lib/libssl/ssl_asn1.c

   1 /* $OpenBSD: ssl_asn1.c,v 1.57 2018/08/27 16:42:48 jsing Exp $ */
   2 /*
   3  * Copyright (c) 2016 Joel Sing <jsing@openbsd.org>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #include <limits.h>
  19
  20 #include <openssl/ssl.h>
  21 #include <openssl/x509.h>
  22
  23 #include "ssl_locl.h"
  24
  25 #include "bytestring.h"
  26
  27 #define SSLASN1_TAG     (CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC)
  28 #define SSLASN1_TIME_TAG                (SSLASN1_TAG | 1)
  29 #define SSLASN1_TIMEOUT_TAG             (SSLASN1_TAG | 2)
  30 #define SSLASN1_PEER_CERT_TAG           (SSLASN1_TAG | 3)
  31 #define SSLASN1_SESSION_ID_CTX_TAG      (SSLASN1_TAG | 4)
  32 #define SSLASN1_VERIFY_RESULT_TAG       (SSLASN1_TAG | 5)
  33 #define SSLASN1_HOSTNAME_TAG            (SSLASN1_TAG | 6)
  34 #define SSLASN1_LIFETIME_TAG            (SSLASN1_TAG | 9)
  35 #define SSLASN1_TICKET_TAG              (SSLASN1_TAG | 10)
  36
  37 static uint64_t
  38 time_max(void)
  39 {
  40         if (sizeof(time_t) == sizeof(int32_t))
  41                 return INT32_MAX;
  42         if (sizeof(time_t) == sizeof(int64_t))
  43                 return INT64_MAX;
  44         return 0;
  45 }
  46
  47 static int
  48 SSL_SESSION_encode(SSL_SESSION *s, unsigned char **out, size_t *out_len,
  49     int ticket_encoding)
  50 {
  51         CBB cbb, session, cipher_suite, session_id, master_key, time, timeout;
  52         CBB peer_cert, sidctx, verify_result, hostname, lifetime, ticket, value;
  53         unsigned char *peer_cert_bytes = NULL;
  54         int len, rv = 0;
  55         uint16_t cid;
  56
  57         if (!CBB_init(&cbb, 0))
  58                 goto err;
  59
  60         if (!CBB_add_asn1(&cbb, &session, CBS_ASN1_SEQUENCE))
  61                 goto err;
  62
  63         /* Session ASN1 version. */
  64         if (!CBB_add_asn1_uint64(&session, SSL_SESSION_ASN1_VERSION))
  65                 goto err;
  66
  67         /* TLS/SSL protocol version. */
  68         if (s->ssl_version < 0)
  69                 goto err;
  70         if (!CBB_add_asn1_uint64(&session, s->ssl_version))
  71                 goto err;
  72
  73         /* Cipher suite ID. */
  74         /* XXX - require cipher to be non-NULL or always/only use cipher_id. */
  75         cid = (uint16_t)(s->cipher_id & 0xffff);
  76         if (s->cipher != NULL)
  77                 cid = ssl3_cipher_get_value(s->cipher);
  78         if (!CBB_add_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING))
  79                 goto err;
  80         if (!CBB_add_u16(&cipher_suite, cid))
  81                 goto err;
  82
  83         /* Session ID - zero length for a ticket. */
  84         if (!CBB_add_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING))
  85                 goto err;
  86         if (!CBB_add_bytes(&session_id, s->session_id,
  87             ticket_encoding ? 0 : s->session_id_length))
  88                 goto err;
  89
  90         /* Master key. */
  91         if (!CBB_add_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING))
  92                 goto err;
  93         if (!CBB_add_bytes(&master_key, s->master_key, s->master_key_length))
  94                 goto err;
  95
  96         /* Time [1]. */
  97         if (s->time != 0) {
  98                 if (s->time < 0)
  99                         goto err;
 100                 if (!CBB_add_asn1(&session, &time, SSLASN1_TIME_TAG))
 101                         goto err;
 102                 if (!CBB_add_asn1_uint64(&time, s->time))
 103                         goto err;
 104         }
 105
 106         /* Timeout [2]. */
 107         if (s->timeout != 0) {
 108                 if (s->timeout < 0)
 109                         goto err;
 110                 if (!CBB_add_asn1(&session, &timeout, SSLASN1_TIMEOUT_TAG))
 111                         goto err;
 112                 if (!CBB_add_asn1_uint64(&timeout, s->timeout))
 113                         goto err;
 114         }
 115
 116         /* Peer certificate [3]. */
 117         if (s->peer != NULL) {
 118                 if ((len = i2d_X509(s->peer, &peer_cert_bytes)) <= 0)
 119                         goto err;
 120                 if (!CBB_add_asn1(&session, &peer_cert, SSLASN1_PEER_CERT_TAG))
 121                         goto err;
 122                 if (!CBB_add_bytes(&peer_cert, peer_cert_bytes, len))
 123                         goto err;
 124         }
 125
 126         /* Session ID context [4]. */
 127         /* XXX - Actually handle this as optional? */
 128         if (!CBB_add_asn1(&session, &sidctx, SSLASN1_SESSION_ID_CTX_TAG))
 129                 goto err;
 130         if (!CBB_add_asn1(&sidctx, &value, CBS_ASN1_OCTETSTRING))
 131                 goto err;
 132         if (!CBB_add_bytes(&value, s->sid_ctx, s->sid_ctx_length))
 133                 goto err;
 134
 135         /* Verify result [5]. */
 136         if (s->verify_result != X509_V_OK) {
 137                 if (s->verify_result < 0)
 138                         goto err;
 139                 if (!CBB_add_asn1(&session, &verify_result,
 140                     SSLASN1_VERIFY_RESULT_TAG))
 141                         goto err;
 142                 if (!CBB_add_asn1_uint64(&verify_result, s->verify_result))
 143                         goto err;
 144         }
 145
 146         /* Hostname [6]. */
 147         if (s->tlsext_hostname != NULL) {
 148                 if (!CBB_add_asn1(&session, &hostname, SSLASN1_HOSTNAME_TAG))
 149                         goto err;
 150                 if (!CBB_add_asn1(&hostname, &value, CBS_ASN1_OCTETSTRING))
 151                         goto err;
 152                 if (!CBB_add_bytes(&value, (const uint8_t *)s->tlsext_hostname,
 153                     strlen(s->tlsext_hostname)))
 154                         goto err;
 155         }
 156
 157         /* PSK identity hint [7]. */
 158         /* PSK identity [8]. */
 159
 160         /* Ticket lifetime hint [9]. */
 161         if (s->tlsext_tick_lifetime_hint > 0) {
 162                 if (!CBB_add_asn1(&session, &lifetime, SSLASN1_LIFETIME_TAG))
 163                         goto err;
 164                 if (!CBB_add_asn1_uint64(&lifetime,
 165                     s->tlsext_tick_lifetime_hint))
 166                         goto err;
 167         }
 168
 169         /* Ticket [10]. */
 170         if (s->tlsext_tick != NULL) {
 171                 if (!CBB_add_asn1(&session, &ticket, SSLASN1_TICKET_TAG))
 172                         goto err;
 173                 if (!CBB_add_asn1(&ticket, &value, CBS_ASN1_OCTETSTRING))
 174                         goto err;
 175                 if (!CBB_add_bytes(&value, s->tlsext_tick, s->tlsext_ticklen))
 176                         goto err;
 177         }
 178
 179         /* Compression method [11]. */
 180         /* SRP username [12]. */
 181
 182         if (!CBB_finish(&cbb, out, out_len))
 183                 goto err;
 184
 185         rv = 1;
 186
 187  err:
 188         CBB_cleanup(&cbb);
 189         free(peer_cert_bytes);
 190
 191         return rv;
 192 }
 193
 194 int
 195 SSL_SESSION_ticket(SSL_SESSION *ss, unsigned char **out, size_t *out_len)
 196 {
 197         if (ss == NULL)
 198                 return 0;
 199
 200         if (ss->cipher == NULL && ss->cipher_id == 0)
 201                 return 0;
 202
 203         return SSL_SESSION_encode(ss, out, out_len, 1);
 204 }
 205
 206 int
 207 i2d_SSL_SESSION(SSL_SESSION *ss, unsigned char **pp)
 208 {
 209         unsigned char *data = NULL;
 210         size_t data_len = 0;
 211         int rv = -1;
 212
 213         if (ss == NULL)
 214                 return 0;
 215
 216         if (ss->cipher == NULL && ss->cipher_id == 0)
 217                 return 0;
 218
 219         if (!SSL_SESSION_encode(ss, &data, &data_len, 0))
 220                 goto err;
 221
 222         if (data_len > INT_MAX)
 223                 goto err;
 224
 225         if (pp != NULL) {
 226                 if (*pp == NULL) {
 227                         *pp = data;
 228                         data = NULL;
 229                 } else {
 230                         memcpy(*pp, data, data_len);
 231                         *pp += data_len;
 232                 }
 233         }
 234
 235         rv = (int)data_len;
 236
 237  err:
 238         freezero(data, data_len);
 239
 240         return rv;
 241 }
 242
 243 SSL_SESSION *
 244 d2i_SSL_SESSION(SSL_SESSION **a, const unsigned char **pp, long length)
 245 {
 246         CBS cbs, session, cipher_suite, session_id, master_key, peer_cert;
 247         CBS hostname, ticket;
 248         uint64_t version, tls_version, stime, timeout, verify_result, lifetime;
 249         const unsigned char *peer_cert_bytes;
 250         uint16_t cipher_value;
 251         SSL_SESSION *s = NULL;
 252         size_t data_len;
 253         int present;
 254
 255         if (a != NULL)
 256                 s = *a;
 257
 258         if (s == NULL) {
 259                 if ((s = SSL_SESSION_new()) == NULL) {
 260                         SSLerrorx(ERR_R_MALLOC_FAILURE);
 261                         return (NULL);
 262                 }
 263         }
 264
 265         CBS_init(&cbs, *pp, length);
 266
 267         if (!CBS_get_asn1(&cbs, &session, CBS_ASN1_SEQUENCE))
 268                 goto err;
 269
 270         /* Session ASN1 version. */
 271         if (!CBS_get_asn1_uint64(&session, &version))
 272                 goto err;
 273         if (version != SSL_SESSION_ASN1_VERSION)
 274                 goto err;
 275
 276         /* TLS/SSL Protocol Version. */
 277         if (!CBS_get_asn1_uint64(&session, &tls_version))
 278                 goto err;
 279         if (tls_version > INT_MAX)
 280                 goto err;
 281         s->ssl_version = (int)tls_version;
 282
 283         /* Cipher suite. */
 284         if (!CBS_get_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING))
 285                 goto err;
 286         if (!CBS_get_u16(&cipher_suite, &cipher_value))
 287                 goto err;
 288         if (CBS_len(&cipher_suite) != 0)
 289                 goto err;
 290
 291         /* XXX - populate cipher instead? */
 292         s->cipher = NULL;
 293         s->cipher_id = SSL3_CK_ID | cipher_value;
 294
 295         /* Session ID. */
 296         if (!CBS_get_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING))
 297                 goto err;
 298         if (!CBS_write_bytes(&session_id, s->session_id, sizeof(s->session_id),
 299             &data_len))
 300                 goto err;
 301         if (data_len > UINT_MAX)
 302                 goto err;
 303         s->session_id_length = (unsigned int)data_len;
 304
 305         /* Master key. */
 306         if (!CBS_get_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING))
 307                 goto err;
 308         if (!CBS_write_bytes(&master_key, s->master_key, sizeof(s->master_key),
 309             &data_len))
 310                 goto err;
 311         if (data_len > INT_MAX)
 312                 goto err;
 313         s->master_key_length = (int)data_len;
 314
 315         /* Time [1]. */
 316         s->time = time(NULL);
 317         if (!CBS_get_optional_asn1_uint64(&session, &stime, SSLASN1_TIME_TAG,
 318             0))
 319                 goto err;
 320         if (stime > time_max())
 321                 goto err;
 322         if (stime != 0)
 323                 s->time = (time_t)stime;
 324
 325         /* Timeout [2]. */
 326         s->timeout = 3;
 327         if (!CBS_get_optional_asn1_uint64(&session, &timeout,
 328             SSLASN1_TIMEOUT_TAG, 0))
 329                 goto err;
 330         if (timeout > LONG_MAX)
 331                 goto err;
 332         if (timeout != 0)
 333                 s->timeout = (long)timeout;
 334
 335         /* Peer certificate [3]. */
 336         X509_free(s->peer);
 337         s->peer = NULL;
 338         if (!CBS_get_optional_asn1(&session, &peer_cert, &present,
 339             SSLASN1_PEER_CERT_TAG))
 340                 goto err;
 341         if (present) {
 342                 data_len = CBS_len(&peer_cert);
 343                 if (data_len > LONG_MAX)
 344                         goto err;
 345                 peer_cert_bytes = CBS_data(&peer_cert);
 346                 if (d2i_X509(&s->peer, &peer_cert_bytes,
 347                     (long)data_len) == NULL)
 348                         goto err;
 349         }
 350
 351         /* Session ID context [4]. */
 352         s->sid_ctx_length = 0;
 353         if (!CBS_get_optional_asn1_octet_string(&session, &session_id, &present,
 354             SSLASN1_SESSION_ID_CTX_TAG))
 355                 goto err;
 356         if (present) {
 357                 if (!CBS_write_bytes(&session_id, (uint8_t *)&s->sid_ctx,
 358                     sizeof(s->sid_ctx), &data_len))
 359                         goto err;
 360                 if (data_len > UINT_MAX)
 361                         goto err;
 362                 s->sid_ctx_length = (unsigned int)data_len;
 363         }
 364
 365         /* Verify result [5]. */
 366         s->verify_result = X509_V_OK;
 367         if (!CBS_get_optional_asn1_uint64(&session, &verify_result,
 368             SSLASN1_VERIFY_RESULT_TAG, X509_V_OK))
 369                 goto err;
 370         if (verify_result > LONG_MAX)
 371                 goto err;
 372         s->verify_result = (long)verify_result;
 373
 374         /* Hostname [6]. */
 375         free(s->tlsext_hostname);
 376         s->tlsext_hostname = NULL;
 377         if (!CBS_get_optional_asn1_octet_string(&session, &hostname, &present,
 378             SSLASN1_HOSTNAME_TAG))
 379                 goto err;
 380         if (present) {
 381                 if (CBS_contains_zero_byte(&hostname))
 382                         goto err;
 383                 if (!CBS_strdup(&hostname, &s->tlsext_hostname))
 384                         goto err;
 385         }
 386
 387         /* PSK identity hint [7]. */
 388         /* PSK identity [8]. */
 389
 390         /* Ticket lifetime [9]. */
 391         s->tlsext_tick_lifetime_hint = 0;
 392         /* XXX - tlsext_ticklen is not yet set... */
 393         if (s->tlsext_ticklen > 0 && s->session_id_length > 0)
 394                 s->tlsext_tick_lifetime_hint = -1;
 395         if (!CBS_get_optional_asn1_uint64(&session, &lifetime,
 396             SSLASN1_LIFETIME_TAG, 0))
 397                 goto err;
 398         if (lifetime > LONG_MAX)
 399                 goto err;
 400         if (lifetime > 0)
 401                 s->tlsext_tick_lifetime_hint = (long)lifetime;
 402
 403         /* Ticket [10]. */
 404         free(s->tlsext_tick);
 405         s->tlsext_tick = NULL;
 406         if (!CBS_get_optional_asn1_octet_string(&session, &ticket, &present,
 407             SSLASN1_TICKET_TAG))
 408                 goto err;
 409         if (present) {
 410                 if (!CBS_stow(&ticket, &s->tlsext_tick, &s->tlsext_ticklen))
 411                         goto err;
 412         }
 413
 414         /* Compression method [11]. */
 415         /* SRP username [12]. */
 416
 417         *pp = CBS_data(&cbs);
 418
 419         if (a != NULL)
 420                 *a = s;
 421
 422         return (s);
 423
 424 err:
 425         ERR_asprintf_error_data("offset=%d", (int)(CBS_data(&cbs) - *pp));
 426
 427         if (s != NULL && (a == NULL || *a != s))
 428                 SSL_SESSION_free(s);
 429
 430         return (NULL);
 431 }