ustream-openssl.c

   1 /*
   2  * ustream-ssl - library for SSL over ustream
   3  *
   4  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <string.h>
  20 #include <ctype.h>
  21 #include <openssl/x509v3.h>
  22 #include "ustream-ssl.h"
  23 #include "ustream-internal.h"
  24
  25
  26 /* Ciphersuite preference:
  27  * - key exchange: prefer ECDHE, then DHE(client only), then RSA
  28  * - prefer AEAD ciphers:
  29  *      chacha20-poly1305, the fastest in software, 256-bits
  30  *      aes128-gcm, 128-bits
  31  *      aes256-gcm, 256-bits
  32  * - CBC ciphers
  33  *      aes128, aes256, 3DES(client only)
  34  */
  35
  36 #ifdef WOLFSSL_SSL_H
  37 # define top_ciphers                                                    \
  38                                 "TLS13-CHACHA20-POLY1305-SHA256:"       \
  39                                 "TLS13-AES128-GCM-SHA256:"              \
  40                                 "TLS13-AES256-GCM-SHA384:"              \
  41                                 ecdhe_ciphers
  42 #else
  43 # define tls13_ciphersuites     "TLS_CHACHA20_POLY1305_SHA256:"         \
  44                                 "TLS_AES_128_GCM_SHA256:"               \
  45                                 "TLS_AES_256_GCM_SHA384"
  46
  47 # define top_ciphers                                                    \
  48                                 ecdhe_ciphers
  49 #endif
  50
  51 #define ecdhe_ciphers                                                   \
  52                                 "ECDHE-ECDSA-CHACHA20-POLY1305:"        \
  53                                 "ECDHE-ECDSA-AES128-GCM-SHA256:"        \
  54                                 "ECDHE-ECDSA-AES256-GCM-SHA384:"        \
  55                                 "ECDHE-ECDSA-AES128-SHA:"               \
  56                                 "ECDHE-ECDSA-AES256-SHA:"               \
  57                                 "ECDHE-RSA-CHACHA20-POLY1305:"          \
  58                                 "ECDHE-RSA-AES128-GCM-SHA256:"          \
  59                                 "ECDHE-RSA-AES256-GCM-SHA384:"          \
  60                                 "ECDHE-RSA-AES128-SHA:"                 \
  61                                 "ECDHE-RSA-AES256-SHA"
  62
  63 #define dhe_ciphers                                                     \
  64                                 "DHE-RSA-CHACHA20-POLY1305:"            \
  65                                 "DHE-RSA-AES128-GCM-SHA256:"            \
  66                                 "DHE-RSA-AES256-GCM-SHA384:"            \
  67                                 "DHE-RSA-AES128-SHA:"                   \
  68                                 "DHE-RSA-AES256-SHA:"                   \
  69                                 "DHE-DES-CBC3-SHA"
  70
  71 #define non_pfs_aes                                                     \
  72                                 "AES128-GCM-SHA256:"                    \
  73                                 "AES256-GCM-SHA384:"                    \
  74                                 "AES128-SHA:"                           \
  75                                 "AES256-SHA"
  76
  77 #define server_cipher_list                                              \
  78                                 top_ciphers ":"                         \
  79                                 non_pfs_aes
  80
  81 #define client_cipher_list                                              \
  82                                 top_ciphers ":"                         \
  83                                 dhe_ciphers ":"                         \
  84                                 non_pfs_aes ":"                         \
  85                                 "DES-CBC3-SHA"
  86
  87 __hidden struct ustream_ssl_ctx *
  88 __ustream_ssl_context_new(bool server)
  89 {
  90         const void *m;
  91         SSL_CTX *c;
  92
  93 #if OPENSSL_VERSION_NUMBER < 0x10100000L
  94         static bool _init = false;
  95
  96         if (!_init) {
  97                 SSL_load_error_strings();
  98                 SSL_library_init();
  99                 _init = true;
 100         }
 101 # define TLS_server_method SSLv23_server_method
 102 # define TLS_client_method SSLv23_client_method
 103 #endif
 104
 105         if (server) {
 106                 m = TLS_server_method();
 107         } else
 108                 m = TLS_client_method();
 109
 110         c = SSL_CTX_new((void *) m);
 111         if (!c)
 112                 return NULL;
 113
 114         SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
 115         SSL_CTX_set_options(c, SSL_OP_NO_COMPRESSION | SSL_OP_SINGLE_ECDH_USE |
 116                                SSL_OP_CIPHER_SERVER_PREFERENCE);
 117 #if defined(SSL_CTX_set_ecdh_auto) && OPENSSL_VERSION_NUMBER < 0x10100000L
 118         SSL_CTX_set_ecdh_auto(c, 1);
 119 #elif OPENSSL_VERSION_NUMBER >= 0x10101000L
 120         SSL_CTX_set_ciphersuites(c, tls13_ciphersuites);
 121 #endif
 122         if (server) {
 123 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
 124                 SSL_CTX_set_min_proto_version(c, TLS1_2_VERSION);
 125 #else
 126                 SSL_CTX_set_options(c, SSL_OP_NO_SSLv3 | SSL_OP_NO_TLSv1 |
 127                                        SSL_OP_NO_TLSv1_1);
 128 #endif
 129                 SSL_CTX_set_cipher_list(c, server_cipher_list);
 130         } else {
 131                 SSL_CTX_set_cipher_list(c, client_cipher_list);
 132         }
 133         SSL_CTX_set_quiet_shutdown(c, 1);
 134
 135         return (void *) c;
 136 }
 137
 138 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 139 {
 140         int ret;
 141
 142         ret = SSL_CTX_load_verify_locations((void *) ctx, file, NULL);
 143         if (ret < 1)
 144                 return -1;
 145
 146         return 0;
 147 }
 148
 149 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 150 {
 151         int ret;
 152
 153         ret = SSL_CTX_use_certificate_chain_file((void *) ctx, file);
 154         if (ret < 1)
 155                 ret = SSL_CTX_use_certificate_file((void *) ctx, file, SSL_FILETYPE_ASN1);
 156
 157         if (ret < 1)
 158                 return -1;
 159
 160         return 0;
 161 }
 162
 163 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
 164 {
 165         int ret;
 166
 167         ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_PEM);
 168         if (ret < 1)
 169                 ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_ASN1);
 170
 171         if (ret < 1)
 172                 return -1;
 173
 174         return 0;
 175 }
 176
 177 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 178 {
 179         SSL_CTX_free((void *) ctx);
 180 }
 181
 182 void __ustream_ssl_session_free(void *ssl)
 183 {
 184         SSL_shutdown(ssl);
 185         SSL_free(ssl);
 186 }
 187
 188 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 189 {
 190         us->error = ret;
 191         uloop_timeout_set(&us->error_timer, 0);
 192 }
 193
 194 #ifndef CYASSL_OPENSSL_H_
 195
 196 static bool ustream_ssl_verify_cn(struct ustream_ssl *us, X509 *cert)
 197 {
 198         int ret;
 199
 200         if (!us->peer_cn)
 201                 return false;
 202
 203         ret = X509_check_host(cert, us->peer_cn, 0, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS, NULL);
 204         return ret == 1;
 205 }
 206
 207
 208 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 209 {
 210         void *ssl = us->ssl;
 211         X509 *cert;
 212         int res;
 213
 214         res = SSL_get_verify_result(ssl);
 215         if (res != X509_V_OK) {
 216                 if (us->notify_verify_error)
 217                         us->notify_verify_error(us, res, X509_verify_cert_error_string(res));
 218                 return;
 219         }
 220
 221         cert = SSL_get_peer_certificate(ssl);
 222         if (!cert)
 223                 return;
 224
 225         us->valid_cert = true;
 226         us->valid_cn = ustream_ssl_verify_cn(us, cert);
 227         X509_free(cert);
 228 }
 229
 230 #endif
 231
 232 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 233 {
 234         void *ssl = us->ssl;
 235         int r;
 236
 237         if (us->server)
 238                 r = SSL_accept(ssl);
 239         else
 240                 r = SSL_connect(ssl);
 241
 242         if (r == 1) {
 243 #ifndef CYASSL_OPENSSL_H_
 244                 ustream_ssl_verify_cert(us);
 245 #endif
 246                 return U_SSL_OK;
 247         }
 248
 249         r = SSL_get_error(ssl, r);
 250         if (r == SSL_ERROR_WANT_READ || r == SSL_ERROR_WANT_WRITE)
 251                 return U_SSL_PENDING;
 252
 253         ustream_ssl_error(us, r);
 254         return U_SSL_ERROR;
 255 }
 256
 257 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 258 {
 259         void *ssl = us->ssl;
 260         int ret = SSL_write(ssl, buf, len);
 261
 262         if (ret < 0) {
 263                 int err = SSL_get_error(ssl, ret);
 264                 if (err == SSL_ERROR_WANT_WRITE)
 265                         return 0;
 266
 267                 ustream_ssl_error(us, err);
 268                 return -1;
 269         }
 270
 271         return ret;
 272 }
 273
 274 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 275 {
 276         int ret = SSL_read(us->ssl, buf, len);
 277
 278         if (ret < 0) {
 279                 ret = SSL_get_error(us->ssl, ret);
 280                 if (ret == SSL_ERROR_WANT_READ)
 281                         return U_SSL_PENDING;
 282
 283                 ustream_ssl_error(us, ret);
 284                 return U_SSL_ERROR;
 285         }
 286
 287         return ret;
 288 }
 289