def crypto_sign(msg, sk):
if len(sk) != SECRETKEYBYTES:<EOL><INDENT>raise ValueError("<STR_LIT>" % len(sk))<EOL><DEDENT>vkbytes = sk[PUBLICKEYBYTES:]<EOL>skbytes = sk[:PUBLICKEYBYTES]<EOL>sig = djbec.signature(msg, skbytes, vkbytes)<EOL>return sig + msg<EOL>
Return signature+message given message and secret key.
    The signature is the first SIGNATUREBYTES bytes of the return value.
    A copy of msg is in the remainder.