1/* ssl/s3_both.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
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.
8 *
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).
15 *
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.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
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)"
40 *
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
51 * SUCH DAMAGE.
52 *
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.]
57 */
58/* ====================================================================
59 * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
60 *
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
63 * are met:
64 *
65 * 1. Redistributions of source code must retain the above copyright
66 *    notice, this list of conditions and the following disclaimer.
67 *
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
71 *    distribution.
72 *
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/)"
77 *
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.
82 *
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.
86 *
87 * 6. Redistributions of any form whatsoever must retain the following
88 *    acknowledgment:
89 *    "This product includes software developed by the OpenSSL Project
90 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91 *
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 * ====================================================================
105 *
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).
109 *
110 */
111/* ====================================================================
112 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
113 * ECC cipher suite support in OpenSSL originally developed by
114 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
115 */
116
117#include <limits.h>
118#include <string.h>
119#include <stdio.h>
120#include "ssl_locl.h"
121#include <openssl/buffer.h>
122#include <openssl/rand.h>
123#include <openssl/objects.h>
124#include <openssl/evp.h>
125#include <openssl/x509.h>
126
127/*
128 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
129 * SSL3_RT_CHANGE_CIPHER_SPEC)
130 */
131int ssl3_do_write(SSL *s, int type)
132{
133    int ret;
134
135    ret = ssl3_write_bytes(s, type, &s->init_buf->data[s->init_off],
136                           s->init_num);
137    if (ret < 0)
138        return (-1);
139    if (type == SSL3_RT_HANDSHAKE)
140        /*
141         * should not be done for 'Hello Request's, but in that case we'll
142         * ignore the result anyway
143         */
144        ssl3_finish_mac(s, (unsigned char *)&s->init_buf->data[s->init_off],
145                        ret);
146
147    if (ret == s->init_num) {
148        if (s->msg_callback)
149            s->msg_callback(1, s->version, type, s->init_buf->data,
150                            (size_t)(s->init_off + s->init_num), s,
151                            s->msg_callback_arg);
152        return (1);
153    }
154    s->init_off += ret;
155    s->init_num -= ret;
156    return (0);
157}
158
159int ssl3_send_finished(SSL *s, int a, int b, const char *sender, int slen)
160{
161    unsigned char *p;
162    int i;
163    unsigned long l;
164
165    if (s->state == a) {
166        p = ssl_handshake_start(s);
167
168        i = s->method->ssl3_enc->final_finish_mac(s,
169                                                  sender, slen,
170                                                  s->s3->tmp.finish_md);
171        if (i <= 0)
172            return 0;
173        s->s3->tmp.finish_md_len = i;
174        memcpy(p, s->s3->tmp.finish_md, i);
175        l = i;
176
177        /*
178         * Copy the finished so we can use it for renegotiation checks
179         */
180        if (s->type == SSL_ST_CONNECT) {
181            OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
182            memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
183            s->s3->previous_client_finished_len = i;
184        } else {
185            OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
186            memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
187            s->s3->previous_server_finished_len = i;
188        }
189
190#ifdef OPENSSL_SYS_WIN16
191        /*
192         * MSVC 1.5 does not clear the top bytes of the word unless I do
193         * this.
194         */
195        l &= 0xffff;
196#endif
197        ssl_set_handshake_header(s, SSL3_MT_FINISHED, l);
198        s->state = b;
199    }
200
201    /* SSL3_ST_SEND_xxxxxx_HELLO_B */
202    return ssl_do_write(s);
203}
204
205#ifndef OPENSSL_NO_NEXTPROTONEG
206/*
207 * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
208 * to far.
209 */
210static void ssl3_take_mac(SSL *s)
211{
212    const char *sender;
213    int slen;
214    /*
215     * If no new cipher setup return immediately: other functions will set
216     * the appropriate error.
217     */
218    if (s->s3->tmp.new_cipher == NULL)
219        return;
220    if (s->state & SSL_ST_CONNECT) {
221        sender = s->method->ssl3_enc->server_finished_label;
222        slen = s->method->ssl3_enc->server_finished_label_len;
223    } else {
224        sender = s->method->ssl3_enc->client_finished_label;
225        slen = s->method->ssl3_enc->client_finished_label_len;
226    }
227
228    s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
229                                                                          sender,
230                                                                          slen,
231                                                                          s->s3->tmp.peer_finish_md);
232}
233#endif
234
235int ssl3_get_finished(SSL *s, int a, int b)
236{
237    int al, i, ok;
238    long n;
239    unsigned char *p;
240
241#ifdef OPENSSL_NO_NEXTPROTONEG
242    /*
243     * the mac has already been generated when we received the change cipher
244     * spec message and is in s->s3->tmp.peer_finish_md
245     */
246#endif
247
248    /* 64 argument should actually be 36+4 :-) */
249    n = s->method->ssl_get_message(s, a, b, SSL3_MT_FINISHED, 64, &ok);
250
251    if (!ok)
252        return ((int)n);
253
254    /* If this occurs, we have missed a message */
255    if (!s->s3->change_cipher_spec) {
256        al = SSL_AD_UNEXPECTED_MESSAGE;
257        SSLerr(SSL_F_SSL3_GET_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
258        goto f_err;
259    }
260    s->s3->change_cipher_spec = 0;
261
262    p = (unsigned char *)s->init_msg;
263    i = s->s3->tmp.peer_finish_md_len;
264
265    if (i != n) {
266        al = SSL_AD_DECODE_ERROR;
267        SSLerr(SSL_F_SSL3_GET_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
268        goto f_err;
269    }
270
271    if (CRYPTO_memcmp(p, s->s3->tmp.peer_finish_md, i) != 0) {
272        al = SSL_AD_DECRYPT_ERROR;
273        SSLerr(SSL_F_SSL3_GET_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
274        goto f_err;
275    }
276
277    /*
278     * Copy the finished so we can use it for renegotiation checks
279     */
280    if (s->type == SSL_ST_ACCEPT) {
281        OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
282        memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md, i);
283        s->s3->previous_client_finished_len = i;
284    } else {
285        OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
286        memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md, i);
287        s->s3->previous_server_finished_len = i;
288    }
289
290    return (1);
291 f_err:
292    ssl3_send_alert(s, SSL3_AL_FATAL, al);
293    return (0);
294}
295
296/*-
297 * for these 2 messages, we need to
298 * ssl->enc_read_ctx                    re-init
299 * ssl->s3->read_sequence               zero
300 * ssl->s3->read_mac_secret             re-init
301 * ssl->session->read_sym_enc           assign
302 * ssl->session->read_compression       assign
303 * ssl->session->read_hash              assign
304 */
305int ssl3_send_change_cipher_spec(SSL *s, int a, int b)
306{
307    unsigned char *p;
308
309    if (s->state == a) {
310        p = (unsigned char *)s->init_buf->data;
311        *p = SSL3_MT_CCS;
312        s->init_num = 1;
313        s->init_off = 0;
314
315        s->state = b;
316    }
317
318    /* SSL3_ST_CW_CHANGE_B */
319    return (ssl3_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
320}
321
322unsigned long ssl3_output_cert_chain(SSL *s, CERT_PKEY *cpk)
323{
324    unsigned char *p;
325    unsigned long l = 3 + SSL_HM_HEADER_LENGTH(s);
326
327    if (!ssl_add_cert_chain(s, cpk, &l))
328        return 0;
329
330    l -= 3 + SSL_HM_HEADER_LENGTH(s);
331    p = ssl_handshake_start(s);
332    l2n3(l, p);
333    l += 3;
334    ssl_set_handshake_header(s, SSL3_MT_CERTIFICATE, l);
335    return l + SSL_HM_HEADER_LENGTH(s);
336}
337
338/*
339 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum
340 * acceptable body length 'max'. The first four bytes (msg_type and length)
341 * are read in state 'st1', the body is read in state 'stn'.
342 */
343long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
344{
345    unsigned char *p;
346    unsigned long l;
347    long n;
348    int i, al;
349
350    if (s->s3->tmp.reuse_message) {
351        s->s3->tmp.reuse_message = 0;
352        if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
353            al = SSL_AD_UNEXPECTED_MESSAGE;
354            SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
355            goto f_err;
356        }
357        *ok = 1;
358        s->state = stn;
359        s->init_msg = s->init_buf->data + 4;
360        s->init_num = (int)s->s3->tmp.message_size;
361        return s->init_num;
362    }
363
364    p = (unsigned char *)s->init_buf->data;
365
366    if (s->state == st1) {      /* s->init_num < 4 */
367        int skip_message;
368
369        do {
370            while (s->init_num < 4) {
371                i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
372                                              &p[s->init_num],
373                                              4 - s->init_num, 0);
374                if (i <= 0) {
375                    s->rwstate = SSL_READING;
376                    *ok = 0;
377                    return i;
378                }
379                s->init_num += i;
380            }
381
382            skip_message = 0;
383            if (!s->server)
384                if (p[0] == SSL3_MT_HELLO_REQUEST)
385                    /*
386                     * The server may always send 'Hello Request' messages --
387                     * we are doing a handshake anyway now, so ignore them if
388                     * their format is correct. Does not count for 'Finished'
389                     * MAC.
390                     */
391                    if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
392                        s->init_num = 0;
393                        skip_message = 1;
394
395                        if (s->msg_callback)
396                            s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
397                                            p, 4, s, s->msg_callback_arg);
398                    }
399        }
400        while (skip_message);
401
402        /* s->init_num == 4 */
403
404        if ((mt >= 0) && (*p != mt)) {
405            al = SSL_AD_UNEXPECTED_MESSAGE;
406            SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
407            goto f_err;
408        }
409
410        s->s3->tmp.message_type = *(p++);
411
412        n2l3(p, l);
413        if (l > (unsigned long)max) {
414            al = SSL_AD_ILLEGAL_PARAMETER;
415            SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
416            goto f_err;
417        }
418        if (l > (INT_MAX - 4)) { /* BUF_MEM_grow takes an 'int' parameter */
419            al = SSL_AD_ILLEGAL_PARAMETER;
420            SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
421            goto f_err;
422        }
423        if (l && !BUF_MEM_grow_clean(s->init_buf, (int)l + 4)) {
424            SSLerr(SSL_F_SSL3_GET_MESSAGE, ERR_R_BUF_LIB);
425            goto err;
426        }
427        s->s3->tmp.message_size = l;
428        s->state = stn;
429
430        s->init_msg = s->init_buf->data + 4;
431        s->init_num = 0;
432    }
433
434    /* next state (stn) */
435    p = s->init_msg;
436    n = s->s3->tmp.message_size - s->init_num;
437    while (n > 0) {
438        i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &p[s->init_num],
439                                      n, 0);
440        if (i <= 0) {
441            s->rwstate = SSL_READING;
442            *ok = 0;
443            return i;
444        }
445        s->init_num += i;
446        n -= i;
447    }
448
449#ifndef OPENSSL_NO_NEXTPROTONEG
450    /*
451     * If receiving Finished, record MAC of prior handshake messages for
452     * Finished verification.
453     */
454    if (*s->init_buf->data == SSL3_MT_FINISHED)
455        ssl3_take_mac(s);
456#endif
457
458    /* Feed this message into MAC computation. */
459    ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, s->init_num + 4);
460    if (s->msg_callback)
461        s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
462                        (size_t)s->init_num + 4, s, s->msg_callback_arg);
463    *ok = 1;
464    return s->init_num;
465 f_err:
466    ssl3_send_alert(s, SSL3_AL_FATAL, al);
467 err:
468    *ok = 0;
469    return (-1);
470}
471
472int ssl_cert_type(X509 *x, EVP_PKEY *pkey)
473{
474    EVP_PKEY *pk;
475    int ret = -1, i;
476
477    if (pkey == NULL)
478        pk = X509_get_pubkey(x);
479    else
480        pk = pkey;
481    if (pk == NULL)
482        goto err;
483
484    i = pk->type;
485    if (i == EVP_PKEY_RSA) {
486        ret = SSL_PKEY_RSA_ENC;
487    } else if (i == EVP_PKEY_DSA) {
488        ret = SSL_PKEY_DSA_SIGN;
489    }
490#ifndef OPENSSL_NO_EC
491    else if (i == EVP_PKEY_EC) {
492        ret = SSL_PKEY_ECC;
493    }
494#endif
495    else if (i == NID_id_GostR3410_94 || i == NID_id_GostR3410_94_cc) {
496        ret = SSL_PKEY_GOST94;
497    } else if (i == NID_id_GostR3410_2001 || i == NID_id_GostR3410_2001_cc) {
498        ret = SSL_PKEY_GOST01;
499    } else if (x && (i == EVP_PKEY_DH || i == EVP_PKEY_DHX)) {
500        /*
501         * For DH two cases: DH certificate signed with RSA and DH
502         * certificate signed with DSA.
503         */
504        i = X509_certificate_type(x, pk);
505        if (i & EVP_PKS_RSA)
506            ret = SSL_PKEY_DH_RSA;
507        else if (i & EVP_PKS_DSA)
508            ret = SSL_PKEY_DH_DSA;
509    }
510
511 err:
512    if (!pkey)
513        EVP_PKEY_free(pk);
514    return (ret);
515}
516
517int ssl_verify_alarm_type(long type)
518{
519    int al;
520
521    switch (type) {
522    case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
523    case X509_V_ERR_UNABLE_TO_GET_CRL:
524    case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
525        al = SSL_AD_UNKNOWN_CA;
526        break;
527    case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
528    case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
529    case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
530    case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
531    case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
532    case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
533    case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
534    case X509_V_ERR_CERT_NOT_YET_VALID:
535    case X509_V_ERR_CRL_NOT_YET_VALID:
536    case X509_V_ERR_CERT_UNTRUSTED:
537    case X509_V_ERR_CERT_REJECTED:
538        al = SSL_AD_BAD_CERTIFICATE;
539        break;
540    case X509_V_ERR_CERT_SIGNATURE_FAILURE:
541    case X509_V_ERR_CRL_SIGNATURE_FAILURE:
542        al = SSL_AD_DECRYPT_ERROR;
543        break;
544    case X509_V_ERR_CERT_HAS_EXPIRED:
545    case X509_V_ERR_CRL_HAS_EXPIRED:
546        al = SSL_AD_CERTIFICATE_EXPIRED;
547        break;
548    case X509_V_ERR_CERT_REVOKED:
549        al = SSL_AD_CERTIFICATE_REVOKED;
550        break;
551    case X509_V_ERR_OUT_OF_MEM:
552        al = SSL_AD_INTERNAL_ERROR;
553        break;
554    case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
555    case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
556    case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
557    case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
558    case X509_V_ERR_CERT_CHAIN_TOO_LONG:
559    case X509_V_ERR_PATH_LENGTH_EXCEEDED:
560    case X509_V_ERR_INVALID_CA:
561        al = SSL_AD_UNKNOWN_CA;
562        break;
563    case X509_V_ERR_APPLICATION_VERIFICATION:
564        al = SSL_AD_HANDSHAKE_FAILURE;
565        break;
566    case X509_V_ERR_INVALID_PURPOSE:
567        al = SSL_AD_UNSUPPORTED_CERTIFICATE;
568        break;
569    default:
570        al = SSL_AD_CERTIFICATE_UNKNOWN;
571        break;
572    }
573    return (al);
574}
575
576#ifndef OPENSSL_NO_BUF_FREELISTS
577/*-
578 * On some platforms, malloc() performance is bad enough that you can't just
579 * free() and malloc() buffers all the time, so we need to use freelists from
580 * unused buffers.  Currently, each freelist holds memory chunks of only a
581 * given size (list->chunklen); other sized chunks are freed and malloced.
582 * This doesn't help much if you're using many different SSL option settings
583 * with a given context.  (The options affecting buffer size are
584 * max_send_fragment, read buffer vs write buffer,
585 * SSL_OP_MICROSOFT_BIG_WRITE_BUFFER, SSL_OP_NO_COMPRESSION, and
586 * SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS.)  Using a separate freelist for every
587 * possible size is not an option, since max_send_fragment can take on many
588 * different values.
589 *
590 * If you are on a platform with a slow malloc(), and you're using SSL
591 * connections with many different settings for these options, and you need to
592 * use the SSL_MOD_RELEASE_BUFFERS feature, you have a few options:
593 *    - Link against a faster malloc implementation.
594 *    - Use a separate SSL_CTX for each option set.
595 *    - Improve this code.
596 */
597static void *freelist_extract(SSL_CTX *ctx, int for_read, int sz)
598{
599    SSL3_BUF_FREELIST *list;
600    SSL3_BUF_FREELIST_ENTRY *ent = NULL;
601    void *result = NULL;
602
603    CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
604    list = for_read ? ctx->rbuf_freelist : ctx->wbuf_freelist;
605    if (list != NULL && sz == (int)list->chunklen)
606        ent = list->head;
607    if (ent != NULL) {
608        list->head = ent->next;
609        result = ent;
610        if (--list->len == 0)
611            list->chunklen = 0;
612    }
613    CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
614    if (!result)
615        result = OPENSSL_malloc(sz);
616    return result;
617}
618
619static void freelist_insert(SSL_CTX *ctx, int for_read, size_t sz, void *mem)
620{
621    SSL3_BUF_FREELIST *list;
622    SSL3_BUF_FREELIST_ENTRY *ent;
623
624    CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
625    list = for_read ? ctx->rbuf_freelist : ctx->wbuf_freelist;
626    if (list != NULL &&
627        (sz == list->chunklen || list->chunklen == 0) &&
628        list->len < ctx->freelist_max_len && sz >= sizeof(*ent)) {
629        list->chunklen = sz;
630        ent = mem;
631        ent->next = list->head;
632        list->head = ent;
633        ++list->len;
634        mem = NULL;
635    }
636
637    CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
638    if (mem)
639        OPENSSL_free(mem);
640}
641#else
642# define freelist_extract(c,fr,sz) OPENSSL_malloc(sz)
643# define freelist_insert(c,fr,sz,m) OPENSSL_free(m)
644#endif
645
646int ssl3_setup_read_buffer(SSL *s)
647{
648    unsigned char *p;
649    size_t len, align = 0, headerlen;
650
651    if (SSL_IS_DTLS(s))
652        headerlen = DTLS1_RT_HEADER_LENGTH;
653    else
654        headerlen = SSL3_RT_HEADER_LENGTH;
655
656#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
657    align = (-SSL3_RT_HEADER_LENGTH) & (SSL3_ALIGN_PAYLOAD - 1);
658#endif
659
660    if (s->s3->rbuf.buf == NULL) {
661        len = SSL3_RT_MAX_PLAIN_LENGTH
662            + SSL3_RT_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
663        if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER) {
664            s->s3->init_extra = 1;
665            len += SSL3_RT_MAX_EXTRA;
666        }
667#ifndef OPENSSL_NO_COMP
668        if (!(s->options & SSL_OP_NO_COMPRESSION))
669            len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
670#endif
671        if ((p = freelist_extract(s->ctx, 1, len)) == NULL)
672            goto err;
673        s->s3->rbuf.buf = p;
674        s->s3->rbuf.len = len;
675    }
676
677    s->packet = &(s->s3->rbuf.buf[0]);
678    return 1;
679
680 err:
681    SSLerr(SSL_F_SSL3_SETUP_READ_BUFFER, ERR_R_MALLOC_FAILURE);
682    return 0;
683}
684
685int ssl3_setup_write_buffer(SSL *s)
686{
687    unsigned char *p;
688    size_t len, align = 0, headerlen;
689
690    if (SSL_IS_DTLS(s))
691        headerlen = DTLS1_RT_HEADER_LENGTH + 1;
692    else
693        headerlen = SSL3_RT_HEADER_LENGTH;
694
695#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
696    align = (-SSL3_RT_HEADER_LENGTH) & (SSL3_ALIGN_PAYLOAD - 1);
697#endif
698
699    if (s->s3->wbuf.buf == NULL) {
700        len = s->max_send_fragment
701            + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
702#ifndef OPENSSL_NO_COMP
703        if (!(s->options & SSL_OP_NO_COMPRESSION))
704            len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
705#endif
706        if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))
707            len += headerlen + align + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
708
709        if ((p = freelist_extract(s->ctx, 0, len)) == NULL)
710            goto err;
711        s->s3->wbuf.buf = p;
712        s->s3->wbuf.len = len;
713    }
714
715    return 1;
716
717 err:
718    SSLerr(SSL_F_SSL3_SETUP_WRITE_BUFFER, ERR_R_MALLOC_FAILURE);
719    return 0;
720}
721
722int ssl3_setup_buffers(SSL *s)
723{
724    if (!ssl3_setup_read_buffer(s))
725        return 0;
726    if (!ssl3_setup_write_buffer(s))
727        return 0;
728    return 1;
729}
730
731int ssl3_release_write_buffer(SSL *s)
732{
733    if (s->s3->wbuf.buf != NULL) {
734        freelist_insert(s->ctx, 0, s->s3->wbuf.len, s->s3->wbuf.buf);
735        s->s3->wbuf.buf = NULL;
736    }
737    return 1;
738}
739
740int ssl3_release_read_buffer(SSL *s)
741{
742    if (s->s3->rbuf.buf != NULL) {
743        freelist_insert(s->ctx, 1, s->s3->rbuf.len, s->s3->rbuf.buf);
744        s->s3->rbuf.buf = NULL;
745    }
746    return 1;
747}
748