sigalrm_seen = FALSE;
if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
do
- {
rc = gnutls_handshake(state->session);
- } while ((rc == GNUTLS_E_AGAIN) ||
- (rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen));
+while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen);
alarm(0);
if (rc != GNUTLS_E_SUCCESS)
{
- tls_error(US"gnutls_handshake",
- sigalrm_seen ? "timed out" : gnutls_strerror(rc), NULL);
/* It seems that, except in the case of a timeout, we have to close the
connection right here; otherwise if the other end is running OpenSSL it hangs
until the server times out. */
- if (!sigalrm_seen)
+ if (sigalrm_seen)
+ {
+ tls_error(US"gnutls_handshake", "timed out", NULL, errstr);
+ gnutls_db_remove_session(state->session);
+ }
+ else
{
+ tls_error(US"gnutls_handshake", gnutls_strerror(rc), NULL, errstr);
+ (void) gnutls_alert_send_appropriate(state->session, rc);
+ gnutls_deinit(state->session);
+ gnutls_certificate_free_credentials(state->x509_cred);
+ millisleep(500);
+ shutdown(state->fd_out, SHUT_WR);
+ for (rc = 1024; fgetc(smtp_in) != EOF && rc > 0; ) rc--; /* drain skt */
(void)fclose(smtp_out);
(void)fclose(smtp_in);
+ smtp_out = smtp_in = NULL;
}
return FAIL;
/* Verify after the fact */
-if (state->verify_requirement != VERIFY_NONE)
+if ( state->verify_requirement != VERIFY_NONE
+ && !verify_certificate(state, errstr))
{
- if (!verify_certificate(state, &error))
+ if (state->verify_requirement != VERIFY_OPTIONAL)
{
- if (state->verify_requirement == VERIFY_OPTIONAL)
- {
- DEBUG(D_tls)
- debug_printf("TLS: continuing on only because verification was optional, after: %s\n",
- error);
- }
- else
- {
- tls_error(US"certificate verification failed", error, NULL);
- return FAIL;
- }
+ (void) tls_error(US"certificate verification failed", *errstr, NULL, errstr);
+ return FAIL;
}
+ DEBUG(D_tls)
+ debug_printf("TLS: continuing on only because verification was optional, after: %s\n",
+ *errstr);
}
/* Figure out peer DN, and if authenticated, etc. */
-rc = peer_status(state);
-if (rc != OK) return rc;
+if ((rc = peer_status(state, NULL)) != OK) return rc;
/* Sets various Exim expansion variables; always safe within server */
-extract_exim_vars_from_tls_state(state, TRUE);
+extract_exim_vars_from_tls_state(state);
/* TLS has been set up. Adjust the input functions to read via TLS,
and initialize appropriately. */
state->xfer_buffer = store_malloc(ssl_xfer_buffer_size);
receive_getc = tls_getc;
+receive_get_cache = tls_get_cache;
receive_ungetc = tls_ungetc;
receive_feof = tls_feof;
receive_ferror = tls_ferror;
+static void
+tls_client_setup_hostname_checks(host_item * host, exim_gnutls_state_st * state,
+ smtp_transport_options_block * ob)
+{
+if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK)
+ {
+ state->exp_tls_verify_cert_hostnames =
+#ifdef SUPPORT_I18N
+ string_domain_utf8_to_alabel(host->name, NULL);
+#else
+ host->name;
+#endif
+ DEBUG(D_tls)
+ debug_printf("TLS: server cert verification includes hostname: \"%s\".\n",
+ state->exp_tls_verify_cert_hostnames);
+ }
+}
+
+
/*************************************************
* Start a TLS session in a client *
*************************************************/
fd the fd of the connection
host connected host (for messages)
addr the first address (not used)
- certificate certificate file
- privatekey private key file
- sni TLS SNI to send to remote host
- verify_certs file for certificate verify
- verify_crl CRL for verify
- require_ciphers list of allowed ciphers or NULL
- dh_min_bits minimum number of bits acceptable in server's DH prime
- timeout startup timeout
- verify_hosts mandatory client verification
- try_verify_hosts optional client verification
+ tb transport (always smtp)
+
+ errstr error string pointer
Returns: OK/DEFER/FAIL (because using common functions),
but for a client, DEFER and FAIL have the same meaning
int
tls_client_start(int fd, host_item *host,
address_item *addr ARG_UNUSED,
- uschar *certificate, uschar *privatekey, uschar *sni,
- uschar *verify_certs, uschar *verify_crl,
- uschar *require_ciphers,
-#ifdef EXPERIMENTAL_OCSP
- uschar *require_ocsp ARG_UNUSED,
+ transport_instance * tb,
+#ifdef EXPERIMENTAL_DANE
+ dns_answer * tlsa_dnsa ARG_UNUSED,
#endif
- int dh_min_bits, int timeout,
- uschar *verify_hosts, uschar *try_verify_hosts)
+ uschar ** errstr)
{
+smtp_transport_options_block *ob =
+ (smtp_transport_options_block *)tb->options_block;
int rc;
-const char *error;
exim_gnutls_state_st *state = NULL;
+#ifndef DISABLE_OCSP
+BOOL require_ocsp =
+ verify_check_given_host(&ob->hosts_require_ocsp, host) == OK;
+BOOL request_ocsp = require_ocsp ? TRUE
+ : verify_check_given_host(&ob->hosts_request_ocsp, host) == OK;
+#endif
DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", fd);
-rc = tls_init(host, certificate, privatekey,
- sni, verify_certs, verify_crl, require_ciphers, &state);
-if (rc != OK) return rc;
+if ((rc = tls_init(host, ob->tls_certificate, ob->tls_privatekey,
+ ob->tls_sni, ob->tls_verify_certificates, ob->tls_crl,
+ ob->tls_require_ciphers, &state, errstr)) != OK)
+ return rc;
-if (dh_min_bits < EXIM_CLIENT_DH_MIN_MIN_BITS)
{
- DEBUG(D_tls)
- debug_printf("WARNING: tls_dh_min_bits far too low, clamping %d up to %d\n",
- dh_min_bits, EXIM_CLIENT_DH_MIN_MIN_BITS);
- dh_min_bits = EXIM_CLIENT_DH_MIN_MIN_BITS;
+ int dh_min_bits = ob->tls_dh_min_bits;
+ if (dh_min_bits < EXIM_CLIENT_DH_MIN_MIN_BITS)
+ {
+ DEBUG(D_tls)
+ debug_printf("WARNING: tls_dh_min_bits far too low,"
+ " clamping %d up to %d\n",
+ dh_min_bits, EXIM_CLIENT_DH_MIN_MIN_BITS);
+ dh_min_bits = EXIM_CLIENT_DH_MIN_MIN_BITS;
+ }
+
+ DEBUG(D_tls) debug_printf("Setting D-H prime minimum"
+ " acceptable bits to %d\n",
+ dh_min_bits);
+ gnutls_dh_set_prime_bits(state->session, dh_min_bits);
}
-DEBUG(D_tls) debug_printf("Setting D-H prime minimum acceptable bits to %d\n",
- dh_min_bits);
-gnutls_dh_set_prime_bits(state->session, dh_min_bits);
+/* Stick to the old behaviour for compatibility if tls_verify_certificates is
+set but both tls_verify_hosts and tls_try_verify_hosts are unset. Check only
+the specified host patterns if one of them is defined */
-/* stick to the old behaviour for compatibility if tls_verify_certificates is
- set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only
- the specified host patterns if one of them is defined */
-if (((state->exp_tls_verify_certificates != NULL) && (verify_hosts == NULL) && (try_verify_hosts == NULL)) ||
- (verify_check_host(&verify_hosts) == OK))
+if ( ( state->exp_tls_verify_certificates
+ && !ob->tls_verify_hosts
+ && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts)
+ )
+ || verify_check_given_host(&ob->tls_verify_hosts, host) == OK
+ )
{
- DEBUG(D_tls) debug_printf("TLS: server certificate verification required.\n");
+ tls_client_setup_hostname_checks(host, state, ob);
+ DEBUG(D_tls)
+ debug_printf("TLS: server certificate verification required.\n");
state->verify_requirement = VERIFY_REQUIRED;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE);
}
-else if (verify_check_host(&try_verify_hosts) == OK)
+else if (verify_check_given_host(&ob->tls_try_verify_hosts, host) == OK)
{
- DEBUG(D_tls) debug_printf("TLS: server certificate verification optional.\n");
+ tls_client_setup_hostname_checks(host, state, ob);
+ DEBUG(D_tls)
+ debug_printf("TLS: server certificate verification optional.\n");
state->verify_requirement = VERIFY_OPTIONAL;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST);
}
else
{
- DEBUG(D_tls) debug_printf("TLS: server certificate verification not required.\n");
+ DEBUG(D_tls)
+ debug_printf("TLS: server certificate verification not required.\n");
state->verify_requirement = VERIFY_NONE;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE);
}
-gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr)fd);
+#ifndef DISABLE_OCSP
+ /* supported since GnuTLS 3.1.3 */
+if (request_ocsp)
+ {
+ DEBUG(D_tls) debug_printf("TLS: will request OCSP stapling\n");
+ if ((rc = gnutls_ocsp_status_request_enable_client(state->session,
+ NULL, 0, NULL)) != OK)
+ return tls_error(US"cert-status-req",
+ gnutls_strerror(rc), state->host, errstr);
+ tls_out.ocsp = OCSP_NOT_RESP;
+ }
+#endif
+
+#ifndef DISABLE_EVENT
+if (tb->event_action)
+ {
+ state->event_action = tb->event_action;
+ gnutls_session_set_ptr(state->session, state);
+ gnutls_certificate_set_verify_function(state->x509_cred, verify_cb);
+ }
+#endif
+
+gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr_t)(long) fd);
state->fd_in = fd;
state->fd_out = fd;
+DEBUG(D_tls) debug_printf("about to gnutls_handshake\n");
/* There doesn't seem to be a built-in timeout on connection. */
sigalrm_seen = FALSE;
-alarm(timeout);
+alarm(ob->command_timeout);
do
{
rc = gnutls_handshake(state->session);
alarm(0);
if (rc != GNUTLS_E_SUCCESS)
- return tls_error(US"gnutls_handshake",
- sigalrm_seen ? "timed out" : gnutls_strerror(rc), state->host);
+ if (sigalrm_seen)
+ {
+ gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_USER_CANCELED);
+ return tls_error(US"gnutls_handshake", "timed out", state->host, errstr);
+ }
+ else
+ return tls_error(US"gnutls_handshake", gnutls_strerror(rc), state->host, errstr);
DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n");
/* Verify late */
if (state->verify_requirement != VERIFY_NONE &&
- !verify_certificate(state, &error))
- return tls_error(US"certificate verification failed", error, state->host);
+ !verify_certificate(state, errstr))
+ return tls_error(US"certificate verification failed", *errstr, state->host, errstr);
+
+#ifndef DISABLE_OCSP
+if (require_ocsp)
+ {
+ DEBUG(D_tls)
+ {
+ gnutls_datum_t stapling;
+ gnutls_ocsp_resp_t resp;
+ gnutls_datum_t printed;
+ if ( (rc= gnutls_ocsp_status_request_get(state->session, &stapling)) == 0
+ && (rc= gnutls_ocsp_resp_init(&resp)) == 0
+ && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0
+ && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_FULL, &printed)) == 0
+ )
+ {
+ debug_printf("%.4096s", printed.data);
+ gnutls_free(printed.data);
+ }
+ else
+ (void) tls_error(US"ocsp decode", gnutls_strerror(rc), state->host, errstr);
+ }
+
+ if (gnutls_ocsp_status_request_is_checked(state->session, 0) == 0)
+ {
+ tls_out.ocsp = OCSP_FAILED;
+ return tls_error(US"certificate status check failed", NULL, state->host, errstr);
+ }
+ DEBUG(D_tls) debug_printf("Passed OCSP checking\n");
+ tls_out.ocsp = OCSP_VFIED;
+ }
+#endif
/* Figure out peer DN, and if authenticated, etc. */
-rc = peer_status(state);
-if (rc != OK) return rc;
+if ((rc = peer_status(state, errstr)) != OK)
+ return rc;
/* Sets various Exim expansion variables; may need to adjust for ACL callouts */
-extract_exim_vars_from_tls_state(state, FALSE);
+extract_exim_vars_from_tls_state(state);
return OK;
}
}
gnutls_deinit(state->session);
+gnutls_certificate_free_credentials(state->x509_cred);
+
state->tlsp->active = -1;
memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init));
gnutls_global_deinit();
exim_gnutls_base_init_done = FALSE;
}
-
}
This feeds DKIM and should be used for all message-body reads.
-Arguments: none
+Arguments: lim Maximum amount to read/bufffer
Returns: the next character or EOF
*/
int
-tls_getc(void)
+tls_getc(unsigned lim)
{
exim_gnutls_state_st *state = &state_server;
if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm)
if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
inbytes = gnutls_record_recv(state->session, state->xfer_buffer,
- ssl_xfer_buffer_size);
+ MIN(ssl_xfer_buffer_size, lim));
alarm(0);
- /* A zero-byte return appears to mean that the TLS session has been
+ /* Timeouts do not get this far; see command_timeout_handler().
+ A zero-byte return appears to mean that the TLS session has been
closed down, not that the socket itself has been closed down. Revert to
non-TLS handling. */
- if (inbytes == 0)
+ if (sigalrm_seen)
+ {
+ DEBUG(D_tls) debug_printf("Got tls read timeout\n");
+ state->xfer_error = 1;
+ return EOF;
+ }
+
+ else if (inbytes == 0)
{
DEBUG(D_tls) debug_printf("Got TLS_EOF\n");
receive_getc = smtp_getc;
+ receive_get_cache = smtp_get_cache;
receive_ungetc = smtp_ungetc;
receive_feof = smtp_feof;
receive_ferror = smtp_ferror;
receive_smtp_buffered = smtp_buffered;
gnutls_deinit(state->session);
+ gnutls_certificate_free_credentials(state->x509_cred);
+
state->session = NULL;
state->tlsp->active = -1;
state->tlsp->bits = 0;
state->tlsp->certificate_verified = FALSE;
- tls_channelbinding_b64 = NULL; /*XXX JGH */
+ tls_channelbinding_b64 = NULL;
state->tlsp->cipher = NULL;
+ state->tlsp->peercert = NULL;
state->tlsp->peerdn = NULL;
- return smtp_getc();
+ return smtp_getc(lim);
}
/* Handle genuine errors */
return state->xfer_buffer[state->xfer_buffer_lwm++];
}
+void
+tls_get_cache()
+{
+#ifndef DISABLE_DKIM
+exim_gnutls_state_st * state = &state_server;
+int n = state->xfer_buffer_hwm - state->xfer_buffer_lwm;
+if (n > 0)
+ dkim_exim_verify_feed(state->xfer_buffer+state->xfer_buffer_lwm, n);
+#endif
+}
+
uschar *expciphers = NULL;
gnutls_priority_t priority_cache;
const char *errpos;
+uschar * dummy_errstr;
#define validate_check_rc(Label) do { \
if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) gnutls_global_deinit(); \
if (!(tls_require_ciphers && *tls_require_ciphers))
return_deinit(NULL);
-if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers,
+ &dummy_errstr))
return_deinit(US"failed to expand tls_require_ciphers");
if (!(expciphers && *expciphers))
gnutls_check_version(NULL));
}
+/* vi: aw ai sw=2
+*/
/* End of tls-gnu.c */
git://git.exim.org / users / jgh / exim.git / blobdiff