diff options
Diffstat (limited to 'libavutil')
| -rw-r--r-- | libavutil/blowfish.c | 44 |
1 files changed, 18 insertions, 26 deletions
diff --git a/libavutil/blowfish.c b/libavutil/blowfish.c index fd894cdb80..5fe95e8d8a 100644 --- a/libavutil/blowfish.c +++ b/libavutil/blowfish.c @@ -294,24 +294,12 @@ static const uint32_t orig_s[4][256] = { 0xB74E6132, 0xCE77E25B, 0x578FDFE3, 0x3AC372E6 } }; -static void F(AVBlowfish *ctx, uint32_t *xl, uint32_t *xr, int i) -{ - uint32_t Xl, Xr; - uint32_t y; - - Xl = *xl; - Xr = *xr; - - Xl ^= ctx->p[i]; - y = ctx->s[0][(Xl >> 24) & 0xFF]; - y += ctx->s[1][(Xl >> 16) & 0xFF]; - y ^= ctx->s[2][(Xl >> 8) & 0xFF]; - y += ctx->s[3][ Xl & 0xFF]; - Xr ^= y; - - *xl = Xr; - *xr = Xl; -} +#define F(Xl, Xr, P) \ + Xr ^=((( ctx->s[0][ Xl >> 24 ] \ + + ctx->s[1][(Xl >> 16) & 0xFF])\ + ^ ctx->s[2][(Xl >> 8) & 0xFF])\ + + ctx->s[3][ Xl & 0xFF])\ + ^ P; av_cold void av_blowfish_init(AVBlowfish *ctx, const uint8_t *key, int key_len) { @@ -358,17 +346,21 @@ void av_blowfish_crypt_ecb(AVBlowfish *ctx, uint32_t *xl, uint32_t *xr, Xr = *xr; if (decrypt) { - for (i = AV_BF_ROUNDS + 1; i > 1; --i) - F(ctx, &Xl, &Xr, i); + Xl ^= ctx->p[AV_BF_ROUNDS + 1]; + for (i = AV_BF_ROUNDS; i > 0; i-=2) { + F(Xl, Xr, ctx->p[i ]); + F(Xr, Xl, ctx->p[i-1]); + } - Xl = Xl ^ ctx->p[1]; - Xr = Xr ^ ctx->p[0]; + Xr ^= ctx->p[0]; } else { - for (i = 0; i < AV_BF_ROUNDS; ++i) - F(ctx, &Xl, &Xr, i); + Xl ^= ctx->p[0]; + for (i = 1; i < AV_BF_ROUNDS+1; i+=2){ + F(Xl, Xr, ctx->p[i ]); + F(Xr, Xl, ctx->p[i+1]); + } - Xl = Xl ^ ctx->p[AV_BF_ROUNDS]; - Xr = Xr ^ ctx->p[AV_BF_ROUNDS + 1]; + Xr ^= ctx->p[AV_BF_ROUNDS + 1]; } *xl = Xr; |