func Parse()

in calnex/cert/cert.go [83:135]
45 lines of code
12 McCabe index (conditional complexity)

func Parse(data []byte) (*Bundle, error) {
	bundle := &Bundle{}

	for len(data) > 0 {
		var block *pem.Block

		block, data = pem.Decode(data)
		if block == nil {
			return nil, ErrFailedToParsePEM
		}

		if block.Type == "CERTIFICATE" {
			cert, err := x509.ParseCertificate(block.Bytes)
			if err != nil {
				return nil, err
			}
			bundle.Certs = append(bundle.Certs, cert)
		} else if strings.Contains(block.Type, "PRIVATE KEY") {
			if bundle.PrivKey != nil {
				return nil, ErrMultiplePrivKeys
			}

			var key *rsa.PrivateKey
			var err error

			if block.Type == "RSA PRIVATE KEY" {
				key, err = x509.ParsePKCS1PrivateKey(block.Bytes)
				if err != nil {
					return nil, err
				}
			} else if block.Type == "PRIVATE KEY" {
				tmpKey, err := x509.ParsePKCS8PrivateKey(block.Bytes)
				if err != nil {
					return nil, err
				}

				ok := false
				key, ok = tmpKey.(*rsa.PrivateKey)
				if !ok {
					return nil, ErrOnlyRSA
				}
			} else {
				return nil, ErrUnsupportedPEMBlock
			}

			bundle.PrivKey = key
		} else {
			return nil, ErrUnsupportedPEMBlock
		}
	}

	return bundle, nil
}