first commit

pkg/aes/aes.go

@@ -0,0 +1,120 @@
+package aes
+
+import (
+	cryptoAes "crypto/aes"
+	"crypto/cipher"
+	"encoding/base64"
+)
+
+var _ Aes = (*aes)(nil)
+
+type Aes interface {
+	i()
+
+	EncryptCBC(encryptStr string, urlEncode bool) (string, error)
+	DecryptCBC(decryptStr string, urlEncode bool) (string, error)
+
+	EncryptCFB(plain string, urlEncode bool) (string, error)
+	DecryptCFB(encrypted string, urlEncode bool) (string, error)
+}
+
+type aes struct {
+	key string
+	iv  string
+}
+
+func New(key, iv string) Aes {
+	return &aes{
+		key: key,
+		iv:  iv,
+	}
+}
+
+func (a *aes) i() {}
+
+func (a *aes) EncryptCBC(encryptStr string, urlEncode bool) (string, error) {
+	encoder := base64.StdEncoding
+	if urlEncode {
+		encoder = base64.URLEncoding
+	}
+
+	encryptBytes := []byte(encryptStr)
+	block, err := cryptoAes.NewCipher([]byte(a.key))
+	if err != nil {
+		return "", err
+	}
+
+	blockSize := block.BlockSize()
+	encryptBytes = pkcsPadding(encryptBytes, blockSize)
+	blockMode := cipher.NewCBCEncrypter(block, []byte(a.iv))
+	encrypted := make([]byte, len(encryptBytes))
+	blockMode.CryptBlocks(encrypted, encryptBytes)
+
+	return encoder.EncodeToString(encrypted), nil
+}
+
+func (a *aes) DecryptCBC(decryptStr string, urlEncode bool) (string, error) {
+	encoder := base64.StdEncoding
+	if urlEncode {
+		encoder = base64.URLEncoding
+	}
+
+	decryptBytes, err := encoder.DecodeString(decryptStr)
+	if err != nil {
+		return "", err
+	}
+
+	block, err := cryptoAes.NewCipher([]byte(a.key))
+	if err != nil {
+		return "", err
+	}
+
+	blockMode := cipher.NewCBCDecrypter(block, []byte(a.iv))
+	decrypted := make([]byte, len(decryptBytes))
+	blockMode.CryptBlocks(decrypted, decryptBytes)
+	decrypted = pkcsUnPadding(decrypted)
+
+	return string(decrypted), nil
+}
+
+func (a *aes) EncryptCFB(plain string, urlEncode bool) (string, error) {
+	encoder := base64.StdEncoding
+	if urlEncode {
+		encoder = base64.URLEncoding
+	}
+
+	block, err := cryptoAes.NewCipher([]byte(a.key))
+	if err != nil {
+		return "", err
+	}
+
+	encrypted := make([]byte, len(plain))
+	stream := cipher.NewCFBEncrypter(block, []byte(a.iv))
+	stream.XORKeyStream(encrypted, []byte(plain))
+
+	return encoder.EncodeToString(encrypted), nil
+
+}
+
+func (a *aes) DecryptCFB(encrypted string, urlEncode bool) (string, error) {
+	encoder := base64.StdEncoding
+	if urlEncode {
+		encoder = base64.URLEncoding
+	}
+
+	decryptBytes, err := encoder.DecodeString(encrypted)
+	if err != nil {
+		return "", err
+	}
+
+	block, err := cryptoAes.NewCipher([]byte(a.key))
+	if err != nil {
+		return "", err
+	}
+
+	plain := make([]byte, len(decryptBytes))
+	stream := cipher.NewCFBDecrypter(block, []byte(a.iv))
+	stream.XORKeyStream(plain, decryptBytes)
+
+	return string(plain), nil
+}

pkg/aes/padding.go

@@ -0,0 +1,25 @@
+package aes
+
+import (
+	"bytes"
+)
+
+/**
+ * 填充有六种：NoPadding, PKCS#5, PKCS#7, ISO 10126, ANSI X9.23和ZerosPadding
+ * 对于AES来说PKCS5Padding和PKCS7Padding是完全一样的，不同在于PKCS5限定了块大小为8bytes而PKCS7没有限定
+ * 因此对于AES来说两者完全相同，但是对于Rijndael就不一样了
+ * AES是Rijndael在块大小为8bytes时的特例，对于使用其他信息块大小的Rijndael算法只能使用PKCS7
+ * 在AES加密当中严格来说是不能使用pkcs5的，因为AES的块大小是16bytes而pkcs5只能用于8bytes，通常我们在AES加密中所说的pkcs5指的就是pkcs7
+ */
+
+func pkcsPadding(cipherText []byte, blockSize int) []byte {
+	p := blockSize - len(cipherText)%blockSize
+	padText := bytes.Repeat([]byte{byte(p)}, p)
+	return append(cipherText, padText...)
+}
+
+func pkcsUnPadding(decrypted []byte) []byte {
+	length := len(decrypted)
+	u := int(decrypted[length-1])
+	return decrypted[:(length - u)]
+}