1 files changed, 62 insertions, 0 deletions
diff --git a/internal/player/hardening_password_params_test.go b/internal/player/hardening_password_params_test.go
new file mode 100644
index 0000000..4c171f1
--- /dev/null
+++ b/internal/player/hardening_password_params_test.go
@@ -0,0 +1,62 @@
+package player
+
+// Regression: Argon2id parameters parsed from a stored hash must be bounded
+// before they reach argon2.IDKey. A hand-edited or corrupted account file
+// (e.g. argon2id:1:4294967295:...) must fail the check, not request a
+// multi-TiB allocation that kills the process.
+
+import (
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"testing"
+)
+
+func TestCheckPasswordRejectsOutOfRangeArgonParams(t *testing.T) {
+	// Enormous memory cost (0xFFFFFFFF KiB) with an otherwise well-formed
+	// hash: must be rejected before hashing.
+	huge := "argon2id:1:4294967295:2:AAAAAAAAAAAAAAAAAAAAAA:0011223344556677889900112233445566778899001122334455667788990011"
+	if CheckPassword("pw", huge) {
+		t.Fatal("out-of-range Argon2 memory cost was accepted")
+	}
+
+	// Negative values would wrap through uint32 under a naive conversion.
+	negative := "argon2id:-1:-1:-1:AAAAAAAAAAAAAAAAAAAAAA:0011223344556677889900112233445566778899001122334455667788990011"
+	if CheckPassword("pw", negative) {
+		t.Fatal("negative Argon2 parameters were accepted")
+	}
+
+	// Absurd time cost is bounded too.
+	slow := "argon2id:4294967295:65536:2:AAAAAAAAAAAAAAAAAAAAAA:0011223344556677889900112233445566778899001122334455667788990011"
+	if CheckPassword("pw", slow) {
+		t.Fatal("out-of-range Argon2 time cost was accepted")
+	}
+}
+
+func TestCheckPasswordAcceptsNormalAndLegacyHashes(t *testing.T) {
+	hashed, err := HashPassword("s3cret")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !CheckPassword("s3cret", hashed) {
+		t.Fatal("valid Argon2id hash rejected")
+	}
+	if CheckPassword("wrong", hashed) {
+		t.Fatal("wrong password accepted")
+	}
+
+	// Legacy single-pass sha256 hashes must keep verifying so old accounts
+	// can still log in and be upgraded.
+	salt := []byte("sixteen-byte-slt")
+	sum := sha256.Sum256(append(append([]byte{}, salt...), []byte("pw")...))
+	legacy := "sha256:" + base64.RawStdEncoding.EncodeToString(salt) + ":" + hex.EncodeToString(sum[:])
+	if !CheckPassword("pw", legacy) {
+		t.Fatal("legacy sha256 hash rejected")
+	}
+	if CheckPassword("nope", legacy) {
+		t.Fatal("wrong password accepted against legacy sha256 hash")
+	}
+	if !NeedsRehash(legacy) {
+		t.Fatal("legacy sha256 hash not flagged for rehash")
+	}
+}