ssl/record/ssl3_buffer.c

   1 /*
   2  * Copyright 1995-2017 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_read_buffer(SSL *s)
  38 {
  39     unsigned char *p;
  40     size_t len, align = 0, headerlen;
  41     SSL3_BUFFER *b;
  42
  43     b = RECORD_LAYER_get_rbuf(&s->rlayer);
  44
  45     if (SSL_IS_DTLS(s))
  46         headerlen = DTLS1_RT_HEADER_LENGTH;
  47     else
  48         headerlen = SSL3_RT_HEADER_LENGTH;
  49
  50 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
  51     align = (-SSL3_RT_HEADER_LENGTH) & (SSL3_ALIGN_PAYLOAD - 1);
  52 #endif
  53
  54     if (b->buf == NULL) {
  55         len = SSL3_RT_MAX_PLAIN_LENGTH
  56             + SSL3_RT_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
  57 #ifndef OPENSSL_NO_COMP
  58         if (ssl_allow_compression(s))
  59             len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
  60 #endif
  61         if (b->default_len > len)
  62             len = b->default_len;
  63         if ((p = OPENSSL_malloc(len)) == NULL) {
  64             /*
  65              * We've got a malloc failure, and we're still initialising buffers.
  66              * We assume we're so doomed that we won't even be able to send an
  67              * alert.
  68              */
  69             SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_SETUP_READ_BUFFER,
  70                      ERR_R_MALLOC_FAILURE);
  71             return 0;
  72         }
  73         b->buf = p;
  74         b->len = len;
  75     }
  76
  77     RECORD_LAYER_set_packet(&s->rlayer, &(b->buf[0]));
  78     return 1;
  79 }
  80
  81 int ssl3_setup_write_buffer(SSL *s, size_t numwpipes, size_t len)
  82 {
  83     unsigned char *p;
  84     size_t align = 0, headerlen;
  85     SSL3_BUFFER *wb;
  86     size_t currpipe;
  87
  88     s->rlayer.numwpipes = numwpipes;
  89
  90     if (len == 0) {
  91         if (SSL_IS_DTLS(s))
  92             headerlen = DTLS1_RT_HEADER_LENGTH + 1;
  93         else
  94             headerlen = SSL3_RT_HEADER_LENGTH;
  95
  96 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
  97         align = (-SSL3_RT_HEADER_LENGTH) & (SSL3_ALIGN_PAYLOAD - 1);
  98 #endif
  99
 100         len = ssl_get_max_send_fragment(s)
 101             + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
 102 #ifndef OPENSSL_NO_COMP
 103         if (ssl_allow_compression(s))
 104             len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
 105 #endif
 106         if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))
 107             len += headerlen + align + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
 108     }
 109
 110     wb = RECORD_LAYER_get_wbuf(&s->rlayer);
 111     for (currpipe = 0; currpipe < numwpipes; currpipe++) {
 112         SSL3_BUFFER *thiswb = &wb[currpipe];
 113
 114         if (thiswb->len != len) {
 115             OPENSSL_free(thiswb->buf);
 116             thiswb->buf = NULL;         /* force reallocation */
 117         }
 118
 119         if (thiswb->buf == NULL) {
 120             if (s->wbio == NULL || !BIO_get_ktls_send(s->wbio)) {
 121                 p = OPENSSL_malloc(len);
 122                 if (p == NULL) {
 123                     s->rlayer.numwpipes = currpipe;
 124                     /*
 125                      * We've got a malloc failure, and we're still initialising
 126                      * buffers. We assume we're so doomed that we won't even be able
 127                      * to send an alert.
 128                      */
 129                     SSLfatal(s, SSL_AD_NO_ALERT,
 130                             SSL_F_SSL3_SETUP_WRITE_BUFFER, ERR_R_MALLOC_FAILURE);
 131                     return 0;
 132                 }
 133             } else {
 134                 p = NULL;
 135             }
 136             memset(thiswb, 0, sizeof(SSL3_BUFFER));
 137             thiswb->buf = p;
 138             thiswb->len = len;
 139         }
 140     }
 141
 142     return 1;
 143 }
 144
 145 int ssl3_setup_buffers(SSL *s)
 146 {
 147     if (!ssl3_setup_read_buffer(s)) {
 148         /* SSLfatal() already called */
 149         return 0;
 150     }
 151     if (!ssl3_setup_write_buffer(s, 1, 0)) {
 152         /* SSLfatal() already called */
 153         return 0;
 154     }
 155     return 1;
 156 }
 157
 158 int ssl3_release_write_buffer(SSL *s)
 159 {
 160     SSL3_BUFFER *wb;
 161     size_t pipes;
 162
 163     pipes = s->rlayer.numwpipes;
 164     while (pipes > 0) {
 165         wb = &RECORD_LAYER_get_wbuf(&s->rlayer)[pipes - 1];
 166
 167         if (s->wbio == NULL || !BIO_get_ktls_send(s->wbio))
 168             OPENSSL_free(wb->buf);
 169         wb->buf = NULL;
 170         pipes--;
 171     }
 172     s->rlayer.numwpipes = 0;
 173     return 1;
 174 }
 175
 176 int ssl3_release_read_buffer(SSL *s)
 177 {
 178     SSL3_BUFFER *b;
 179
 180     b = RECORD_LAYER_get_rbuf(&s->rlayer);
 181     OPENSSL_free(b->buf);
 182     b->buf = NULL;
 183     return 1;
 184 }