加密解密在實(shí)際開發(fā)中應(yīng)用比較廣泛，常用加解密分為：“對(duì)稱式”、“非對(duì)稱式”和”數(shù)字簽名“。對(duì)稱式：對(duì)稱加密(也叫私鑰加密)指加密和解密使用相同密鑰的加密算法。具體算法主要有DES算法，3DES算法，TDEA算法，Blowfish算法，RC5算法，IDEA算法。非對(duì)稱加密(公鑰加密)：指加密和解密使用不同密鑰的加密算法，也稱為公私鑰加密。具體算法主要有RSA、Elgamal、背包算法、Rabin、D-H、ECC（橢圓曲線加密算法）。數(shù)字簽名：數(shù)字簽名是非對(duì)稱密鑰加密技術(shù)與數(shù)字摘要技術(shù)的應(yīng)用。主要算法有md5、hmac、sha1等。以下介紹golang語(yǔ)言主要的加密解密算法實(shí)現(xiàn)。

md5

MD5信息摘要算法是一種被廣泛使用的密碼散列函數(shù)，可以產(chǎn)生出一個(gè)128位（16進(jìn)制，32個(gè)字符）的散列值（hash value），用于確保信息傳輸完整一致。

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func?GetMd5String(s?string)?string?{
????h?:=?md5.New()
????h.Write([]byte(s))
????return?hex.EncodeToString(h.Sum(nil))
}

?

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hmac

HMAC是密鑰相關(guān)的哈希運(yùn)算消息認(rèn)證碼（Hash-based Message Authentication Code）的縮寫， 它通過(guò)一個(gè)標(biāo)準(zhǔn)算法，在計(jì)算哈希的過(guò)程中，把key混入計(jì)算過(guò)程中。和自定義的加salt算法不同，Hmac算法針對(duì)所有哈希算法都通用，無(wú)論是MD5還是SHA-1。采用Hmac替代自己的salt算法，可以使程序算法更標(biāo)準(zhǔn)化，也更安全。示例

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//key隨意設(shè)置?data?要加密數(shù)據(jù)
func?Hmac(key,?data?string)?string?{
????hash:=?hmac.New(md5.New,?[]byte(key))?//?創(chuàng)建對(duì)應(yīng)的md5哈希加密算法
????hash.Write([]byte(data))
????return?hex.EncodeToString(hash.Sum([]byte("")))
}
func?HmacSha256(key,?data?string)?string?{
????hash:=?hmac.New(sha256.New,?[]byte(key))?//創(chuàng)建對(duì)應(yīng)的sha256哈希加密算法
????hash.Write([]byte(data))
????return?hex.EncodeToString(hash.Sum([]byte("")))
}

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sha1

SHA-1可以生成一個(gè)被稱為消息摘要的160位（20字節(jié)）散列值，散列值通常的呈現(xiàn)形式為40個(gè)十六進(jìn)制數(shù)。

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func?Sha1(data?string)?string?{
????sha1?:=?sha1.New()
????sha1.Write([]byte(data))
????return?hex.EncodeToString(sha1.Sum([]byte("")))
}

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AES

密碼學(xué)中的高級(jí)加密標(biāo)準(zhǔn)（Advanced Encryption Standard，AES），又稱Rijndael加密法，是美國(guó)聯(lián)邦政府采用的一種區(qū)塊加密標(biāo)準(zhǔn)。這個(gè)標(biāo)準(zhǔn)用來(lái)替代原先的DES（Data Encryption Standard），已經(jīng)被多方分析且廣為全世界所使用。AES中常見(jiàn)的有三種解決方案，分別為AES-128、AES-192和AES-256。如果采用真正的128位加密技術(shù)甚至256位加密技術(shù)，蠻力攻擊要取得成功需要耗費(fèi)相當(dāng)長(zhǎng)的時(shí)間。AES 有五種加密模式：

電碼本模式（Electronic Codebook Book (ECB)）

密碼分組鏈接模式（Cipher Block Chaining (CBC)）

計(jì)算器模式（Counter (CTR)）

密碼反饋模式（Cipher FeedBack (CFB)）

輸出反饋模式（Output FeedBack (OFB)）

ECB模式

出于安全考慮，golang默認(rèn)并不支持ECB模式。

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?

package?main

import?(
????"crypto/aes"
????"fmt"
)

func?AESEncrypt(src?[]byte,?key?[]byte)?(encrypted?[]byte)?{
????cipher,?_?:=?aes.NewCipher(generateKey(key))
????length?:=?(len(src)?+?aes.BlockSize)?/?aes.BlockSize
????plain?:=?make([]byte,?length*aes.BlockSize)
????copy(plain,?src)
????pad?:=?byte(len(plain)?-?len(src))
????for?i?:=?len(src);?i??0?{
????????trim?=?len(decrypted)?-?int(decrypted[len(decrypted)-1])
????}

????return?decrypted[:trim]
}

func?generateKey(key?[]byte)?(genKey?[]byte)?{
????genKey?=?make([]byte,?16)
????copy(genKey,?key)
????for?i?:=?16;?i?

	?

	?

	CBC模式

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package?main
import(
????"bytes"
????"crypto/aes"
????"fmt"
????"crypto/cipher"
????"encoding/base64"
)
func?main()?{
????orig?:=?"hello?world"
????key?:=?"0123456789012345"
????fmt.Println("原文：",?orig)
????encryptCode?:=?AesEncrypt(orig,?key)
????fmt.Println("密文："?,?encryptCode)
????decryptCode?:=?AesDecrypt(encryptCode,?key)
????fmt.Println("解密結(jié)果：",?decryptCode)
}
func?AesEncrypt(orig?string,?key?string)?string?{
????//?轉(zhuǎn)成字節(jié)數(shù)組
????origData?:=?[]byte(orig)
????k?:=?[]byte(key)
????//?分組秘鑰
????//?NewCipher該函數(shù)限制了輸入k的長(zhǎng)度必須為16,?24或者32
????block,?_?:=?aes.NewCipher(k)
????//?獲取秘鑰塊的長(zhǎng)度
????blockSize?:=?block.BlockSize()
????//?補(bǔ)全碼
????origData?=?PKCS7Padding(origData,?blockSize)
????//?加密模式
????blockMode?:=?cipher.NewCBCEncrypter(block,?k[:blockSize])
????//?創(chuàng)建數(shù)組
????cryted?:=?make([]byte,?len(origData))
????//?加密
????blockMode.CryptBlocks(cryted,?origData)
????return?base64.StdEncoding.EncodeToString(cryted)
}
func?AesDecrypt(cryted?string,?key?string)?string?{
????//?轉(zhuǎn)成字節(jié)數(shù)組
????crytedByte,?_?:=?base64.StdEncoding.DecodeString(cryted)
????k?:=?[]byte(key)
????//?分組秘鑰
????block,?_?:=?aes.NewCipher(k)
????//?獲取秘鑰塊的長(zhǎng)度
????blockSize?:=?block.BlockSize()
????//?加密模式
????blockMode?:=?cipher.NewCBCDecrypter(block,?k[:blockSize])
????//?創(chuàng)建數(shù)組
????orig?:=?make([]byte,?len(crytedByte))
????//?解密
????blockMode.CryptBlocks(orig,?crytedByte)
????//?去補(bǔ)全碼
????orig?=?PKCS7UnPadding(orig)
????return?string(orig)
}
//補(bǔ)碼
//AES加密數(shù)據(jù)塊分組長(zhǎng)度必須為128bit(byte[16])，密鑰長(zhǎng)度可以是128bit(byte[16])、192bit(byte[24])、256bit(byte[32])中的任意一個(gè)。
func?PKCS7Padding(ciphertext?[]byte,?blocksize?int)?[]byte?{
????padding?:=?blocksize?-?len(ciphertext)%blocksize
????padtext?:=?bytes.Repeat([]byte{byte(padding)},?padding)
????return?append(ciphertext,?padtext...)
}
//去碼
func?PKCS7UnPadding(origData?[]byte)?[]byte?{
????length?:=?len(origData)
????unpadding?:=?int(origData[length-1])
????return?origData[:(length?-?unpadding)]
}


	?

	?

	CRT模式

	?

	?
package?main

import?(
????"bytes"
????"crypto/aes"
????"crypto/cipher"
????"fmt"
)
//加密
func?aesCtrCrypt(plainText?[]byte,?key?[]byte)?([]byte,?error)?{

????//1.?創(chuàng)建cipher.Block接口
????block,?err?:=?aes.NewCipher(key)
????if?err?!=?nil?{
????????return?nil,?err
????}
????//2.?創(chuàng)建分組模式，在crypto/cipher包中
????iv?:=?bytes.Repeat([]byte("1"),?block.BlockSize())
????stream?:=?cipher.NewCTR(block,?iv)
????//3.?加密
????dst?:=?make([]byte,?len(plainText))
????stream.XORKeyStream(dst,?plainText)

????return?dst,?nil
}


func?main()?{
????source:="hello?world"
????fmt.Println("原字符：",source)

????key:="1443flfsaWfdasds"
????encryptCode,_:=aesCtrCrypt([]byte(source),[]byte(key))
????fmt.Println("密文：",string(encryptCode))

????decryptCode,_:=aesCtrCrypt(encryptCode,[]byte(key))

????fmt.Println("解密：",string(decryptCode))
}


	?

	?

	CFB模式

	?

	?
package?main

import?(
????"crypto/aes"
????"crypto/cipher"
????"crypto/rand"
????"encoding/hex"
????"fmt"
????"io"
)
func?AesEncryptCFB(origData?[]byte,?key?[]byte)?(encrypted?[]byte)?{
????block,?err?:=?aes.NewCipher(key)
????if?err?!=?nil?{
????????//panic(err)
????}
????encrypted?=?make([]byte,?aes.BlockSize+len(origData))
????iv?:=?encrypted[:aes.BlockSize]
????if?_,?err?:=?io.ReadFull(rand.Reader,?iv);?err?!=?nil?{
????????//panic(err)
????}
????stream?:=?cipher.NewCFBEncrypter(block,?iv)
????stream.XORKeyStream(encrypted[aes.BlockSize:],?origData)
????return?encrypted
}
func?AesDecryptCFB(encrypted?[]byte,?key?[]byte)?(decrypted?[]byte)?{
????block,?_?:=?aes.NewCipher(key)
????if?len(encrypted)?

	?

	?

	OFB模式

	?

	?
package?main

import?(
????"bytes"
????"crypto/aes"
????"crypto/cipher"
????"crypto/rand"
????"encoding/hex"
????"fmt"
????"io"
)
func?aesEncryptOFB(?data[]byte,key?[]byte)?([]byte,?error)?{
????data?=?PKCS7Padding(data,?aes.BlockSize)
????block,?_?:=?aes.NewCipher([]byte(key))
????out?:=?make([]byte,?aes.BlockSize?+?len(data))
????iv?:=?out[:aes.BlockSize]
????if?_,?err?:=?io.ReadFull(rand.Reader,?iv);?err?!=?nil?{
????????return?nil,?err
????}

????stream?:=?cipher.NewOFB(block,?iv)
????stream.XORKeyStream(out[aes.BlockSize:],?data)
????return?out,?nil
}

func?aesDecryptOFB(?data[]byte,key?[]byte)?([]byte,?error)?{
????block,?_?:=?aes.NewCipher([]byte(key))
????iv??:=?data[:aes.BlockSize]
????data?=?data[aes.BlockSize:]
????if?len(data)?%?aes.BlockSize?!=?0?{
????????return?nil,?fmt.Errorf("data?is?not?a?multiple?of?the?block?size")
????}

????out?:=?make([]byte,?len(data))
????mode?:=?cipher.NewOFB(block,?iv)
????mode.XORKeyStream(out,?data)

????out=?PKCS7UnPadding(out)
????return?out,?nil
}
//補(bǔ)碼
//AES加密數(shù)據(jù)塊分組長(zhǎng)度必須為128bit(byte[16])，密鑰長(zhǎng)度可以是128bit(byte[16])、192bit(byte[24])、256bit(byte[32])中的任意一個(gè)。
func?PKCS7Padding(ciphertext?[]byte,?blocksize?int)?[]byte?{
????padding?:=?blocksize?-?len(ciphertext)%blocksize
????padtext?:=?bytes.Repeat([]byte{byte(padding)},?padding)
????return?append(ciphertext,?padtext...)
}
//去碼
func?PKCS7UnPadding(origData?[]byte)?[]byte?{
????length?:=?len(origData)
????unpadding?:=?int(origData[length-1])
????return?origData[:(length?-?unpadding)]
}
func?main()?{
????source:="hello?world"
????fmt.Println("原字符：",source)
????key:="1111111111111111"http://16位??32位均可
????encryptCode,_:=aesEncryptOFB([]byte(source),[]byte(key))
????fmt.Println("密文：",hex.EncodeToString(encryptCode))
????decryptCode,_:=aesDecryptOFB(encryptCode,[]byte(key))

????fmt.Println("解密：",string(decryptCode))
}


	?

	?

	RSA加密

	首先使用openssl生成公私鑰

	?

	?
package?main

import?(
????"crypto/rand"
????"crypto/rsa"
????"crypto/x509"
????"encoding/base64"
????"encoding/pem"
????"errors"
????"fmt"
)

//?私鑰生成
//openssl?genrsa?-out?rsa_private_key.pem?1024
var?privateKey?=?[]byte(`
-----BEGIN?RSA?PRIVATE?KEY-----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-----END?RSA?PRIVATE?KEY-----
`)

//?公鑰:?根據(jù)私鑰生成
//openssl?rsa?-in?rsa_private_key.pem?-pubout?-out?rsa_public_key.pem
var?publicKey?=?[]byte(`
-----BEGIN?PUBLIC?KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDcGsUIIAINHfRTdMmgGwLrjzfM
NSrtgIf4EGsNaYwmC1GjF/bMh0Mcm10oLhNrKNYCTTQVGGIxuc5heKd1gOzb7bdT
nCDPPZ7oV7p1B9Pud+6zPacoqDz2M24vHFWYY2FbIIJh8fHhKcfXNXOLovdVBE7Z
y682X1+R1lRK8D+vmQIDAQAB
-----END?PUBLIC?KEY-----
`)

//?加密
func?RsaEncrypt(origData?[]byte)?([]byte,?error)?{
????//解密pem格式的公鑰
????block,?_?:=?pem.Decode(publicKey)
????if?block?==?nil?{
????????return?nil,?errors.New("public?key?error")
????}
????//?解析公鑰
????pubInterface,?err?:=?x509.ParsePKIXPublicKey(block.Bytes)
????if?err?!=?nil?{
????????return?nil,?err
????}
????//?類型斷言
????pub?:=?pubInterface.(*rsa.PublicKey)
????//加密
????return?rsa.EncryptPKCS1v15(rand.Reader,?pub,?origData)
}

//?解密
func?RsaDecrypt(ciphertext?[]byte)?([]byte,?error)?{
????//解密
????block,?_?:=?pem.Decode(privateKey)
????if?block?==?nil?{
????????return?nil,?errors.New("private?key?error!")
????}
????//解析PKCS1格式的私鑰
????priv,?err?:=?x509.ParsePKCS1PrivateKey(block.Bytes)
????if?err?!=?nil?{
????????return?nil,?err
????}
????//?解密
????return?rsa.DecryptPKCS1v15(rand.Reader,?priv,?ciphertext)
}
func?main()?{
????data,?_?:=?RsaEncrypt([]byte("hello?world"))
????fmt.Println(base64.StdEncoding.EncodeToString(data))
????origData,?_?:=?RsaDecrypt(data)
????fmt.Println(string(origData))
}
編輯：黃飛

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