snapshot of https://github.com/ory/kratos.git (master, 2026-09-15; blobs > 131072B omitted)

hash/hasher_pbkdf2.go

@@ -0,0 +1,95 @@
+// Copyright © 2023 Ory Corp
+// SPDX-License-Identifier: Apache-2.0
+
+package hash
+
+import (
+	"bytes"
+	"context"
+	"crypto/pbkdf2"
+	"crypto/rand"
+	"crypto/sha1" //#nosec G505 -- compatibility for imported passwords
+	"crypto/sha256"
+	"crypto/sha3"
+	"crypto/sha512"
+	"encoding/base64"
+	"fmt"
+	"hash"
+
+	"github.com/pkg/errors"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+
+	"github.com/ory/x/otelx"
+)
+
+type Pbkdf2 struct {
+	Algorithm  string
+	Iterations uint32
+	SaltLength uint32
+	KeyLength  uint32
+}
+
+func (h *Pbkdf2) Generate(ctx context.Context, password []byte) (_ []byte, err error) {
+	_, span := otel.GetTracerProvider().Tracer(tracingComponent).Start(ctx, "hash.Generate", trace.WithAttributes(
+		attribute.String("hash.type", "pbkdf2"),
+		attribute.String("hash.config", fmt.Sprintf("%#v", h)),
+	))
+	defer otelx.End(span, &err)
+
+	salt := make([]byte, h.SaltLength)
+	if _, err := rand.Read(salt); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	// ensure that the context is not canceled before doing the heavy lifting
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+
+	key, err := pbkdf2.Key(getPseudorandomFunctionForPbkdf2(h.Algorithm), string(password), salt, int(h.Iterations), int(h.KeyLength))
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	var b bytes.Buffer
+	if _, err := fmt.Fprintf(
+		&b,
+		"$pbkdf2-%s$i=%d,l=%d$%s$%s",
+		h.Algorithm,
+		h.Iterations,
+		h.KeyLength,
+		base64.RawStdEncoding.EncodeToString(salt),
+		base64.RawStdEncoding.EncodeToString(key),
+	); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return b.Bytes(), nil
+}
+
+func (h *Pbkdf2) Understands(hash []byte) bool {
+	return IsPbkdf2Hash(hash)
+}
+
+func getPseudorandomFunctionForPbkdf2(alg string) func() hash.Hash {
+	switch alg {
+	case "sha1":
+		return sha1.New
+	case "sha224":
+		// Kept for backwards compatibility: this historically mapped to
+		// SHA3-224, not SHA2-224. Changing it would break verification of
+		// previously imported hashes.
+		return func() hash.Hash { return sha3.New224() }
+	case "sha256":
+		return sha256.New
+	case "sha384":
+		// Kept for backwards compatibility: SHA3-384, see above.
+		return func() hash.Hash { return sha3.New384() }
+	case "sha512":
+		return sha512.New
+	default:
+		return sha256.New
+	}
+}