ssl/s3_msg.c

   1 /*
   2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (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 #define USE_SOCKETS
  11 #include "ssl_locl.h"
  12
  13 int ssl3_do_change_cipher_spec(SSL *s)
  14 {
  15     int i;
  16     size_t finish_md_len;
  17     const char *sender;
  18     size_t slen;
  19
  20     if (s->server)
  21         i = SSL3_CHANGE_CIPHER_SERVER_READ;
  22     else
  23         i = SSL3_CHANGE_CIPHER_CLIENT_READ;
  24
  25     if (s->s3->tmp.key_block == NULL) {
  26         if (s->session == NULL || s->session->master_key_length == 0) {
  27             /* might happen if dtls1_read_bytes() calls this */
  28             SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
  29             return (0);
  30         }
  31
  32         s->session->cipher = s->s3->tmp.new_cipher;
  33         if (!s->method->ssl3_enc->setup_key_block(s))
  34             return (0);
  35     }
  36
  37     if (!s->method->ssl3_enc->change_cipher_state(s, i))
  38         return (0);
  39
  40     /*
  41      * we have to record the message digest at this point so we can get it
  42      * before we read the finished message
  43      */
  44     if (!s->server) {
  45         sender = s->method->ssl3_enc->server_finished_label;
  46         slen = s->method->ssl3_enc->server_finished_label_len;
  47     } else {
  48         sender = s->method->ssl3_enc->client_finished_label;
  49         slen = s->method->ssl3_enc->client_finished_label_len;
  50     }
  51
  52     finish_md_len = s->method->ssl3_enc->final_finish_mac(s, sender, slen,
  53                                             s->s3->tmp.peer_finish_md);
  54     if (finish_md_len == 0) {
  55         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
  56         return 0;
  57     }
  58     s->s3->tmp.peer_finish_md_len = finish_md_len;
  59
  60     return (1);
  61 }
  62
  63 int ssl3_send_alert(SSL *s, int level, int desc)
  64 {
  65     /* Map tls/ssl alert value to correct one */
  66     desc = s->method->ssl3_enc->alert_value(desc);
  67     if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
  68         desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have
  69                                           * protocol_version alerts */
  70     if (desc < 0)
  71         return -1;
  72     /* If a fatal one, remove from cache */
  73     if ((level == SSL3_AL_FATAL) && (s->session != NULL))
  74         SSL_CTX_remove_session(s->session_ctx, s->session);
  75
  76     s->s3->alert_dispatch = 1;
  77     s->s3->send_alert[0] = level;
  78     s->s3->send_alert[1] = desc;
  79     if (!RECORD_LAYER_write_pending(&s->rlayer)) {
  80         /* data still being written out? */
  81         return s->method->ssl_dispatch_alert(s);
  82     }
  83     /*
  84      * else data is still being written out, we will get written some time in
  85      * the future
  86      */
  87     return -1;
  88 }
  89
  90 int ssl3_dispatch_alert(SSL *s)
  91 {
  92     int i, j;
  93     size_t alertlen;
  94     void (*cb) (const SSL *ssl, int type, int val) = NULL;
  95     size_t written;
  96
  97     s->s3->alert_dispatch = 0;
  98     alertlen = 2;
  99     i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], &alertlen, 1, 0,
 100                       &written);
 101     if (i <= 0) {
 102         s->s3->alert_dispatch = 1;
 103     } else {
 104         /*
 105          * Alert sent to BIO.  If it is important, flush it now. If the
 106          * message does not get sent due to non-blocking IO, we will not
 107          * worry too much.
 108          */
 109         if (s->s3->send_alert[0] == SSL3_AL_FATAL)
 110             (void)BIO_flush(s->wbio);
 111
 112         if (s->msg_callback)
 113             s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
 114                             2, s, s->msg_callback_arg);
 115
 116         if (s->info_callback != NULL)
 117             cb = s->info_callback;
 118         else if (s->ctx->info_callback != NULL)
 119             cb = s->ctx->info_callback;
 120
 121         if (cb != NULL) {
 122             j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
 123             cb(s, SSL_CB_WRITE_ALERT, j);
 124         }
 125     }
 126     return i;
 127 }