ustream-openssl: clear error stack before SSL_read/SSL_write
[project/ustream-ssl.git] / ustream-openssl.c
index 787cc383a818644b9ce5624aa4a2c26bf05efc11..fa99e67b7fca9194afb9ceb1b96f07710f4de4f5 100644 (file)
 
 #include <string.h>
 #include <ctype.h>
-#include <openssl/x509v3.h>
 #include "ustream-ssl.h"
 #include "ustream-internal.h"
+#include <openssl/x509v3.h>
+
+/* Ciphersuite preference:
+ * - for server, no weak ciphers are used if you use an ECDSA key.
+ * - forward-secret (pfs), authenticated (AEAD) ciphers are at the top:
+ *     chacha20-poly1305, the fastest in software, 256-bits
+ *     aes128-gcm, 128-bits
+ *     aes256-gcm, 256-bits
+ * - key exchange: prefer ECDHE, then DHE (client only)
+ * - forward-secret ECDSA CBC ciphers (client-only)
+ * - forward-secret RSA CBC ciphers
+ * - non-pfs ciphers
+ *     aes128, aes256, 3DES(client only)
+ */
+
+#ifdef WOLFSSL_SSL_H
+# define top_ciphers                                                   \
+                               "TLS13-CHACHA20-POLY1305-SHA256:"       \
+                               "TLS13-AES128-GCM-SHA256:"              \
+                               "TLS13-AES256-GCM-SHA384:"              \
+                               ecdhe_aead_ciphers
+#else
+# define tls13_ciphersuites    "TLS_CHACHA20_POLY1305_SHA256:"         \
+                               "TLS_AES_128_GCM_SHA256:"               \
+                               "TLS_AES_256_GCM_SHA384"
+
+# define top_ciphers                                                   \
+                               ecdhe_aead_ciphers
+#endif
+
+#define ecdhe_aead_ciphers                                             \
+                               "ECDHE-ECDSA-CHACHA20-POLY1305:"        \
+                               "ECDHE-ECDSA-AES128-GCM-SHA256:"        \
+                               "ECDHE-ECDSA-AES256-GCM-SHA384:"        \
+                               "ECDHE-RSA-CHACHA20-POLY1305:"          \
+                               "ECDHE-RSA-AES128-GCM-SHA256:"          \
+                               "ECDHE-RSA-AES256-GCM-SHA384"
+
+#define dhe_aead_ciphers                                               \
+                               "DHE-RSA-CHACHA20-POLY1305:"            \
+                               "DHE-RSA-AES128-GCM-SHA256:"            \
+                               "DHE-RSA-AES256-GCM-SHA384"
+
+#define ecdhe_ecdsa_cbc_ciphers                                                \
+                               "ECDHE-ECDSA-AES128-SHA:"               \
+                               "ECDHE-ECDSA-AES256-SHA"
+
+#define ecdhe_rsa_cbc_ciphers                                          \
+                               "ECDHE-RSA-AES128-SHA:"                 \
+                               "ECDHE-RSA-AES256-SHA"
+
+#define dhe_cbc_ciphers                                                        \
+                               "DHE-RSA-AES128-SHA:"                   \
+                               "DHE-RSA-AES256-SHA:"                   \
+                               "DHE-DES-CBC3-SHA"
+
+#define non_pfs_aes                                                    \
+                               "AES128-GCM-SHA256:"                    \
+                               "AES256-GCM-SHA384:"                    \
+                               "AES128-SHA:"                           \
+                               "AES256-SHA"
+
+#define server_cipher_list                                             \
+                               top_ciphers ":"                         \
+                               ecdhe_rsa_cbc_ciphers ":"               \
+                               non_pfs_aes
+
+#define client_cipher_list                                             \
+                               top_ciphers ":"                         \
+                               dhe_aead_ciphers ":"                    \
+                               ecdhe_ecdsa_cbc_ciphers ":"             \
+                               ecdhe_rsa_cbc_ciphers ":"               \
+                               dhe_cbc_ciphers ":"                     \
+                               non_pfs_aes ":"                         \
+                               "DES-CBC3-SHA"
 
 __hidden struct ustream_ssl_ctx *
 __ustream_ssl_context_new(bool server)
 {
-       static bool _init = false;
        const void *m;
        SSL_CTX *c;
 
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+       static bool _init = false;
+
        if (!_init) {
                SSL_load_error_strings();
                SSL_library_init();
                _init = true;
        }
-
-#ifdef CYASSL_OPENSSL_H_
-       if (server)
-               m = SSLv23_server_method();
-       else
-               m = SSLv23_client_method();
-#else
-       if (server)
-               m = TLSv1_server_method();
-       else
-               m = TLSv1_client_method();
+# ifndef TLS_server_method
+#  define TLS_server_method SSLv23_server_method
+# endif
+# ifndef TLS_client_method
+#  define TLS_client_method SSLv23_client_method
+# endif
 #endif
 
+       if (server) {
+               m = TLS_server_method();
+       } else
+               m = TLS_client_method();
+
        c = SSL_CTX_new((void *) m);
        if (!c)
                return NULL;
 
        SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
+       SSL_CTX_set_options(c, SSL_OP_NO_COMPRESSION | SSL_OP_SINGLE_ECDH_USE |
+                              SSL_OP_CIPHER_SERVER_PREFERENCE);
+#if defined(SSL_CTX_set_ecdh_auto) && OPENSSL_VERSION_NUMBER < 0x10100000L
+       SSL_CTX_set_ecdh_auto(c, 1);
+#elif OPENSSL_VERSION_NUMBER >= 0x10101000L
+       SSL_CTX_set_ciphersuites(c, tls13_ciphersuites);
+#endif
+       if (server) {
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+               SSL_CTX_set_min_proto_version(c, TLS1_2_VERSION);
+#else
+               SSL_CTX_set_options(c, SSL_OP_NO_SSLv3 | SSL_OP_NO_TLSv1 |
+                                      SSL_OP_NO_TLSv1_1);
+#endif
+               SSL_CTX_set_cipher_list(c, server_cipher_list);
+       } else {
+               SSL_CTX_set_cipher_list(c, client_cipher_list);
+       }
+       SSL_CTX_set_quiet_shutdown(c, 1);
 
        return (void *) c;
 }
@@ -100,119 +195,36 @@ __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
        SSL_CTX_free((void *) ctx);
 }
 
-static void ustream_ssl_error(struct ustream_ssl *us, int ret)
+void __ustream_ssl_session_free(void *ssl)
 {
-       us->error = ret;
-       uloop_timeout_set(&us->error_timer, 0);
+       SSL_shutdown(ssl);
+       SSL_free(ssl);
 }
 
-#ifndef CYASSL_OPENSSL_H_
-
-static bool host_pattern_match(const unsigned char *pattern, const char *cn)
-{
-       char c;
-
-       for (; (c = tolower(*pattern++)) != 0; cn++) {
-               if (c != '*') {
-                       if (c != *cn)
-                               return false;
-                       continue;
-               }
-
-               do {
-                       c = tolower(*pattern++);
-               } while (c == '*');
-
-               while (*cn) {
-                       if (c == tolower(*cn) &&
-                           host_pattern_match(pattern, cn))
-                               return true;
-                       if (*cn == '.')
-                               return false;
-                       cn++;
-               }
-
-               return !c;
-       }
-       return !*cn;
-}
-
-static bool host_pattern_match_asn1(ASN1_STRING *asn1, const char *cn)
+static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 {
-       unsigned char *pattern;
-       bool ret = false;
-
-       if (ASN1_STRING_to_UTF8(&pattern, asn1) < 0)
-               return false;
-
-       if (!pattern)
-               return false;
-
-       if (strlen((char *) pattern) == ASN1_STRING_length(asn1))
-               ret = host_pattern_match(pattern, cn);
-
-       OPENSSL_free(pattern);
-
-       return ret;
+       us->error = ret;
+       uloop_timeout_set(&us->error_timer, 0);
 }
 
-static bool ustream_ssl_verify_cn_alt(struct ustream_ssl *us, X509 *cert)
-{
-       GENERAL_NAMES *alt_names;
-       int i, n_alt;
-
-       alt_names = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
-       if (!alt_names)
-               return false;
-
-       n_alt = sk_GENERAL_NAME_num(alt_names);
-       for (i = 0; i < n_alt; i++) {
-               const GENERAL_NAME *name = sk_GENERAL_NAME_value(alt_names, i);
-
-               if (!name)
-                       continue;
-
-               if (name->type != GEN_DNS)
-                       continue;
-
-               if (host_pattern_match_asn1(name->d.dNSName, us->peer_cn))
-                       return true;
-       }
-
-       return false;
-}
+#ifndef NO_X509_CHECK_HOST
 
 static bool ustream_ssl_verify_cn(struct ustream_ssl *us, X509 *cert)
 {
-       ASN1_STRING *astr;
-       X509_NAME *xname;
-       int i, last;
+       int ret;
 
        if (!us->peer_cn)
                return false;
 
-       if (ustream_ssl_verify_cn_alt(us, cert))
-               return true;
-
-       xname = X509_get_subject_name(cert);
-
-       last = -1;
-       while (1) {
-               i = X509_NAME_get_index_by_NID(xname, NID_commonName, last);
-               if (i < 0)
-                       break;
-
-               last = i;
-       }
-
-       if (last < 0)
-               return false;
-
-       astr = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(xname, last));
-
-       return host_pattern_match_asn1(astr, us->peer_cn);
+# ifndef WOLFSSL_OPENSSL_H_
+       ret = X509_check_host(cert, us->peer_cn, 0, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS, NULL);
+# else
+       ret = wolfSSL_X509_check_host(cert, us->peer_cn, 0, 0, NULL);
+# endif
+       return ret == 1;
 }
 
+#endif
 
 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 {
@@ -232,26 +244,27 @@ static void ustream_ssl_verify_cert(struct ustream_ssl *us)
                return;
 
        us->valid_cert = true;
+#ifndef NO_X509_CHECK_HOST
        us->valid_cn = ustream_ssl_verify_cn(us, cert);
+#endif
        X509_free(cert);
 }
 
-#endif
 
 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 {
        void *ssl = us->ssl;
        int r;
 
+       ERR_clear_error();
+
        if (us->server)
                r = SSL_accept(ssl);
        else
                r = SSL_connect(ssl);
 
        if (r == 1) {
-#ifndef CYASSL_OPENSSL_H_
                ustream_ssl_verify_cert(us);
-#endif
                return U_SSL_OK;
        }
 
@@ -266,7 +279,11 @@ __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 {
        void *ssl = us->ssl;
-       int ret = SSL_write(ssl, buf, len);
+       int ret;
+
+       ERR_clear_error();
+
+       ret = SSL_write(ssl, buf, len);
 
        if (ret < 0) {
                int err = SSL_get_error(ssl, ret);
@@ -282,7 +299,11 @@ __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int le
 
 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 {
-       int ret = SSL_read(us->ssl, buf, len);
+       int ret;
+
+       ERR_clear_error();
+
+       ret = SSL_read(us->ssl, buf, len);
 
        if (ret < 0) {
                ret = SSL_get_error(us->ssl, ret);