1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.]
56  */
57 /* ====================================================================
58  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
59  *
60  * Redistribution and use in source and binary forms, with or without
61  * modification, are permitted provided that the following conditions
62  * are met:
63  *
64  * 1. Redistributions of source code must retain the above copyright
65  *    notice, this list of conditions and the following disclaimer.
66  *
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in
69  *    the documentation and/or other materials provided with the
70  *    distribution.
71  *
72  * 3. All advertising materials mentioning features or use of this
73  *    software must display the following acknowledgment:
74  *    "This product includes software developed by the OpenSSL Project
75  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
76  *
77  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
78  *    endorse or promote products derived from this software without
79  *    prior written permission. For written permission, please contact
80  *    openssl-core@openssl.org.
81  *
82  * 5. Products derived from this software may not be called "OpenSSL"
83  *    nor may "OpenSSL" appear in their names without prior written
84  *    permission of the OpenSSL Project.
85  *
86  * 6. Redistributions of any form whatsoever must retain the following
87  *    acknowledgment:
88  *    "This product includes software developed by the OpenSSL Project
89  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
90  *
91  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
92  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
95  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
96  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
97  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
98  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
99  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
100  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
101  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
102  * OF THE POSSIBILITY OF SUCH DAMAGE.
103  * ====================================================================
104  *
105  * This product includes cryptographic software written by Eric Young
106  * (eay@cryptsoft.com).  This product includes software written by Tim
107  * Hudson (tjh@cryptsoft.com). */
108 
109 #include <openssl/ssl.h>
110 
111 #include <assert.h>
112 #include <string.h>
113 
114 #include <openssl/bytestring.h>
115 #include <openssl/err.h>
116 #include <openssl/mem.h>
117 
118 #include "internal.h"
119 #include "../crypto/internal.h"
120 
121 
122 /* kMaxEmptyRecords is the number of consecutive, empty records that will be
123  * processed. Without this limit an attacker could send empty records at a
124  * faster rate than we can process and cause record processing to loop
125  * forever. */
126 static const uint8_t kMaxEmptyRecords = 32;
127 
128 /* kMaxEarlyDataSkipped is the maximum number of rejected early data bytes that
129  * will be skipped. Without this limit an attacker could send records at a
130  * faster rate than we can process and cause trial decryption to loop forever.
131  * This value should be slightly above kMaxEarlyDataAccepted in tls13_server.c,
132  * which is measured in plaintext. */
133 static const size_t kMaxEarlyDataSkipped = 16384;
134 
135 /* kMaxWarningAlerts is the number of consecutive warning alerts that will be
136  * processed. */
137 static const uint8_t kMaxWarningAlerts = 4;
138 
139 /* ssl_needs_record_splitting returns one if |ssl|'s current outgoing cipher
140  * state needs record-splitting and zero otherwise. */
ssl_needs_record_splitting(const SSL * ssl)141 static int ssl_needs_record_splitting(const SSL *ssl) {
142   return ssl->s3->aead_write_ctx != NULL &&
143          ssl->s3->aead_write_ctx->version < TLS1_1_VERSION &&
144          (ssl->mode & SSL_MODE_CBC_RECORD_SPLITTING) != 0 &&
145          SSL_CIPHER_is_block_cipher(ssl->s3->aead_write_ctx->cipher);
146 }
147 
ssl_record_sequence_update(uint8_t * seq,size_t seq_len)148 int ssl_record_sequence_update(uint8_t *seq, size_t seq_len) {
149   for (size_t i = seq_len - 1; i < seq_len; i--) {
150     ++seq[i];
151     if (seq[i] != 0) {
152       return 1;
153     }
154   }
155   OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
156   return 0;
157 }
158 
ssl_record_prefix_len(const SSL * ssl)159 size_t ssl_record_prefix_len(const SSL *ssl) {
160   size_t header_len;
161   if (SSL_is_dtls(ssl)) {
162     header_len = DTLS1_RT_HEADER_LENGTH;
163   } else {
164     header_len = SSL3_RT_HEADER_LENGTH;
165   }
166 
167   return header_len + SSL_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_read_ctx);
168 }
169 
ssl_seal_align_prefix_len(const SSL * ssl)170 size_t ssl_seal_align_prefix_len(const SSL *ssl) {
171   if (SSL_is_dtls(ssl)) {
172     return DTLS1_RT_HEADER_LENGTH +
173            SSL_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_write_ctx);
174   }
175 
176   size_t ret = SSL3_RT_HEADER_LENGTH +
177                SSL_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_write_ctx);
178   if (ssl_needs_record_splitting(ssl)) {
179     ret += SSL3_RT_HEADER_LENGTH;
180     ret += ssl_cipher_get_record_split_len(ssl->s3->aead_write_ctx->cipher);
181   }
182   return ret;
183 }
184 
SSL_max_seal_overhead(const SSL * ssl)185 size_t SSL_max_seal_overhead(const SSL *ssl) {
186   if (SSL_is_dtls(ssl)) {
187     return dtls_max_seal_overhead(ssl, dtls1_use_current_epoch);
188   }
189 
190   size_t ret = SSL3_RT_HEADER_LENGTH;
191   ret += SSL_AEAD_CTX_max_overhead(ssl->s3->aead_write_ctx);
192   /* TLS 1.3 needs an extra byte for the encrypted record type. */
193   if (ssl->s3->aead_write_ctx != NULL &&
194       ssl->s3->aead_write_ctx->version >= TLS1_3_VERSION) {
195     ret += 1;
196   }
197   if (ssl_needs_record_splitting(ssl)) {
198     ret *= 2;
199   }
200   return ret;
201 }
202 
tls_open_record(SSL * ssl,uint8_t * out_type,CBS * out,size_t * out_consumed,uint8_t * out_alert,uint8_t * in,size_t in_len)203 enum ssl_open_record_t tls_open_record(SSL *ssl, uint8_t *out_type, CBS *out,
204                                        size_t *out_consumed, uint8_t *out_alert,
205                                        uint8_t *in, size_t in_len) {
206   *out_consumed = 0;
207 
208   CBS cbs;
209   CBS_init(&cbs, in, in_len);
210 
211   /* Decode the record header. */
212   uint8_t type;
213   uint16_t version, ciphertext_len;
214   if (!CBS_get_u8(&cbs, &type) ||
215       !CBS_get_u16(&cbs, &version) ||
216       !CBS_get_u16(&cbs, &ciphertext_len)) {
217     *out_consumed = SSL3_RT_HEADER_LENGTH;
218     return ssl_open_record_partial;
219   }
220 
221   int version_ok;
222   if (ssl->s3->aead_read_ctx == NULL) {
223     /* Only check the first byte. Enforcing beyond that can prevent decoding
224      * version negotiation failure alerts. */
225     version_ok = (version >> 8) == SSL3_VERSION_MAJOR;
226   } else if (ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
227     /* Earlier versions of TLS switch the record version. */
228     version_ok = version == ssl->version;
229   } else {
230     /* Starting TLS 1.3, the version field is frozen at {3, 1}. */
231     version_ok = version == TLS1_VERSION;
232   }
233 
234   if (!version_ok) {
235     OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_NUMBER);
236     *out_alert = SSL_AD_PROTOCOL_VERSION;
237     return ssl_open_record_error;
238   }
239 
240   /* Check the ciphertext length. */
241   if (ciphertext_len > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
242     OPENSSL_PUT_ERROR(SSL, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
243     *out_alert = SSL_AD_RECORD_OVERFLOW;
244     return ssl_open_record_error;
245   }
246 
247   /* Extract the body. */
248   CBS body;
249   if (!CBS_get_bytes(&cbs, &body, ciphertext_len)) {
250     *out_consumed = SSL3_RT_HEADER_LENGTH + (size_t)ciphertext_len;
251     return ssl_open_record_partial;
252   }
253 
254   ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_HEADER, in,
255                       SSL3_RT_HEADER_LENGTH);
256 
257   *out_consumed = in_len - CBS_len(&cbs);
258 
259   /* Skip early data received when expecting a second ClientHello if we rejected
260    * 0RTT. */
261   if (ssl->s3->skip_early_data &&
262       ssl->s3->aead_read_ctx == NULL &&
263       type == SSL3_RT_APPLICATION_DATA) {
264     goto skipped_data;
265   }
266 
267   /* Decrypt the body in-place. */
268   if (!SSL_AEAD_CTX_open(ssl->s3->aead_read_ctx, out, type, version,
269                          ssl->s3->read_sequence, (uint8_t *)CBS_data(&body),
270                          CBS_len(&body))) {
271     if (ssl->s3->skip_early_data &&
272         ssl->s3->aead_read_ctx != NULL) {
273       ERR_clear_error();
274       goto skipped_data;
275     }
276 
277     OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
278     *out_alert = SSL_AD_BAD_RECORD_MAC;
279     return ssl_open_record_error;
280   }
281 
282   ssl->s3->skip_early_data = 0;
283 
284   if (!ssl_record_sequence_update(ssl->s3->read_sequence, 8)) {
285     *out_alert = SSL_AD_INTERNAL_ERROR;
286     return ssl_open_record_error;
287   }
288 
289   /* TLS 1.3 hides the record type inside the encrypted data. */
290   if (ssl->s3->aead_read_ctx != NULL &&
291       ssl->s3->aead_read_ctx->version >= TLS1_3_VERSION) {
292     /* The outer record type is always application_data. */
293     if (type != SSL3_RT_APPLICATION_DATA) {
294       OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_OUTER_RECORD_TYPE);
295       *out_alert = SSL_AD_DECODE_ERROR;
296       return ssl_open_record_error;
297     }
298 
299     do {
300       if (!CBS_get_last_u8(out, &type)) {
301         OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
302         *out_alert = SSL_AD_DECRYPT_ERROR;
303         return ssl_open_record_error;
304       }
305     } while (type == 0);
306   }
307 
308   /* Check the plaintext length. */
309   if (CBS_len(out) > SSL3_RT_MAX_PLAIN_LENGTH) {
310     OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG);
311     *out_alert = SSL_AD_RECORD_OVERFLOW;
312     return ssl_open_record_error;
313   }
314 
315   /* Limit the number of consecutive empty records. */
316   if (CBS_len(out) == 0) {
317     ssl->s3->empty_record_count++;
318     if (ssl->s3->empty_record_count > kMaxEmptyRecords) {
319       OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_EMPTY_FRAGMENTS);
320       *out_alert = SSL_AD_UNEXPECTED_MESSAGE;
321       return ssl_open_record_error;
322     }
323     /* Apart from the limit, empty records are returned up to the caller. This
324      * allows the caller to reject records of the wrong type. */
325   } else {
326     ssl->s3->empty_record_count = 0;
327   }
328 
329   if (type == SSL3_RT_ALERT) {
330     /* Return end_of_early_data alerts as-is for the caller to process. */
331     if (CBS_len(out) == 2 &&
332         CBS_data(out)[0] == SSL3_AL_WARNING &&
333         CBS_data(out)[1] == TLS1_AD_END_OF_EARLY_DATA) {
334       *out_type = type;
335       return ssl_open_record_success;
336     }
337 
338     return ssl_process_alert(ssl, out_alert, CBS_data(out), CBS_len(out));
339   }
340 
341   ssl->s3->warning_alert_count = 0;
342 
343   *out_type = type;
344   return ssl_open_record_success;
345 
346 skipped_data:
347   ssl->s3->early_data_skipped += *out_consumed;
348   if (ssl->s3->early_data_skipped < *out_consumed) {
349     ssl->s3->early_data_skipped = kMaxEarlyDataSkipped + 1;
350   }
351 
352   if (ssl->s3->early_data_skipped > kMaxEarlyDataSkipped) {
353     OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MUCH_SKIPPED_EARLY_DATA);
354     *out_alert = SSL_AD_UNEXPECTED_MESSAGE;
355     return ssl_open_record_error;
356   }
357 
358   return ssl_open_record_discard;
359 }
360 
do_seal_record(SSL * ssl,uint8_t * out,size_t * out_len,size_t max_out,uint8_t type,const uint8_t * in,size_t in_len)361 static int do_seal_record(SSL *ssl, uint8_t *out, size_t *out_len,
362                           size_t max_out, uint8_t type, const uint8_t *in,
363                           size_t in_len) {
364   assert(!buffers_alias(in, in_len, out, max_out));
365 
366   /* TLS 1.3 hides the actual record type inside the encrypted data. */
367   if (ssl->s3->aead_write_ctx != NULL &&
368       ssl->s3->aead_write_ctx->version >= TLS1_3_VERSION) {
369     if (in_len > in_len + SSL3_RT_HEADER_LENGTH + 1 ||
370         max_out < in_len + SSL3_RT_HEADER_LENGTH + 1) {
371       OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
372       return 0;
373     }
374 
375     OPENSSL_memcpy(out + SSL3_RT_HEADER_LENGTH, in, in_len);
376     out[SSL3_RT_HEADER_LENGTH + in_len] = type;
377     in = out + SSL3_RT_HEADER_LENGTH;
378     type = SSL3_RT_APPLICATION_DATA;
379     in_len++;
380   }
381 
382   if (max_out < SSL3_RT_HEADER_LENGTH) {
383     OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
384     return 0;
385   }
386 
387   /* The TLS record-layer version number is meaningless and, starting in
388    * TLS 1.3, is frozen at TLS 1.0. But for historical reasons, SSL 3.0
389    * ClientHellos should use SSL 3.0 and pre-TLS-1.3 expects the version
390    * to change after version negotiation. */
391   uint16_t wire_version = TLS1_VERSION;
392   if (ssl->version == SSL3_VERSION ||
393       (ssl->s3->have_version && ssl3_protocol_version(ssl) < TLS1_3_VERSION)) {
394     wire_version = ssl->version;
395   }
396 
397   /* Write the non-length portions of the header. */
398   out[0] = type;
399   out[1] = wire_version >> 8;
400   out[2] = wire_version & 0xff;
401   out += 3;
402   max_out -= 3;
403 
404   /* Write the ciphertext, leaving two bytes for the length. */
405   size_t ciphertext_len;
406   if (!SSL_AEAD_CTX_seal(ssl->s3->aead_write_ctx, out + 2, &ciphertext_len,
407                          max_out - 2, type, wire_version,
408                          ssl->s3->write_sequence, in, in_len) ||
409       !ssl_record_sequence_update(ssl->s3->write_sequence, 8)) {
410     return 0;
411   }
412 
413   /* Fill in the length. */
414   if (ciphertext_len >= 1 << 15) {
415     OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
416     return 0;
417   }
418   out[0] = ciphertext_len >> 8;
419   out[1] = ciphertext_len & 0xff;
420 
421   *out_len = SSL3_RT_HEADER_LENGTH + ciphertext_len;
422 
423   ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_HEADER, out,
424                       SSL3_RT_HEADER_LENGTH);
425   return 1;
426 }
427 
tls_seal_record(SSL * ssl,uint8_t * out,size_t * out_len,size_t max_out,uint8_t type,const uint8_t * in,size_t in_len)428 int tls_seal_record(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out,
429                     uint8_t type, const uint8_t *in, size_t in_len) {
430   if (buffers_alias(in, in_len, out, max_out)) {
431     OPENSSL_PUT_ERROR(SSL, SSL_R_OUTPUT_ALIASES_INPUT);
432     return 0;
433   }
434 
435   size_t frag_len = 0;
436   if (type == SSL3_RT_APPLICATION_DATA && in_len > 1 &&
437       ssl_needs_record_splitting(ssl)) {
438     if (!do_seal_record(ssl, out, &frag_len, max_out, type, in, 1)) {
439       return 0;
440     }
441     in++;
442     in_len--;
443     out += frag_len;
444     max_out -= frag_len;
445 
446 #if !defined(BORINGSSL_UNSAFE_FUZZER_MODE)
447     assert(SSL3_RT_HEADER_LENGTH + ssl_cipher_get_record_split_len(
448                                        ssl->s3->aead_write_ctx->cipher) ==
449            frag_len);
450 #endif
451   }
452 
453   if (!do_seal_record(ssl, out, out_len, max_out, type, in, in_len)) {
454     return 0;
455   }
456   *out_len += frag_len;
457   return 1;
458 }
459 
ssl_process_alert(SSL * ssl,uint8_t * out_alert,const uint8_t * in,size_t in_len)460 enum ssl_open_record_t ssl_process_alert(SSL *ssl, uint8_t *out_alert,
461                                          const uint8_t *in, size_t in_len) {
462   /* Alerts records may not contain fragmented or multiple alerts. */
463   if (in_len != 2) {
464     *out_alert = SSL_AD_DECODE_ERROR;
465     OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
466     return ssl_open_record_error;
467   }
468 
469   ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_ALERT, in, in_len);
470 
471   const uint8_t alert_level = in[0];
472   const uint8_t alert_descr = in[1];
473 
474   uint16_t alert = (alert_level << 8) | alert_descr;
475   ssl_do_info_callback(ssl, SSL_CB_READ_ALERT, alert);
476 
477   if (alert_level == SSL3_AL_WARNING) {
478     if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
479       ssl->s3->recv_shutdown = ssl_shutdown_close_notify;
480       return ssl_open_record_close_notify;
481     }
482 
483     /* Warning alerts do not exist in TLS 1.3. */
484     if (ssl->s3->have_version &&
485         ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
486       *out_alert = SSL_AD_DECODE_ERROR;
487       OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
488       return ssl_open_record_error;
489     }
490 
491     ssl->s3->warning_alert_count++;
492     if (ssl->s3->warning_alert_count > kMaxWarningAlerts) {
493       *out_alert = SSL_AD_UNEXPECTED_MESSAGE;
494       OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_WARNING_ALERTS);
495       return ssl_open_record_error;
496     }
497     return ssl_open_record_discard;
498   }
499 
500   if (alert_level == SSL3_AL_FATAL) {
501     ssl->s3->recv_shutdown = ssl_shutdown_fatal_alert;
502 
503     char tmp[16];
504     OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr);
505     BIO_snprintf(tmp, sizeof(tmp), "%d", alert_descr);
506     ERR_add_error_data(2, "SSL alert number ", tmp);
507     return ssl_open_record_fatal_alert;
508   }
509 
510   *out_alert = SSL_AD_ILLEGAL_PARAMETER;
511   OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
512   return ssl_open_record_error;
513 }
514