func parseKeyPairFromPEMBlock()

in pkg/internal/token/clientcertcredential.go [137:172]

30 lines of code
8 McCabe index (conditional complexity)


func parseKeyPairFromPEMBlock(pemBlock []byte) (*x509.Certificate, *rsa.PrivateKey, error) {
	certPEM, keyPEM := splitPEMBlock(pemBlock)

	privateKey, err := parseRsaPrivateKey(keyPEM)
	if err != nil {
		return nil, nil, err
	}

	found := false
	var cert *x509.Certificate
	for {
		var certBlock *pem.Block
		var err error
		certBlock, certPEM = pem.Decode(certPEM)
		if certBlock == nil {
			break
		}

		cert, err = x509.ParseCertificate(certBlock.Bytes)
		if err != nil {
			return nil, nil, fmt.Errorf("unable to parse certificate: %w", err)
		}

		certPublicKey, ok := cert.PublicKey.(*rsa.PublicKey)
		if ok && isPublicKeyEqual(certPublicKey, &privateKey.PublicKey) {
			found = true
			break
		}
	}

	if !found {
		return nil, nil, fmt.Errorf("unable to find a matching public certificate")
	}

	return cert, privateKey, nil
}