snapshot of https://github.com/ory/keto.git (master, 2026-09-16; blobs > 131072B omitted)

oryx/hasherx/hasher_pbkdf2.go

@@ -0,0 +1,103 @@
+package hasherx
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"crypto/sha1" // #nosec G505 - compatibility for imported passwords
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/base64"
+	"fmt"
+	"hash"
+
+	"github.com/pkg/errors"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/codes"
+	"golang.org/x/crypto/pbkdf2"
+	"golang.org/x/crypto/sha3"
+
+	"github.com/ory/x/otelx"
+)
+
+type (
+	// PBKDF2 is a PBKDF2 hasher.
+	PBKDF2 struct {
+		c PBKDF2Configurator
+	}
+
+	// PBKDF2Config is the configuration for a PBKDF2 hasher.
+	PBKDF2Config struct {
+		// Algorithm can be one of sha1, sha224, sha256, sha384, sha512
+		Algorithm string
+		// Iterations is the number of iterations to use.
+		Iterations uint32
+		// KeyLength is the length of the salt.
+		SaltLength uint32
+		// KeyLength is the length of the key.
+		KeyLength uint32
+	}
+
+	// PBKDF2Configurator is a configurator for a PBKDF2 hasher.
+	PBKDF2Configurator interface {
+		HasherPBKDF2Config(ctx context.Context) *PBKDF2Config
+	}
+)
+
+// NewHasherPBKDF2 creates a new PBKDF2 hasher.
+func NewHasherPBKDF2(c PBKDF2Configurator) *PBKDF2 {
+	return &PBKDF2{c: c}
+}
+
+// Generate generates a hash for the given password.
+func (h *PBKDF2) Generate(ctx context.Context, password []byte) (hash []byte, err error) {
+	ctx, span := otel.GetTracerProvider().Tracer("").Start(ctx, "hash.PBKDF2.Generate")
+	defer otelx.End(span, &err)
+
+	conf := h.c.HasherPBKDF2Config(ctx)
+	salt := make([]byte, conf.SaltLength)
+	if _, err := rand.Read(salt); err != nil {
+		return nil, err
+	}
+
+	key := pbkdf2.Key(password, salt, int(conf.Iterations), int(conf.KeyLength), getPseudorandomFunctionForPbkdf2(conf.Algorithm))
+
+	var b bytes.Buffer
+	if _, err := fmt.Fprintf(
+		&b,
+		"$pbkdf2-%s$i=%d,l=%d$%s$%s",
+		conf.Algorithm,
+		conf.Iterations,
+		conf.KeyLength,
+		base64.RawStdEncoding.EncodeToString(salt),
+		base64.RawStdEncoding.EncodeToString(key),
+	); err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
+		return nil, errors.WithStack(err)
+	}
+
+	return b.Bytes(), nil
+}
+
+// Understands checks if the given hash is in the correct format.
+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":
+		return sha3.New224
+	case "sha256":
+		return sha256.New
+	case "sha384":
+		return sha3.New384
+	case "sha512":
+		return sha512.New
+	default:
+		return sha256.New
+	}
+}