101 lines
2.3 KiB
Go
101 lines
2.3 KiB
Go
package crypto
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import (
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"bytes"
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"fmt"
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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)
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// DefaultAESKey 默认AES密钥(16字节)
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var DefaultAESKey = []byte("f51d66a73d8a0927")
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// GenerateAESKey 生成AES密钥
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func GenerateAESKey(length int) ([]byte, error) {
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if length != 16 && length != 24 && length != 32 {
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return nil, fmt.Errorf("invalid key length: %d, must be 16, 24, or 32 bytes", length)
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}
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key := make([]byte, length)
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_, err := rand.Read(key)
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if err != nil {
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return nil, err
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}
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return key, nil
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}
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// PKCS5Padding 填充明文
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func PKCS5Padding(plaintext []byte, blockSize int) []byte {
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padding := blockSize - len(plaintext)%blockSize
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padText := bytes.Repeat([]byte{byte(padding)}, padding)
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return append(plaintext, padText...)
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}
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// PKCS5UnPadding 去除填充数据
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func PKCS5UnPadding(origData []byte) []byte {
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length := len(origData)
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unpadding := int(origData[length-1])
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return origData[:(length - unpadding)]
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}
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// AesEncrypt AES加密
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func AesEncrypt(plainText, key, iv []byte) ([]byte, error) {
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if plainText == nil {
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return nil, fmt.Errorf("plain text is nil")
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}
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if key == nil {
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return nil, fmt.Errorf("key is nil")
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}
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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// AES分组长度为128位，所以blockSize=16，单位字节
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blockSize := block.BlockSize()
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if iv == nil {
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// 初始向量的长度必须等于块block的长度16字节
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iv = key[:blockSize]
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}
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plainText = PKCS5Padding(plainText, blockSize)
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blockMode := cipher.NewCBCEncrypter(block, iv)
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cryptedText := make([]byte, len(plainText))
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blockMode.CryptBlocks(cryptedText, plainText)
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return cryptedText, nil
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}
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// AesDecrypt AES解密
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func AesDecrypt(cryptedText, key, iv []byte) ([]byte, error) {
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if cryptedText == nil {
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return nil, fmt.Errorf("crypted text is nil")
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}
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if key == nil {
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return nil, fmt.Errorf("key is nil")
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}
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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//AES分组长度为128位，所以blockSize=16，单位字节
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blockSize := block.BlockSize()
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if iv == nil {
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// 初始向量的长度必须等于块block的长度16字节
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iv = key[:blockSize]
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}
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blockMode := cipher.NewCBCDecrypter(block, iv)
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plainText := make([]byte, len(cryptedText))
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blockMode.CryptBlocks(plainText, cryptedText)
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plainText = PKCS5UnPadding(plainText)
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return plainText, nil
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}
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