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 "ustream-ssl.h"
  22 #include "ustream-internal.h"
  23
  24 #if !defined(HAVE_WOLFSSL)
  25 #include <openssl/x509v3.h>
  26 #endif
  27
  28 #if defined(HAVE_WOLFSSL) && defined(DEBUG)
  29 #include <wolfssl/test.h>
  30 #endif
  31
  32 /* Ciphersuite preference:
  33  * - for server, no weak ciphers are used if you use an ECDSA key.
  34  * - forward-secret (pfs), authenticated (AEAD) ciphers are at the top:
  35  *      chacha20-poly1305, the fastest in software, 256-bits
  36  *      aes128-gcm, 128-bits
  37  *      aes256-gcm, 256-bits
  38  * - key exchange: prefer ECDHE, then DHE (client only)
  39  * - forward-secret ECDSA CBC ciphers (client-only)
  40  * - forward-secret RSA CBC ciphers
  41  * - non-pfs ciphers
  42  *      aes128, aes256, 3DES(client only)
  43  */
  44
  45 #ifdef WOLFSSL_SSL_H
  46 # define top_ciphers                                                    \
  47                                 "TLS13-CHACHA20-POLY1305-SHA256:"       \
  48                                 "TLS13-AES128-GCM-SHA256:"              \
  49                                 "TLS13-AES256-GCM-SHA384:"              \
  50                                 ecdhe_aead_ciphers
  51 #else
  52 # define tls13_ciphersuites     "TLS_CHACHA20_POLY1305_SHA256:"         \
  53                                 "TLS_AES_128_GCM_SHA256:"               \
  54                                 "TLS_AES_256_GCM_SHA384"
  55
  56 # define top_ciphers                                                    \
  57                                 ecdhe_aead_ciphers
  58 #endif
  59
  60 #define ecdhe_aead_ciphers                                              \
  61                                 "ECDHE-ECDSA-CHACHA20-POLY1305:"        \
  62                                 "ECDHE-ECDSA-AES128-GCM-SHA256:"        \
  63                                 "ECDHE-ECDSA-AES256-GCM-SHA384:"        \
  64                                 "ECDHE-RSA-CHACHA20-POLY1305:"          \
  65                                 "ECDHE-RSA-AES128-GCM-SHA256:"          \
  66                                 "ECDHE-RSA-AES256-GCM-SHA384"
  67
  68 #define dhe_aead_ciphers                                                \
  69                                 "DHE-RSA-CHACHA20-POLY1305:"            \
  70                                 "DHE-RSA-AES128-GCM-SHA256:"            \
  71                                 "DHE-RSA-AES256-GCM-SHA384"
  72
  73 #define ecdhe_ecdsa_cbc_ciphers                                         \
  74                                 "ECDHE-ECDSA-AES128-SHA:"               \
  75                                 "ECDHE-ECDSA-AES256-SHA"
  76
  77 #define ecdhe_rsa_cbc_ciphers                                           \
  78                                 "ECDHE-RSA-AES128-SHA:"                 \
  79                                 "ECDHE-RSA-AES256-SHA"
  80
  81 #define dhe_cbc_ciphers                                                 \
  82                                 "DHE-RSA-AES128-SHA:"                   \
  83                                 "DHE-RSA-AES256-SHA:"                   \
  84                                 "DHE-DES-CBC3-SHA"
  85
  86 #define non_pfs_aes                                                     \
  87                                 "AES128-GCM-SHA256:"                    \
  88                                 "AES256-GCM-SHA384:"                    \
  89                                 "AES128-SHA:"                           \
  90                                 "AES256-SHA"
  91
  92 #define server_cipher_list                                              \
  93                                 top_ciphers ":"                         \
  94                                 ecdhe_rsa_cbc_ciphers ":"               \
  95                                 non_pfs_aes
  96
  97 #define client_cipher_list                                              \
  98                                 top_ciphers ":"                         \
  99                                 dhe_aead_ciphers ":"                    \
 100                                 ecdhe_ecdsa_cbc_ciphers ":"             \
 101                                 ecdhe_rsa_cbc_ciphers ":"               \
 102                                 dhe_cbc_ciphers ":"                     \
 103                                 non_pfs_aes ":"                         \
 104                                 "DES-CBC3-SHA"
 105
 106 __hidden struct ustream_ssl_ctx *
 107 __ustream_ssl_context_new(bool server)
 108 {
 109         const void *m;
 110         SSL_CTX *c;
 111
 112 #if OPENSSL_VERSION_NUMBER < 0x10100000L
 113         static bool _init = false;
 114
 115         if (!_init) {
 116                 SSL_load_error_strings();
 117                 SSL_library_init();
 118                 _init = true;
 119         }
 120 # ifndef TLS_server_method
 121 #  define TLS_server_method SSLv23_server_method
 122 # endif
 123 # ifndef TLS_client_method
 124 #  define TLS_client_method SSLv23_client_method
 125 # endif
 126 #endif
 127
 128         if (server) {
 129                 m = TLS_server_method();
 130         } else
 131                 m = TLS_client_method();
 132
 133         c = SSL_CTX_new((void *) m);
 134         if (!c)
 135                 return NULL;
 136
 137 #if defined(HAVE_WOLFSSL)
 138         if (server)
 139                 SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
 140         else
 141                 SSL_CTX_set_verify(c, SSL_VERIFY_PEER, NULL);
 142 #else
 143         SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
 144 #endif
 145
 146         SSL_CTX_set_options(c, SSL_OP_NO_COMPRESSION | SSL_OP_SINGLE_ECDH_USE |
 147                                SSL_OP_CIPHER_SERVER_PREFERENCE);
 148 #if defined(SSL_CTX_set_ecdh_auto) && OPENSSL_VERSION_NUMBER < 0x10100000L
 149         SSL_CTX_set_ecdh_auto(c, 1);
 150 #elif OPENSSL_VERSION_NUMBER >= 0x10101000L
 151         SSL_CTX_set_ciphersuites(c, tls13_ciphersuites);
 152 #endif
 153         if (server) {
 154 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
 155                 SSL_CTX_set_min_proto_version(c, TLS1_2_VERSION);
 156 #else
 157                 SSL_CTX_set_options(c, SSL_OP_NO_SSLv3 | SSL_OP_NO_TLSv1 |
 158                                        SSL_OP_NO_TLSv1_1);
 159 #endif
 160 #if defined(HAVE_WOLFSSL)
 161                 SSL_CTX_set_options(c, SSL_AD_NO_RENEGOTIATION);
 162 #else
 163                 SSL_CTX_set_options(c, SSL_OP_NO_RENEGOTIATION);
 164 #endif
 165
 166                 SSL_CTX_set_cipher_list(c, server_cipher_list);
 167         } else {
 168                 SSL_CTX_set_cipher_list(c, client_cipher_list);
 169         }
 170         SSL_CTX_set_quiet_shutdown(c, 1);
 171
 172         return (void *) c;
 173 }
 174
 175 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 176 {
 177         int ret;
 178
 179         ret = SSL_CTX_load_verify_locations((void *) ctx, file, NULL);
 180         if (ret < 1)
 181                 return -1;
 182
 183         return 0;
 184 }
 185
 186 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 187 {
 188         int ret;
 189
 190         ret = SSL_CTX_use_certificate_chain_file((void *) ctx, file);
 191         if (ret < 1)
 192                 ret = SSL_CTX_use_certificate_file((void *) ctx, file, SSL_FILETYPE_ASN1);
 193
 194         if (ret < 1)
 195                 return -1;
 196
 197         return 0;
 198 }
 199
 200 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
 201 {
 202         int ret;
 203
 204         ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_PEM);
 205         if (ret < 1)
 206                 ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_ASN1);
 207
 208         if (ret < 1)
 209                 return -1;
 210
 211         return 0;
 212 }
 213
 214 __hidden int __ustream_ssl_set_ciphers(struct ustream_ssl_ctx *ctx, const char *ciphers)
 215 {
 216         int ret = SSL_CTX_set_cipher_list((void *) ctx, ciphers);
 217
 218         if (ret == 0)
 219                 return -1;
 220
 221         return 0;
 222 }
 223
 224 __hidden int __ustream_ssl_set_require_validation(struct ustream_ssl_ctx *ctx, bool require)
 225 {
 226         int mode = SSL_VERIFY_PEER;
 227
 228         if (!require)
 229                 mode = SSL_VERIFY_NONE;
 230
 231         SSL_CTX_set_verify((void *) ctx, mode, NULL);
 232
 233         return 0;
 234 }
 235
 236 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 237 {
 238         SSL_CTX_free((void *) ctx);
 239 }
 240
 241 void __ustream_ssl_session_free(void *ssl)
 242 {
 243         BIO *bio = SSL_get_wbio(ssl);
 244         struct bio_ctx *ctx = BIO_get_data(bio);
 245
 246         SSL_shutdown(ssl);
 247         SSL_free(ssl);
 248         if (ctx) {
 249                 BIO_meth_free(ctx->meth);
 250                 free(ctx);
 251         }
 252 }
 253
 254 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 255 {
 256         us->error = ret;
 257         uloop_timeout_set(&us->error_timer, 0);
 258 }
 259
 260 static bool ustream_ssl_verify_cn(struct ustream_ssl *us, X509 *cert)
 261 {
 262         int ret;
 263
 264         if (!us->peer_cn)
 265                 return false;
 266
 267 # ifndef WOLFSSL_OPENSSL_H_
 268         ret = X509_check_host(cert, us->peer_cn, 0, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS, NULL);
 269 # else
 270         ret = wolfSSL_X509_check_host(cert, us->peer_cn, 0, 0, NULL);
 271 # endif
 272         return ret == 1;
 273 }
 274
 275 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 276 {
 277         void *ssl = us->ssl;
 278         X509 *cert;
 279         int res;
 280
 281 #if defined(HAVE_WOLFSSL) && defined(DEBUG)
 282         showPeer(ssl);
 283 #endif
 284
 285         res = SSL_get_verify_result(ssl);
 286         if (res != X509_V_OK) {
 287                 if (us->notify_verify_error)
 288                         us->notify_verify_error(us, res, X509_verify_cert_error_string(res));
 289                 return;
 290         }
 291
 292         cert = SSL_get_peer_certificate(ssl);
 293         if (!cert)
 294                 return;
 295
 296         us->valid_cert = true;
 297         us->valid_cn = ustream_ssl_verify_cn(us, cert);
 298
 299         X509_free(cert);
 300 }
 301
 302 #ifdef WOLFSSL_SSL_H
 303 static bool handle_wolfssl_asn_error(struct ustream_ssl *us, int r)
 304 {
 305         switch (r) {
 306         case ASN_PARSE_E:
 307         case ASN_VERSION_E:
 308         case ASN_GETINT_E:
 309         case ASN_RSA_KEY_E:
 310         case ASN_OBJECT_ID_E:
 311         case ASN_TAG_NULL_E:
 312         case ASN_EXPECT_0_E:
 313         case ASN_BITSTR_E:
 314         case ASN_UNKNOWN_OID_E:
 315         case ASN_DATE_SZ_E:
 316         case ASN_BEFORE_DATE_E:
 317         case ASN_AFTER_DATE_E:
 318         case ASN_SIG_OID_E:
 319         case ASN_TIME_E:
 320         case ASN_INPUT_E:
 321         case ASN_SIG_CONFIRM_E:
 322         case ASN_SIG_HASH_E:
 323         case ASN_SIG_KEY_E:
 324         case ASN_DH_KEY_E:
 325 #if LIBWOLFSSL_VERSION_HEX < 0x05000000
 326         case ASN_NTRU_KEY_E:
 327 #endif
 328         case ASN_CRIT_EXT_E:
 329         case ASN_ALT_NAME_E:
 330         case ASN_NO_PEM_HEADER:
 331         case ASN_ECC_KEY_E:
 332         case ASN_NO_SIGNER_E:
 333         case ASN_CRL_CONFIRM_E:
 334         case ASN_CRL_NO_SIGNER_E:
 335         case ASN_OCSP_CONFIRM_E:
 336         case ASN_NAME_INVALID_E:
 337         case ASN_NO_SKID:
 338         case ASN_NO_AKID:
 339         case ASN_NO_KEYUSAGE:
 340         case ASN_COUNTRY_SIZE_E:
 341         case ASN_PATHLEN_SIZE_E:
 342         case ASN_PATHLEN_INV_E:
 343         case ASN_SELF_SIGNED_E:
 344                 if (us->notify_verify_error)
 345                         us->notify_verify_error(us, r, wc_GetErrorString(r));
 346                 return true;
 347         }
 348
 349         return false;
 350 }
 351 #endif
 352
 353 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 354 {
 355         void *ssl = us->ssl;
 356         int r;
 357
 358         ERR_clear_error();
 359
 360         if (us->server)
 361                 r = SSL_accept(ssl);
 362         else
 363                 r = SSL_connect(ssl);
 364
 365         if (r == 1) {
 366                 ustream_ssl_verify_cert(us);
 367                 return U_SSL_OK;
 368         }
 369
 370         r = SSL_get_error(ssl, r);
 371         if (r == SSL_ERROR_WANT_READ || r == SSL_ERROR_WANT_WRITE)
 372                 return U_SSL_PENDING;
 373
 374 #ifdef WOLFSSL_SSL_H
 375         if (handle_wolfssl_asn_error(us, r))
 376                 return U_SSL_OK;
 377 #endif
 378
 379         ustream_ssl_error(us, r);
 380         return U_SSL_ERROR;
 381 }
 382
 383 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 384 {
 385         void *ssl = us->ssl;
 386         int ret;
 387
 388         ERR_clear_error();
 389
 390         ret = SSL_write(ssl, buf, len);
 391
 392         if (ret < 0) {
 393                 int err = SSL_get_error(ssl, ret);
 394                 if (err == SSL_ERROR_WANT_WRITE)
 395                         return 0;
 396
 397                 ustream_ssl_error(us, err);
 398                 return -1;
 399         }
 400
 401         return ret;
 402 }
 403
 404 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 405 {
 406         int ret;
 407
 408         ERR_clear_error();
 409
 410         ret = SSL_read(us->ssl, buf, len);
 411
 412         if (ret < 0) {
 413                 ret = SSL_get_error(us->ssl, ret);
 414                 if (ret == SSL_ERROR_WANT_READ)
 415                         return U_SSL_PENDING;
 416
 417                 ustream_ssl_error(us, ret);
 418                 return U_SSL_ERROR;
 419         }
 420
 421         return ret;
 422 }