diff options
| author | Sebastian Kirmayer <ffmpeg@kirmayer.eu> | 2021-08-09 03:26:20 +0200 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2021-12-19 01:02:59 +0100 |
| commit | dfd06ee710b547e0027a38f63cabe868e9ef1a3c (patch) | |
| tree | e38fc1510f0a7daca4f0fd7871c745ffccc4f0bb | |
| parent | bb69b734c74cc22301a4fa2c3263077ffe7064b1 (diff) | |
avutil/twofish: Fixed decryption
The previous implementation swapped the two halves of the plaintext. The
existing tests only decrypted data with a plaintext of all zeroes, which is
not affected by swapping the halves. Tests which detect the old buggy behavior
have been added.
Signed-off-by: Sebastian Kirmayer <ffmpeg@kirmayer.eu>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
| -rw-r--r-- | libavutil/tests/twofish.c | 15 | ||||
| -rw-r--r-- | libavutil/twofish.c | 8 |
2 files changed, 16 insertions, 7 deletions
diff --git a/libavutil/tests/twofish.c b/libavutil/tests/twofish.c index 74e0926eaf..7e8b129230 100644 --- a/libavutil/tests/twofish.c +++ b/libavutil/tests/twofish.c @@ -39,7 +39,7 @@ int main(int argc, char *argv[]) }; uint8_t temp[32], iv[16], rpt[32] = {0}; const int kbits[3] = {128, 192, 256}; - int i, j, err = 0; + int i, j, k, err = 0; struct AVTWOFISH *cs; cs = av_twofish_alloc(); if (!cs) @@ -70,10 +70,19 @@ int main(int argc, char *argv[]) memcpy(Key+16,Key,(kbits[j]-128) >> 3); memcpy(Key,rpt,16); memcpy(rpt,temp,16); + av_twofish_crypt(cs, temp, temp, 1, NULL, 1); + for (k = 0; k < 16; k++) { + // Need to compare to Key here, because the plaintext comes + // from rpt but was moved over to Key. + if (Key[k] != temp[k]) { + av_log(NULL, AV_LOG_ERROR, "%d %02x %02x\n", k, Key[k], temp[k]); + err = 1; + } + } } for (i = 0; i < 16; i++) { - if (rct[3 + j][i] != temp[i]) { - av_log(NULL, AV_LOG_ERROR, "%d %02x %02x\n", i, rct[3 + j][i], temp[i]); + if (rct[3 + j][i] != rpt[i]) { + av_log(NULL, AV_LOG_ERROR, "%d %02x %02x\n", i, rct[3 + j][i], rpt[i]); err = 1; } } diff --git a/libavutil/twofish.c b/libavutil/twofish.c index d84fa4f363..649b4bc41b 100644 --- a/libavutil/twofish.c +++ b/libavutil/twofish.c @@ -260,10 +260,10 @@ static void twofish_decrypt(AVTWOFISH *cs, uint8_t *dst, const uint8_t *src, uin P[3] ^= AV_RL32(iv + 12); memcpy(iv, src, 16); } - AV_WL32(dst, P[2]); - AV_WL32(dst + 4, P[3]); - AV_WL32(dst + 8, P[0]); - AV_WL32(dst + 12, P[1]); + AV_WL32(dst, P[0]); + AV_WL32(dst + 4, P[1]); + AV_WL32(dst + 8, P[2]); + AV_WL32(dst + 12, P[3]); } av_cold int av_twofish_init(AVTWOFISH *cs, const uint8_t *key, int key_bits) |