diff --git a/pkg/auth/sender_test.go b/pkg/auth/sender_test.go
new file mode 100644
index 00000000..0731d674
--- /dev/null
+++ b/pkg/auth/sender_test.go
@@ -0,0 +1,53 @@
+package auth
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/aler9/gortsplib/pkg/base"
+)
+
+func TestSenderError(t *testing.T) {
+	for _, ca := range []struct {
+		name string
+		hv   base.HeaderValue
+		err  string
+	}{
+		{
+			"invalid method",
+			base.HeaderValue{`Invalid`},
+			"no authentication methods available",
+		},
+		{
+			"digest invalid",
+			base.HeaderValue{`Digest`},
+			"unable to split between method and keys (Digest)",
+		},
+		{
+			"digest, missing realm",
+			base.HeaderValue{`Digest nonce=123`},
+			"realm is missing",
+		},
+		{
+			"digest, missing nonce",
+			base.HeaderValue{`Digest realm=123`},
+			"nonce is missing",
+		},
+		{
+			"basic invalid",
+			base.HeaderValue{`Basic`},
+			"unable to split between method and keys (Basic)",
+		},
+		{
+			"basic, missing realm",
+			base.HeaderValue{`Basic nonce=123`},
+			"realm is missing",
+		},
+	} {
+		t.Run(ca.name, func(t *testing.T) {
+			_, err := NewSender(ca.hv, "myuser", "mypass")
+			require.Equal(t, ca.err, err.Error())
+		})
+	}
+}
diff --git a/pkg/auth/validator_test.go b/pkg/auth/validator_test.go
new file mode 100644
index 00000000..8720b5f1
--- /dev/null
+++ b/pkg/auth/validator_test.go
@@ -0,0 +1,65 @@
+package auth
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/aler9/gortsplib/pkg/base"
+)
+
+func TestValidatorError(t *testing.T) {
+	for _, ca := range []struct {
+		name string
+		hv   base.HeaderValue
+		err  string
+	}{
+		{
+			"invalid auth",
+			base.HeaderValue{`Invalid`},
+			"invalid authorization header",
+		},
+		{
+			"digest missing realm",
+			base.HeaderValue{`Digest `},
+			"realm is missing",
+		},
+		{
+			"digest missing nonce",
+			base.HeaderValue{`Digest realm=123`},
+			"nonce is missing",
+		},
+		{
+			"digest missing username",
+			base.HeaderValue{`Digest realm=123,nonce=123`},
+			"username is missing",
+		},
+		{
+			"digest missing uri",
+			base.HeaderValue{`Digest realm=123,nonce=123,username=123`},
+			"uri is missing",
+		},
+		{
+			"digest missing response",
+			base.HeaderValue{`Digest realm=123,nonce=123,username=123,uri=123`},
+			"response is missing",
+		},
+		{
+			"digest wrong nonce",
+			base.HeaderValue{`Digest realm=123,nonce=123,username=123,uri=123,response=123`},
+			"wrong nonce",
+		},
+		{
+			"digest wrong realm",
+			base.HeaderValue{`Digest realm=123,nonce=abcde,username=123,uri=123,response=123`},
+			"wrong realm",
+		},
+	} {
+		t.Run(ca.name, func(t *testing.T) {
+			va := NewValidator("myuser", "mypass", nil)
+			va.nonce = "abcde"
+			err := va.ValidateHeader(ca.hv, base.Describe, nil, nil)
+			require.Equal(t, ca.err, err.Error())
+		})
+	}
+}