forked from ProtonMail/gopenpgp
/
subtle.go
35 lines (30 loc) · 1.08 KB
/
subtle.go
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// Package subtle contains subtly insecure methods not recommended for casual
// use.
package subtle
import (
"crypto/aes"
"crypto/cipher"
"golang.org/x/crypto/scrypt"
)
// EncryptWithoutIntegrity encrypts data with AES-CTR. Note: this encryption
// mode is not secure when stored/sent on an untrusted medium.
func EncryptWithoutIntegrity(key, input, iv []byte) (output []byte, err error) {
var block cipher.Block
if block, err = aes.NewCipher(key); err != nil {
return
}
output = make([]byte, len(input))
stream := cipher.NewCTR(block, iv)
stream.XORKeyStream(output, input)
return
}
// DecryptWithoutIntegrity decrypts data encrypted with AES-CTR.
func DecryptWithoutIntegrity(key, input, iv []byte) ([]byte, error) {
// AES-CTR decryption is identical to encryption.
return EncryptWithoutIntegrity(key, input, iv)
}
// DeriveKey derives a key from a password using scrypt. N should be set to the
// highest power of 2 you can derive within 100 milliseconds.
func DeriveKey(password string, salt []byte, N int) ([]byte, error) {
return scrypt.Key([]byte(password), salt, N, 8, 1, 32)
}