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

hash/hasher_argon2.go

@@ -0,0 +1,91 @@
+// Copyright © 2023 Ory Corp
+// SPDX-License-Identifier: Apache-2.0
+
+package hash
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+
+	"github.com/inhies/go-bytesize"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+
+	"github.com/pkg/errors"
+	"golang.org/x/crypto/argon2"
+
+	"github.com/ory/kratos/driver/config"
+	"github.com/ory/x/otelx"
+)
+
+var (
+	ErrInvalidHash               = errors.New("the encoded hash is not in the correct format")
+	ErrIncompatibleVersion       = errors.New("incompatible version of argon2")
+	ErrMismatchedHashAndPassword = errors.New("passwords do not match")
+)
+
+type Argon2 struct {
+	c Argon2Configuration
+}
+
+type Argon2Configuration interface {
+	config.Provider
+}
+
+func NewHasherArgon2(c Argon2Configuration) *Argon2 {
+	return &Argon2{c: c}
+}
+
+func toKB(mem bytesize.ByteSize) uint32 {
+	//nolint:gosec // disable G115
+	return uint32(mem / bytesize.KB)
+}
+
+func (h *Argon2) Generate(ctx context.Context, password []byte) (_ []byte, err error) {
+	conf := h.c.Config().HasherArgon2(ctx)
+
+	_, span := otel.GetTracerProvider().Tracer(tracingComponent).Start(ctx, "hash.Generate", trace.WithAttributes(
+		attribute.String("hash.type", "argon2id"),
+		attribute.String("hash.config", fmt.Sprintf("%#v", conf)),
+	))
+	defer otelx.End(span, &err)
+
+	salt := make([]byte, conf.SaltLength)
+	if _, err := rand.Read(salt); err != nil {
+		return nil, err
+	}
+
+	// ensure that the context is not canceled before doing the heavy lifting
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+
+	// Pass the plaintext password, salt and parameters to the argon2.IDKey
+	// function. This will generate a hash of the password using the Argon2id
+	// variant.
+	hash := argon2.IDKey(password, salt, conf.Iterations, toKB(conf.Memory), conf.Parallelism, conf.KeyLength)
+
+	var b bytes.Buffer
+	if _, err := fmt.Fprintf(
+		&b,
+		"$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s",
+		argon2.Version, toKB(conf.Memory), conf.Iterations, conf.Parallelism,
+		base64.RawStdEncoding.EncodeToString(salt),
+		base64.RawStdEncoding.EncodeToString(hash),
+	); err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
+		return nil, errors.WithStack(err)
+	}
+
+	return b.Bytes(), nil
+}
+
+func (h *Argon2) Understands(hash []byte) bool {
+	return IsArgon2idHash(hash)
+}