def gen_dsa_pub_key(dsa_key, old_key):
der = base64.b64decode(old_key)
cert = asn1.DerSequence()
cert.decode(der)
y_asn = asn1.DerInteger()
y_asn.decode(cert[1][4:])
y = y_asn.value
pubkeyInfo = asn1.DerSequence()
pubkeyInfo.decode(cert[0])
pubkeys = asn1.DerSequence()
pubkeys[:] = [dsa_key.p, dsa_key.q, dsa_key.g]
pubkeyInfo[1] = pubkeys.encode()
y_asn = asn1.DerInteger(dsa_key.y).encode()
y_asn_prefix = struct.pack('BBBB', 3, 0x81, len(y_asn) + 1, 0)
cert[:] = [pubkeyInfo.encode(), y_asn_prefix + y_asn]
return base64.b64encode(cert.encode())
def load_dsa_key(pub_key):
der = base64.b64decode(pub_key)
cert = asn1.DerSequence()
cert.decode(der)
y_asn = asn1.DerInteger()
y_asn.decode(cert[1][4:])
y = y_asn.value
pubkeyInfo = asn1.DerSequence()
pubkeyInfo.decode(cert[0])
pubkeys = asn1.DerSequence()
pubkeys.decode(pubkeyInfo[1])
p, q, g = pubkeys[:]
return DSA.construct((y, g, p, q))
def decode_int(data):
der = asn1.DerInteger()
der.decode(data)
return der.value