hashes passwords support

cmd/dkl-local-server/sha512crypt.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"encoding/base64"
+
+	crypthash "github.com/sergeymakinen/go-crypt/hash"
+	"github.com/sergeymakinen/go-crypt/sha512"
+)
+
+// for some reason, no implementation of crypt's sha512 is clean enough :(
+
+func sha512crypt(password, seed []byte) (string, error) {
+	// loose salt entropy because of character restriction in the salt
+	salt := []byte(base64.RawStdEncoding.EncodeToString(seed))[:sha512.MaxSaltLength]
+	// - base64 allows '+' where the salt accepts '.'
+	for i, c := range salt {
+		if c == '+' {
+			salt[i] = '.'
+		}
+	}
+
+	scheme := struct {
+		HashPrefix string
+		Rounds     uint32 `hash:"param:rounds,omitempty"`
+		Salt       []byte
+		Sum        [86]byte
+	}{
+		HashPrefix: sha512.Prefix,
+		Rounds:     sha512.DefaultRounds,
+		Salt:       salt,
+	}
+
+	key, err := sha512.Key([]byte(password), scheme.Salt, scheme.Rounds)
+	if err != nil {
+		return "", err
+	}
+	crypthash.LittleEndianEncoding.Encode(scheme.Sum[:], key)
+	return crypthash.Marshal(scheme)
+}