github.com/aacfactory/fns@v1.2.86-0.20240310083819-80d667fc0a17/commons/signatures/hmac.go (about)

     1  /*
     2   * Copyright 2023 Wang Min Xiang
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   * 	http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   *
    16   */
    17  
    18  package signatures
    19  
    20  import (
    21  	"crypto/hmac"
    22  	"encoding/hex"
    23  	"github.com/cespare/xxhash/v2"
    24  	"hash"
    25  	"sync"
    26  )
    27  
    28  func HMAC(key []byte) Signature {
    29  	h := &hmacSigner{
    30  		key:  key,
    31  		pool: sync.Pool{},
    32  	}
    33  	h.pool.New = func() any {
    34  		return hmac.New(func() hash.Hash {
    35  			return xxhash.New()
    36  		}, h.key)
    37  	}
    38  	return h
    39  }
    40  
    41  type hmacSigner struct {
    42  	key  []byte
    43  	pool sync.Pool
    44  }
    45  
    46  func (s *hmacSigner) acquire() (h hash.Hash) {
    47  	v := s.pool.Get()
    48  	if v != nil {
    49  		h = v.(hash.Hash)
    50  		return
    51  	}
    52  	h = hmac.New(func() hash.Hash {
    53  		return xxhash.New()
    54  	}, s.key)
    55  	return
    56  }
    57  
    58  func (s *hmacSigner) release(h hash.Hash) {
    59  	h.Reset()
    60  	s.pool.Put(h)
    61  	return
    62  }
    63  
    64  func (s *hmacSigner) Sign(target []byte) (signature []byte) {
    65  	h := s.acquire()
    66  	h.Write(target)
    67  	p := h.Sum(nil)
    68  	s.release(h)
    69  	signature = make([]byte, hex.EncodedLen(len(p)))
    70  	hex.Encode(signature, p)
    71  	return
    72  }
    73  
    74  func (s *hmacSigner) Verify(target []byte, signature []byte) (ok bool) {
    75  	n, err := hex.Decode(signature, signature)
    76  	if err != nil {
    77  		return
    78  	}
    79  	signature = signature[0:n]
    80  	h := s.acquire()
    81  	h.Write(target)
    82  	p := h.Sum(nil)
    83  	s.release(h)
    84  	ok = hmac.Equal(p, signature)
    85  	return
    86  }