ffmpeg | branch: master | Supraja Meedinti <supraja0...@gmail.com> | Thu Dec 18 15:44:32 2014 +0530| [4e1ecfe21476ee2631525a7d6dc2a0bc8151d0a9] | committer: Michael Niedermayer
libavutil: Added cbc mode to cast128 Signed-off-by: Supraja Meedinti <supraja0...@gmail.com> Previous version reviewed-by: Giorgio Vazzana <mywin...@gmail.com> Signed-off-by: Michael Niedermayer <michae...@gmx.at> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4e1ecfe21476ee2631525a7d6dc2a0bc8151d0a9 --- libavutil/cast5.c | 44 ++++++++++++++++++++++++++++++++++++++++++-- libavutil/cast5.h | 14 +++++++++++++- 2 files changed, 55 insertions(+), 3 deletions(-) diff --git a/libavutil/cast5.c b/libavutil/cast5.c index 14dd701..6f58382 100644 --- a/libavutil/cast5.c +++ b/libavutil/cast5.c @@ -416,7 +416,7 @@ static void encipher(AVCAST5* cs, uint8_t* dst, const uint8_t* src) AV_WB32(dst + 4, l); } -static void decipher(AVCAST5* cs, uint8_t* dst, const uint8_t* src) +static void decipher(AVCAST5* cs, uint8_t* dst, const uint8_t* src, uint8_t *iv) { uint32_t f, I, r, l; l = AV_RB32(src); @@ -439,6 +439,11 @@ static void decipher(AVCAST5* cs, uint8_t* dst, const uint8_t* src) F3(r, l, 3); F2(l, r, 2); F1(r, l, 1); + if (iv) { + r ^= AV_RB32(iv); + l ^= AV_RB32(iv + 4); + memcpy(iv, src, 8); + } AV_WB32(dst, r); AV_WB32(dst + 4, l); } @@ -468,11 +473,31 @@ av_cold int av_cast5_init(AVCAST5* cs, const uint8_t *key, int key_bits) return 0; } +void av_cast5_crypt2(AVCAST5* cs, uint8_t* dst, const uint8_t* src, int count, uint8_t *iv, int decrypt) +{ + int i; + while (count--) { + if (decrypt) { + decipher(cs, dst, src, iv); + } else { + if (iv) { + for (i = 0; i < 8; i++) + dst[i] = src[i] ^ iv[i]; + encipher(cs, dst, dst); + memcpy(iv, dst, 8); + } else { + encipher(cs, dst, src); + } + } + src = src + 8; + dst = dst + 8; + } +} void av_cast5_crypt(AVCAST5* cs, uint8_t* dst, const uint8_t* src, int count, int decrypt) { while (count--) { if (decrypt){ - decipher(cs, dst, src); + decipher(cs, dst, src, NULL); } else { encipher(cs, dst, src); } @@ -504,6 +529,7 @@ int main(int argc, char** argv) {0xee, 0xa9, 0xd0, 0xa2, 0x49, 0xfd, 0x3b, 0xa6, 0xb3, 0x43, 0x6f, 0xb8, 0x9d, 0x6d, 0xca, 0x92}, {0xb2, 0xc9, 0x5e, 0xb0, 0x0c, 0x31, 0xad, 0x71, 0x80, 0xac, 0x05, 0xb8, 0xe8, 0x3d, 0x69, 0x6e} }; + const uint8_t iv[8] = {0xee, 0xa9, 0xd0, 0xa2, 0x49, 0xfd, 0x3b, 0xa6}; static uint8_t rpt2[2][16]; int i, j, err = 0; static int key_bits[3] = {128, 80, 40}; @@ -547,6 +573,20 @@ int main(int argc, char** argv) } } } + for (j = 0; j < 3; j++) { + + av_cast5_init(cs, Key[j], key_bits[j]); + memcpy(temp, iv, 8); + av_cast5_crypt2(cs, rpt2[0], rct2[0], 2, temp, 0); + memcpy(temp, iv, 8); + av_cast5_crypt2(cs, rpt2[0], rpt2[0], 2, temp, 1); + for (i = 0; i < 16; i++) { + if (rct2[0][i] != rpt2[0][i]) { + av_log(NULL, AV_LOG_ERROR, "%d %02x %02x\n", i, rct2[0][i], rpt2[0][i]); + err = 1; + } + } + } av_free(cs); return err; } diff --git a/libavutil/cast5.h b/libavutil/cast5.h index 913d048..e5cc8b1 100644 --- a/libavutil/cast5.h +++ b/libavutil/cast5.h @@ -52,7 +52,7 @@ struct AVCAST5 *av_cast5_alloc(void); int av_cast5_init(struct AVCAST5 *ctx, const uint8_t *key, int key_bits); /** - * Encrypt or decrypt a buffer using a previously initialized context + * Encrypt or decrypt a buffer using a previously initialized context, ECB mode only * * @param ctx an AVCAST5 context * @param dst destination array, can be equal to src @@ -61,6 +61,18 @@ int av_cast5_init(struct AVCAST5 *ctx, const uint8_t *key, int key_bits); * @param decrypt 0 for encryption, 1 for decryption */ void av_cast5_crypt(struct AVCAST5 *ctx, uint8_t *dst, const uint8_t *src, int count, int decrypt); + +/** + * Encrypt or decrypt a buffer using a previously initialized context + * + * @param ctx an AVCAST5 context + * @param dst destination array, can be equal to src + * @param src source array, can be equal to dst + * @param count number of 8 byte blocks + * @param iv initialization vector for CBC mode, NULL for ECB mode + * @param decrypt 0 for encryption, 1 for decryption + */ +void av_cast5_crypt2(struct AVCAST5 *ctx, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt); /** * @} */ _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
