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| author | Reimar Döffinger <Reimar.Doeffinger@gmx.de> | 2009-02-03 16:45:42 +0000 |
|---|---|---|
| committer | Reimar Döffinger <Reimar.Doeffinger@gmx.de> | 2009-02-03 16:45:42 +0000 |
| commit | bc17cc01edd4ae42d8ecda4f0a0cd275ae17cb3c (patch) | |
| tree | b2f497667aa2be284776c7985014295303d095fc /libavutil/des.c | |
| parent | 1a534c7f1e2cf672bbdd800e229cfe34eb089cc5 (diff) | |
| download | ffmpeg-bc17cc01edd4ae42d8ecda4f0a0cd275ae17cb3c.tar.gz | |
Add support for 3DES to DES module
Originally committed as revision 16971 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavutil/des.c')
| -rw-r--r-- | libavutil/des.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/libavutil/des.c b/libavutil/des.c index bf23df5056..5551073396 100644 --- a/libavutil/des.c +++ b/libavutil/des.c @@ -293,10 +293,14 @@ uint64_t ff_des_encdec(uint64_t in, uint64_t key, int decrypt) { #endif int av_des_init(AVDES *d, const uint8_t *key, int key_bits, int decrypt) { - if (key_bits != 64) + if (key_bits != 64 && key_bits != 192) return -1; - d->triple_des = 0; + d->triple_des = key_bits > 64; gen_roundkeys(d->round_keys[0], AV_RB64(key)); + if (d->triple_des) { + gen_roundkeys(d->round_keys[1], AV_RB64(key + 8)); + gen_roundkeys(d->round_keys[2], AV_RB64(key + 16)); + } return 0; } @@ -306,10 +310,18 @@ void av_des_crypt(AVDES *d, uint8_t *dst, const uint8_t *src, int count, uint8_t uint64_t dst_val; uint64_t src_val = src ? be2me_64(*(const uint64_t *)src) : 0; if (decrypt) { + if (d->triple_des) { + src_val = des_encdec(src_val, d->round_keys[2], 1); + src_val = des_encdec(src_val, d->round_keys[1], 0); + } dst_val = des_encdec(src_val, d->round_keys[0], 1) ^ iv_val; iv_val = iv ? src_val : 0; } else { dst_val = des_encdec(src_val ^ iv_val, d->round_keys[0], 0); + if (d->triple_des) { + dst_val = des_encdec(dst_val, d->round_keys[1], 1); + dst_val = des_encdec(dst_val, d->round_keys[2], 0); + } iv_val = iv ? dst_val : 0; } *(uint64_t *)dst = be2me_64(dst_val); |