From 3d4cd35846d5b2641f0d4e9ee833d01120c8d8f3 Mon Sep 17 00:00:00 2001
From: ale <ale@incal.net>
Date: Sat, 25 Jan 2025 13:03:04 +0000
Subject: [PATCH] Add Argon2id support
---
pwhash/argon2.go | 112 ++++++++++++++++++++++++++++++++--------
pwhash/password.go | 21 ++++----
pwhash/password_test.go | 11 +++-
3 files changed, 111 insertions(+), 33 deletions(-)
diff --git a/pwhash/argon2.go b/pwhash/argon2.go
index 87df12f..1a7de11 100644
--- a/pwhash/argon2.go
+++ b/pwhash/argon2.go
@@ -12,8 +12,9 @@ import (
"golang.org/x/crypto/argon2"
)
-var (
- argonKeyLen uint32 = 32
+const (
+ argonLegacyKeySize = 32
+ argonDefaultKeySize = 16
argonSaltLen = 16
)
@@ -28,9 +29,11 @@ type argon2PasswordHash struct {
// newArgon2PasswordHash returns an Argon2i-based PasswordHash using the
// specified parameters for time, memory, and number of threads.
-func newArgon2PasswordHash(time, mem uint32, threads uint8, codec argon2Codec) PasswordHash {
+func newArgon2PasswordHash(kind string, keySize int, time, mem uint32, threads uint8, codec argon2Codec) PasswordHash {
return &argon2PasswordHash{
params: argon2Params{
+ KeySize: keySize,
+ Kind: kind,
Time: time,
Memory: mem,
Threads: threads,
@@ -51,7 +54,7 @@ func NewArgon2() PasswordHash {
// NewArgon2WithParams returns an Argon2i-based PasswordHash using the
// specified parameters for time, memory, and number of threads.
func NewArgon2WithParams(time, mem uint32, threads uint8) PasswordHash {
- return newArgon2PasswordHash(time, mem, threads, &a2Codec{})
+ return newArgon2PasswordHash(kindArgon2I, argonLegacyKeySize, time, mem, threads, &a2LegacyCodec{})
}
// NewArgon2Std returns an Argon2i-based PasswordHash that conforms
@@ -64,12 +67,12 @@ func NewArgon2Std() PasswordHash {
)
}
-// NewArgon2StdWithParams returns an Argon2i-based PasswordHash using
+// NewArgon2StdWithParams returns an Argon2id-based PasswordHash using
// the specified parameters for time, memory, and number of
-// threads. This will use the string encoding ("$argon2$") documented
+// threads. This will use the string encoding ("$argon2id$") documented
// in the argon2 reference implementation.
func NewArgon2StdWithParams(time, mem uint32, threads uint8) PasswordHash {
- return newArgon2PasswordHash(time, mem, threads, &argon2StdCodec{})
+ return newArgon2PasswordHash(kindArgon2ID, argonDefaultKeySize, time, mem, threads, &argon2StdCodec{})
}
// ComparePassword returns true if the given password matches the
@@ -79,28 +82,53 @@ func (s *argon2PasswordHash) ComparePassword(encrypted, password string) bool {
if err != nil {
return false
}
- dk2 := argon2.Key([]byte(password), salt, params.Time, params.Memory, params.Threads, argonKeyLen)
+
+ dk2 := params.hash(password, salt)
return subtle.ConstantTimeCompare(dk, dk2) == 1
}
// Encrypt the given password with the Argon2 algorithm.
func (s *argon2PasswordHash) Encrypt(password string) string {
salt := getRandomBytes(argonSaltLen)
- dk := argon2.Key([]byte(password), salt, s.params.Time, s.params.Memory, s.params.Threads, argonKeyLen)
+ dk := s.params.hash(password, salt)
return s.codec.encodeArgon2Hash(s.params, salt, dk)
}
+const (
+ kindArgon2I = "argon2i"
+ kindArgon2ID = "argon2id"
+)
+
type argon2Params struct {
+ Kind string
+ KeySize int
Time uint32
Memory uint32
Threads uint8
}
+func (p argon2Params) hash(password string, salt []byte) []byte {
+ if p.KeySize == 0 {
+ panic("key size is 0")
+ }
+
+ switch p.Kind {
+ case kindArgon2I:
+ return argon2.Key([]byte(password), salt, p.Time, p.Memory, p.Threads, uint32(p.KeySize))
+ case kindArgon2ID:
+ return argon2.IDKey([]byte(password), salt, p.Time, p.Memory, p.Threads, uint32(p.KeySize))
+ default:
+ panic("unknown argon2 hash kind")
+ }
+}
+
// Default Argon2 parameters are tuned for a high-traffic
// authentication service (<1ms per operation).
var defaultArgon2Params = argon2Params{
+ Kind: kindArgon2ID,
+ KeySize: 16,
Time: 1,
- Memory: 4 * 1024,
+ Memory: 64 * 1024,
Threads: 4,
}
@@ -109,13 +137,14 @@ type argon2Codec interface {
decodeArgon2Hash(string) (argon2Params, []byte, []byte, error)
}
-type a2Codec struct{}
+// Argon2i legacy encoding, do not use.
+type a2LegacyCodec struct{}
-func (*a2Codec) encodeArgon2Hash(params argon2Params, salt, dk []byte) string {
+func (*a2LegacyCodec) encodeArgon2Hash(params argon2Params, salt, dk []byte) string {
return fmt.Sprintf("$a2$%d$%d$%d$%x$%x", params.Time, params.Memory, params.Threads, salt, dk)
}
-func (*a2Codec) decodeArgon2Hash(s string) (params argon2Params, salt []byte, dk []byte, err error) {
+func (*a2LegacyCodec) decodeArgon2Hash(s string) (params argon2Params, salt []byte, dk []byte, err error) {
if !strings.HasPrefix(s, "$a2$") {
err = errors.New("not an Argon2 password hash")
return
@@ -127,6 +156,8 @@ func (*a2Codec) decodeArgon2Hash(s string) (params argon2Params, salt []byte, dk
return
}
+ params.Kind = kindArgon2I
+
var i uint64
if i, err = strconv.ParseUint(parts[0], 10, 32); err != nil {
@@ -148,16 +179,36 @@ func (*a2Codec) decodeArgon2Hash(s string) (params argon2Params, salt []byte, dk
if err != nil {
return
}
+
dk, err = hex.DecodeString(parts[4])
+ if err != nil {
+ return
+ }
+
+ params.KeySize = len(dk)
+ switch len(dk) {
+ case 16, 24, 32:
+ default:
+ err = errors.New("bad key size")
+ }
+
return
}
+// Standard Argon2 encoding as per the reference implementation in
+// https://github.com/P-H-C/phc-winner-argon2/blob/4ac8640c2adc1257677d27d3f833c8d1ee68c7d2/src/encoding.c#L242-L252
type argon2StdCodec struct{}
+const argon2HashVersionStr = "v=19"
+
func (*argon2StdCodec) encodeArgon2Hash(params argon2Params, salt, dk []byte) string {
encSalt := base64.RawStdEncoding.EncodeToString(salt)
encDK := base64.RawStdEncoding.EncodeToString(dk)
- return fmt.Sprintf("$argon2i$v=19$m=%d,t=%d,p=%d$%s$%s", params.Memory, params.Time, params.Threads, encSalt, encDK)
+ return fmt.Sprintf(
+ "$%s$%s$m=%d,t=%d,p=%d$%s$%s",
+ params.Kind, argon2HashVersionStr,
+ params.Memory, params.Time, params.Threads,
+ encSalt, encDK)
}
func parseArgon2HashParams(s string) (params argon2Params, err error) {
@@ -181,7 +232,7 @@ func parseArgon2HashParams(s string) (params argon2Params, err error) {
i, err = strconv.ParseUint(kv[1], 10, 8)
params.Threads = uint8(i)
default:
- err = errors.New("unknown parameter in hash")
+ err = fmt.Errorf("unknown parameter '%s' in hash", kv[0])
}
if err != nil {
return
@@ -191,29 +242,46 @@ func parseArgon2HashParams(s string) (params argon2Params, err error) {
}
func (*argon2StdCodec) decodeArgon2Hash(s string) (params argon2Params, salt []byte, dk []byte, err error) {
- if !strings.HasPrefix(s, "$argon2i$") {
+ var kind string
+ switch {
+ case strings.HasPrefix(s, "$argon2i$"):
+ kind = kindArgon2I
+ case strings.HasPrefix(s, "$argon2id$"):
+ kind = kindArgon2ID
+ default:
err = errors.New("not an Argon2 password hash")
return
}
- parts := strings.SplitN(s[9:], "$", 4)
- if len(parts) != 4 {
+ parts := strings.SplitN(s, "$", 6)
+ if len(parts) != 6 {
err = errors.New("bad encoding")
return
}
- if parts[0] != "v=19" {
+ if parts[2] != argon2HashVersionStr {
err = errors.New("bad argon2 hash version")
return
}
- params, err = parseArgon2HashParams(parts[1])
+ params, err = parseArgon2HashParams(parts[3])
if err != nil {
return
}
- if salt, err = base64.RawStdEncoding.DecodeString(parts[2]); err != nil {
+ params.Kind = kind
+
+ if salt, err = base64.RawStdEncoding.DecodeString(parts[4]); err != nil {
+ return
+ }
+ if dk, err = base64.RawStdEncoding.DecodeString(parts[5]); err != nil {
return
}
- dk, err = base64.RawStdEncoding.DecodeString(parts[3])
+
+ params.KeySize = len(dk)
+ switch len(dk) {
+ case 16, 24, 32:
+ default:
+ err = errors.New("bad key size")
+ }
return
}
diff --git a/pwhash/password.go b/pwhash/password.go
index 07b093d..8c0b911 100644
--- a/pwhash/password.go
+++ b/pwhash/password.go
@@ -4,7 +4,7 @@
// The format is the well-known dollar-separated field string,
// extended with optional algorithm-specific parameters:
//
-// $id[$params...]$salt$encrypted
+// $id[$params...]$salt$encrypted
//
// We extend 'id' beyond the values supported by the libc crypt(3)
// function with the following hashing algorithms:
@@ -16,9 +16,8 @@
// the parameterized benchmarks are named with
// time/memory(MB)/threads. For nicer results:
//
-// go test -bench=Argon2 -run=none . 2>&1 | \
-// awk '/^Bench/ {ops=1000000000 / $3; print $1 " " ops " ops/sec"}'
-//
+// go test -bench=Argon2 -run=none . 2>&1 | \
+// awk '/^Bench/ {ops=1000000000 / $3; print $1 " " ops " ops/sec"}'
package pwhash
import (
@@ -49,12 +48,13 @@ func getRandomBytes(n int) []byte {
// A registry of default handlers for decoding passwords.
var prefixRegistry = map[string]PasswordHash{
- "$1$": NewSystemCrypt(),
- "$5$": NewSystemCrypt(),
- "$6$": NewSystemCrypt(),
- "$s$": NewScrypt(),
- "$a2$": NewArgon2(),
- "$argon2i$": NewArgon2Std(),
+ "$1$": NewSystemCrypt(),
+ "$5$": NewSystemCrypt(),
+ "$6$": NewSystemCrypt(),
+ "$s$": NewScrypt(),
+ "$a2$": NewArgon2(),
+ "$argon2i$": NewArgon2Std(),
+ "$argon2id$": NewArgon2Std(),
}
// ComparePassword returns true if the given password matches the
@@ -65,6 +65,7 @@ func ComparePassword(encrypted, password string) bool {
return h.ComparePassword(encrypted, password)
}
}
+
return false
}
diff --git a/pwhash/password_test.go b/pwhash/password_test.go
index e1cbfde..cef83a6 100644
--- a/pwhash/password_test.go
+++ b/pwhash/password_test.go
@@ -65,7 +65,7 @@ func testImpl(t *testing.T, h PasswordHash) {
}
}
-func TestStandardArgon2Password(t *testing.T) {
+func TestStandardArgon2IPassword(t *testing.T) {
enc := "$argon2i$v=19$m=32768,t=4,p=1$DG0B56zlrrx+VMVaM6wvsw$8iV+HwTKmofjrb+q9I2zZGQnGXzXtiIXv8VdHdvbbX8"
pw := "idontmindbirds"
if !ComparePassword(enc, pw) {
@@ -73,6 +73,15 @@ func TestStandardArgon2Password(t *testing.T) {
}
}
+func TestStandardArgon2IDPassword(t *testing.T) {
+ // python3 -c 'from argon2 import PasswordHasher ; print(PasswordHasher().hash("idontmindbirds"))'
+ enc := "$argon2id$v=19$m=102400,t=2,p=8$7hQLBrHoxYxRO0R8km62pA$Dv5+BCctW4nCrxsy5C9JBg"
+ pw := "idontmindbirds"
+ if !ComparePassword(enc, pw) {
+ t.Fatal("comparison failed")
+ }
+}
+
func BenchmarkArgon2(b *testing.B) {
var testParams []argon2Params
for iTime := 1; iTime <= 5; iTime++ {
--
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