/
cryptojs.go
72 lines (58 loc) · 1.25 KB
/
cryptojs.go
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package main
import (
"crypto/aes"
"crypto/cipher"
"crypto/md5"
"encoding/base64"
"encoding/json"
)
// Cryptojs object
type Crypto struct {
Iv string `json:"iv"`
Salt string `json:"s"`
Ct string `json:"ct"`
}
func buildDecryptionKey(pw string, salt string) []byte {
var key []byte
cPw := pw + salt
hash := getMD5(cPw)
key = hash
for i := 0; i < 2; i++ {
hash = getMD5(string(hash) + cPw)
key = append(key, hash...)
}
return key[:32]
}
// Takes json string
func Decrypt(s string, password string) (string, error) {
var obj Crypto
if err := json.Unmarshal([]byte(s), &obj); err != nil {
return "", err
}
iv, err := base64.StdEncoding.DecodeString(obj.Iv)
if err != nil {
return "", err
}
salt, err := base64.StdEncoding.DecodeString(obj.Salt)
if err != nil {
return "", err
}
ct, err := base64.StdEncoding.DecodeString(obj.Ct)
if err != nil {
return "", err
}
key := buildDecryptionKey(password, string(salt))
block, err := aes.NewCipher(key[:32])
if err != nil {
panic(err)
}
decrypter := cipher.NewCBCDecrypter(block, iv)
data := make([]byte, len(ct))
decrypter.CryptBlocks(data, ct)
return string(data), nil
}
func getMD5(str string) []byte {
hasher := md5.New()
hasher.Write([]byte(str))
return hasher.Sum(nil)
}