126 lines
2.2 KiB
Go
126 lines
2.2 KiB
Go
package cryptojs
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import (
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"encoding/base64"
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"crypto/md5"
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"crypto/aes"
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"crypto/cipher"
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"math/rand"
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"errors"
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"git.meow.tf/tyler/go-pastee/evpkdf"
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"bytes"
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)
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const (
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keySize = 32
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)
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func Encrypt(data, passphrase string) (string, error) {
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salt := make([]byte, 8)
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if _, err := rand.Read(salt); err != nil {
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return "", err
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}
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key := make([]byte, keySize)
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iv := make([]byte, aes.BlockSize)
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keymat := evpkdf.New(md5.New, []byte(passphrase), salt, keySize + aes.BlockSize, 1)
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keymatbuf := bytes.NewReader(keymat)
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n, err := keymatbuf.Read(key)
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if n != keySize || err != nil {
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return "", err
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}
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n, err = keymatbuf.Read(iv)
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if n != aes.BlockSize || err != nil {
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return "", err
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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 "", err
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}
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padded, err := pkcs7Pad([]byte(data), block.BlockSize())
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if err != nil {
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return "", err
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}
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ciphertext := make([]byte, len(padded))
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cbc := cipher.NewCBCEncrypter(block, iv)
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cbc.CryptBlocks(ciphertext, padded)
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return encode(ciphertext, salt), nil
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}
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func Decrypt(b64, passphrase string) ([]byte, error) {
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salt, ct, err := decode(b64)
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if err != nil {
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return nil, err
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}
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key := make([]byte, keySize)
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iv := make([]byte, aes.BlockSize)
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keymat := evpkdf.New(md5.New, []byte(passphrase), salt, keySize + aes.BlockSize, 1)
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keymatbuf := bytes.NewReader(keymat)
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n, err := keymatbuf.Read(key)
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if n != keySize || err != nil {
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return nil, err
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}
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n, err = keymatbuf.Read(iv)
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if n != aes.BlockSize || err != nil {
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return nil, err
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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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cbc := cipher.NewCBCDecrypter(block, iv)
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cbc.CryptBlocks(ct, ct)
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plain, err := pkcs7Unpad(ct, block.BlockSize())
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if err != nil {
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return nil, err
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}
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return plain, nil
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}
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func encode(ct []byte, salt []byte) string {
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b := []byte("Salted__")
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b = append(b, salt...)
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b = append(b, ct...)
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return base64.StdEncoding.EncodeToString(b)
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}
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func decode(b64 string) ([]byte, []byte, error) {
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decoded, err := base64.StdEncoding.DecodeString(b64)
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if err != nil {
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return nil, nil, err
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}
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if string(decoded[0:8]) != "Salted__" {
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return nil, nil, errors.New("invalid data")
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}
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return decoded[8:16], decoded[16:], nil
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} |