From ac9c19da66b54e690f17001e7eb855bae5f23d0d Mon Sep 17 00:00:00 2001 From: Måns Rullgård Date: Tue, 24 Aug 2010 13:42:28 +0000 Subject: asfcrypt: fix unaligned accesses with armcc Compilers may assume a pointer has natural alignment, even if it was assigned from a pointer type with weaker alignment requirements. It is thus not safe to assign a possibly unaligned value to a pointer, regardless of how it is subsequently dereferenced. Originally committed as revision 24897 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/asfcrypt.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'libavformat/asfcrypt.c') diff --git a/libavformat/asfcrypt.c b/libavformat/asfcrypt.c index cb3516fc50..59986e0a2c 100644 --- a/libavformat/asfcrypt.c +++ b/libavformat/asfcrypt.c @@ -139,7 +139,7 @@ void ff_asfcrypt_dec(const uint8_t key[20], uint8_t *data, int len) { struct AVDES des; struct AVRC4 rc4; int num_qwords = len >> 3; - uint64_t *qwords = (uint64_t *)data; + uint8_t *qwords = data; uint64_t rc4buff[8]; uint64_t packetkey; uint32_t ms_keys[12]; @@ -156,7 +156,7 @@ void ff_asfcrypt_dec(const uint8_t key[20], uint8_t *data, int len) { av_rc4_crypt(&rc4, (uint8_t *)rc4buff, NULL, sizeof(rc4buff), NULL, 1); multiswap_init((uint8_t *)rc4buff, ms_keys); - packetkey = AV_RN64(&qwords[num_qwords - 1]); + packetkey = AV_RN64(&qwords[num_qwords*8 - 8]); packetkey ^= rc4buff[7]; av_des_init(&des, key + 12, 64, 1); av_des_crypt(&des, (uint8_t *)&packetkey, (uint8_t *)&packetkey, 1, NULL, 1); @@ -166,7 +166,7 @@ void ff_asfcrypt_dec(const uint8_t key[20], uint8_t *data, int len) { av_rc4_crypt(&rc4, data, data, len, NULL, 1); ms_state = 0; - for (i = 0; i < num_qwords - 1; i++, qwords++) + for (i = 0; i < num_qwords - 1; i++, qwords += 8) ms_state = multiswap_enc(ms_keys, ms_state, AV_RL64(qwords)); multiswap_invert_keys(ms_keys); packetkey = (packetkey << 32) | (packetkey >> 32); -- cgit v1.2.3