Digital Signatures (DS)
=======================

**Data Types**:

:DSSignKey: The RSA private key for public-key signatures with RSA.
:DSVerifyKey: The RSA public key, used for verifying RSA signatures.

**Functions**:

.. function:: DSKeyGen() (DSSignKey, DSVerifyKey, error)

    Generate a 256-byte (2048-bit) RSA key pair for digital signatures.

    :rtype: DSSignKey, DSVerifyKey, error

.. function:: DSSign(sk DSSignKey, msg []byte) ([]byte, error)

    Use the RSA private key to create a signature.

    :param sk: RSA signing (private) key
    :type sk: DSSignKey
    :param msg: Arbitrary-length message to sign
    :type msg: []byte

    :rtype: []byte, error

.. function:: DSVerify(vk DSVerifyKey, msg []byte, sig []byte) (error)

    Use the RSA public key to verify a signature.

    :param vk: RSA verification (public) key
    :type vk: DSVerifyKey
    :param msg: Arbitrary-length message to verify
    :type msg: []byte
    :param sig: Signature to verify
    :type sig: []byte

    :rtype: error