forked from ThalesGroup/pkcs11
/
crypto.go
71 lines (60 loc) · 2.04 KB
/
crypto.go
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package aes
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"io"
"github.com/pkg/errors"
)
type Client interface {
Decrypt(key []byte, value []byte) (decryptedTarget []byte, err error)
DecryptWithBase64(key []byte, valueBase64 string) (decryptedTarget []byte, err error)
Encrypt(key []byte, value []byte) (encryptedTarget []byte, err error)
EncryptFromString(key []byte, valueStr string) (encryptedTarget []byte, err error)
}
type aesClient struct{}
func (a *aesClient) Decrypt(key []byte, value []byte) (decryptedTarget []byte, err error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, errors.Wrap(err, "create cipher.Block failed.")
}
decryptedText := make([]byte, len(value[aes.BlockSize:]))
decryptStream := cipher.NewCTR(block, value[:aes.BlockSize])
decryptStream.XORKeyStream(decryptedText, value[aes.BlockSize:])
return decryptedText, nil
}
func (a *aesClient) DecryptWithBase64(key []byte, valueBase64 string) (decryptedTarget []byte, err error) {
value, err := base64.StdEncoding.DecodeString(valueBase64)
if err != nil {
return nil, errors.Wrap(err, "base64 decode failed.")
}
data, err := a.Decrypt(key, value)
if err != nil {
return nil, errors.Wrap(err, "Encrypt failed.")
}
return data, nil
}
func (a *aesClient) Encrypt(key []byte, value []byte) (encryptedTarget []byte, err error) {
// Create new AES cipher block
block, err := aes.NewCipher(key)
if err != nil {
return nil, errors.Wrap(err, "create cipher.Block failed.")
}
// Create IV
cipherText := make([]byte, aes.BlockSize+len(value))
iv := cipherText[:aes.BlockSize]
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
return nil, errors.Wrap(err, "failed to read IV.")
}
// Encrypt
encryptStream := cipher.NewCTR(block, iv)
encryptStream.XORKeyStream(cipherText[aes.BlockSize:], value)
return cipherText, nil
}
func (a *aesClient) EncryptFromString(key []byte, valueStr string) (encryptedTarget []byte, err error) {
return a.Encrypt(key, []byte(valueStr))
}
func NewClient() *aesClient {
return &aesClient{}
}