1 files changed, 67 insertions, 0 deletions
diff --git a/modules/auth/password/hash/pbkdf2.go b/modules/auth/password/hash/pbkdf2.go
new file mode 100644
index 0000000..27382fe
--- /dev/null
+++ b/modules/auth/password/hash/pbkdf2.go
@@ -0,0 +1,67 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package hash
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"strings"
+
+	"code.gitea.io/gitea/modules/log"
+
+	"golang.org/x/crypto/pbkdf2"
+)
+
+func init() {
+	MustRegister("pbkdf2", NewPBKDF2Hasher)
+}
+
+// PBKDF2Hasher implements PasswordHasher
+// and uses the PBKDF2 key derivation function.
+type PBKDF2Hasher struct {
+	iter, keyLen int
+}
+
+// HashWithSaltBytes a provided password and salt
+func (hasher *PBKDF2Hasher) HashWithSaltBytes(password string, salt []byte) string {
+	if hasher == nil {
+		return ""
+	}
+	return hex.EncodeToString(pbkdf2.Key([]byte(password), salt, hasher.iter, hasher.keyLen, sha256.New))
+}
+
+// NewPBKDF2Hasher is a factory method to create an PBKDF2Hasher
+// config should be either empty or of the form:
+// "<iter>$<keyLen>", where <x> is the string representation
+// of an integer
+func NewPBKDF2Hasher(config string) *PBKDF2Hasher {
+	// This default configuration uses the following parameters:
+	// iter=10000, keyLen=50.
+	// This matches the original configuration for `pbkdf2` prior to storing parameters
+	// in the database.
+	// THESE VALUES MUST NOT BE CHANGED OR BACKWARDS COMPATIBILITY WILL BREAK
+	hasher := &PBKDF2Hasher{
+		iter:   10_000,
+		keyLen: 50,
+	}
+
+	if config == "" {
+		return hasher
+	}
+
+	vals := strings.SplitN(config, "$", 2)
+	if len(vals) != 2 {
+		log.Error("invalid pbkdf2 hash spec %s", config)
+		return nil
+	}
+
+	var err error
+	hasher.iter, err = parseIntParam(vals[0], "iter", "pbkdf2", config, nil)
+	hasher.keyLen, err = parseIntParam(vals[1], "keyLen", "pbkdf2", config, err)
+	if err != nil {
+		return nil
+	}
+
+	return hasher
+}