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"
116 #include <openssl/evp.h>
117 #include <openssl/buffer.h>
119 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
120 unsigned int len, int create_empty_fragment);
121 static int ssl3_get_record(SSL *s);
123 int ssl3_read_n(SSL *s, int n, int max, int extend)
125 /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
126 * packet by another n bytes.
127 * The packet will be in the sub-array of s->s3->rbuf.buf specified
128 * by s->packet and s->packet_length.
129 * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
130 * [plus s->packet_length bytes if extend == 1].)
136 /* start with empty packet ... */
137 if (s->s3->rbuf.left == 0)
138 s->s3->rbuf.offset = 0;
139 s->packet = s->s3->rbuf.buf + s->s3->rbuf.offset;
140 s->packet_length = 0;
141 /* ... now we can act as if 'extend' was set */
144 /* For DTLS/UDP reads should not span multiple packets
145 * because the read operation returns the whole packet
146 * at once (as long as it fits into the buffer). */
147 if (SSL_version(s) == DTLS1_VERSION)
149 if ( s->s3->rbuf.left > 0 && n > s->s3->rbuf.left)
150 n = s->s3->rbuf.left;
153 /* if there is enough in the buffer from a previous read, take some */
154 if (s->s3->rbuf.left >= (int)n)
158 s->s3->rbuf.offset+=n;
162 /* else we need to read more data */
167 /* avoid buffer overflow */
168 int max_max = s->s3->rbuf.len - s->packet_length;
172 if (n > max) /* does not happen */
174 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
178 off = s->packet_length;
179 newb = s->s3->rbuf.left;
180 /* Move any available bytes to front of buffer:
181 * 'off' bytes already pointed to by 'packet',
182 * 'newb' extra ones at the end */
183 if (s->packet != s->s3->rbuf.buf)
186 memmove(s->s3->rbuf.buf, s->packet, off+newb);
187 s->packet = s->s3->rbuf.buf;
192 /* Now we have off+newb bytes at the front of s->s3->rbuf.buf and need
193 * to read in more until we have off+n (up to off+max if possible) */
198 s->rwstate=SSL_READING;
199 i=BIO_read(s->rbio, &(s->s3->rbuf.buf[off+newb]), max-newb);
203 SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
209 s->s3->rbuf.left = newb;
213 /* reads should *never* span multiple packets for DTLS because
214 * the underlying transport protocol is message oriented as opposed
215 * to byte oriented as in the TLS case. */
216 if (SSL_version(s) == DTLS1_VERSION)
219 n = newb; /* makes the while condition false */
223 /* done reading, now the book-keeping */
224 s->s3->rbuf.offset = off + n;
225 s->s3->rbuf.left = newb - n;
226 s->packet_length += n;
227 s->rwstate=SSL_NOTHING;
231 /* Call this to get a new input record.
232 * It will return <= 0 if more data is needed, normally due to an error
233 * or non-blocking IO.
234 * When it finishes, one packet has been decoded and can be found in
235 * ssl->s3->rrec.type - is the type of record
236 * ssl->s3->rrec.data, - data
237 * ssl->s3->rrec.length, - number of bytes
239 /* used only by ssl3_read_bytes */
240 static int ssl3_get_record(SSL *s)
242 int ssl_major,ssl_minor,al;
243 int enc_err,n,i,ret= -1;
247 unsigned char md[EVP_MAX_MD_SIZE];
249 unsigned mac_size, orig_len;
255 if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
256 extra=SSL3_RT_MAX_EXTRA;
259 if (extra != s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE)
261 /* actually likely an application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
262 * set after ssl3_setup_buffers() was done */
263 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
268 /* check if we have the header */
269 if ( (s->rstate != SSL_ST_READ_BODY) ||
270 (s->packet_length < SSL3_RT_HEADER_LENGTH))
272 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
273 if (n <= 0) return(n); /* error or non-blocking */
274 s->rstate=SSL_ST_READ_BODY;
278 /* Pull apart the header into the SSL3_RECORD */
282 version=(ssl_major<<8)|ssl_minor;
285 /* Lets check version */
286 if (!s->first_packet)
288 if (version != s->version)
290 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
291 if ((s->version & 0xFF00) == (version & 0xFF00))
292 /* Send back error using their minor version number :-) */
293 s->version = (unsigned short)version;
294 al=SSL_AD_PROTOCOL_VERSION;
299 if ((version>>8) != SSL3_VERSION_MAJOR)
301 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
305 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
307 al=SSL_AD_RECORD_OVERFLOW;
308 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
312 /* now s->rstate == SSL_ST_READ_BODY */
315 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
317 if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
319 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
321 n=ssl3_read_n(s,i,i,1);
322 if (n <= 0) return(n); /* error or non-blocking io */
323 /* now n == rr->length,
324 * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
327 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
329 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
330 * and we have that many bytes in s->packet
332 rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
334 /* ok, we can now read from 's->packet' data into 'rr'
335 * rr->input points at rr->length bytes, which
336 * need to be copied into rr->data by either
337 * the decryption or by the decompression
338 * When the data is 'copied' into the rr->data buffer,
339 * rr->input will be pointed at the new buffer */
341 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
342 * rr->length bytes of encrypted compressed stuff. */
344 /* check is not needed I believe */
345 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
347 al=SSL_AD_RECORD_OVERFLOW;
348 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
352 /* decrypt in place in 'rr->input' */
355 enc_err = s->method->ssl3_enc->enc(s,0);
357 * 0: (in non-constant time) if the record is publically invalid.
358 * 1: if the padding is valid
359 * -1: if the padding is invalid */
362 al=SSL_AD_DECRYPTION_FAILED;
363 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
368 printf("dec %d\n",rr->length);
369 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
373 /* r->length is now the compressed data plus mac */
374 if ((sess != NULL) &&
375 (s->enc_read_ctx != NULL) &&
376 (s->read_hash != NULL))
378 /* s->read_hash != NULL => mac_size != -1 */
379 unsigned char *mac = NULL;
380 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
381 mac_size=EVP_MD_size(s->read_hash);
382 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
384 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
385 orig_len = rr->length+((unsigned int)rr->type>>8);
387 /* orig_len is the length of the record before any padding was
388 * removed. This is public information, as is the MAC in use,
389 * therefore we can safely process the record in a different
390 * amount of time if it's too short to possibly contain a MAC.
392 if (orig_len < mac_size ||
393 /* CBC records must have a padding length byte too. */
394 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
395 orig_len < mac_size+1))
397 al=SSL_AD_DECODE_ERROR;
398 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
402 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
404 /* We update the length so that the TLS header bytes
405 * can be constructed correctly but we need to extract
406 * the MAC in constant time from within the record,
407 * without leaking the contents of the padding bytes.
410 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
411 rr->length -= mac_size;
415 /* In this case there's no padding, so |orig_len|
416 * equals |rec->length| and we checked that there's
417 * enough bytes for |mac_size| above. */
418 rr->length -= mac_size;
419 mac = &rr->data[rr->length];
422 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
423 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
425 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
431 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
432 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
433 * failure is directly visible from the ciphertext anyway,
434 * we should not reveal which kind of error occured -- this
435 * might become visible to an attacker (e.g. via a logfile) */
436 al=SSL_AD_BAD_RECORD_MAC;
437 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
441 /* r->length is now just compressed */
442 if (s->expand != NULL)
444 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
446 al=SSL_AD_RECORD_OVERFLOW;
447 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
450 if (!ssl3_do_uncompress(s))
452 al=SSL_AD_DECOMPRESSION_FAILURE;
453 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
458 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
460 al=SSL_AD_RECORD_OVERFLOW;
461 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
466 /* So at this point the following is true
467 * ssl->s3->rrec.type is the type of record
468 * ssl->s3->rrec.length == number of bytes in record
469 * ssl->s3->rrec.off == offset to first valid byte
470 * ssl->s3->rrec.data == where to take bytes from, increment
474 /* we have pulled in a full packet so zero things */
477 /* just read a 0 length packet */
478 if (rr->length == 0) goto again;
483 ssl3_send_alert(s,SSL3_AL_FATAL,al);
488 int ssl3_do_uncompress(SSL *ssl)
490 #ifndef OPENSSL_NO_COMP
494 rr= &(ssl->s3->rrec);
495 i=COMP_expand_block(ssl->expand,rr->comp,
496 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
506 int ssl3_do_compress(SSL *ssl)
508 #ifndef OPENSSL_NO_COMP
512 wr= &(ssl->s3->wrec);
513 i=COMP_compress_block(ssl->compress,wr->data,
514 SSL3_RT_MAX_COMPRESSED_LENGTH,
515 wr->input,(int)wr->length);
526 /* Call this to write data in records of type 'type'
527 * It will return <= 0 if not all data has been sent or non-blocking IO.
529 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
531 const unsigned char *buf=buf_;
532 unsigned int tot,n,nw;
535 s->rwstate=SSL_NOTHING;
539 if (SSL_in_init(s) && !s->in_handshake)
541 i=s->handshake_func(s);
542 if (i < 0) return(i);
545 SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
553 if (n > SSL3_RT_MAX_PLAIN_LENGTH)
554 nw=SSL3_RT_MAX_PLAIN_LENGTH;
558 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
566 (type == SSL3_RT_APPLICATION_DATA &&
567 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
569 /* next chunk of data should get another prepended empty fragment
570 * in ciphersuites with known-IV weakness: */
571 s->s3->empty_fragment_done = 0;
581 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
582 unsigned int len, int create_empty_fragment)
584 unsigned char *p,*plen;
585 int i,mac_size,clear=0;
591 /* first check if there is a SSL3_BUFFER still being written
592 * out. This will happen with non blocking IO */
593 if (s->s3->wbuf.left != 0)
594 return(ssl3_write_pending(s,type,buf,len));
596 /* If we have an alert to send, lets send it */
597 if (s->s3->alert_dispatch)
599 i=s->method->ssl_dispatch_alert(s);
602 /* if it went, fall through and send more stuff */
605 if (len == 0 && !create_empty_fragment)
612 if ( (sess == NULL) ||
613 (s->enc_write_ctx == NULL) ||
614 (s->write_hash == NULL))
620 mac_size=EVP_MD_size(s->write_hash);
622 /* 'create_empty_fragment' is true only when this function calls itself */
623 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
625 /* countermeasure against known-IV weakness in CBC ciphersuites
626 * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
628 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
630 /* recursive function call with 'create_empty_fragment' set;
631 * this prepares and buffers the data for an empty fragment
632 * (these 'prefix_len' bytes are sent out later
633 * together with the actual payload) */
634 prefix_len = do_ssl3_write(s, type, buf, 0, 1);
638 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
640 /* insufficient space */
641 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
646 s->s3->empty_fragment_done = 1;
649 p = wb->buf + prefix_len;
651 /* write the header */
656 *(p++)=(s->version>>8);
657 *(p++)=s->version&0xff;
659 /* field where we are to write out packet length */
663 /* lets setup the record stuff. */
666 wr->input=(unsigned char *)buf;
668 /* we now 'read' from wr->input, wr->length bytes into
671 /* first we compress */
672 if (s->compress != NULL)
674 if (!ssl3_do_compress(s))
676 SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
682 memcpy(wr->data,wr->input,wr->length);
686 /* we should still have the output to wr->data and the input
687 * from wr->input. Length should be wr->length.
688 * wr->data still points in the wb->buf */
692 s->method->ssl3_enc->mac(s,&(p[wr->length]),1);
693 wr->length+=mac_size;
698 /* ssl3_enc can only have an error on read */
699 s->method->ssl3_enc->enc(s,1);
701 /* record length after mac and block padding */
702 s2n(wr->length,plen);
704 /* we should now have
705 * wr->data pointing to the encrypted data, which is
707 wr->type=type; /* not needed but helps for debugging */
708 wr->length+=SSL3_RT_HEADER_LENGTH;
710 if (create_empty_fragment)
712 /* we are in a recursive call;
713 * just return the length, don't write out anything here
718 /* now let's set up wb */
719 wb->left = prefix_len + wr->length;
722 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
723 s->s3->wpend_tot=len;
724 s->s3->wpend_buf=buf;
725 s->s3->wpend_type=type;
726 s->s3->wpend_ret=len;
728 /* we now just need to write the buffer */
729 return ssl3_write_pending(s,type,buf,len);
734 /* if s->s3->wbuf.left != 0, we need to call this */
735 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
741 if ((s->s3->wpend_tot > (int)len)
742 || ((s->s3->wpend_buf != buf) &&
743 !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
744 || (s->s3->wpend_type != type))
746 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
755 s->rwstate=SSL_WRITING;
757 (char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]),
758 (unsigned int)s->s3->wbuf.left);
762 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
765 if (i == s->s3->wbuf.left)
768 s->rwstate=SSL_NOTHING;
769 return(s->s3->wpend_ret);
772 if (s->version == DTLS1_VERSION ||
773 s->version == DTLS1_BAD_VER) {
774 /* For DTLS, just drop it. That's kind of the whole
775 point in using a datagram service */
776 s->s3->wbuf.left = 0;
780 s->s3->wbuf.offset+=i;
785 /* Return up to 'len' payload bytes received in 'type' records.
786 * 'type' is one of the following:
788 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
789 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
790 * - 0 (during a shutdown, no data has to be returned)
792 * If we don't have stored data to work from, read a SSL/TLS record first
793 * (possibly multiple records if we still don't have anything to return).
795 * This function must handle any surprises the peer may have for us, such as
796 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
797 * a surprise, but handled as if it were), or renegotiation requests.
798 * Also if record payloads contain fragments too small to process, we store
799 * them until there is enough for the respective protocol (the record protocol
800 * may use arbitrary fragmentation and even interleaving):
801 * Change cipher spec protocol
802 * just 1 byte needed, no need for keeping anything stored
804 * 2 bytes needed (AlertLevel, AlertDescription)
806 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
807 * to detect unexpected Client Hello and Hello Request messages
808 * here, anything else is handled by higher layers
809 * Application data protocol
810 * none of our business
812 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
817 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
819 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
820 if (!ssl3_setup_buffers(s))
823 if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
824 (peek && (type != SSL3_RT_APPLICATION_DATA)))
826 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
830 if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
831 /* (partially) satisfy request from storage */
833 unsigned char *src = s->s3->handshake_fragment;
834 unsigned char *dst = buf;
839 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
842 len--; s->s3->handshake_fragment_len--;
845 /* move any remaining fragment bytes: */
846 for (k = 0; k < s->s3->handshake_fragment_len; k++)
847 s->s3->handshake_fragment[k] = *src++;
851 /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
853 if (!s->in_handshake && SSL_in_init(s))
855 /* type == SSL3_RT_APPLICATION_DATA */
856 i=s->handshake_func(s);
857 if (i < 0) return(i);
860 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
865 s->rwstate=SSL_NOTHING;
867 /* s->s3->rrec.type - is the type of record
868 * s->s3->rrec.data, - data
869 * s->s3->rrec.off, - offset into 'data' for next read
870 * s->s3->rrec.length, - number of bytes. */
873 /* get new packet if necessary */
874 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
876 ret=ssl3_get_record(s);
877 if (ret <= 0) return(ret);
880 /* we now have a packet which can be read and processed */
882 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
883 * reset by ssl3_get_finished */
884 && (rr->type != SSL3_RT_HANDSHAKE))
886 al=SSL_AD_UNEXPECTED_MESSAGE;
887 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
891 /* If the other end has shut down, throw anything we read away
892 * (even in 'peek' mode) */
893 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
896 s->rwstate=SSL_NOTHING;
901 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
903 /* make sure that we are not getting application data when we
904 * are doing a handshake for the first time */
905 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
906 (s->enc_read_ctx == NULL))
908 al=SSL_AD_UNEXPECTED_MESSAGE;
909 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
913 if (len <= 0) return(len);
915 if ((unsigned int)len > rr->length)
918 n = (unsigned int)len;
920 memcpy(buf,&(rr->data[rr->off]),n);
927 s->rstate=SSL_ST_READ_HEADER;
935 /* If we get here, then type != rr->type; if we have a handshake
936 * message, then it was unexpected (Hello Request or Client Hello). */
938 /* In case of record types for which we have 'fragment' storage,
939 * fill that so that we can process the data at a fixed place.
942 unsigned int dest_maxlen = 0;
943 unsigned char *dest = NULL;
944 unsigned int *dest_len = NULL;
946 if (rr->type == SSL3_RT_HANDSHAKE)
948 dest_maxlen = sizeof s->s3->handshake_fragment;
949 dest = s->s3->handshake_fragment;
950 dest_len = &s->s3->handshake_fragment_len;
952 else if (rr->type == SSL3_RT_ALERT)
954 dest_maxlen = sizeof s->s3->alert_fragment;
955 dest = s->s3->alert_fragment;
956 dest_len = &s->s3->alert_fragment_len;
961 n = dest_maxlen - *dest_len; /* available space in 'dest' */
963 n = rr->length; /* available bytes */
965 /* now move 'n' bytes: */
968 dest[(*dest_len)++] = rr->data[rr->off++];
972 if (*dest_len < dest_maxlen)
973 goto start; /* fragment was too small */
977 /* s->s3->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE;
978 * s->s3->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT.
979 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
981 /* If we are a client, check for an incoming 'Hello Request': */
983 (s->s3->handshake_fragment_len >= 4) &&
984 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
985 (s->session != NULL) && (s->session->cipher != NULL))
987 s->s3->handshake_fragment_len = 0;
989 if ((s->s3->handshake_fragment[1] != 0) ||
990 (s->s3->handshake_fragment[2] != 0) ||
991 (s->s3->handshake_fragment[3] != 0))
993 al=SSL_AD_DECODE_ERROR;
994 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
999 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1001 if (SSL_is_init_finished(s) &&
1002 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1003 !s->s3->renegotiate)
1005 ssl3_renegotiate(s);
1006 if (ssl3_renegotiate_check(s))
1008 i=s->handshake_func(s);
1009 if (i < 0) return(i);
1012 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1016 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1018 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1021 /* In the case where we try to read application data,
1022 * but we trigger an SSL handshake, we return -1 with
1023 * the retry option set. Otherwise renegotiation may
1024 * cause nasty problems in the blocking world */
1025 s->rwstate=SSL_READING;
1026 bio=SSL_get_rbio(s);
1027 BIO_clear_retry_flags(bio);
1028 BIO_set_retry_read(bio);
1034 /* we either finished a handshake or ignored the request,
1035 * now try again to obtain the (application) data we were asked for */
1038 /* If we are a server and get a client hello when renegotiation isn't
1039 * allowed send back a no renegotiation alert and carry on.
1040 * WARNING: experimental code, needs reviewing (steve)
1043 SSL_is_init_finished(s) &&
1044 !s->s3->send_connection_binding &&
1045 (s->version > SSL3_VERSION) &&
1046 (s->s3->handshake_fragment_len >= 4) &&
1047 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1048 (s->session != NULL) && (s->session->cipher != NULL) &&
1049 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1052 /*s->s3->handshake_fragment_len = 0;*/
1054 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1057 if (s->s3->alert_fragment_len >= 2)
1059 int alert_level = s->s3->alert_fragment[0];
1060 int alert_descr = s->s3->alert_fragment[1];
1062 s->s3->alert_fragment_len = 0;
1064 if (s->msg_callback)
1065 s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1067 if (s->info_callback != NULL)
1068 cb=s->info_callback;
1069 else if (s->ctx->info_callback != NULL)
1070 cb=s->ctx->info_callback;
1074 j = (alert_level << 8) | alert_descr;
1075 cb(s, SSL_CB_READ_ALERT, j);
1078 if (alert_level == 1) /* warning */
1080 s->s3->warn_alert = alert_descr;
1081 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1083 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1086 /* This is a warning but we receive it if we requested
1087 * renegotiation and the peer denied it. Terminate with
1088 * a fatal alert because if application tried to
1089 * renegotiatie it presumably had a good reason and
1090 * expects it to succeed.
1092 * In future we might have a renegotiation where we
1093 * don't care if the peer refused it where we carry on.
1095 else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1097 al = SSL_AD_HANDSHAKE_FAILURE;
1098 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1102 else if (alert_level == 2) /* fatal */
1106 s->rwstate=SSL_NOTHING;
1107 s->s3->fatal_alert = alert_descr;
1108 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1109 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1110 ERR_add_error_data(2,"SSL alert number ",tmp);
1111 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1112 SSL_CTX_remove_session(s->ctx,s->session);
1117 al=SSL_AD_ILLEGAL_PARAMETER;
1118 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1125 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1127 s->rwstate=SSL_NOTHING;
1132 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1134 /* 'Change Cipher Spec' is just a single byte, so we know
1135 * exactly what the record payload has to look like */
1136 if ( (rr->length != 1) || (rr->off != 0) ||
1137 (rr->data[0] != SSL3_MT_CCS))
1139 al=SSL_AD_ILLEGAL_PARAMETER;
1140 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1144 /* Check we have a cipher to change to */
1145 if (s->s3->tmp.new_cipher == NULL)
1147 al=SSL_AD_UNEXPECTED_MESSAGE;
1148 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1154 if (s->msg_callback)
1155 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1157 s->s3->change_cipher_spec=1;
1158 if (!ssl3_do_change_cipher_spec(s))
1164 /* Unexpected handshake message (Client Hello, or protocol violation) */
1165 if ((s->s3->handshake_fragment_len >= 4) && !s->in_handshake)
1167 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1168 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1170 #if 0 /* worked only because C operator preferences are not as expected (and
1171 * because this is not really needed for clients except for detecting
1172 * protocol violations): */
1173 s->state=SSL_ST_BEFORE|(s->server)
1177 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1181 i=s->handshake_func(s);
1182 if (i < 0) return(i);
1185 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1189 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1191 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1194 /* In the case where we try to read application data,
1195 * but we trigger an SSL handshake, we return -1 with
1196 * the retry option set. Otherwise renegotiation may
1197 * cause nasty problems in the blocking world */
1198 s->rwstate=SSL_READING;
1199 bio=SSL_get_rbio(s);
1200 BIO_clear_retry_flags(bio);
1201 BIO_set_retry_read(bio);
1211 #ifndef OPENSSL_NO_TLS
1212 /* TLS just ignores unknown message types */
1213 if (s->version == TLS1_VERSION)
1219 al=SSL_AD_UNEXPECTED_MESSAGE;
1220 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1222 case SSL3_RT_CHANGE_CIPHER_SPEC:
1224 case SSL3_RT_HANDSHAKE:
1225 /* we already handled all of these, with the possible exception
1226 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1227 * should not happen when type != rr->type */
1228 al=SSL_AD_UNEXPECTED_MESSAGE;
1229 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1231 case SSL3_RT_APPLICATION_DATA:
1232 /* At this point, we were expecting handshake data,
1233 * but have application data. If the library was
1234 * running inside ssl3_read() (i.e. in_read_app_data
1235 * is set) and it makes sense to read application data
1236 * at this point (session renegotiation not yet started),
1237 * we will indulge it.
1239 if (s->s3->in_read_app_data &&
1240 (s->s3->total_renegotiations != 0) &&
1242 (s->state & SSL_ST_CONNECT) &&
1243 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1244 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1246 (s->state & SSL_ST_ACCEPT) &&
1247 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1248 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1252 s->s3->in_read_app_data=2;
1257 al=SSL_AD_UNEXPECTED_MESSAGE;
1258 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1265 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1270 int ssl3_do_change_cipher_spec(SSL *s)
1276 if (s->state & SSL_ST_ACCEPT)
1277 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1279 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1281 if (s->s3->tmp.key_block == NULL)
1283 if (s->session == NULL)
1285 /* might happen if dtls1_read_bytes() calls this */
1286 SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1290 s->session->cipher=s->s3->tmp.new_cipher;
1291 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1294 if (!s->method->ssl3_enc->change_cipher_state(s,i))
1297 /* we have to record the message digest at
1298 * this point so we can get it before we read
1299 * the finished message */
1300 if (s->state & SSL_ST_CONNECT)
1302 sender=s->method->ssl3_enc->server_finished_label;
1303 slen=s->method->ssl3_enc->server_finished_label_len;
1307 sender=s->method->ssl3_enc->client_finished_label;
1308 slen=s->method->ssl3_enc->client_finished_label_len;
1311 s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1312 &(s->s3->finish_dgst1),
1313 &(s->s3->finish_dgst2),
1314 sender,slen,s->s3->tmp.peer_finish_md);
1319 int ssl3_send_alert(SSL *s, int level, int desc)
1321 /* Map tls/ssl alert value to correct one */
1322 desc=s->method->ssl3_enc->alert_value(desc);
1323 if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1324 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1325 if (desc < 0) return -1;
1326 /* If a fatal one, remove from cache */
1327 if ((level == 2) && (s->session != NULL))
1328 SSL_CTX_remove_session(s->ctx,s->session);
1330 s->s3->alert_dispatch=1;
1331 s->s3->send_alert[0]=level;
1332 s->s3->send_alert[1]=desc;
1333 if (s->s3->wbuf.left == 0) /* data still being written out? */
1334 return s->method->ssl_dispatch_alert(s);
1335 /* else data is still being written out, we will get written
1336 * some time in the future */
1340 int ssl3_dispatch_alert(SSL *s)
1343 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1345 s->s3->alert_dispatch=0;
1346 i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1349 s->s3->alert_dispatch=1;
1353 /* Alert sent to BIO. If it is important, flush it now.
1354 * If the message does not get sent due to non-blocking IO,
1355 * we will not worry too much. */
1356 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1357 (void)BIO_flush(s->wbio);
1359 if (s->msg_callback)
1360 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1362 if (s->info_callback != NULL)
1363 cb=s->info_callback;
1364 else if (s->ctx->info_callback != NULL)
1365 cb=s->ctx->info_callback;
1369 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1370 cb(s,SSL_CB_WRITE_ALERT,j);