vendor.github.com.pion.stun.internal.hmac.pool.go Maven / Gradle / Ivy
package hmac
import (
"crypto/sha1"
"crypto/sha256"
"hash"
"sync"
)
// setZeroes sets all bytes from b to zeroes.
//
// See https://github.com/golang/go/issues/5373
func setZeroes(b []byte) {
for i := range b {
b[i] = 0
}
}
func (h *hmac) resetTo(key []byte) {
h.outer.Reset()
h.inner.Reset()
setZeroes(h.ipad)
setZeroes(h.opad)
if len(key) > h.blocksize {
// If key is too big, hash it.
h.outer.Write(key)
key = h.outer.Sum(nil)
}
copy(h.ipad, key)
copy(h.opad, key)
for i := range h.ipad {
h.ipad[i] ^= 0x36
}
for i := range h.opad {
h.opad[i] ^= 0x5c
}
h.inner.Write(h.ipad)
}
var hmacSHA1Pool = &sync.Pool{
New: func() interface{} {
h := New(sha1.New, make([]byte, sha1.BlockSize))
return h
},
}
// AcquireSHA1 returns new HMAC from pool.
func AcquireSHA1(key []byte) hash.Hash {
h := hmacSHA1Pool.Get().(*hmac)
assertHMACSize(h, sha1.Size, sha1.BlockSize)
h.resetTo(key)
return h
}
// PutSHA1 puts h to pool.
func PutSHA1(h hash.Hash) {
hm := h.(*hmac)
assertHMACSize(hm, sha1.Size, sha1.BlockSize)
hmacSHA1Pool.Put(hm)
}
var hmacSHA256Pool = &sync.Pool{
New: func() interface{} {
h := New(sha256.New, make([]byte, sha256.BlockSize))
return h
},
}
// AcquireSHA256 returns new HMAC from SHA256 pool.
func AcquireSHA256(key []byte) hash.Hash {
h := hmacSHA256Pool.Get().(*hmac)
assertHMACSize(h, sha256.Size, sha256.BlockSize)
h.resetTo(key)
return h
}
// PutSHA256 puts h to SHA256 pool.
func PutSHA256(h hash.Hash) {
hm := h.(*hmac)
assertHMACSize(hm, sha256.Size, sha256.BlockSize)
hmacSHA256Pool.Put(hm)
}
// assertHMACSize panics if h.size != size or h.blocksize != blocksize.
//
// Put and Acquire functions are internal functions to project, so
// checking it via such assert is optimal.
func assertHMACSize(h *hmac, size, blocksize int) {
if h.size != size || h.blocksize != blocksize {
panic("BUG: hmac size invalid") // nolint
}
}