feat(auth): add safe Argon2id local user registry

2026-08-16 18:24:20 +02:00
parent f99bddcdf0
commit f6e4dbcae2
16 changed files with 1269 additions and 3 deletions
@@ -0,0 +1,103 @@
+package authconfig
+
+import (
+	"bytes"
+	"encoding/hex"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+type passwordVector struct {
+	Password    string `json:"password"`
+	SaltHex     string `json:"saltHex"`
+	MemoryKiB   uint32 `json:"memoryKiB"`
+	Passes      uint32 `json:"passes"`
+	Parallelism uint8  `json:"parallelism"`
+	KeyLength   uint32 `json:"keyLength"`
+	PHC         string `json:"phc"`
+}
+
+func TestHashPasswordMatchesSharedFixedArgon2idVector(t *testing.T) {
+	vector := loadPasswordVector(t)
+	salt, err := hex.DecodeString(vector.SaltHex)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := HashPassword([]byte(vector.Password), bytes.NewReader(salt))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != vector.PHC {
+		t.Fatalf("HashPassword() = %q, want shared PHC vector %q", got, vector.PHC)
+	}
+}
+
+func TestVerifyPasswordAcceptsOnlyTheMatchingPassword(t *testing.T) {
+	vector := loadPasswordVector(t)
+	if !VerifyPassword([]byte(vector.Password), vector.PHC) {
+		t.Fatal("VerifyPassword() rejected the shared fixed vector")
+	}
+	if VerifyPassword([]byte(vector.Password+"!"), vector.PHC) {
+		t.Fatal("VerifyPassword() accepted a one-byte password change")
+	}
+}
+
+func TestVerifyPasswordRejectsMalformedAndOversizedPHCBeforeHashing(t *testing.T) {
+	password := []byte("correct horse battery staple")
+	for name, encoded := range map[string]string{
+		"wrong algorithm":       "$argon2i$v=19$m=65536,t=3,p=1$AAECAwQFBgcICQoLDA0ODw$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4",
+		"wrong version":         "$argon2id$v=18$m=65536,t=3,p=1$AAECAwQFBgcICQoLDA0ODw$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4",
+		"wrong parameter order": "$argon2id$v=19$t=3,m=65536,p=1$AAECAwQFBgcICQoLDA0ODw$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4",
+		"padded base64":         "$argon2id$v=19$m=65536,t=3,p=1$AAECAwQFBgcICQoLDA0ODw==$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4",
+		"memory too large":      "$argon2id$v=19$m=262145,t=1,p=1$AAECAwQFBgcICQoLDA0ODw$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4",
+		"passes too large":      "$argon2id$v=19$m=65536,t=11,p=1$AAECAwQFBgcICQoLDA0ODw$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4",
+		"parallelism too large": "$argon2id$v=19$m=65536,t=3,p=5$AAECAwQFBgcICQoLDA0ODw$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4",
+		"short salt":            "$argon2id$v=19$m=65536,t=3,p=1$AAECAwQFBgcICQoLDA0O$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4",
+		"long digest":           "$argon2id$v=19$m=65536,t=3,p=1$AAECAwQFBgcICQoLDA0ODw$AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
+	} {
+		t.Run(name, func(t *testing.T) {
+			if VerifyPassword(password, encoded) {
+				t.Fatal("VerifyPassword() accepted an invalid PHC string")
+			}
+		})
+	}
+}
+
+func TestHashPasswordRejectsPasswordsOutsideUTF8ByteBounds(t *testing.T) {
+	for name, password := range map[string][]byte{
+		"too short": bytes.Repeat([]byte("a"), 11),
+		"too long":  bytes.Repeat([]byte("a"), 1025),
+	} {
+		t.Run(name, func(t *testing.T) {
+			if _, err := HashPassword(password, bytes.NewReader(make([]byte, 16))); err == nil {
+				t.Fatal("HashPassword() accepted an out-of-bounds password")
+			}
+		})
+	}
+}
+
+func loadPasswordVector(t *testing.T) passwordVector {
+	t.Helper()
+	_, testFile, _, ok := runtime.Caller(0)
+	if !ok {
+		t.Fatal("locate password test fixture")
+	}
+	path := filepath.Join(filepath.Dir(testFile), "..", "..", "..", "..", "backend", "test", "fixtures", "argon2id-vectors.json")
+	contents, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var vectors []passwordVector
+	if err := json.Unmarshal(contents, &vectors); err != nil {
+		t.Fatal(err)
+	}
+	if len(vectors) != 1 || vectors[0].Password == "" || strings.Contains(vectors[0].PHC, "\n") {
+		t.Fatal("shared Argon2id fixture is invalid")
+	}
+	return vectors[0]
+}