lib/paymentrequest.py

   1 import hashlib
   2 import httplib
   3 import os.path
   4 import re
   5 import sys
   6 import threading
   7 import time
   8 import traceback
   9 import urllib2
  10
  11 try:
  12     import paymentrequest_pb2
  13 except:
  14     print "protoc --proto_path=lib/ --python_out=lib/ lib/paymentrequest.proto"
  15     raise Exception()
  16
  17 import urlparse
  18 import requests
  19 from M2Crypto import X509
  20
  21 from bitcoin import is_valid
  22 import urlparse
  23
  24
  25 import util
  26 import transaction
  27
  28
  29 REQUEST_HEADERS = {'Accept': 'application/bitcoin-paymentrequest', 'User-Agent': 'Electrum'}
  30 ACK_HEADERS = {'Content-Type':'application/bitcoin-payment','Accept':'application/bitcoin-paymentack','User-Agent':'Electrum'}
  31
  32 ca_path = os.path.expanduser("~/.electrum/ca/ca-bundle.crt")
  33 ca_list = {}
  34 try:
  35     with open(ca_path, 'r') as ca_f:
  36         c = ""
  37         for line in ca_f:
  38             if line == "-----BEGIN CERTIFICATE-----\n":
  39                 c = line
  40             else:
  41                 c += line
  42             if line == "-----END CERTIFICATE-----\n":
  43                 x = X509.load_cert_string(c)
  44                 ca_list[x.get_fingerprint()] = x
  45 except Exception:
  46     print "ERROR: Could not open %s"%ca_path
  47     print "ca-bundle.crt file should be placed in ~/.electrum/ca/ca-bundle.crt"
  48     print "Documentation on how to download or create the file here: http://curl.haxx.se/docs/caextract.html"
  49     print "Payment will continue with manual verification."
  50     raise Exception()
  51
  52
  53 class PaymentRequest:
  54
  55     def __init__(self, url):
  56         self.url = url
  57         self.outputs = []
  58
  59     def get_amount(self):
  60         return sum(map(lambda x:x[1], self.outputs))
  61
  62
  63     def verify(self):
  64         u = urlparse.urlparse(self.url)
  65         self.domain = u.netloc
  66
  67         connection = httplib.HTTPConnection(u.netloc) if u.scheme == 'http' else httplib.HTTPSConnection(u.netloc)
  68         connection.request("GET",u.geturl(), headers=REQUEST_HEADERS)
  69         resp = connection.getresponse()
  70
  71         r = resp.read()
  72         paymntreq = paymentrequest_pb2.PaymentRequest()
  73         paymntreq.ParseFromString(r)
  74
  75         sig = paymntreq.signature
  76         if not sig:
  77             print "No signature"
  78             return
  79
  80         cert = paymentrequest_pb2.X509Certificates()
  81         cert.ParseFromString(paymntreq.pki_data)
  82         cert_num = len(cert.certificate)
  83
  84         x509_1 = X509.load_cert_der_string(cert.certificate[0])
  85         if self.domain != x509_1.get_subject().CN:
  86             validcert = False
  87             try:
  88                 SANs = x509_1.get_ext("subjectAltName").get_value().split(",")
  89                 for s in SANs:
  90                     s = s.strip()
  91                     if s.startswith("DNS:") and s[4:] == self.domain:
  92                         validcert = True
  93                         print "Match SAN DNS"
  94                     elif s.startswith("IP:") and s[3:] == self.domain:
  95                         validcert = True
  96                         print "Match SAN IP"
  97                     elif s.startswith("email:") and s[6:] == self.domain:
  98                         validcert = True
  99                         print "Match SAN email"
 100             except Exception, e:
 101                 print "ERROR: No SAN data"
 102             if not validcert:
 103                 ###TODO: check for wildcards
 104                 print "ERROR: Certificate Subject Domain Mismatch and SAN Mismatch"
 105                 print self.domain, x509_1.get_subject().CN
 106                 return
 107
 108         x509 = []
 109         CA_OU = ''
 110
 111         if cert_num > 1:
 112             for i in range(cert_num - 1):
 113                 x509.append(X509.load_cert_der_string(cert.certificate[i+1]))
 114                 if x509[i].check_ca() == 0:
 115                     print "ERROR: Supplied CA Certificate Error"
 116                     return
 117             for i in range(cert_num - 1):
 118                 if i == 0:
 119                     if x509_1.verify(x509[i].get_pubkey()) != 1:
 120                         print "ERROR: Certificate not Signed by Provided CA Certificate Chain"
 121                         return
 122                 else:
 123                     if x509[i-1].verify(x509[i].get_pubkey()) != 1:
 124                         print "ERROR: CA Certificate not Signed by Provided CA Certificate Chain"
 125                         return
 126
 127             supplied_CA_fingerprint = x509[cert_num-2].get_fingerprint()
 128             supplied_CA_CN = x509[cert_num-2].get_subject().CN
 129             CA_match = False
 130
 131             x = ca_list.get(supplied_CA_fingerprint)
 132             if x:
 133                 CA_OU = x.get_subject().OU
 134                 CA_match = True
 135                 if x.get_subject().CN != supplied_CA_CN:
 136                     print "ERROR: Trusted CA CN Mismatch; however CA has trusted fingerprint"
 137                     print "Payment will continue with manual verification."
 138             else:
 139                 print "ERROR: Supplied CA Not Found in Trusted CA Store."
 140                 print "Payment will continue with manual verification."
 141         else:
 142             print "ERROR: CA Certificate Chain Not Provided by Payment Processor"
 143             return False
 144
 145         paymntreq.signature = ''
 146         s = paymntreq.SerializeToString()
 147         pubkey_1 = x509_1.get_pubkey()
 148
 149         if paymntreq.pki_type == "x509+sha256":
 150             pubkey_1.reset_context(md="sha256")
 151         elif paymntreq.pki_type == "x509+sha1":
 152             pubkey_1.reset_context(md="sha1")
 153         else:
 154             print "ERROR: Unsupported PKI Type for Message Signature"
 155             return False
 156
 157         pubkey_1.verify_init()
 158         pubkey_1.verify_update(s)
 159         if pubkey_1.verify_final(sig) != 1:
 160             print "ERROR: Invalid Signature for Payment Request Data"
 161             return False
 162
 163         ### SIG Verified
 164
 165         self.payment_details = pay_det = paymentrequest_pb2.PaymentDetails()
 166         pay_det.ParseFromString(paymntreq.serialized_payment_details)
 167
 168         if pay_det.expires and pay_det.expires < int(time.time()):
 169             print "ERROR: Payment Request has Expired."
 170             #return False
 171
 172         for o in pay_det.outputs:
 173             addr = transaction.get_address_from_output_script(o.script)[1]
 174             self.outputs.append( (addr, o.amount) )
 175
 176         if CA_match:
 177             print 'Signed By Trusted CA: ', CA_OU
 178
 179         return pay_det
 180
 181
 182
 183     def send_ack(self, raw_tx, refund_addr):
 184
 185         pay_det = self.payment_details
 186         if pay_det.payment_url:
 187             paymnt = paymentrequest_pb2.Payment()
 188
 189             paymnt.merchant_data = pay_det.merchant_data
 190             paymnt.transactions.append(raw_tx)
 191
 192             ref_out = paymnt.refund_to.add()
 193             ref_out.script = transaction.Transaction.pay_script(refund_addr)
 194             paymnt.memo = "Paid using Electrum"
 195             pm = paymnt.SerializeToString()
 196
 197             payurl = urlparse.urlparse(pay_det.payment_url)
 198             try:
 199                 r = requests.post(payurl.geturl(), data=pm, headers=ACK_HEADERS, verify=ca_path)
 200             except requests.exceptions.SSLError:
 201                 print "Payment Message/PaymentACK verify Failed"
 202                 try:
 203                     r = requests.post(payurl.geturl(), data=pm, headers=ACK_HEADERS, verify=False)
 204                 except Exception as e:
 205                     print "Payment Message/PaymentACK Failed"
 206                     print e
 207                     return
 208             try:
 209                 paymntack = paymentrequest_pb2.PaymentACK()
 210                 paymntack.ParseFromString(r.content)
 211                 print "PaymentACK message received: %s" % paymntack.memo
 212             except Exception:
 213                 print "PaymentACK could not be processed. Payment was sent; please manually verify that payment was received."
 214
 215
 216
 217
 218 if __name__ == "__main__":
 219
 220     try:
 221         uri = sys.argv[1]
 222     except:
 223         print "usage: %s url"%sys.argv[0]
 224         print "example url: \"bitcoin:mpu3yTLdqA1BgGtFUwkVJmhnU3q5afaFkf?r=https%3A%2F%2Fbitcoincore.org%2F%7Egavin%2Ff.php%3Fh%3D2a828c05b8b80dc440c80a5d58890298&amount=1\""
 225         sys.exit(1)
 226
 227     address, amount, label, message, request_url, url = util.parse_url(uri)
 228     pr = PaymentRequest(request_url)
 229     if not pr.verify():
 230         sys.exit(1)
 231
 232     print 'Payment Request Verified Domain: ', pr.domain
 233     print 'outputs', pr.outputs
 234     print 'Payment Memo: ', pr.payment_details.memo
 235
 236     tx = "blah"
 237     pr.send_ack(tx, refund_addr = "1vXAXUnGitimzinpXrqDWVU4tyAAQ34RA")
 238