Sha256: 45898ef0e205c50a6cd02ad2fba345339683d0658da005038a5548780646befb
Contents?: true
Size: 702 Bytes
Versions: 16
Compression:
Stored size: 702 Bytes
Contents
package crypto
import "fmt"
// ConstantTimeByteCompare is a constant-time byte comparison of x and y. This function performs an absolute comparison
// if the two byte slices assuming they represent a big-endian number.
//
// error if len(x) != len(y)
// -1 if x < y
// 0 if x == y
// +1 if x > y
func ConstantTimeByteCompare(x, y []byte) (int, error) {
if len(x) != len(y) {
return 0, fmt.Errorf("slice lengths do not match")
}
xLarger, yLarger := 0, 0
for i := 0; i < len(x); i++ {
xByte, yByte := int(x[i]), int(y[i])
x := ((yByte - xByte) >> 8) & 1
y := ((xByte - yByte) >> 8) & 1
xLarger |= x &^ yLarger
yLarger |= y &^ xLarger
}
return xLarger - yLarger, nil
}
Version data entries
16 entries across 16 versions & 1 rubygems