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

oryx/hasherx/hasher_argon2.go

@@ -0,0 +1,118 @@
+package hasherx
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"math"
+	"time"
+
+	"github.com/ory/x/otelx"
+
+	"github.com/inhies/go-bytesize"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+
+	"github.com/pkg/errors"
+	"golang.org/x/crypto/argon2"
+)
+
+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 (
+	// Argon2Config is the configuration for a Argon2 hasher.
+	Argon2Config struct {
+		// Memory is the amount of memory to use.
+		Memory bytesize.ByteSize `json:"memory"`
+
+		// Iterations is the number of iterations to use.
+		Iterations uint32 `json:"iterations"`
+
+		// Parallelism is the number of threads to use.
+		Parallelism uint8 `json:"parallelism"`
+
+		// SaltLength is the length of the salt to use.
+		SaltLength uint32 `json:"salt_length"`
+
+		// KeyLength is the length of the key to use.
+		KeyLength uint32 `json:"key_length"`
+
+		// ExpectedDuration is the expected duration of the hash.
+		ExpectedDuration time.Duration `json:"expected_duration"`
+
+		// ExpectedDeviation is the expected deviation of the hash.
+		ExpectedDeviation time.Duration `json:"expected_deviation"`
+
+		// DedicatedMemory is the amount of dedicated memory to use.
+		DedicatedMemory bytesize.ByteSize `json:"dedicated_memory"`
+	}
+	// Argon2 is a hasher that uses the Argon2 algorithm.
+	Argon2 struct {
+		c Argon2Configurator
+	}
+	// Argon2Configurator is a function that returns the Argon2 configuration.
+	Argon2Configurator interface {
+		HasherArgon2Config(ctx context.Context) *Argon2Config
+	}
+)
+
+func NewHasherArgon2(c Argon2Configurator) *Argon2 {
+	return &Argon2{c: c}
+}
+
+func toKB(mem bytesize.ByteSize) (uint32, error) {
+	kb := uint64(mem / bytesize.KB)
+	if kb > math.MaxUint32 {
+		return 0, errors.Errorf("memory %v is too large", mem)
+	}
+	return uint32(kb), nil
+}
+
+// Generate generates a hash for the given password.
+func (h *Argon2) Generate(ctx context.Context, password []byte) (_ []byte, err error) {
+	ctx, span := otel.GetTracerProvider().Tracer(tracingComponent).Start(ctx, "hash.Argon2.Generate")
+	defer otelx.End(span, &err)
+	p := h.c.HasherArgon2Config(ctx)
+	span.SetAttributes(attribute.String("argon2.config", fmt.Sprintf("#%v", p)))
+
+	salt := make([]byte, p.SaltLength)
+	if _, err := rand.Read(salt); err != nil {
+		return nil, err
+	}
+
+	mem, err := toKB(p.Memory)
+	if err != nil {
+		return nil, 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, p.Iterations, mem, p.Parallelism, p.KeyLength)
+
+	var b bytes.Buffer
+	if _, err := fmt.Fprintf(
+		&b,
+		"$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s",
+		argon2.Version, mem, p.Iterations, p.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
+}
+
+// Understands checks if the given hash is in the correct format.
+func (h *Argon2) Understands(hash []byte) bool {
+	return IsArgon2idHash(hash)
+}