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