Function TestPickSignatureAlgorithmRespectsSignerPreference

ssh/client_auth_test.go:1913–1957

(t *testing.T)

}

func TestPickSignatureAlgorithmRespectsSignerPreference(t *testing.T) {
	algoSigner, ok := testSigners["rsa"].(AlgorithmSigner)
	if !ok {
		t.Fatalf("rsa test signer does not implement the AlgorithmSigner interface")
	}

	serverExtensions := map[string][]byte{
		"server-sig-algs": []byte(KeyAlgoRSASHA256 + "," + KeyAlgoRSASHA512),
	}

	tests := []struct {
		name         string
		signerPrefs  []string
		expectedAlgo string
	}{
		{
			name:         "Signer prefers SHA512 then SHA256",
			signerPrefs:  []string{KeyAlgoRSASHA512, KeyAlgoRSASHA256},
			expectedAlgo: KeyAlgoRSASHA512,
		},
		{
			name:         "Signer prefers SHA256 then SHA512",
			signerPrefs:  []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512},
			expectedAlgo: KeyAlgoRSASHA256,
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			orderedSigner, err := NewSignerWithAlgorithms(algoSigner, tc.signerPrefs)
			if err != nil {
				t.Fatalf("failed to create ordered signer: %v", err)
			}

			_, selectedAlgo, err := pickSignatureAlgorithm(orderedSigner, serverExtensions)
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}

			if selectedAlgo != tc.expectedAlgo {
				t.Errorf("Algorithm mismatch; got %q want %q", selectedAlgo, tc.expectedAlgo)
			}
		})
	}
}

// configurablePublicKeyCallback is a public key callback that allows to
// configure the signature algorithm and format. This way we can emulate the