sys.exit('Error: Unable to import public key, aborting.')
if clargs.file is None:
message = sys.stdin.read().encode()
else:
with open(clargs.file, 'r') as msgfile:
message = msgfile.read().encode()
if (message is None) or (len(message) == 0):
sys.exit('Error: Plaintext length 0, aborting.')
# generate a random (ephemeral) private key
eprivkey = FieldElement.urandom(curve.p)
SharedPt = Pubkey * eprivkey
sbytes = SharedPt.compressed()
key = sha256(sbytes).digest()
nonce = pysodium.randombytes(pysodium.crypto_stream_NONCEBYTES)
assert pysodium.crypto_stream_NONCEBYTES == 24
assert pysodium.crypto_stream_KEYBYTES == 32
ctext = pysodium.crypto_stream_xor(message, len(message), nonce, key)
# public key point for ephemeral key
Gpt = ECPoint(curve, curve.G)
ePubkey = Gpt * eprivkey
DERmsg = der_encode_message(ePubkey, nonce, ctext)
print(pem_wrap(DERmsg, 'ECDHE_XSALSA20 ENCRYPTED MESSAGE'))
parser = ArgumentParser(description=desc)
parser.add_argument('-f',
'--file',
default=None,
help='read private key from file instead of stdin')
clargs = parser.parse_args()
if clargs.file is None:
Inkey = sys.stdin.read()
else:
with open(clargs.file, 'r') as keyfile:
Inkey = keyfile.read()
DERkey = pem_unwrap(Inkey, 'ECDH PRIVATE KEY')
try:
(privkey, curve) = der_decode_privkey(DERkey)
except ValueError:
sys.exit('Error: Unable to import private key, aborting.')
if privkey is None:
sys.exit('Error: Unable to import private key, aborting.')
Gpt = ECPoint(curve, curve.G)
Pubkey = Gpt * privkey
DERkey = der_encode_pubkey(Pubkey, curve)
print(pem_wrap(DERkey, 'ECDH PUBLIC KEY'))
with open(clargs.privkey, 'r') as keyfile:
Inkey = keyfile.read()
DERkey = pem_unwrap(Inkey, 'ECDH PRIVATE KEY')
if DERkey == None:
sys.exit('unable to decode ECDH PRIVATE KEY in base64 PEM format')
try:
(Privkey, curve) = der_decode_privkey(DERkey)
except ValueError:
sys.exit('Error: Unable to import private key, aborting.')
if Privkey is None:
sys.exit('Error: Unable to import public key, aborting.')
if clargs.file is None:
message = sys.stdin.read().encode()
else:
with open(clargs.file, 'r') as msgfile:
message = msgfile.read().encode()
if (message is None) or (len(message) == 0):
sys.exit('Error: Plaintext length 0, aborting.')
ss = ECDSASignatureScheme(curve, SHA512)
sig = ss.Sign(Privkey, message)
sigbytes = sig.AsBytes()
print(pem_wrap(message, 'ECDSA SIGNED MESSAGE'))
print(pem_wrap(sigbytes, 'ECDSA SIGNATURE'))
sys.exit('Error: Unable to import public key, aborting.')
if clargs.file is None:
ptxt_wrapped = sys.stdin.read()
else:
with open(clargs.file, 'r') as msgfile:
ptxt_wrapped=msgfile.read()
if (ptxt_wrapped is None) or (len(ptxt_wrapped) == 0):
sys.exit('Error: Plaintext length 0, aborting.')
DERptxt = pem_unwrap(ptxt_wrapped, 'ECDH PUBLIC KEY')
if DERptxt == None:
sys.exit('unable to decode plaintext (ECDH PUBLIC KEY) in base64 PEM format')
try:
(Plaintext, curve2) = der_decode_pubkey(DERptxt)
except ValueError:
sys.exit('Error: Unable to import private key, aborting.')
if Plaintext is None:
sys.exit('Error: Unable to import public key, aborting.')
if curve != curve2:
sys.exit('Error: key and plaintext must be on the same curve, aborting.')
ctext = ECElgamalCiphertext.encrypt(Pubkey, Plaintext)
DERmsg = der_encode_ecelgamal_ctxt(ctext, curve)
print(pem_wrap(DERmsg, 'ECELGAMAL ENCRYPTED MESSAGE'))
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
from ECC import FieldElement, ECurve
from example_der import der_encode_privkey
from example_pem import pem_wrap
from argparse import ArgumentParser
import base64
import sys
desc = ('ecdh-gen generates a private key for elliptic curve cryptography '
'based on a specific curve. The private key value is simply a '
'random number ')
parser = ArgumentParser(description=desc)
parser.add_argument('-l', '--list_curves', action='store_true', help='list supported curves')
parser.add_argument('-c', '--curve', default='secp256k1', help='choose standard curve')
clargs = parser.parse_args()
if clargs.list_curves:
clist = ECurve._CurveNames()
for c in clist:
print(c)
sys.exit(0)
curve = ECurve(clargs.curve)
privkey = int(FieldElement.urandom(curve.p))
DERkey = der_encode_privkey(privkey, curve)
print(pem_wrap(DERkey, 'ECDH PRIVATE KEY'))
