mirror of https://github.com/schollz/croc.git
58 lines
1.3 KiB
Go
58 lines
1.3 KiB
Go
package crypt
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import (
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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"crypto/sha256"
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"golang.org/x/crypto/pbkdf2"
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)
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type encryption struct {
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key []byte
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passphrase []byte
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salt []byte
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}
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// New generates a new encryption, using the supplied passphrase and
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// an optional supplied salt.
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func New(passphrase []byte, salt []byte) (e encryption, err error) {
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e.passphrase = passphrase
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if salt == nil {
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e.salt = make([]byte, 8)
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// http://www.ietf.org/rfc/rfc2898.txt
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// Salt.
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rand.Read(e.salt)
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} else {
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e.salt = salt
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}
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e.key = pbkdf2.Key([]byte(passphrase), e.salt, 100, 32, sha256.New)
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return
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}
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func (e encryption) Salt() []byte {
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return e.salt
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}
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// Encrypt will generate an encryption, prefixed with the IV
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func (e encryption) Encrypt(plaintext []byte) []byte {
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// generate a random iv each time
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// http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf
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// Section 8.2
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ivBytes := make([]byte, 12)
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rand.Read(ivBytes)
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b, _ := aes.NewCipher(e.key)
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aesgcm, _ := cipher.NewGCM(b)
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encrypted := aesgcm.Seal(nil, ivBytes, plaintext, nil)
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return append(ivBytes, encrypted...)
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}
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// Decrypt an encryption
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func (e encryption) Decrypt(encrypted []byte) (plaintext []byte, err error) {
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b, _ := aes.NewCipher(e.key)
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aesgcm, _ := cipher.NewGCM(b)
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plaintext, err = aesgcm.Open(nil, encrypted[:12], encrypted[12:], nil)
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return
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}
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