allow ek cert to be parsed as TPMT_PUBLIC (#203)

Author: gh4683

service/biz/tpm20_utils.go

@@ -827,8 +827,18 @@ func (u *DefaultTPM20Utils) ParseTCGCSRIDevIDContent(csrBytes []byte) (*TCGCSRID
 	}
 	ekCert, err := certificateDerToPem(ekCertBytes)
 	if err != nil {
-		return nil, fmt.Errorf("failed to convert EK Cert to PEM: %w", err)
+		pub, tpmErr := tpm20.Unmarshal[tpm20.TPMTPublic](ekCertBytes)
+		if tpmErr != nil {
+			return nil, fmt.Errorf("failed to parse ekCert as X509 certificate (%v) or TPMTPublic (%v)", err, tpmErr)
+		}
+
+		log.Infof("Successfully parsed ekCertBytes as TPMTPublic structure. Converting to PEM.")
+		ekCert, err = u.TPMTPublicToPEM(pub)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert TPMTPublic to PEM: %w", err)
+		}
 	}
+
 	result.EKCert = ekCert
 
 	// attestPub - Attestation Key public key (IAK)

service/biz/tpm20_utils_test.go

@@ -636,6 +636,23 @@ func generateCsrBytes(options CsrOptions) []byte {
 }
 
 func TestParseTCGCSRIDevIDContent(t *testing.T) {
+	u := DefaultTPM20Utils{}
+	privKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		t.Fatalf("Failed to generate RSA key for testing: %v", err)
+	}
+	tpmtPub, err := u.RSAEKPublicKeyToTPMTPublic(&privKey.PublicKey)
+	if err != nil {
+		t.Fatalf("Failed to create TPMT Public for testing: %v", err)
+	}
+	tpmtPubPEM, err := u.TPMTPublicToPEM(tpmtPub)
+	if err != nil {
+		t.Fatalf("Failed to convert TPMT Public to PEM for testing: %v", err)
+	}
+	tpmtPubBytes := tpm20.Marshal(tpmtPub)
+
+	validCSRWithTPMTPub := *validCSR
+	validCSRWithTPMTPub.EKCert = tpmtPubPEM
 	// Define test cases
 	tests := []struct {
 		name           string
@@ -736,7 +753,7 @@ func TestParseTCGCSRIDevIDContent(t *testing.T) {
 		{
 			name:          "Invalid EK Cert",
 			csrBytes:      generateCsrBytes(CsrOptions{EKCert: []byte("invalid-ek-cert")}),
-			expectedError: errors.New("failed to convert EK Cert to PEM"),
+			expectedError: errors.New("failed to parse ekCert as X509 certificate"),
 		},
 		{
 			name:          "Invalid Attest Pub Bytes",
@@ -763,6 +780,12 @@ func TestParseTCGCSRIDevIDContent(t *testing.T) {
 			csrBytes:      generateCsrBytes(CsrOptions{AddExtraBytesToEnd: true}),
 			expectedError: errors.New("leftover bytes in TCG_CSR_IDEVID_CONTENT block after parsing"),
 		},
+		{
+			name:           "Valid CSR bytes: PPK in EkCert field as TPMTPublic",
+			csrBytes:       generateCsrBytes(CsrOptions{EKCert: tpmtPubBytes}),
+			expectedError:  nil,
+			expectedResult: &validCSRWithTPMTPub,
+		},
 	}
 
 	for _, tc := range tests {