#!/usr/bin/env python2

import sys
import pywii as wii

if len(sys.argv) != 4:
	print "Usage: %s keyfile.priv infile outfile"%sys.argv[0]
	sys.exit(1)

if sys.argv[1] == "-":
	k = sys.stdin.read()
else:
	k = open(sys.argv[1],"rb").read()

if len(k) != 30:
	print "Failed to read private key"
	sys.exit(2)

indata = open(sys.argv[2],"rb").read()
sha = wii.SHA.new(indata).digest()

print "SHA1: %s"%sha.encode('hex')
print
print "Signature:"
r,s = wii.ec.generate_ecdsa(k,sha)
print "R =",r[:15].encode('hex')
print "   ",r[15:].encode('hex')
print "S =",s[:15].encode('hex')
print "   ",s[15:].encode('hex')

outdata = "SIG0" + r + s + indata

fd = open(sys.argv[3],"wb")
fd.write(outdata)
fd.close()