Commit 9f81ffe4 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

PR: 2089 

Submitted by: Robin Seggelmann <seggelmann@fh-muenster.de>
Approved by: steve@openssl.org

DTLS Fragment size bug fix.
parent 81649308

ssl/d1_both.c

+15 −3
Original line number Diff line number Diff line
@@ -177,7 +177,7 @@ int dtls1_do_write(SSL *s, int type) 
	{

	int ret;

	int curr_mtu;

	unsigned int len, frag_off;

	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))
@@ -225,11 +225,22 @@ int dtls1_do_write(SSL *s, int type) 
		OPENSSL_assert(s->init_num == 

			(int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);



	if (s->write_hash)

		mac_size = EVP_MD_CTX_size(s->write_hash);

	else

		mac_size = 0;



	if (s->enc_write_ctx && 

		(EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))

		blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);

	else

		blocksize = 0;



	frag_off = 0;

	while( s->init_num)

		{

		curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 

			DTLS1_RT_HEADER_LENGTH;

			DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;



		if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)

			{
@@ -237,7 +248,8 @@ int dtls1_do_write(SSL *s, int type) 
			ret = BIO_flush(SSL_get_wbio(s));

			if ( ret <= 0)

				return ret;

			curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH;

			curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -

				mac_size - blocksize;

			}



		if ( s->init_num > curr_mtu)