openmedialibrary_platform/Linux_i686/bin/edsig

89 lines
2.6 KiB
Text
Raw Normal View History

2014-05-17 18:11:40 +00:00
#!/usr/bin/python
import os, sys
import ed25519
from hashlib import sha256
def help():
print """\
Usage: (ed25519 version %s)
edsig generate [STEM]
creates keypair, writes to 'STEM.signing.key' and 'STEM.verifying.key'
default is to 'signing.key' and 'verifying.key'
edsig sign (signing.key|keyfile) message.file
prints signature to stdout
If message.file is "-", reads from stdin.
edsig verify (verifying.key|keyfile) message.file (signature|sigfile)
prints 'good signature!' or raises exception
If message.file is "-", reads from stdin.
Key-providing arguments can either be the key itself, or point to a file
containing the key.
""" % ed25519.__version__
def remove_prefix(prefix, s):
if not s.startswith(prefix):
raise ValueError("no prefix found")
return s[len(prefix):]
def data_from_arg(arg, prefix, keylen, readable):
if (readable
and arg.startswith(prefix)
and len(remove_prefix(prefix, arg))==keylen):
return arg
if os.path.isfile(arg):
return open(arg,"r").read()
raise ValueError("unable to get data from '%s'" % arg)
def message_rep(msg_arg):
if msg_arg == "-":
f = sys.stdin
else:
f = open(msg_arg, "rb")
h = sha256()
while True:
data = f.read(16*1024)
if not data:
break
h.update(data)
return h.digest()
if len(sys.argv) < 2:
help()
elif sys.argv[1] == "generate":
sk,vk = ed25519.create_keypair()
if len(sys.argv) > 2:
sk_outfile = sys.argv[2]+".signing.key"
vk_outfile = sys.argv[2]+".verifying.key"
else:
sk_outfile = "signing.key"
vk_outfile = "verifying.key"
sk_s = sk.to_seed(prefix="sign0-")
vk_s = vk.to_ascii("verf0-", "base32")
open(sk_outfile,"w").write(sk_s)
open(vk_outfile,"w").write(vk_s+"\n")
print "wrote private signing key to", sk_outfile
print "write public verifying key to", vk_outfile
elif sys.argv[1] == "sign":
sk_arg = sys.argv[2]
msg_arg = sys.argv[3]
sk = ed25519.SigningKey(data_from_arg(sk_arg, "sign0-", 52, False),
prefix="sign0-")
sig = sk.sign(message_rep(msg_arg), prefix="sig0-", encoding="base32")
print sig
elif sys.argv[1] == "verify":
vk_arg = sys.argv[2]
msg_arg = sys.argv[3]
sig_arg = sys.argv[4]
vk = ed25519.VerifyingKey(data_from_arg(vk_arg, "verf0-", 52, True),
prefix="verf0-", encoding="base32")
sig = data_from_arg(sig_arg, "sig0-", 103, True)
vk.verify(sig, message_rep(msg_arg),
prefix="sig0-", encoding="base32") # could raise BadSignature
print "good signature!"
else:
help()