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         self.error = ""
  59
  60     def get_amount(self):
  61         return sum(map(lambda x:x[1], self.outputs))
  62
  63
  64     def verify(self):
  65         u = urlparse.urlparse(self.url)
  66         self.domain = u.netloc
  67
  68         try:
  69             connection = httplib.HTTPConnection(u.netloc) if u.scheme == 'http' else httplib.HTTPSConnection(u.netloc)
  70             connection.request("GET",u.geturl(), headers=REQUEST_HEADERS)
  71             resp = connection.getresponse()
  72         except:
  73             self.error = "cannot read url"
  74             return
  75
  76         paymntreq = paymentrequest_pb2.PaymentRequest()
  77         try:
  78             r = resp.read()
  79             paymntreq.ParseFromString(r)
  80         except:
  81             self.error = "cannot parse payment request"
  82             return
  83
  84         sig = paymntreq.signature
  85         if not sig:
  86             self.error = "No signature"
  87             return
  88
  89         cert = paymentrequest_pb2.X509Certificates()
  90         cert.ParseFromString(paymntreq.pki_data)
  91         cert_num = len(cert.certificate)
  92
  93         x509_1 = X509.load_cert_der_string(cert.certificate[0])
  94         if self.domain != x509_1.get_subject().CN:
  95             validcert = False
  96             try:
  97                 SANs = x509_1.get_ext("subjectAltName").get_value().split(",")
  98                 for s in SANs:
  99                     s = s.strip()
 100                     if s.startswith("DNS:") and s[4:] == self.domain:
 101                         validcert = True
 102                         print "Match SAN DNS"
 103                     elif s.startswith("IP:") and s[3:] == self.domain:
 104                         validcert = True
 105                         print "Match SAN IP"
 106                     elif s.startswith("email:") and s[6:] == self.domain:
 107                         validcert = True
 108                         print "Match SAN email"
 109             except Exception, e:
 110                 print "ERROR: No SAN data"
 111             if not validcert:
 112                 ###TODO: check for wildcards
 113                 self.error = "ERROR: Certificate Subject Domain Mismatch and SAN Mismatch"
 114                 return
 115
 116         x509 = []
 117         CA_OU = ''
 118
 119         if cert_num > 1:
 120             for i in range(cert_num - 1):
 121                 x509.append(X509.load_cert_der_string(cert.certificate[i+1]))
 122                 if x509[i].check_ca() == 0:
 123                     self.error = "ERROR: Supplied CA Certificate Error"
 124                     return
 125             for i in range(cert_num - 1):
 126                 if i == 0:
 127                     if x509_1.verify(x509[i].get_pubkey()) != 1:
 128                         self.error = "ERROR: Certificate not Signed by Provided CA Certificate Chain"
 129                         return
 130                 else:
 131                     if x509[i-1].verify(x509[i].get_pubkey()) != 1:
 132                         self.error = "ERROR: CA Certificate not Signed by Provided CA Certificate Chain"
 133                         return
 134
 135             supplied_CA_fingerprint = x509[cert_num-2].get_fingerprint()
 136             supplied_CA_CN = x509[cert_num-2].get_subject().CN
 137             CA_match = False
 138
 139             x = ca_list.get(supplied_CA_fingerprint)
 140             if x:
 141                 CA_OU = x.get_subject().OU
 142                 CA_match = True
 143                 if x.get_subject().CN != supplied_CA_CN:
 144                     print "ERROR: Trusted CA CN Mismatch; however CA has trusted fingerprint"
 145                     print "Payment will continue with manual verification."
 146             else:
 147                 print "ERROR: Supplied CA Not Found in Trusted CA Store."
 148                 print "Payment will continue with manual verification."
 149         else:
 150             self.error = "ERROR: CA Certificate Chain Not Provided by Payment Processor"
 151             return False
 152
 153         paymntreq.signature = ''
 154         s = paymntreq.SerializeToString()
 155         pubkey_1 = x509_1.get_pubkey()
 156
 157         if paymntreq.pki_type == "x509+sha256":
 158             pubkey_1.reset_context(md="sha256")
 159         elif paymntreq.pki_type == "x509+sha1":
 160             pubkey_1.reset_context(md="sha1")
 161         else:
 162             self.error = "ERROR: Unsupported PKI Type for Message Signature"
 163             return False
 164
 165         pubkey_1.verify_init()
 166         pubkey_1.verify_update(s)
 167         if pubkey_1.verify_final(sig) != 1:
 168             self.error = "ERROR: Invalid Signature for Payment Request Data"
 169             return False
 170
 171         ### SIG Verified
 172
 173         self.payment_details = pay_det = paymentrequest_pb2.PaymentDetails()
 174         pay_det.ParseFromString(paymntreq.serialized_payment_details)
 175
 176         if pay_det.expires and pay_det.expires < int(time.time()):
 177             self.error = "ERROR: Payment Request has Expired."
 178             return False
 179
 180         for o in pay_det.outputs:
 181             addr = transaction.get_address_from_output_script(o.script)[1]
 182             self.outputs.append( (addr, o.amount) )
 183
 184         self.memo = pay_det.memo
 185
 186         if CA_match:
 187             print 'Signed By Trusted CA: ', CA_OU
 188
 189         print "payment url", pay_det.payment_url
 190         return True
 191
 192
 193
 194     def send_ack(self, raw_tx, refund_addr):
 195
 196         pay_det = self.payment_details
 197         if not pay_det.payment_url:
 198             return False, "no url"
 199
 200         paymnt = paymentrequest_pb2.Payment()
 201         paymnt.merchant_data = pay_det.merchant_data
 202         paymnt.transactions.append(raw_tx)
 203
 204         ref_out = paymnt.refund_to.add()
 205         ref_out.script = transaction.Transaction.pay_script(refund_addr)
 206         paymnt.memo = "Paid using Electrum"
 207         pm = paymnt.SerializeToString()
 208
 209         payurl = urlparse.urlparse(pay_det.payment_url)
 210         try:
 211             r = requests.post(payurl.geturl(), data=pm, headers=ACK_HEADERS, verify=ca_path)
 212         except requests.exceptions.SSLError:
 213             print "Payment Message/PaymentACK verify Failed"
 214             try:
 215                 r = requests.post(payurl.geturl(), data=pm, headers=ACK_HEADERS, verify=False)
 216             except Exception as e:
 217                 print e
 218                 return False, "Payment Message/PaymentACK Failed"
 219
 220         if r.status_code >= 500:
 221             return False, r.reason
 222
 223         try:
 224             paymntack = paymentrequest_pb2.PaymentACK()
 225             paymntack.ParseFromString(r.content)
 226         except Exception:
 227             return False, "PaymentACK could not be processed. Payment was sent; please manually verify that payment was received."
 228
 229         print "PaymentACK message received: %s" % paymntack.memo
 230         return True, paymntack.memo
 231
 232
 233
 234
 235 if __name__ == "__main__":
 236
 237     try:
 238         uri = sys.argv[1]
 239     except:
 240         print "usage: %s url"%sys.argv[0]
 241         print "example url: \"bitcoin:mpu3yTLdqA1BgGtFUwkVJmhnU3q5afaFkf?r=https%3A%2F%2Fbitcoincore.org%2F%7Egavin%2Ff.php%3Fh%3D2a828c05b8b80dc440c80a5d58890298&amount=1\""
 242         sys.exit(1)
 243
 244     address, amount, label, message, request_url, url = util.parse_url(uri)
 245     pr = PaymentRequest(request_url)
 246     if not pr.verify():
 247         sys.exit(1)
 248
 249     print 'Payment Request Verified Domain: ', pr.domain
 250     print 'outputs', pr.outputs
 251     print 'Payment Memo: ', pr.payment_details.memo
 252
 253     tx = "blah"
 254     pr.send_ack(tx, refund_addr = "1vXAXUnGitimzinpXrqDWVU4tyAAQ34RA")
 255