Fix for CVE-2014-0195

[openssl.git] / ssl / d1_both.c

diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index 48db2464247c0b16d13aadb398cb6e4e864bbca3..7de9ae4b5fd86c9533d54183d6c536f5f1d2bf61 100644 (file)
--- a/ssl/d1_both.c
+++ b/ssl/d1_both.c
@@ -214,6 +214,12 @@ dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
 static void
 dtls1_hm_fragment_free(hm_fragment *frag)
        {
+
+       if (frag->msg_header.is_ccs)
+               {
+               EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
+               EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
+               }
        if (frag->fragment) OPENSSL_free(frag->fragment);
        if (frag->reassembly) OPENSSL_free(frag->reassembly);
        OPENSSL_free(frag);
@@ -227,14 +233,14 @@ int dtls1_do_write(SSL *s, int type)
        unsigned int len, frag_off, mac_size, blocksize;
 
        /* AHA!  Figure out the MTU, and stick to the right size */
-       if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
+       if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
                {
                s->d1->mtu = 
                        BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 
                /* I've seen the kernel return bogus numbers when it doesn't know
                 * (initial write), so just make sure we have a reasonable number */
-               if ( s->d1->mtu < dtls1_min_mtu())
+               if (s->d1->mtu < dtls1_min_mtu())
                        {
                        s->d1->mtu = 0;
                        s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
@@ -313,9 +319,10 @@ int dtls1_do_write(SSL *s, int type)
                                s->init_off -= DTLS1_HM_HEADER_LENGTH;
                                s->init_num += DTLS1_HM_HEADER_LENGTH;
 
-                               /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
-                               if ( len <= DTLS1_HM_HEADER_LENGTH)  
-                                       len += DTLS1_HM_HEADER_LENGTH;
+                               if ( s->init_num > curr_mtu)
+                                       len = curr_mtu;
+                               else
+                                       len = s->init_num;
                                }
 
                        dtls1_fix_message_header(s, frag_off, 
@@ -620,7 +627,16 @@ dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
                frag->msg_header.frag_off = 0;
                }
        else
+               {
                frag = (hm_fragment*) item->data;
+               if (frag->msg_header.msg_len != msg_hdr->msg_len)
+                       {
+                       item = NULL;
+                       frag = NULL;
+                       goto err;
+                       }
+               }
+
 
        /* If message is already reassembled, this must be a
         * retransmit and can be dropped.
@@ -667,8 +683,8 @@ dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
                item = pitem_new(seq64be, frag);
                if (item == NULL)
                        {
-                       goto err;
                        i = -1;
+                       goto err;
                        }
 
                pqueue_insert(s->d1->buffered_messages, item);
@@ -1452,26 +1468,36 @@ dtls1_process_heartbeat(SSL *s)
        unsigned int payload;
        unsigned int padding = 16; /* Use minimum padding */
 
-       /* Read type and payload length first */
-       hbtype = *p++;
-       n2s(p, payload);
-       pl = p;
-
        if (s->msg_callback)
                s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
                        &s->s3->rrec.data[0], s->s3->rrec.length,
                        s, s->msg_callback_arg);
 
+       /* Read type and payload length first */
+       if (1 + 2 + 16 > s->s3->rrec.length)
+               return 0; /* silently discard */
+       hbtype = *p++;
+       n2s(p, payload);
+       if (1 + 2 + payload + 16 > s->s3->rrec.length)
+               return 0; /* silently discard per RFC 6520 sec. 4 */
+       pl = p;
+
        if (hbtype == TLS1_HB_REQUEST)
                {
                unsigned char *buffer, *bp;
+               unsigned int write_length = 1 /* heartbeat type */ +
+                                           2 /* heartbeat length */ +
+                                           payload + padding;
                int r;
 
+               if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
+                       return 0;
+
                /* Allocate memory for the response, size is 1 byte
                 * message type, plus 2 bytes payload length, plus
                 * payload, plus padding
                 */
-               buffer = OPENSSL_malloc(1 + 2 + payload + padding);
+               buffer = OPENSSL_malloc(write_length);
                bp = buffer;
 
                /* Enter response type, length and copy payload */
@@ -1482,11 +1508,11 @@ dtls1_process_heartbeat(SSL *s)
                /* Random padding */
                RAND_pseudo_bytes(bp, padding);
 
-               r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding);
+               r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
 
                if (r >= 0 && s->msg_callback)
                        s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
-                               buffer, 3 + payload + padding,
+                               buffer, write_length,
                                s, s->msg_callback_arg);
 
                OPENSSL_free(buffer);