ssl/record/ssl3_buffer.c

   1 /*
   2  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include "../ssl_local.h"
  11 #include "record_local.h"
  12
  13 void SSL3_BUFFER_set_data(SSL3_BUFFER *b, const unsigned char *d, size_t n)
  14 {
  15     if (d != NULL)
  16         memcpy(b->buf, d, n);
  17     b->left = n;
  18     b->offset = 0;
  19 }
  20
  21 /*
  22  * Clear the contents of an SSL3_BUFFER but retain any memory allocated. Also
  23  * retains the default_len setting
  24  */
  25 void SSL3_BUFFER_clear(SSL3_BUFFER *b)
  26 {
  27     b->offset = 0;
  28     b->left = 0;
  29 }
  30
  31 void SSL3_BUFFER_release(SSL3_BUFFER *b)
  32 {
  33     OPENSSL_free(b->buf);
  34     b->buf = NULL;
  35 }
  36
  37 int ssl3_setup_write_buffer(SSL_CONNECTION *s, size_t numwpipes, size_t len)
  38 {
  39     unsigned char *p;
  40     size_t align = 0, headerlen;
  41     SSL3_BUFFER *wb;
  42     size_t currpipe;
  43
  44     s->rlayer.numwpipes = numwpipes;
  45
  46     if (len == 0) {
  47         if (SSL_CONNECTION_IS_DTLS(s))
  48             headerlen = DTLS1_RT_HEADER_LENGTH + 1;
  49         else
  50             headerlen = SSL3_RT_HEADER_LENGTH;
  51
  52 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
  53         align = SSL3_ALIGN_PAYLOAD - 1;
  54 #endif
  55
  56         len = ssl_get_max_send_fragment(s)
  57             + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
  58 #ifndef OPENSSL_NO_COMP
  59         if (ssl_allow_compression(s))
  60             len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
  61 #endif
  62         if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))
  63             len += headerlen + align + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
  64     }
  65
  66     wb = RECORD_LAYER_get_wbuf(&s->rlayer);
  67     for (currpipe = 0; currpipe < numwpipes; currpipe++) {
  68         SSL3_BUFFER *thiswb = &wb[currpipe];
  69
  70         if (thiswb->len != len) {
  71             OPENSSL_free(thiswb->buf);
  72             thiswb->buf = NULL;         /* force reallocation */
  73         }
  74
  75         if (thiswb->buf == NULL) {
  76             if (s->wbio == NULL || !BIO_get_ktls_send(s->wbio)) {
  77                 p = OPENSSL_malloc(len);
  78                 if (p == NULL) {
  79                     s->rlayer.numwpipes = currpipe;
  80                     /*
  81                      * We've got a malloc failure, and we're still initialising
  82                      * buffers. We assume we're so doomed that we won't even be able
  83                      * to send an alert.
  84                      */
  85                     SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_MALLOC_FAILURE);
  86                     return 0;
  87                 }
  88             } else {
  89                 p = NULL;
  90             }
  91             memset(thiswb, 0, sizeof(SSL3_BUFFER));
  92             thiswb->buf = p;
  93             thiswb->len = len;
  94         }
  95     }
  96
  97     return 1;
  98 }
  99
 100 int ssl3_setup_buffers(SSL_CONNECTION *s)
 101 {
 102     if (!ssl3_setup_write_buffer(s, 1, 0)) {
 103         /* SSLfatal() already called */
 104         return 0;
 105     }
 106     return 1;
 107 }
 108
 109 int ssl3_release_write_buffer(SSL_CONNECTION *s)
 110 {
 111     SSL3_BUFFER *wb;
 112     size_t pipes;
 113
 114     pipes = s->rlayer.numwpipes;
 115     while (pipes > 0) {
 116         wb = &RECORD_LAYER_get_wbuf(&s->rlayer)[pipes - 1];
 117
 118         if (SSL3_BUFFER_is_app_buffer(wb))
 119             SSL3_BUFFER_set_app_buffer(wb, 0);
 120         else
 121             OPENSSL_free(wb->buf);
 122         wb->buf = NULL;
 123         pipes--;
 124     }
 125     s->rlayer.numwpipes = 0;
 126     return 1;
 127 }