ustream-polarssl.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 <sys/types.h>
  20 #include <fcntl.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23
  24 #include "ustream-ssl.h"
  25 #include "ustream-internal.h"
  26
  27 static int urandom_fd = -1;
  28
  29 static int s_ustream_read(void *ctx, unsigned char *buf, size_t len)
  30 {
  31         struct ustream *s = ctx;
  32         char *sbuf;
  33         int slen;
  34
  35         if (s->eof)
  36                 return 0;
  37
  38         sbuf = ustream_get_read_buf(s, &slen);
  39         if (slen > len)
  40                 slen = len;
  41
  42         if (!slen)
  43                 return POLARSSL_ERR_NET_WANT_READ;
  44
  45         memcpy(buf, sbuf, slen);
  46         ustream_consume(s, slen);
  47
  48         return slen;
  49 }
  50
  51 static int s_ustream_write(void *ctx, const unsigned char *buf, size_t len)
  52 {
  53         struct ustream *s = ctx;
  54         int ret;
  55
  56         ret = ustream_write(s, (const char *) buf, len, false);
  57         if (ret < 0 || s->write_error)
  58                 return POLARSSL_ERR_NET_SEND_FAILED;
  59
  60         return ret;
  61 }
  62
  63 __hidden void ustream_set_io(struct ustream_ssl_ctx *ctx, void *ssl, struct ustream *conn)
  64 {
  65         ssl_set_bio(ssl, s_ustream_read, conn, s_ustream_write, conn);
  66 }
  67
  68 static bool urandom_init(void)
  69 {
  70         if (urandom_fd > -1)
  71                 return true;
  72
  73         urandom_fd = open("/dev/urandom", O_RDONLY);
  74         if (urandom_fd < 0)
  75                 return false;
  76
  77         return true;
  78 }
  79
  80 static int _urandom(void *ctx, unsigned char *out, size_t len)
  81 {
  82         read(urandom_fd, out, len);
  83         return 0;
  84 }
  85
  86 __hidden struct ustream_ssl_ctx *
  87 __ustream_ssl_context_new(bool server)
  88 {
  89         struct ustream_ssl_ctx *ctx;
  90
  91         if (!urandom_init())
  92                 return NULL;
  93
  94         ctx = calloc(1, sizeof(*ctx));
  95         if (!ctx)
  96                 return NULL;
  97
  98         ctx->server = server;
  99 #ifdef USE_VERSION_1_3
 100         pk_init(&ctx->key);
 101 #else
 102         rsa_init(&ctx->key, RSA_PKCS_V15, 0);
 103 #endif
 104
 105         return ctx;
 106 }
 107
 108 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 109 {
 110         int ret;
 111
 112 #ifdef USE_VERSION_1_3
 113         ret = x509_crt_parse_file(&ctx->ca_cert, file);
 114 #else
 115         ret = x509parse_crtfile(&ctx->ca_cert, file);
 116 #endif
 117         if (ret)
 118                 return -1;
 119
 120         return 0;
 121 }
 122
 123 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 124 {
 125         int ret;
 126
 127 #ifdef USE_VERSION_1_3
 128         ret = x509_crt_parse_file(&ctx->cert, file);
 129 #else
 130         ret = x509parse_crtfile(&ctx->cert, file);
 131 #endif
 132         if (ret)
 133                 return -1;
 134
 135         return 0;
 136 }
 137
 138 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
 139 {
 140         int ret;
 141
 142 #ifdef USE_VERSION_1_3
 143         ret = pk_parse_keyfile(&ctx->key, file, NULL);
 144 #else
 145         ret = x509parse_keyfile(&ctx->key, file, NULL);
 146 #endif
 147         if (ret)
 148                 return -1;
 149
 150         return 0;
 151 }
 152
 153 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 154 {
 155 #ifdef USE_VERSION_1_3
 156         pk_free(&ctx->key);
 157         x509_crt_free(&ctx->cert);
 158 #else
 159         rsa_free(&ctx->key);
 160         x509_free(&ctx->cert);
 161 #endif
 162         free(ctx);
 163 }
 164
 165 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 166 {
 167         us->error = ret;
 168         uloop_timeout_set(&us->error_timer, 0);
 169 }
 170
 171 static bool ssl_do_wait(int ret)
 172 {
 173         switch(ret) {
 174         case POLARSSL_ERR_NET_WANT_READ:
 175         case POLARSSL_ERR_NET_WANT_WRITE:
 176                 return true;
 177         default:
 178                 return false;
 179         }
 180 }
 181
 182 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 183 {
 184         void *ssl = us->ssl;
 185         const char *msg = NULL;
 186         bool cn_mismatch;
 187         int r;
 188
 189         r = ssl_get_verify_result(ssl);
 190         cn_mismatch = r & BADCERT_CN_MISMATCH;
 191         r &= ~BADCERT_CN_MISMATCH;
 192
 193         if (r & BADCERT_EXPIRED)
 194                 msg = "certificate has expired";
 195         else if (r & BADCERT_REVOKED)
 196                 msg = "certificate has been revoked";
 197         else if (r & BADCERT_NOT_TRUSTED)
 198                 msg = "certificate is self-signed or not signed by a trusted CA";
 199         else
 200                 msg = "unknown error";
 201
 202         if (r) {
 203                 us->notify_verify_error(us, r, msg);
 204                 return;
 205         }
 206
 207         if (!cn_mismatch)
 208                 us->valid_cn = true;
 209 }
 210
 211 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 212 {
 213         void *ssl = us->ssl;
 214         int r;
 215
 216         r = ssl_handshake(ssl);
 217         if (r == 0) {
 218                 ustream_ssl_verify_cert(us);
 219                 return U_SSL_OK;
 220         }
 221
 222         if (ssl_do_wait(r))
 223                 return U_SSL_PENDING;
 224
 225         ustream_ssl_error(us, r);
 226         return U_SSL_ERROR;
 227 }
 228
 229 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 230 {
 231         void *ssl = us->ssl;
 232         int ret = ssl_write(ssl, (const unsigned char *) buf, len);
 233
 234         if (ret < 0) {
 235                 if (ssl_do_wait(ret))
 236                         return 0;
 237
 238                 ustream_ssl_error(us, ret);
 239                 return -1;
 240         }
 241
 242         return ret;
 243 }
 244
 245 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 246 {
 247         int ret = ssl_read(us->ssl, (unsigned char *) buf, len);
 248
 249         if (ret < 0) {
 250                 if (ssl_do_wait(ret))
 251                         return U_SSL_PENDING;
 252
 253                 ustream_ssl_error(us, ret);
 254                 return U_SSL_ERROR;
 255         }
 256
 257         return ret;
 258 }
 259
 260 static const int default_ciphersuites[] =
 261 {
 262 #if defined(POLARSSL_AES_C)
 263 #if defined(POLARSSL_SHA2_C)
 264     TLS_RSA_WITH_AES_256_CBC_SHA256,
 265 #endif /* POLARSSL_SHA2_C */
 266 #if defined(POLARSSL_GCM_C) && defined(POLARSSL_SHA4_C)
 267     TLS_RSA_WITH_AES_256_GCM_SHA384,
 268 #endif /* POLARSSL_SHA2_C */
 269     TLS_RSA_WITH_AES_256_CBC_SHA,
 270 #endif
 271 #if defined(POLARSSL_CAMELLIA_C)
 272 #if defined(POLARSSL_SHA2_C)
 273     TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256,
 274 #endif /* POLARSSL_SHA2_C */
 275     TLS_RSA_WITH_CAMELLIA_256_CBC_SHA,
 276 #endif
 277 #if defined(POLARSSL_AES_C)
 278 #if defined(POLARSSL_SHA2_C)
 279     TLS_RSA_WITH_AES_128_CBC_SHA256,
 280 #endif /* POLARSSL_SHA2_C */
 281 #if defined(POLARSSL_GCM_C) && defined(POLARSSL_SHA2_C)
 282     TLS_RSA_WITH_AES_128_GCM_SHA256,
 283 #endif /* POLARSSL_SHA2_C */
 284     TLS_RSA_WITH_AES_128_CBC_SHA,
 285 #endif
 286 #if defined(POLARSSL_CAMELLIA_C)
 287 #if defined(POLARSSL_SHA2_C)
 288     TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256,
 289 #endif /* POLARSSL_SHA2_C */
 290     TLS_RSA_WITH_CAMELLIA_128_CBC_SHA,
 291 #endif
 292 #if defined(POLARSSL_DES_C)
 293     TLS_RSA_WITH_3DES_EDE_CBC_SHA,
 294 #endif
 295 #if defined(POLARSSL_ARC4_C)
 296     TLS_RSA_WITH_RC4_128_SHA,
 297     TLS_RSA_WITH_RC4_128_MD5,
 298 #endif
 299     0
 300 };
 301
 302 __hidden void *__ustream_ssl_session_new(struct ustream_ssl_ctx *ctx)
 303 {
 304         ssl_context *ssl;
 305         int auth;
 306         int ep;
 307
 308         ssl = calloc(1, sizeof(ssl_context));
 309         if (!ssl)
 310                 return NULL;
 311
 312         if (ssl_init(ssl)) {
 313                 free(ssl);
 314                 return NULL;
 315         }
 316
 317         if (ctx->server) {
 318                 ep = SSL_IS_SERVER;
 319                 auth = SSL_VERIFY_NONE;
 320         } else {
 321                 ep = SSL_IS_CLIENT;
 322                 auth = SSL_VERIFY_OPTIONAL;
 323         }
 324
 325         ssl_set_ciphersuites(ssl, default_ciphersuites);
 326         ssl_set_endpoint(ssl, ep);
 327         ssl_set_authmode(ssl, auth);
 328         ssl_set_rng(ssl, _urandom, NULL);
 329
 330         if (ctx->server) {
 331                 if (ctx->cert.next)
 332                         ssl_set_ca_chain(ssl, ctx->cert.next, NULL, NULL);
 333                 ssl_set_own_cert(ssl, &ctx->cert, &ctx->key);
 334         } else {
 335                 ssl_set_ca_chain(ssl, &ctx->cert, NULL, NULL);
 336         }
 337
 338         ssl_session_reset(ssl);
 339
 340         return ssl;
 341 }
 342
 343 __hidden void __ustream_ssl_session_free(void *ssl)
 344 {
 345         ssl_free(ssl);
 346         free(ssl);
 347 }
 348
 349 __hidden void __ustream_ssl_update_peer_cn(struct ustream_ssl *us)
 350 {
 351         struct ustream_ssl_ctx *ctx = us->ctx;
 352
 353         ssl_set_ca_chain(us->ssl, &ctx->ca_cert, NULL, us->peer_cn);
 354 }