Initial commit

app/utils/hash.go

@@ -0,0 +1,81 @@
+package utils
+
+import (
+	"crypto/rand"
+	"crypto/subtle"
+	"encoding/base64"
+	"fmt"
+	"strings"
+
+	"golang.org/x/crypto/argon2"
+)
+
+const (
+	argon2Time    = 3
+	argon2Memory  = 64 * 1024
+	argon2Threads = 4
+	argon2KeyLen  = 32
+	saltLength    = 16
+)
+
+func Hash(password string) (string, error) {
+	salt := make([]byte, saltLength)
+	if _, err := rand.Read(salt); err != nil {
+		return "", err
+	}
+
+	hash := argon2.IDKey([]byte(password), salt, argon2Time, argon2Memory, argon2Threads, argon2KeyLen)
+
+	b64Salt := base64.RawStdEncoding.EncodeToString(salt)
+	b64Hash := base64.RawStdEncoding.EncodeToString(hash)
+
+	encodedHash := fmt.Sprintf("$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s",
+		argon2.Version, argon2Memory, argon2Time, argon2Threads, b64Salt, b64Hash)
+
+	return encodedHash, nil
+}
+
+func Verify(password, encodedHash string) (bool, error) {
+	parts := strings.Split(encodedHash, "$")
+	if len(parts) != 6 {
+		return false, fmt.Errorf("invalid hash format")
+	}
+
+	if parts[1] != "argon2id" {
+		return false, fmt.Errorf("unsupported hash algorithm")
+	}
+
+	var version int
+	_, err := fmt.Sscanf(parts[2], "v=%d", &version)
+	if err != nil {
+		return false, err
+	}
+	if version != argon2.Version {
+		return false, fmt.Errorf("incompatible version")
+	}
+
+	var memory, time uint32
+	var threads uint8
+	_, err = fmt.Sscanf(parts[3], "m=%d,t=%d,p=%d", &memory, &time, &threads)
+	if err != nil {
+		return false, err
+	}
+
+	salt, err := base64.RawStdEncoding.DecodeString(parts[4])
+	if err != nil {
+		return false, err
+	}
+
+	hash, err := base64.RawStdEncoding.DecodeString(parts[5])
+	if err != nil {
+		return false, err
+	}
+
+	otherHash := argon2.IDKey([]byte(password), salt, time, memory, threads, uint32(len(hash)))
+
+	if subtle.ConstantTimeCompare(hash, otherHash) == 1 {
+		return true, nil
+	}
+
+	return false, nil
+}