1 /* $OpenBSD: s3_pkt.c,v 1.57 2015/09/12 16:10:07 doug Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
58 /* ====================================================================
59 * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
68 * 2. Redistributions in binary form must reproduce the above copyright
69 * notice, this list of conditions and the following disclaimer in
70 * the documentation and/or other materials provided with the
73 * 3. All advertising materials mentioning features or use of this
74 * software must display the following acknowledgment:
75 * "This product includes software developed by the OpenSSL Project
76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79 * endorse or promote products derived from this software without
80 * prior written permission. For written permission, please contact
81 * openssl-core@openssl.org.
83 * 5. Products derived from this software may not be called "OpenSSL"
84 * nor may "OpenSSL" appear in their names without prior written
85 * permission of the OpenSSL Project.
87 * 6. Redistributions of any form whatsoever must retain the following
89 * "This product includes software developed by the OpenSSL Project
90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103 * OF THE POSSIBILITY OF SUCH DAMAGE.
104 * ====================================================================
106 * This product includes cryptographic software written by Eric Young
107 * (eay@cryptsoft.com). This product includes software written by Tim
108 * Hudson (tjh@cryptsoft.com).
115 #include "ssl_locl.h"
117 #include <openssl/buffer.h>
118 #include <openssl/evp.h>
120 #include "bytestring.h"
122 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
123 unsigned int len, int create_empty_fragment);
124 static int ssl3_get_record(SSL *s);
126 /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
127 * packet by another n bytes.
128 * The packet will be in the sub-array of s->s3->rbuf.buf specified
129 * by s->packet and s->packet_length.
130 * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
131 * [plus s->packet_length bytes if extend == 1].)
134 ssl3_read_n(SSL *s, int n, int max, int extend)
146 if (!ssl3_setup_read_buffer(s))
150 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH;
151 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
154 /* start with empty packet ... */
157 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) {
158 /* check if next packet length is large
159 * enough to justify payload alignment... */
160 pkt = rb->buf + rb->offset;
161 if (pkt[0] == SSL3_RT_APPLICATION_DATA &&
162 (pkt[3]<<8|pkt[4]) >= 128) {
163 /* Note that even if packet is corrupted
164 * and its length field is insane, we can
165 * only be led to wrong decision about
166 * whether memmove will occur or not.
167 * Header values has no effect on memmove
168 * arguments and therefore no buffer
169 * overrun can be triggered. */
170 memmove(rb->buf + align, pkt, left);
174 s->packet = rb->buf + rb->offset;
175 s->packet_length = 0;
176 /* ... now we can act as if 'extend' was set */
179 /* For DTLS/UDP reads should not span multiple packets
180 * because the read operation returns the whole packet
181 * at once (as long as it fits into the buffer). */
182 if (SSL_IS_DTLS(s)) {
183 if (left > 0 && n > left)
187 /* if there is enough in the buffer from a previous read, take some */
189 s->packet_length += n;
195 /* else we need to read more data */
197 len = s->packet_length;
198 pkt = rb->buf + align;
199 /* Move any available bytes to front of buffer:
200 * 'len' bytes already pointed to by 'packet',
201 * 'left' extra ones at the end */
202 if (s->packet != pkt) {
204 memmove(pkt, s->packet, len + left);
206 rb->offset = len + align;
209 if (n > (int)(rb->len - rb->offset)) {
210 /* does not happen */
211 SSLerr(SSL_F_SSL3_READ_N, ERR_R_INTERNAL_ERROR);
215 if (!s->read_ahead) {
216 /* ignore max parameter */
221 if (max > (int)(rb->len - rb->offset))
222 max = rb->len - rb->offset;
226 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
227 * and need to read in more until we have len+n (up to
228 * len+max if possible) */
231 if (s->rbio != NULL) {
232 s->rwstate = SSL_READING;
233 i = BIO_read(s->rbio, pkt + len + left, max - left);
235 SSLerr(SSL_F_SSL3_READ_N, SSL_R_READ_BIO_NOT_SET);
241 if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
244 ssl3_release_read_buffer(s);
251 * reads should *never* span multiple packets for DTLS because
252 * the underlying transport protocol is message oriented as
253 * opposed to byte oriented as in the TLS case.
255 if (SSL_IS_DTLS(s)) {
257 n = left; /* makes the while condition false */
261 /* done reading, now the book-keeping */
264 s->packet_length += n;
265 s->rwstate = SSL_NOTHING;
269 /* Call this to get a new input record.
270 * It will return <= 0 if more data is needed, normally due to an error
271 * or non-blocking IO.
272 * When it finishes, one packet has been decoded and can be found in
273 * ssl->s3->rrec.type - is the type of record
274 * ssl->s3->rrec.data, - data
275 * ssl->s3->rrec.length, - number of bytes
277 /* used only by ssl3_read_bytes */
279 ssl3_get_record(SSL *s)
282 int enc_err, n, i, ret = -1;
285 unsigned char md[EVP_MAX_MD_SIZE];
286 unsigned mac_size, orig_len;
292 /* check if we have the header */
293 if ((s->rstate != SSL_ST_READ_BODY) ||
294 (s->packet_length < SSL3_RT_HEADER_LENGTH)) {
296 uint16_t len, ssl_version;
299 n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
301 return(n); /* error or non-blocking */
302 s->rstate = SSL_ST_READ_BODY;
304 CBS_init(&header, s->packet, n);
306 /* Pull apart the header into the SSL3_RECORD */
307 if (!CBS_get_u8(&header, &type) ||
308 !CBS_get_u16(&header, &ssl_version) ||
309 !CBS_get_u16(&header, &len)) {
310 SSLerr(SSL_F_SSL3_GET_RECORD,
311 SSL_R_BAD_PACKET_LENGTH);
318 /* Lets check version */
319 if (!s->first_packet && ssl_version != s->version) {
320 SSLerr(SSL_F_SSL3_GET_RECORD,
321 SSL_R_WRONG_VERSION_NUMBER);
322 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) &&
323 !s->enc_write_ctx && !s->write_hash)
324 /* Send back error using their minor version number :-) */
325 s->version = ssl_version;
326 al = SSL_AD_PROTOCOL_VERSION;
330 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) {
331 SSLerr(SSL_F_SSL3_GET_RECORD,
332 SSL_R_WRONG_VERSION_NUMBER);
336 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH) {
337 al = SSL_AD_RECORD_OVERFLOW;
338 SSLerr(SSL_F_SSL3_GET_RECORD,
339 SSL_R_PACKET_LENGTH_TOO_LONG);
343 /* now s->rstate == SSL_ST_READ_BODY */
346 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
348 if (rr->length > s->packet_length - SSL3_RT_HEADER_LENGTH) {
349 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
351 n = ssl3_read_n(s, i, i, 1);
353 return(n); /* error or non-blocking io */
354 /* now n == rr->length,
355 * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
358 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
360 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
361 * and we have that many bytes in s->packet
363 rr->input = &(s->packet[SSL3_RT_HEADER_LENGTH]);
365 /* ok, we can now read from 's->packet' data into 'rr'
366 * rr->input points at rr->length bytes, which
367 * need to be copied into rr->data by either
368 * the decryption or by the decompression
369 * When the data is 'copied' into the rr->data buffer,
370 * rr->input will be pointed at the new buffer */
372 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
373 * rr->length bytes of encrypted compressed stuff. */
375 /* check is not needed I believe */
376 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
377 al = SSL_AD_RECORD_OVERFLOW;
378 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
382 /* decrypt in place in 'rr->input' */
383 rr->data = rr->input;
385 enc_err = s->method->ssl3_enc->enc(s, 0);
387 * 0: (in non-constant time) if the record is publically invalid.
388 * 1: if the padding is valid
389 * -1: if the padding is invalid */
391 al = SSL_AD_DECRYPTION_FAILED;
392 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
397 /* r->length is now the compressed data plus mac */
398 if ((sess != NULL) && (s->enc_read_ctx != NULL) &&
399 (EVP_MD_CTX_md(s->read_hash) != NULL)) {
400 /* s->read_hash != NULL => mac_size != -1 */
401 unsigned char *mac = NULL;
402 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
404 mac_size = EVP_MD_CTX_size(s->read_hash);
405 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
407 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
408 orig_len = rr->length + ((unsigned int)rr->type >> 8);
410 /* orig_len is the length of the record before any padding was
411 * removed. This is public information, as is the MAC in use,
412 * therefore we can safely process the record in a different
413 * amount of time if it's too short to possibly contain a MAC.
415 if (orig_len < mac_size ||
416 /* CBC records must have a padding length byte too. */
417 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
418 orig_len < mac_size + 1)) {
419 al = SSL_AD_DECODE_ERROR;
420 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
424 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
425 /* We update the length so that the TLS header bytes
426 * can be constructed correctly but we need to extract
427 * the MAC in constant time from within the record,
428 * without leaking the contents of the padding bytes.
431 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
432 rr->length -= mac_size;
434 /* In this case there's no padding, so |orig_len|
435 * equals |rec->length| and we checked that there's
436 * enough bytes for |mac_size| above. */
437 rr->length -= mac_size;
438 mac = &rr->data[rr->length];
441 i = s->method->ssl3_enc->mac(s,md,0 /* not send */);
442 if (i < 0 || mac == NULL ||
443 timingsafe_memcmp(md, mac, (size_t)mac_size) != 0)
446 SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
452 * A separate 'decryption_failed' alert was introduced with
453 * TLS 1.0, SSL 3.0 only has 'bad_record_mac'. But unless a
454 * decryption failure is directly visible from the ciphertext
455 * anyway, we should not reveal which kind of error
456 * occurred -- this might become visible to an attacker
457 * (e.g. via a logfile)
459 al = SSL_AD_BAD_RECORD_MAC;
460 SSLerr(SSL_F_SSL3_GET_RECORD,
461 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
465 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
466 al = SSL_AD_RECORD_OVERFLOW;
467 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
473 * So at this point the following is true
475 * ssl->s3->rrec.type is the type of record
476 * ssl->s3->rrec.length == number of bytes in record
477 * ssl->s3->rrec.off == offset to first valid byte
478 * ssl->s3->rrec.data == where to take bytes from, increment
482 /* we have pulled in a full packet so zero things */
483 s->packet_length = 0;
485 /* just read a 0 length packet */
492 ssl3_send_alert(s, SSL3_AL_FATAL, al);
497 /* Call this to write data in records of type 'type'
498 * It will return <= 0 if not all data has been sent or non-blocking IO.
501 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
503 const unsigned char *buf = buf_;
504 unsigned int tot, n, nw;
508 SSLerr(SSL_F_SSL3_WRITE_BYTES, ERR_R_INTERNAL_ERROR);
512 s->rwstate = SSL_NOTHING;
516 if (SSL_in_init(s) && !s->in_handshake) {
517 i = s->handshake_func(s);
521 SSLerr(SSL_F_SSL3_WRITE_BYTES,
522 SSL_R_SSL_HANDSHAKE_FAILURE);
531 if (n > s->max_send_fragment)
532 nw = s->max_send_fragment;
536 i = do_ssl3_write(s, type, &(buf[tot]), nw, 0);
542 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA &&
543 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) {
545 * Next chunk of data should get another prepended
546 * empty fragment in ciphersuites with known-IV
549 s->s3->empty_fragment_done = 0;
560 do_ssl3_write(SSL *s, int type, const unsigned char *buf,
561 unsigned int len, int create_empty_fragment)
563 unsigned char *p, *plen;
564 int i, mac_size, clear = 0;
569 SSL3_BUFFER *wb = &(s->s3->wbuf);
573 if (!ssl3_setup_write_buffer(s))
576 /* first check if there is a SSL3_BUFFER still being written
577 * out. This will happen with non blocking IO */
579 return (ssl3_write_pending(s, type, buf, len));
581 /* If we have an alert to send, lets send it */
582 if (s->s3->alert_dispatch) {
583 i = s->method->ssl_dispatch_alert(s);
586 /* if it went, fall through and send more stuff */
587 /* we may have released our buffer, so get it again */
589 if (!ssl3_setup_write_buffer(s))
593 if (len == 0 && !create_empty_fragment)
599 if ((sess == NULL) || (s->enc_write_ctx == NULL) ||
600 (EVP_MD_CTX_md(s->write_hash) == NULL)) {
601 clear = s->enc_write_ctx ? 0 : 1; /* must be AEAD cipher */
604 mac_size = EVP_MD_CTX_size(s->write_hash);
610 * 'create_empty_fragment' is true only when this function calls
613 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done) {
615 * Countermeasure against known-IV weakness in CBC ciphersuites
616 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
618 if (s->s3->need_empty_fragments &&
619 type == SSL3_RT_APPLICATION_DATA) {
620 /* recursive function call with 'create_empty_fragment' set;
621 * this prepares and buffers the data for an empty fragment
622 * (these 'prefix_len' bytes are sent out later
623 * together with the actual payload) */
624 prefix_len = do_ssl3_write(s, type, buf, 0, 1);
629 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD)) {
630 /* insufficient space */
631 SSLerr(SSL_F_DO_SSL3_WRITE,
632 ERR_R_INTERNAL_ERROR);
637 s->s3->empty_fragment_done = 1;
640 if (create_empty_fragment) {
641 /* extra fragment would be couple of cipher blocks,
642 * which would be multiple of SSL3_ALIGN_PAYLOAD, so
643 * if we want to align the real payload, then we can
644 * just pretent we simply have two headers. */
645 align = (size_t)wb->buf + 2 * SSL3_RT_HEADER_LENGTH;
646 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
650 } else if (prefix_len) {
651 p = wb->buf + wb->offset + prefix_len;
653 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH;
654 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
660 /* write the header */
665 *(p++) = (s->version >> 8);
666 /* Some servers hang if iniatial client hello is larger than 256
667 * bytes and record version number > TLS 1.0
669 if (s->state == SSL3_ST_CW_CLNT_HELLO_B && !s->renegotiate &&
670 TLS1_get_version(s) > TLS1_VERSION)
673 *(p++) = s->version&0xff;
675 /* field where we are to write out packet length */
679 /* Explicit IV length. */
680 if (s->enc_write_ctx && SSL_USE_EXPLICIT_IV(s)) {
681 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
682 if (mode == EVP_CIPH_CBC_MODE) {
683 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
687 /* Need explicit part of IV for GCM mode */
688 else if (mode == EVP_CIPH_GCM_MODE)
689 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
692 } else if (s->aead_write_ctx != NULL &&
693 s->aead_write_ctx->variable_nonce_in_record) {
694 eivlen = s->aead_write_ctx->variable_nonce_len;
698 /* lets setup the record stuff. */
699 wr->data = p + eivlen;
700 wr->length = (int)len;
701 wr->input = (unsigned char *)buf;
703 /* we now 'read' from wr->input, wr->length bytes into wr->data */
705 memcpy(wr->data, wr->input, wr->length);
706 wr->input = wr->data;
708 /* we should still have the output to wr->data and the input
709 * from wr->input. Length should be wr->length.
710 * wr->data still points in the wb->buf */
713 if (s->method->ssl3_enc->mac(s,
714 &(p[wr->length + eivlen]), 1) < 0)
716 wr->length += mac_size;
723 /* if (RAND_pseudo_bytes(p, eivlen) <= 0)
726 wr->length += eivlen;
729 /* ssl3_enc can only have an error on read */
730 s->method->ssl3_enc->enc(s, 1);
732 /* record length after mac and block padding */
733 s2n(wr->length, plen);
735 /* we should now have
736 * wr->data pointing to the encrypted data, which is
738 wr->type=type; /* not needed but helps for debugging */
739 wr->length += SSL3_RT_HEADER_LENGTH;
741 if (create_empty_fragment) {
742 /* we are in a recursive call;
743 * just return the length, don't write out anything here
748 /* now let's set up wb */
749 wb->left = prefix_len + wr->length;
751 /* memorize arguments so that ssl3_write_pending can detect
752 * bad write retries later */
753 s->s3->wpend_tot = len;
754 s->s3->wpend_buf = buf;
755 s->s3->wpend_type = type;
756 s->s3->wpend_ret = len;
758 /* we now just need to write the buffer */
759 return ssl3_write_pending(s, type, buf, len);
764 /* if s->s3->wbuf.left != 0, we need to call this */
766 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len)
769 SSL3_BUFFER *wb = &(s->s3->wbuf);
772 if ((s->s3->wpend_tot > (int)len) || ((s->s3->wpend_buf != buf) &&
773 !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) ||
774 (s->s3->wpend_type != type)) {
775 SSLerr(SSL_F_SSL3_WRITE_PENDING, SSL_R_BAD_WRITE_RETRY);
781 if (s->wbio != NULL) {
782 s->rwstate = SSL_WRITING;
783 i = BIO_write(s->wbio,
784 (char *)&(wb->buf[wb->offset]),
785 (unsigned int)wb->left);
787 SSLerr(SSL_F_SSL3_WRITE_PENDING, SSL_R_BIO_NOT_SET);
793 if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
795 ssl3_release_write_buffer(s);
796 s->rwstate = SSL_NOTHING;
797 return (s->s3->wpend_ret);
800 * For DTLS, just drop it. That's kind of the
801 * whole point in using a datagram service.
812 /* Return up to 'len' payload bytes received in 'type' records.
813 * 'type' is one of the following:
815 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
816 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
817 * - 0 (during a shutdown, no data has to be returned)
819 * If we don't have stored data to work from, read a SSL/TLS record first
820 * (possibly multiple records if we still don't have anything to return).
822 * This function must handle any surprises the peer may have for us, such as
823 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
824 * a surprise, but handled as if it were), or renegotiation requests.
825 * Also if record payloads contain fragments too small to process, we store
826 * them until there is enough for the respective protocol (the record protocol
827 * may use arbitrary fragmentation and even interleaving):
828 * Change cipher spec protocol
829 * just 1 byte needed, no need for keeping anything stored
831 * 2 bytes needed (AlertLevel, AlertDescription)
833 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
834 * to detect unexpected Client Hello and Hello Request messages
835 * here, anything else is handled by higher layers
836 * Application data protocol
837 * none of our business
840 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
845 void (*cb)(const SSL *ssl, int type2, int val) = NULL;
847 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
848 if (!ssl3_setup_read_buffer(s))
852 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
856 if ((type && type != SSL3_RT_APPLICATION_DATA &&
857 type != SSL3_RT_HANDSHAKE) ||
858 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
859 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
863 if ((type == SSL3_RT_HANDSHAKE) &&
864 (s->s3->handshake_fragment_len > 0)) {
865 /* (partially) satisfy request from storage */
866 unsigned char *src = s->s3->handshake_fragment;
867 unsigned char *dst = buf;
872 while ((len > 0) && (s->s3->handshake_fragment_len > 0)) {
875 s->s3->handshake_fragment_len--;
878 /* move any remaining fragment bytes: */
879 for (k = 0; k < s->s3->handshake_fragment_len; k++)
880 s->s3->handshake_fragment[k] = *src++;
885 * Now s->s3->handshake_fragment_len == 0 if
886 * type == SSL3_RT_HANDSHAKE.
888 if (!s->in_handshake && SSL_in_init(s)) {
889 /* type == SSL3_RT_APPLICATION_DATA */
890 i = s->handshake_func(s);
894 SSLerr(SSL_F_SSL3_READ_BYTES,
895 SSL_R_SSL_HANDSHAKE_FAILURE);
900 s->rwstate = SSL_NOTHING;
903 * s->s3->rrec.type - is the type of record
904 * s->s3->rrec.data, - data
905 * s->s3->rrec.off, - offset into 'data' for next read
906 * s->s3->rrec.length, - number of bytes.
910 /* get new packet if necessary */
911 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) {
912 ret = ssl3_get_record(s);
917 /* we now have a packet which can be read and processed */
919 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
920 * reset by ssl3_get_finished */
921 && (rr->type != SSL3_RT_HANDSHAKE)) {
922 al = SSL_AD_UNEXPECTED_MESSAGE;
923 SSLerr(SSL_F_SSL3_READ_BYTES,
924 SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
928 /* If the other end has shut down, throw anything we read away
929 * (even in 'peek' mode) */
930 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
932 s->rwstate = SSL_NOTHING;
937 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
938 if (type == rr->type) {
939 /* make sure that we are not getting application data when we
940 * are doing a handshake for the first time */
941 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
942 (s->enc_read_ctx == NULL)) {
943 al = SSL_AD_UNEXPECTED_MESSAGE;
944 SSLerr(SSL_F_SSL3_READ_BYTES,
945 SSL_R_APP_DATA_IN_HANDSHAKE);
952 if ((unsigned int)len > rr->length)
955 n = (unsigned int)len;
957 memcpy(buf, &(rr->data[rr->off]), n);
959 memset(&(rr->data[rr->off]), 0, n);
962 if (rr->length == 0) {
963 s->rstate = SSL_ST_READ_HEADER;
965 if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
966 s->s3->rbuf.left == 0)
967 ssl3_release_read_buffer(s);
974 /* If we get here, then type != rr->type; if we have a handshake
975 * message, then it was unexpected (Hello Request or Client Hello). */
979 * In case of record types for which we have 'fragment'
980 * storage, * fill that so that we can process the data
983 unsigned int dest_maxlen = 0;
984 unsigned char *dest = NULL;
985 unsigned int *dest_len = NULL;
987 if (rr->type == SSL3_RT_HANDSHAKE) {
988 dest_maxlen = sizeof s->s3->handshake_fragment;
989 dest = s->s3->handshake_fragment;
990 dest_len = &s->s3->handshake_fragment_len;
991 } else if (rr->type == SSL3_RT_ALERT) {
992 dest_maxlen = sizeof s->s3->alert_fragment;
993 dest = s->s3->alert_fragment;
994 dest_len = &s->s3->alert_fragment_len;
996 if (dest_maxlen > 0) {
997 /* available space in 'dest' */
998 n = dest_maxlen - *dest_len;
1000 n = rr->length; /* available bytes */
1002 /* now move 'n' bytes: */
1004 dest[(*dest_len)++] = rr->data[rr->off++];
1008 if (*dest_len < dest_maxlen)
1009 goto start; /* fragment was too small */
1013 /* s->s3->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE;
1014 * s->s3->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT.
1015 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1017 /* If we are a client, check for an incoming 'Hello Request': */
1018 if ((!s->server) && (s->s3->handshake_fragment_len >= 4) &&
1019 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1020 (s->session != NULL) && (s->session->cipher != NULL)) {
1021 s->s3->handshake_fragment_len = 0;
1023 if ((s->s3->handshake_fragment[1] != 0) ||
1024 (s->s3->handshake_fragment[2] != 0) ||
1025 (s->s3->handshake_fragment[3] != 0)) {
1026 al = SSL_AD_DECODE_ERROR;
1027 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
1031 if (s->msg_callback)
1032 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1033 s->s3->handshake_fragment, 4, s,
1034 s->msg_callback_arg);
1036 if (SSL_is_init_finished(s) &&
1037 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1038 !s->s3->renegotiate) {
1039 ssl3_renegotiate(s);
1040 if (ssl3_renegotiate_check(s)) {
1041 i = s->handshake_func(s);
1045 SSLerr(SSL_F_SSL3_READ_BYTES,
1046 SSL_R_SSL_HANDSHAKE_FAILURE);
1050 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
1051 if (s->s3->rbuf.left == 0) {
1052 /* no read-ahead left? */
1054 /* In the case where we try to read application data,
1055 * but we trigger an SSL handshake, we return -1 with
1056 * the retry option set. Otherwise renegotiation may
1057 * cause nasty problems in the blocking world */
1058 s->rwstate = SSL_READING;
1059 bio = SSL_get_rbio(s);
1060 BIO_clear_retry_flags(bio);
1061 BIO_set_retry_read(bio);
1067 /* we either finished a handshake or ignored the request,
1068 * now try again to obtain the (application) data we were asked for */
1071 /* If we are a server and get a client hello when renegotiation isn't
1072 * allowed send back a no renegotiation alert and carry on.
1073 * WARNING: experimental code, needs reviewing (steve)
1076 SSL_is_init_finished(s) &&
1077 !s->s3->send_connection_binding &&
1078 (s->s3->handshake_fragment_len >= 4) &&
1079 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1080 (s->session != NULL) && (s->session->cipher != NULL)) {
1081 /*s->s3->handshake_fragment_len = 0;*/
1083 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1086 if (s->s3->alert_fragment_len >= 2) {
1087 int alert_level = s->s3->alert_fragment[0];
1088 int alert_descr = s->s3->alert_fragment[1];
1090 s->s3->alert_fragment_len = 0;
1092 if (s->msg_callback)
1093 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1094 s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1096 if (s->info_callback != NULL)
1097 cb = s->info_callback;
1098 else if (s->ctx->info_callback != NULL)
1099 cb = s->ctx->info_callback;
1102 j = (alert_level << 8) | alert_descr;
1103 cb(s, SSL_CB_READ_ALERT, j);
1106 if (alert_level == 1) {
1108 s->s3->warn_alert = alert_descr;
1109 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
1110 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1113 /* This is a warning but we receive it if we requested
1114 * renegotiation and the peer denied it. Terminate with
1115 * a fatal alert because if application tried to
1116 * renegotiatie it presumably had a good reason and
1117 * expects it to succeed.
1119 * In future we might have a renegotiation where we
1120 * don't care if the peer refused it where we carry on.
1122 else if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
1123 al = SSL_AD_HANDSHAKE_FAILURE;
1124 SSLerr(SSL_F_SSL3_READ_BYTES,
1125 SSL_R_NO_RENEGOTIATION);
1128 } else if (alert_level == 2) {
1130 s->rwstate = SSL_NOTHING;
1131 s->s3->fatal_alert = alert_descr;
1132 SSLerr(SSL_F_SSL3_READ_BYTES,
1133 SSL_AD_REASON_OFFSET + alert_descr);
1134 ERR_asprintf_error_data("SSL alert number %d",
1136 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1137 SSL_CTX_remove_session(s->ctx, s->session);
1140 al = SSL_AD_ILLEGAL_PARAMETER;
1141 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
1148 if (s->shutdown & SSL_SENT_SHUTDOWN) {
1149 /* but we have not received a shutdown */
1150 s->rwstate = SSL_NOTHING;
1155 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1156 /* 'Change Cipher Spec' is just a single byte, so we know
1157 * exactly what the record payload has to look like */
1158 if ((rr->length != 1) || (rr->off != 0) ||
1159 (rr->data[0] != SSL3_MT_CCS)) {
1160 al = SSL_AD_ILLEGAL_PARAMETER;
1161 SSLerr(SSL_F_SSL3_READ_BYTES,
1162 SSL_R_BAD_CHANGE_CIPHER_SPEC);
1166 /* Check we have a cipher to change to */
1167 if (s->s3->tmp.new_cipher == NULL) {
1168 al = SSL_AD_UNEXPECTED_MESSAGE;
1169 SSLerr(SSL_F_SSL3_READ_BYTES,
1170 SSL_R_CCS_RECEIVED_EARLY);
1174 /* Check that we should be receiving a Change Cipher Spec. */
1175 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) {
1176 al = SSL_AD_UNEXPECTED_MESSAGE;
1177 SSLerr(SSL_F_SSL3_READ_BYTES,
1178 SSL_R_CCS_RECEIVED_EARLY);
1181 s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
1185 if (s->msg_callback) {
1186 s->msg_callback(0, s->version,
1187 SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s,
1188 s->msg_callback_arg);
1191 s->s3->change_cipher_spec = 1;
1192 if (!ssl3_do_change_cipher_spec(s))
1198 /* Unexpected handshake message (Client Hello, or protocol violation) */
1199 if ((s->s3->handshake_fragment_len >= 4) && !s->in_handshake) {
1200 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1201 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
1202 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1206 i = s->handshake_func(s);
1210 SSLerr(SSL_F_SSL3_READ_BYTES,
1211 SSL_R_SSL_HANDSHAKE_FAILURE);
1215 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
1216 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
1218 /* In the case where we try to read application data,
1219 * but we trigger an SSL handshake, we return -1 with
1220 * the retry option set. Otherwise renegotiation may
1221 * cause nasty problems in the blocking world */
1222 s->rwstate = SSL_READING;
1223 bio = SSL_get_rbio(s);
1224 BIO_clear_retry_flags(bio);
1225 BIO_set_retry_read(bio);
1235 * TLS up to v1.1 just ignores unknown message types:
1236 * TLS v1.2 give an unexpected message alert.
1238 if (s->version >= TLS1_VERSION &&
1239 s->version <= TLS1_1_VERSION) {
1243 al = SSL_AD_UNEXPECTED_MESSAGE;
1244 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1246 case SSL3_RT_CHANGE_CIPHER_SPEC:
1248 case SSL3_RT_HANDSHAKE:
1249 /* we already handled all of these, with the possible exception
1250 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1251 * should not happen when type != rr->type */
1252 al = SSL_AD_UNEXPECTED_MESSAGE;
1253 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
1255 case SSL3_RT_APPLICATION_DATA:
1256 /* At this point, we were expecting handshake data,
1257 * but have application data. If the library was
1258 * running inside ssl3_read() (i.e. in_read_app_data
1259 * is set) and it makes sense to read application data
1260 * at this point (session renegotiation not yet started),
1261 * we will indulge it.
1263 if (s->s3->in_read_app_data &&
1264 (s->s3->total_renegotiations != 0) &&
1265 (((s->state & SSL_ST_CONNECT) &&
1266 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1267 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)) ||
1268 ((s->state & SSL_ST_ACCEPT) &&
1269 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1270 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
1271 s->s3->in_read_app_data = 2;
1274 al = SSL_AD_UNEXPECTED_MESSAGE;
1275 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1282 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1288 ssl3_do_change_cipher_spec(SSL *s)
1294 if (s->state & SSL_ST_ACCEPT)
1295 i = SSL3_CHANGE_CIPHER_SERVER_READ;
1297 i = SSL3_CHANGE_CIPHER_CLIENT_READ;
1299 if (s->s3->tmp.key_block == NULL) {
1300 if (s->session == NULL || s->session->master_key_length == 0) {
1301 /* might happen if dtls1_read_bytes() calls this */
1302 SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,
1303 SSL_R_CCS_RECEIVED_EARLY);
1307 s->session->cipher = s->s3->tmp.new_cipher;
1308 if (!s->method->ssl3_enc->setup_key_block(s))
1312 if (!s->method->ssl3_enc->change_cipher_state(s, i))
1315 /* we have to record the message digest at
1316 * this point so we can get it before we read
1317 * the finished message */
1318 if (s->state & SSL_ST_CONNECT) {
1319 sender = s->method->ssl3_enc->server_finished_label;
1320 slen = s->method->ssl3_enc->server_finished_label_len;
1322 sender = s->method->ssl3_enc->client_finished_label;
1323 slen = s->method->ssl3_enc->client_finished_label_len;
1326 i = s->method->ssl3_enc->final_finish_mac(s, sender, slen,
1327 s->s3->tmp.peer_finish_md);
1329 SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
1332 s->s3->tmp.peer_finish_md_len = i;
1338 ssl3_send_alert(SSL *s, int level, int desc)
1340 /* Map tls/ssl alert value to correct one */
1341 desc = s->method->ssl3_enc->alert_value(desc);
1344 /* If a fatal one, remove from cache */
1345 if ((level == 2) && (s->session != NULL))
1346 SSL_CTX_remove_session(s->ctx, s->session);
1348 s->s3->alert_dispatch = 1;
1349 s->s3->send_alert[0] = level;
1350 s->s3->send_alert[1] = desc;
1351 if (s->s3->wbuf.left == 0) /* data still being written out? */
1352 return s->method->ssl_dispatch_alert(s);
1354 /* else data is still being written out, we will get written
1355 * some time in the future */
1360 ssl3_dispatch_alert(SSL *s)
1363 void (*cb)(const SSL *ssl, int type, int val) = NULL;
1365 s->s3->alert_dispatch = 0;
1366 i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1368 s->s3->alert_dispatch = 1;
1370 /* Alert sent to BIO. If it is important, flush it now.
1371 * If the message does not get sent due to non-blocking IO,
1372 * we will not worry too much. */
1373 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1374 (void)BIO_flush(s->wbio);
1376 if (s->msg_callback)
1377 s->msg_callback(1, s->version, SSL3_RT_ALERT,
1378 s->s3->send_alert, 2, s, s->msg_callback_arg);
1380 if (s->info_callback != NULL)
1381 cb = s->info_callback;
1382 else if (s->ctx->info_callback != NULL)
1383 cb = s->ctx->info_callback;
1386 j = (s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1387 cb(s, SSL_CB_WRITE_ALERT, j);