Merge remote-tracking branch 'alex/bug162-SSLCipherList'

* alex/bug162-SSLCipherList:
  Cipher list selection for GnuTLS
  ConnSSL_Init_SSL(): correctly set CONN_SSL flag
  Cipher list selection for OpenSSL
  ConnSSL_InitLibrary(): Code cleanup

diff --git a/doc/sample-ngircd.conf.tmpl b/doc/sample-ngircd.conf.tmpl
index ae1b213950b8484ed4ab0ac92e9c9c03d86cea47..1bdf01ee4f2b7309ec864ea75a389694b368e352 100644 (file)
--- a/doc/sample-ngircd.conf.tmpl
+++ b/doc/sample-ngircd.conf.tmpl
@@ -248,6 +248,17 @@
        # SSL Server Key Certificate
        ;CertFile = :ETCDIR:/ssl/server-cert.pem
 
+       # Select cipher suites allowed for SSL/TLS connections. This defaults
+       # to the empty string, so all supported ciphers are allowed. Please
+       # see 'man 1ssl ciphers' (OpenSSL) and 'man 3 gnutls_priority_init'
+       # (GnuTLS) for details.
+       # For example, this setting allows only "high strength" cipher suites,
+       # disables the ones without authentication, and sorts by strength:
+       # For OpenSSL:
+       ;CipherList = HIGH:!aNULL:@STRENGTH
+       # For GnuTLS:
+       ;CipherList = SECURE128
+
        # Diffie-Hellman parameters
        ;DHFile = :ETCDIR:/ssl/dhparams.pem
 

diff --git a/man/ngircd.conf.5.tmpl b/man/ngircd.conf.5.tmpl
index cf926f9a3b80845f1b45715664a66f1709fddb94..862c142403327a0560161e586ec6de8fe854e22a 100644 (file)
--- a/man/ngircd.conf.5.tmpl
+++ b/man/ngircd.conf.5.tmpl
@@ -366,6 +366,15 @@ when it is compiled with support for SSL using OpenSSL or GnuTLS!
 \fBCertFile\fR (string)
 SSL Certificate file of the private server key.
 .TP
+\fBCipherList\fR (string)
+Select cipher suites allowed for SSL/TLS connections. This defaults to the
+empty string, so all supported ciphers are allowed.
+Please see 'man 1ssl ciphers' (OpenSSL) and 'man 3 gnutls_priority_init'
+(GnuTLS) for details.
+For example, this setting allows only "high strength" cipher suites, disables
+the ones without authentication, and sorts by strength:
+"HIGH:!aNULL:@STRENGTH" (OpenSSL), "SECURE128" (GnuTLS).
+.TP
 \fBDHFile\fR (string)
 Name of the Diffie-Hellman Parameter file. Can be created with GnuTLS
 "certtool \-\-generate-dh-params" or "openssl dhparam". If this file is not

diff --git a/src/ngircd/conf.c b/src/ngircd/conf.c
index b10f4905c9ec7befb08b5b5717cc6397cc48bea9..9ab66e54cf194b3c7afe68c90104d62e309e8ae1 100644 (file)
--- a/src/ngircd/conf.c
+++ b/src/ngircd/conf.c
@@ -117,6 +117,9 @@ ConfSSL_Init(void)
        array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 
        array_free(&Conf_SSLOptions.ListenPorts);
+
+       free(Conf_SSLOptions.CipherList);
+       Conf_SSLOptions.CipherList = NULL;
 }
 
 /**
@@ -432,6 +435,8 @@ Conf_Test( void )
        puts("[SSL]");
        printf("  CertFile = %s\n", Conf_SSLOptions.CertFile
                                        ? Conf_SSLOptions.CertFile : "");
+       printf("  CipherList = %s\n", Conf_SSLOptions.CipherList
+                                       ? Conf_SSLOptions.CipherList : "");
        printf("  DHFile = %s\n", Conf_SSLOptions.DHFile
                                        ? Conf_SSLOptions.DHFile : "");
        printf("  KeyFile = %s\n", Conf_SSLOptions.KeyFile
@@ -1869,6 +1874,11 @@ Handle_SSL(const char *File, int Line, char *Var, char *Arg)
                ports_parse(&Conf_SSLOptions.ListenPorts, Line, Arg);
                return;
        }
+       if (strcasecmp(Var, "CipherList") == 0) {
+               assert(Conf_SSLOptions.CipherList == NULL);
+               Conf_SSLOptions.CipherList = strdup_warn(Arg);
+               return;
+       }
 
        Config_Error_Section(File, Line, Var, "SSL");
 }

diff --git a/src/ngircd/conf.h b/src/ngircd/conf.h
index 948749de617bc433b6302edac2633eb1fc6e2bbe..02d23315552b0915020cb8690f1c084e97d69133 100644 (file)
--- a/src/ngircd/conf.h
+++ b/src/ngircd/conf.h
@@ -75,6 +75,7 @@ struct SSLOptions {
        char *DHFile;                   /**< File containing DH parameters */
        array ListenPorts;              /**< Array of listening SSL ports */
        array KeyFilePassword;          /**< Key file password */
+       char *CipherList;               /**< Set SSL cipher list to use */
 };
 #endif
 

diff --git a/src/ngircd/conn-ssl.c b/src/ngircd/conn-ssl.c
index 096ff9512a442ac0091103885b91d738bc05e1c2..b16c6b94e35299a54091ae9bb60dba9e1880c174 100644 (file)
--- a/src/ngircd/conn-ssl.c
+++ b/src/ngircd/conn-ssl.c
@@ -58,6 +58,7 @@ static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c ));
 
 static gnutls_certificate_credentials_t x509_cred;
 static gnutls_dh_params_t dh_params;
+static gnutls_priority_t priorities_cache;
 static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void ));
 #endif
 
@@ -285,8 +286,10 @@ ConnSSL_InitLibrary( void )
        if (!RAND_status()) {
                Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
                /*
-                * it is probably best to fail and let the user install EGD or a similar program if no kernel random device is available.
-                * According to OpenSSL RAND_egd(3): "The automatic query of /var/run/egd-pool et al was added in OpenSSL 0.9.7";
+                * it is probably best to fail and let the user install EGD or
+                * a similar program if no kernel random device is available.
+                * According to OpenSSL RAND_egd(3): "The automatic query of
+                * /var/run/egd-pool et al was added in OpenSSL 0.9.7";
                 * so it makes little sense to deal with PRNGD seeding ourselves.
                 */
                array_free(&Conf_SSLOptions.ListenPorts);
@@ -303,9 +306,23 @@ ConnSSL_InitLibrary( void )
        if (!ConnSSL_LoadServerKey_openssl(newctx))
                goto out;
 
+       if(Conf_SSLOptions.CipherList && *Conf_SSLOptions.CipherList) {
+               if(SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0 ) {
+                       Log(LOG_ERR,
+                           "Failed to apply OpenSSL cipher list \"%s\"!",
+                           Conf_SSLOptions.CipherList);
+                       goto out;
+               } else {
+                       Log(LOG_INFO,
+                           "Successfully applied OpenSSL cipher list \"%s\".",
+                           Conf_SSLOptions.CipherList);
+               }
+       }
+
        SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
        SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
-       SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE, Verify_openssl);
+       SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
+                          Verify_openssl);
        SSL_CTX_free(ssl_ctx);
        ssl_ctx = newctx;
        Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION));
@@ -318,22 +335,50 @@ out:
 #ifdef HAVE_LIBGNUTLS
        int err;
        static bool initialized;
-       if (initialized) /* TODO: cannot reload gnutls keys: can't simply free x509 context -- it may still be in use */
+
+       if (initialized) {
+               /* TODO: cannot reload gnutls keys: can't simply free x509
+                * context -- it may still be in use */
                return false;
+       }
 
        err = gnutls_global_init();
        if (err) {
-               Log(LOG_ERR, "Failed to initialize GnuTLS: %s", gnutls_strerror(err));
-               array_free(&Conf_SSLOptions.ListenPorts);
-               return false;
+               Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
+                   gnutls_strerror(err));
+               goto out;
        }
-       if (!ConnSSL_LoadServerKey_gnutls()) {
-               array_free(&Conf_SSLOptions.ListenPorts);
-               return false;
+
+       if (!ConnSSL_LoadServerKey_gnutls())
+               goto out;
+
+       if(Conf_SSLOptions.CipherList && *Conf_SSLOptions.CipherList) {
+               err = gnutls_priority_init(&priorities_cache,
+                                          Conf_SSLOptions.CipherList, NULL);
+               if (err != GNUTLS_E_SUCCESS) {
+                       Log(LOG_ERR,
+                           "Failed to apply GnuTLS cipher list \"%s\"!",
+                           Conf_SSLOptions.CipherList);
+                       goto out;
+               }
+               Log(LOG_INFO,
+                   "Successfully applied GnuTLS cipher list \"%s\".",
+                   Conf_SSLOptions.CipherList);
+       } else {
+               err = gnutls_priority_init(&priorities_cache, "NORMAL", NULL);
+               if (err != GNUTLS_E_SUCCESS) {
+                       Log(LOG_ERR,
+                           "Failed to apply GnuTLS cipher list \"NORMAL\"!");
+                       goto out;
+               }
        }
+
        Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
        initialized = true;
        return true;
+out:
+       array_free(&Conf_SSLOptions.ListenPorts);
+       return false;
 #endif
 }
 
@@ -360,7 +405,7 @@ ConnSSL_LoadServerKey_gnutls(void)
 
        if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
                Log(LOG_WARNING,
-                   "Ignoring KeyFilePassword: Not supported by GnuTLS.");
+                   "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
 
        if (!Load_DH_params())
                return false;
@@ -430,7 +475,10 @@ static bool
 ConnSSL_Init_SSL(CONNECTION *c)
 {
        int ret;
+
+       LogDebug("Initializing SSL ...");
        assert(c != NULL);
+
 #ifdef HAVE_LIBSSL
        if (!ssl_ctx) {
                Log(LOG_ERR,
@@ -445,6 +493,7 @@ ConnSSL_Init_SSL(CONNECTION *c)
                LogOpenSSLError("Failed to create SSL structure", NULL);
                return false;
        }
+       Conn_OPTION_ADD(c, CONN_SSL);
 
        ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
        if (ret != 1) {
@@ -454,9 +503,10 @@ ConnSSL_Init_SSL(CONNECTION *c)
        }
 #endif
 #ifdef HAVE_LIBGNUTLS
-       ret = gnutls_set_default_priority(c->ssl_state.gnutls_session);
-       if (ret < 0) {
-               Log(LOG_ERR, "Failed to set GnuTLS default priority: %s",
+       Conn_OPTION_ADD(c, CONN_SSL);
+       ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
+       if (ret != 0) {
+               Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
                    gnutls_strerror(ret));
                ConnSSL_Free(c);
                return false;
@@ -467,17 +517,20 @@ ConnSSL_Init_SSL(CONNECTION *c)
         * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
         * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
         */
-       gnutls_transport_set_ptr(c->ssl_state.gnutls_session, (gnutls_transport_ptr_t) (long) c->sock);
-       gnutls_certificate_server_set_request(c->ssl_state.gnutls_session, GNUTLS_CERT_REQUEST);
-       ret = gnutls_credentials_set(c->ssl_state.gnutls_session, GNUTLS_CRD_CERTIFICATE, x509_cred);
-       if (ret < 0) {
-               Log(LOG_ERR, "Failed to set SSL credentials: %s", gnutls_strerror(ret));
+       gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
+                                (gnutls_transport_ptr_t) (long) c->sock);
+       gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
+                                             GNUTLS_CERT_REQUEST);
+       ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
+                                    GNUTLS_CRD_CERTIFICATE, x509_cred);
+       if (ret != 0) {
+               Log(LOG_ERR, "Failed to set SSL credentials: %s",
+                   gnutls_strerror(ret));
                ConnSSL_Free(c);
                return false;
        }
        gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 #endif
-       Conn_OPTION_ADD(c, CONN_SSL);
        return true;
 }
 
@@ -645,7 +698,6 @@ ConnSSL_Accept( CONNECTION *c )
                        return false;
                }
 #endif
-               LogDebug("Initializing SSL data ...");
                if (!ConnSSL_Init_SSL(c))
                        return -1;
        }