diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/chacha20/xor.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/chacha20/xor.go | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/vendor/golang.org/x/crypto/chacha20/xor.go b/vendor/golang.org/x/crypto/chacha20/xor.go index 0110c9865..c2d04851e 100644 --- a/vendor/golang.org/x/crypto/chacha20/xor.go +++ b/vendor/golang.org/x/crypto/chacha20/xor.go @@ -13,10 +13,10 @@ const unaligned = runtime.GOARCH == "386" || runtime.GOARCH == "ppc64le" || runtime.GOARCH == "s390x" -// xor reads a little endian uint32 from src, XORs it with u and +// addXor reads a little endian uint32 from src, XORs it with (a + b) and // places the result in little endian byte order in dst. -func xor(dst, src []byte, u uint32) { - _, _ = src[3], dst[3] // eliminate bounds checks +func addXor(dst, src []byte, a, b uint32) { + _, _ = src[3], dst[3] // bounds check elimination hint if unaligned { // The compiler should optimize this code into // 32-bit unaligned little endian loads and stores. @@ -27,15 +27,16 @@ func xor(dst, src []byte, u uint32) { v |= uint32(src[1]) << 8 v |= uint32(src[2]) << 16 v |= uint32(src[3]) << 24 - v ^= u + v ^= a + b dst[0] = byte(v) dst[1] = byte(v >> 8) dst[2] = byte(v >> 16) dst[3] = byte(v >> 24) } else { - dst[0] = src[0] ^ byte(u) - dst[1] = src[1] ^ byte(u>>8) - dst[2] = src[2] ^ byte(u>>16) - dst[3] = src[3] ^ byte(u>>24) + a += b + dst[0] = src[0] ^ byte(a) + dst[1] = src[1] ^ byte(a>>8) + dst[2] = src[2] ^ byte(a>>16) + dst[3] = src[3] ^ byte(a>>24) } } |