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GO NewCTR用法及代码示例


GO语言"crypto/cipher"包中"NewCTR"函数的用法及代码示例。

用法:

func NewCTR(block Block, iv []byte) Stream

NewCTR 返回一个 Stream,该 Stream 在计数器模式下使用给定的 Block 进行加密/解密。 iv 的长度必须与 Block 的块大小相同。

例子:

package main

import (
	"crypto/aes"
	"crypto/cipher"
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"io"
)

func main() {
	// Load your secret key from a safe place and reuse it across multiple
	// NewCipher calls. (Obviously don't use this example key for anything
	// real.) If you want to convert a passphrase to a key, use a suitable
	// package like bcrypt or scrypt.
	key, _ := hex.DecodeString("6368616e676520746869732070617373")
	plaintext := []byte("some plaintext")

	block, err := aes.NewCipher(key)
	if err != nil {
		panic(err)
	}

	// The IV needs to be unique, but not secure. Therefore it's common to
	// include it at the beginning of the ciphertext.
	ciphertext := make([]byte, aes.BlockSize+len(plaintext))
	iv := ciphertext[:aes.BlockSize]
	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
		panic(err)
	}

	stream := cipher.NewCTR(block, iv)
	stream.XORKeyStream(ciphertext[aes.BlockSize:], plaintext)

	// It's important to remember that ciphertexts must be authenticated
	// (i.e. by using crypto/hmac) as well as being encrypted in order to
	// be secure.

	// CTR mode is the same for both encryption and decryption, so we can
	// also decrypt that ciphertext with NewCTR.

	plaintext2 := make([]byte, len(plaintext))
	stream = cipher.NewCTR(block, iv)
	stream.XORKeyStream(plaintext2, ciphertext[aes.BlockSize:])

	fmt.Printf("%s\n", plaintext2)
}

输出:

some plaintext

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注:本文由纯净天空筛选整理自golang.google.cn大神的英文原创作品 NewCTR。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。