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4bcc2be | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | // Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package subtle implements functions that are often useful in cryptographic
// code but require careful thought to use correctly.
package subtle
import (
"crypto/internal/constanttime"
"crypto/internal/fips140/subtle"
)
// These functions are forwarded to crypto/internal/constanttime for intrinsified
// operations, and to crypto/internal/fips140/subtle for byte slice operations.
// ConstantTimeCompare returns 1 if the two slices, x and y, have equal contents
// and 0 otherwise. The time taken is a function of the length of the slices and
// is independent of the contents. If the lengths of x and y do not match it
// returns 0 immediately.
func ConstantTimeCompare(x, y []byte) int {
return subtle.ConstantTimeCompare(x, y)
}
// ConstantTimeSelect returns x if v == 1 and y if v == 0.
// Its behavior is undefined if v takes any other value.
func ConstantTimeSelect(v, x, y int) int {
return constanttime.Select(v, x, y)
}
// ConstantTimeByteEq returns 1 if x == y and 0 otherwise.
func ConstantTimeByteEq(x, y uint8) int {
return constanttime.ByteEq(x, y)
}
// ConstantTimeEq returns 1 if x == y and 0 otherwise.
func ConstantTimeEq(x, y int32) int {
return constanttime.Eq(x, y)
}
// ConstantTimeCopy copies the contents of y into x (a slice of equal length)
// if v == 1. If v == 0, x is left unchanged. Its behavior is undefined if v
// takes any other value.
func ConstantTimeCopy(v int, x, y []byte) {
subtle.ConstantTimeCopy(v, x, y)
}
// ConstantTimeLessOrEq returns 1 if x <= y and 0 otherwise.
// Its behavior is undefined if x or y are negative or > 2**31 - 1.
func ConstantTimeLessOrEq(x, y int) int {
return constanttime.LessOrEq(x, y)
}
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