v0.4.0 harden jwt, scram, credential handling, remove legacy adapters

scram_fuzz_test.go

@@ -0,0 +1,62 @@
+package auth
+
+import (
+	"encoding/base64"
+	"testing"
+)
+
+func FuzzScramServerMessages(f *testing.F) {
+	s := NewScramServer()
+	f.Cleanup(s.Stop)
+	f.Add("unknown", "nonce", base64.StdEncoding.EncodeToString(make([]byte, 32)))
+	f.Add("", "", "")
+	f.Add("a,n=b", "nonce", "!!!")
+	f.Fuzz(func(t *testing.T, username, nonce, proof string) {
+		first, err := s.ProcessClientFirstMessage(username, nonce)
+		if err != nil {
+			return
+		}
+		// No credential is registered, so even syntactically valid proofs fail.
+		_, err = s.ProcessClientFinalMessage(first.FullNonce, proof)
+		if err == nil {
+			t.Fatal("unknown account authenticated")
+		}
+		_, err = s.ProcessClientFinalMessage(first.FullNonce, proof)
+		errIs(t, err, ErrSCRAMInvalidNonce, "failed proof consumed")
+		if handshakeCount(s) != 0 {
+			t.Fatal("handshake leaked")
+		}
+	})
+}
+
+func FuzzScramClientMessages(f *testing.F) {
+	f.Add("server", base64.StdEncoding.EncodeToString(make([]byte, 16)), uint32(1), uint32(8), uint8(1), "")
+	f.Add("", "!!!", uint32(0), uint32(0), uint8(0), "!!!")
+	f.Add("server", "", uint32(16), uint32(MaxVerifyArgonMemory), uint8(16), "")
+	f.Fuzz(func(t *testing.T, suffix, salt string, iterations, memory uint32, threads uint8, signature string) {
+		// Invalid costs exercise production rejection. Valid costs are restricted
+		// to tiny test profiles so fuzzing cannot multiply expensive KDF work.
+		if checkScramCost(memory, iterations, threads) == nil && (memory > 64 || iterations > 2 || threads > 2) {
+			return
+		}
+		c := NewScramClient("u", "password123", WithMinArgonCost(1, 8))
+		first, err := c.StartAuthentication()
+		noErr(t, err, "start")
+		msg := ServerFirstMessage{FullNonce: first.ClientNonce + suffix, Salt: salt, ArgonTime: iterations, ArgonMemory: memory, ArgonThreads: threads}
+		proof, err := c.ProcessServerFirstMessage(msg)
+		if err != nil {
+			if proof.FullNonce != "" || proof.ClientProof != "" || c.serverKey != nil {
+				t.Fatal("state/values survived error")
+			}
+			return
+		}
+		if proof.FullNonce != msg.FullNonce {
+			t.Fatal("nonce not bound")
+		}
+		_ = c.VerifyServerFinalMessage(ServerFinalMessage{ServerSignature: signature})
+		errIs(t, c.VerifyServerFinalMessage(ServerFinalMessage{ServerSignature: signature}), ErrSCRAMInvalidState, "final consumed")
+		if c.serverKey != nil {
+			t.Fatal("server key survived final")
+		}
+	})
+}