def rsa_pkcs1v15_sign(private_key, data, hash_algorithm):
    """
    Generates an RSASSA-PKCS-v1.5 signature.

    When the hash_algorithm is "raw", the operation is identical to RSA
    private key encryption. That is: the data is not hashed and no ASN.1
    structure with an algorithm identifier of the hash algorithm is placed in
    the encrypted byte string.

    :param private_key:
        The PrivateKey to generate the signature with

    :param data:
        A byte string of the data the signature is for

    :param hash_algorithm:
        A unicode string of "md5", "sha1", "sha256", "sha384", "sha512" or "raw"

    :raises:
        ValueError - when any of the parameters contain an invalid value
        TypeError - when any of the parameters are of the wrong type
        OSError - when an error is returned by the OS crypto library

    :return:
        A byte string of the signature
    """

    if private_key.algorithm != 'rsa':
        raise ValueError('The key specified is not an RSA private key')

    return _sign(private_key, data, hash_algorithm)
Generates an RSASSA-PKCS-v1.5 signature.

    When the hash_algorithm is "raw", the operation is identical to RSA
    private key encryption. That is: the data is not hashed and no ASN.1
    structure with an algorithm identifier of the hash algorithm is placed in
    the encrypted byte string.

    :param private_key:
        The PrivateKey to generate the signature with

    :param data:
        A byte string of the data the signature is for

    :param hash_algorithm:
        A unicode string of "md5", "sha1", "sha256", "sha384", "sha512" or "raw"

    :raises:
        ValueError - when any of the parameters contain an invalid value
        TypeError - when any of the parameters are of the wrong type
        OSError - when an error is returned by the OS crypto library

    :return:
        A byte string of the signature