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