From f08be096517f9bdae8a9d1d837748237db4d13a9 Mon Sep 17 00:00:00 2001 From: Frederik Wedel-Heinen Date: Wed, 13 Mar 2024 10:17:37 +0100 Subject: Avoid a memcpy in dtls_get_reassembled_message() Reviewed-by: Matt Caswell Reviewed-by: Tomas Mraz (Merged from https://github.com/openssl/openssl/pull/23828) --- ssl/statem/statem_dtls.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/ssl/statem/statem_dtls.c b/ssl/statem/statem_dtls.c index 166e2075a4..3897183f81 100644 --- a/ssl/statem/statem_dtls.c +++ b/ssl/statem/statem_dtls.c @@ -800,7 +800,6 @@ static int dtls1_process_out_of_seq_message(SSL_CONNECTION *s, static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype, size_t *len) { - unsigned char wire[DTLS1_HM_HEADER_LENGTH]; size_t mlen, frag_off, frag_len; int i, ret; uint8_t recvd_type; @@ -808,9 +807,12 @@ static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype, size_t readbytes; SSL *ssl = SSL_CONNECTION_GET_SSL(s); int chretran = 0; + unsigned char *p; *errtype = 0; + p = (unsigned char *)s->init_buf->data; + redo: /* see if we have the required fragment already */ ret = dtls1_retrieve_buffered_fragment(s, &frag_len); @@ -825,7 +827,7 @@ static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype, } /* read handshake message header */ - i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, &recvd_type, wire, + i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, &recvd_type, p, DTLS1_HM_HEADER_LENGTH, 0, &readbytes); if (i <= 0) { /* nbio, or an error */ s->rwstate = SSL_READING; @@ -833,13 +835,12 @@ static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype, return 0; } if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) { - if (wire[0] != SSL3_MT_CCS) { + if (p[0] != SSL3_MT_CCS) { SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_BAD_CHANGE_CIPHER_SPEC); goto f_err; } - memcpy(s->init_buf->data, wire, readbytes); s->init_num = readbytes - 1; s->init_msg = s->init_buf->data + 1; s->s3.tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC; @@ -855,7 +856,7 @@ static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype, } /* parse the message fragment header */ - dtls1_get_message_header(wire, &msg_hdr); + dtls1_get_message_header(p, &msg_hdr); mlen = msg_hdr.msg_len; frag_off = msg_hdr.frag_off; @@ -880,7 +881,7 @@ static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype, if (!s->server || msg_hdr.seq != 0 || s->d1->handshake_read_seq != 1 - || wire[0] != SSL3_MT_CLIENT_HELLO + || p[0] != SSL3_MT_CLIENT_HELLO || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) { *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr); return 0; @@ -901,16 +902,16 @@ static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype, if (!s->server && s->d1->r_msg_hdr.frag_off == 0 && s->statem.hand_state != TLS_ST_OK - && wire[0] == SSL3_MT_HELLO_REQUEST) { + && p[0] == SSL3_MT_HELLO_REQUEST) { /* * The server may always send 'Hello Request' messages -- we are * doing a handshake anyway now, so ignore them if their format is * correct. Does not count for 'Finished' MAC. */ - if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) { + if (p[1] == 0 && p[2] == 0 && p[3] == 0) { if (s->msg_callback) s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, - wire, DTLS1_HM_HEADER_LENGTH, ssl, + p, DTLS1_HM_HEADER_LENGTH, ssl, s->msg_callback_arg); s->init_num = 0; @@ -928,8 +929,7 @@ static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype, } if (frag_len > 0) { - unsigned char *p = - (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; + p += DTLS1_HM_HEADER_LENGTH; i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL, &p[frag_off], frag_len, 0, &readbytes); -- cgit v1.2.3