github.com/aacfactory/fns@v1.2.86-0.20240310083819-80d667fc0a17/commons/cryptos/ciphers/cbc.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 ciphers
    19  
    20  import (
    21  	"crypto/cipher"
    22  	"github.com/aacfactory/errors"
    23  )
    24  
    25  func CBCEncrypt(block cipher.Block, plain, iv []byte, padding int) (encrypted []byte, err error) {
    26  	blockSize := block.BlockSize()
    27  	plain = Padding(padding, plain, blockSize)
    28  	encrypted = make([]byte, len(plain))
    29  	if len(iv) != block.BlockSize() {
    30  		err = errors.Warning("cbc: iv length must equal block size")
    31  		return
    32  	}
    33  	mode := cipher.NewCBCEncrypter(block, iv)
    34  	mode.CryptBlocks(encrypted, plain)
    35  	return
    36  }
    37  
    38  func CBCDecrypt(block cipher.Block, encrypted, iv []byte, padding int) (plain []byte, err error) {
    39  	pad := make([]byte, len(encrypted))
    40  	if len(iv) != block.BlockSize() {
    41  		err = errors.Warning("cbc: IV length must equal block size")
    42  		return
    43  	}
    44  	mode := cipher.NewCBCDecrypter(block, iv)
    45  	mode.CryptBlocks(pad, encrypted)
    46  	plain, err = UnPadding(padding, pad)
    47  	return
    48  }