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     sys.exit(1)
  16
  17 import urlparse
  18 import requests
  19 from M2Crypto import X509
  20
  21 from bitcoin import is_valid
  22 import urlparse
  23
  24 import transaction
  25
  26 REQUEST_HEADERS = {'Accept': 'application/bitcoin-paymentrequest', 'User-Agent': 'Electrum'}
  27 ACK_HEADERS = {'Content-Type':'application/bitcoin-payment','Accept':'application/bitcoin-paymentack','User-Agent':'Electrum'}
  28
  29 class PaymentRequest:
  30
  31     def __init__(self):
  32         self.ca_path = os.path.expanduser("~/.electrum/ca/ca-bundle.crt")
  33         self.ca_list = {}
  34         try:
  35             with open(self.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                         self.ca_list[x.get_fingerprint()] = x
  45         except Exception:
  46             print "ERROR: Could not open %s"%self.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
  51
  52
  53     def verify(self, url):
  54
  55         u = urlparse.urlparse(urllib2.unquote(url))
  56         self.domain = u.netloc
  57
  58         connection = httplib.HTTPConnection(u.netloc) if u.scheme == 'http' else httplib.HTTPSConnection(u.netloc)
  59         connection.request("GET",u.geturl(), headers=REQUEST_HEADERS)
  60         resp = connection.getresponse()
  61
  62         r = resp.read()
  63         paymntreq = paymentrequest_pb2.PaymentRequest()
  64         paymntreq.ParseFromString(r)
  65
  66         sig = paymntreq.signature
  67
  68         cert = paymentrequest_pb2.X509Certificates()
  69         cert.ParseFromString(paymntreq.pki_data)
  70         cert_num = len(cert.certificate)
  71
  72         x509_1 = X509.load_cert_der_string(cert.certificate[0])
  73         if self.domain != x509_1.get_subject().CN:
  74             ###TODO: check for subject alt names
  75             ###       check for wildcards
  76             print "ERROR: Certificate Subject Domain Mismatch"
  77             print self.domain, x509_1.get_subject().CN
  78             #return
  79
  80         x509 = []
  81         CA_OU = ''
  82
  83         if cert_num > 1:
  84             for i in range(cert_num - 1):
  85                 x509.append(X509.load_cert_der_string(cert.certificate[i+1]))
  86                 if x509[i].check_ca() == 0:
  87                     print "ERROR: Supplied CA Certificate Error"
  88                     return
  89             for i in range(cert_num - 1):
  90                 if i == 0:
  91                     if x509_1.verify(x509[i].get_pubkey()) != 1:
  92                         print "ERROR: Certificate not Signed by Provided CA Certificate Chain"
  93                         return
  94                 else:
  95                     if x509[i-1].verify(x509[i].get_pubkey()) != 1:
  96                         print "ERROR: CA Certificate not Signed by Provided CA Certificate Chain"
  97                         return
  98
  99             supplied_CA_fingerprint = x509[cert_num-2].get_fingerprint()
 100             supplied_CA_CN = x509[cert_num-2].get_subject().CN
 101             CA_match = False
 102
 103             x = self.ca_list.get(supplied_CA_fingerprint)
 104             if x:
 105                 CA_OU = x.get_subject().OU
 106                 CA_match = True
 107                 if x.get_subject().CN != supplied_CA_CN:
 108                     print "ERROR: Trusted CA CN Mismatch; however CA has trusted fingerprint"
 109                     print "Payment will continue with manual verification."
 110             else:
 111                 print "ERROR: Supplied CA Not Found in Trusted CA Store."
 112                 print "Payment will continue with manual verification."
 113         else:
 114             print "ERROR: CA Certificate Chain Not Provided by Payment Processor"
 115             return False
 116
 117         paymntreq.signature = ''
 118         s = paymntreq.SerializeToString()
 119         pubkey_1 = x509_1.get_pubkey()
 120
 121         if paymntreq.pki_type == "x509+sha256":
 122             pubkey_1.reset_context(md="sha256")
 123         elif paymntreq.pki_type == "x509+sha1":
 124             pubkey_1.reset_context(md="sha1")
 125         else:
 126             print "ERROR: Unsupported PKI Type for Message Signature"
 127             return False
 128
 129         pubkey_1.verify_init()
 130         pubkey_1.verify_update(s)
 131         if pubkey_1.verify_final(sig) != 1:
 132             print "ERROR: Invalid Signature for Payment Request Data"
 133             return False
 134
 135         ### SIG Verified
 136
 137         self.payment_details = pay_det = paymentrequest_pb2.PaymentDetails()
 138         pay_det.ParseFromString(paymntreq.serialized_payment_details)
 139
 140         if pay_det.expires and pay_det.expires < int(time.time()):
 141             print "ERROR: Payment Request has Expired."
 142             return False
 143
 144         self.outputs = []
 145         for o in pay_det.outputs:
 146             addr = transaction.get_address_from_output_script(o.script)[1]
 147             self.outputs.append( (addr, o.amount) )
 148
 149         if CA_match:
 150             print 'Signed By Trusted CA: ', CA_OU
 151
 152         return True
 153
 154
 155
 156     def send_ack(self, raw_tx, refund_addr):
 157
 158         pay_det = self.payment_details
 159         if pay_det.payment_url:
 160             paymnt = paymentrequest_pb2.Payment()
 161
 162             paymnt.merchant_data = pay_det.merchant_data
 163             paymnt.transactions.append(raw_tx)
 164
 165             ref_out = paymnt.refund_to.add()
 166             ref_out.script = transaction.Transaction.pay_script(refund_addr)
 167             paymnt.memo = "Paid using Electrum"
 168             pm = paymnt.SerializeToString()
 169
 170             payurl = urlparse.urlparse(pay_det.payment_url)
 171             try:
 172                 r = requests.post(payurl.geturl(), data=pm, headers=ACK_HEADERS, verify=self.ca_path)
 173             except requests.exceptions.SSLError:
 174                 print "Payment Message/PaymentACK verify Failed"
 175                 try:
 176                     r = requests.post(payurl.geturl(), data=pm, headers=ACK_HEADERS, verify=False)
 177                 except Exception as e:
 178                     print "Payment Message/PaymentACK Failed"
 179                     print e
 180                     return
 181             try:
 182                 paymntack = paymentrequest_pb2.PaymentACK()
 183                 paymntack.ParseFromString(r.content)
 184                 print "PaymentACK message received: %s" % paymntack.memo
 185             except Exception:
 186                 print "PaymentACK could not be processed. Payment was sent; please manually verify that payment was received."
 187
 188
 189 uri = "bitcoin:mpu3yTLdqA1BgGtFUwkVJmhnU3q5afaFkf?r=https%3A%2F%2Fbitcoincore.org%2F%7Egavin%2Ff.php%3Fh%3D26c19879d44c3891214e7897797b9160&amount=1"
 190 url = "https%3A%2F%2Fbitcoincore.org%2F%7Egavin%2Ff.php%3Fh%3D26c19879d44c3891214e7897797b9160"
 191
 192 #uri = "bitcoin:1m9Lw2pFCe6Hs7xUuo9fMJCzEwQNdCo5e?amount=0.0012&r=https%3A%2F%2Fbitpay.com%2Fi%2F8XNDiQU92H2whNG4j8hZ5M"
 193 #url = "https%3A%2F%2Fbitpay.com%2Fi%2F8XNDiQU92H2whNG4j8hZ5M"
 194
 195
 196 if __name__ == "__main__":
 197
 198     pr = PaymentRequest()
 199     if not pr.verify(url):
 200         sys.exit(1)
 201
 202     print 'Payment Request Verified Domain: ', pr.domain
 203     print 'outputs', pr.outputs
 204     print 'Payment Memo: ', pr.payment_details.memo
 205
 206     tx = "blah"
 207     pr.send_ack(tx, "1vXAXUnGitimzinpXrqDWVU4tyAAQ34RA")
 208