Use argon2 for password hashing

7 files changed, 24 insertions, 22 deletions

diff --git a/dec.go b/dec.go
index aa551ad..ae9ec33 100644
--- a/dec.go
+++ b/dec.go
@@ -10,7 +10,7 @@ import (
 )
 
 func (o *decryptOptions) decrypt(w io.Writer, r io.Reader, password string) error {
-	_, err := io.Copy(w, newDecryptingReader(r, password, o.iterations))
+	_, err := io.Copy(w, newDecryptingReader(r, password, o.memory))
 	return err
 }
 
@@ -27,14 +27,14 @@ func (f *decryptFlags) registerFlags(fs *flag.FlagSet) {
 type decryptOptions struct {
 	decryptFlags
 
-	iterations int
+	memory     int
 	passwordIn func() (string, error)
 	stdin      io.Reader
 	stdout     io.Writer
 }
 
 var defaultDecryptOptions = decryptOptions{
-	iterations: defaultPBKDF2Iters,
+	memory:     defaultArgon2Memory,
 	passwordIn: termReadPassword,
 	stdin:      os.Stdin,
 	stdout:     os.Stdout,
diff --git a/enc.go b/enc.go
index 5990121..c24cba8 100644
--- a/enc.go
+++ b/enc.go
@@ -28,7 +28,7 @@ func (f *encryptFlags) registerFlags(fs *flag.FlagSet) {
 type encryptOptions struct {
 	encryptFlags
 
-	iterations  int
+	memory      int
 	passwordIn  func() (string, error)
 	passwordOut io.Writer
 	stdin       io.Reader
@@ -36,7 +36,7 @@ type encryptOptions struct {
 }
 
 var defaultEncryptOptions = encryptOptions{
-	iterations:  defaultPBKDF2Iters,
+	memory:      defaultArgon2Memory,
 	passwordIn:  termReadPassword,
 	passwordOut: os.Stderr,
 	stdin:       os.Stdin,
@@ -44,7 +44,7 @@ var defaultEncryptOptions = encryptOptions{
 }
 
 func (o *encryptOptions) encrypt(w io.Writer, r io.Reader, password string) error {
-	writer := newEncryptingWriter(w, password, o.iterations)
+	writer := newEncryptingWriter(w, password, o.memory)
 	if _, err := io.Copy(writer, r); err != nil {
 		return err
 	}
diff --git a/go.mod b/go.mod
index a1f7c9f..db929f6 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module roseh.moe/cmd/sym
 go 1.25.0
 
 require (
+	golang.org/x/crypto v0.43.0
 	golang.org/x/term v0.36.0
 	roseh.moe/pkg/wordlist v1.0.2
 )
diff --git a/go.sum b/go.sum
index 2b38e1d..56eda83 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,7 @@
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
+golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
 golang.org/x/mod v0.29.0 h1:HV8lRxZC4l2cr3Zq1LvtOsi/ThTgWnUk/y64QSs8GwA=
 golang.org/x/mod v0.29.0/go.mod h1:NyhrlYXJ2H4eJiRy/WDBO6HMqZQ6q9nk4JzS3NuCK+w=
 golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
diff --git a/oae.go b/oae.go
index 5b6140c..a4eb6c8 100644
--- a/oae.go
+++ b/oae.go
@@ -21,15 +21,15 @@ const (
 )
 
 type segmentEncrypter struct {
-	password   string
-	iterations int
+	password string
+	memory   int
 
 	aead  cipher.AEAD
 	nonce [nonceSize]byte
 }
 
 func (se *segmentEncrypter) initialize(salt []byte) error {
-	key, err := hashPassword(se.password, salt, se.iterations)
+	key, err := hashPassword(se.password, salt, se.memory)
 	if err != nil {
 		return err
 	}
@@ -83,12 +83,12 @@ type encryptingWriter struct {
 	initialized bool
 }
 
-func newEncryptingWriter(w io.Writer, password string, iterations int) *encryptingWriter {
+func newEncryptingWriter(w io.Writer, password string, memory int) *encryptingWriter {
 	return &encryptingWriter{
 		w: w,
 		encrypter: segmentEncrypter{
-			password:   password,
-			iterations: iterations,
+			password: password,
+			memory:   memory,
 		},
 	}
 }
@@ -181,12 +181,12 @@ type decryptingReader struct {
 	readFinalBlock bool
 }
 
-func newDecryptingReader(r io.Reader, password string, iterations int) *decryptingReader {
+func newDecryptingReader(r io.Reader, password string, memory int) *decryptingReader {
 	return &decryptingReader{
 		r: bufio.NewReaderSize(r, 0), // we only need .UnreadByte
 		decrypter: segmentEncrypter{
-			password:   password,
-			iterations: iterations,
+			password: password,
+			memory:   memory,
 		},
 	}
 }
diff --git a/pwhash.go b/pwhash.go
index 31f1487..dabafa7 100644
--- a/pwhash.go
+++ b/pwhash.go
@@ -1,17 +1,16 @@
 package main
 
 import (
-	"crypto/pbkdf2"
-	"crypto/sha256"
 	"os"
 
+	"golang.org/x/crypto/argon2"
 	"golang.org/x/term"
 )
 
-const defaultPBKDF2Iters = 35_000_000
+const defaultArgon2Memory = 64 * 1024
 
-func hashPassword(password string, salt []byte, iters int) ([]byte, error) {
-	return pbkdf2.Key(sha256.New, password, salt, iters, 32)
+func hashPassword(password string, salt []byte, memory int) ([]byte, error) {
+	return argon2.IDKey([]byte(password), salt, 1, uint32(memory), 4, 32), nil
 }
 
 func termReadPassword() (string, error) {
diff --git a/sym_test.go b/sym_test.go
index 4d648d3..bb81ab8 100644
--- a/sym_test.go
+++ b/sym_test.go
@@ -9,13 +9,13 @@ import (
 
 var testEncryptOptions = func() encryptOptions {
 	opts := defaultEncryptOptions
-	opts.iterations = 10
+	opts.memory = 1
 	return opts
 }()
 
 var testDecryptOptions = func() decryptOptions {
 	opts := defaultDecryptOptions
-	opts.iterations = 10
+	opts.memory = 1
 	return opts
 }()