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 import bitcoin
  22 from bitcoin import is_valid
  23 import urlparse
  24
  25
  26 import util
  27 import transaction
  28
  29
  30 REQUEST_HEADERS = {'Accept': 'application/bitcoin-paymentrequest', 'User-Agent': 'Electrum'}
  31 ACK_HEADERS = {'Content-Type':'application/bitcoin-payment','Accept':'application/bitcoin-paymentack','User-Agent':'Electrum'}
  32
  33 # status can be:
  34 PR_UNPAID  = 0
  35 PR_EXPIRED = 1
  36 PR_SENT    = 2     # sent but not propagated
  37 PR_PAID    = 3     # send and propagated
  38
  39
  40
  41
  42 ca_path = os.path.expanduser("~/.electrum/ca/ca-bundle.crt")
  43 ca_list = {}
  44 try:
  45     with open(ca_path, 'r') as ca_f:
  46         c = ""
  47         for line in ca_f:
  48             if line == "-----BEGIN CERTIFICATE-----\n":
  49                 c = line
  50             else:
  51                 c += line
  52             if line == "-----END CERTIFICATE-----\n":
  53                 x = X509.load_cert_string(c)
  54                 ca_list[x.get_fingerprint()] = x
  55 except Exception:
  56     print "ERROR: Could not open %s"%ca_path
  57     print "ca-bundle.crt file should be placed in ~/.electrum/ca/ca-bundle.crt"
  58     print "Documentation on how to download or create the file here: http://curl.haxx.se/docs/caextract.html"
  59     print "Payment will continue with manual verification."
  60     raise Exception()
  61
  62
  63 class PaymentRequest:
  64
  65     def __init__(self, config):
  66         self.config = config
  67         self.outputs = []
  68         self.error = ""
  69
  70     def read(self, url):
  71         self.url = url
  72
  73         u = urlparse.urlparse(url)
  74         self.domain = u.netloc
  75
  76         try:
  77             connection = httplib.HTTPConnection(u.netloc) if u.scheme == 'http' else httplib.HTTPSConnection(u.netloc)
  78             connection.request("GET",u.geturl(), headers=REQUEST_HEADERS)
  79             response = connection.getresponse()
  80         except:
  81             self.error = "cannot read url"
  82             return
  83
  84         try:
  85             r = response.read()
  86         except:
  87             self.error = "cannot read"
  88             return
  89
  90         try:
  91             self.data = paymentrequest_pb2.PaymentRequest()
  92             self.data.ParseFromString(r)
  93         except:
  94             self.error = "cannot parse payment request"
  95             return
  96
  97         self.id = bitcoin.sha256(r)[0:16].encode('hex')
  98         print self.id
  99
 100         dir_path = os.path.join( self.config.path, 'requests')
 101         if not os.path.exists(dir_path):
 102             os.mkdir(dir_path)
 103         filename = os.path.join(dir_path, self.id)
 104         with open(filename,'w') as f:
 105             f.write(r)
 106
 107
 108
 109     def verify(self):
 110         paymntreq = self.data
 111         sig = paymntreq.signature
 112         if not sig:
 113             self.error = "No signature"
 114             return
 115
 116         cert = paymentrequest_pb2.X509Certificates()
 117         cert.ParseFromString(paymntreq.pki_data)
 118         cert_num = len(cert.certificate)
 119
 120         x509_1 = X509.load_cert_der_string(cert.certificate[0])
 121         if self.domain != x509_1.get_subject().CN:
 122             validcert = False
 123             try:
 124                 SANs = x509_1.get_ext("subjectAltName").get_value().split(",")
 125                 for s in SANs:
 126                     s = s.strip()
 127                     if s.startswith("DNS:") and s[4:] == self.domain:
 128                         validcert = True
 129                         print "Match SAN DNS"
 130                     elif s.startswith("IP:") and s[3:] == self.domain:
 131                         validcert = True
 132                         print "Match SAN IP"
 133                     elif s.startswith("email:") and s[6:] == self.domain:
 134                         validcert = True
 135                         print "Match SAN email"
 136             except Exception, e:
 137                 print "ERROR: No SAN data"
 138             if not validcert:
 139                 ###TODO: check for wildcards
 140                 self.error = "ERROR: Certificate Subject Domain Mismatch and SAN Mismatch"
 141                 return
 142
 143         x509 = []
 144         CA_OU = ''
 145
 146         if cert_num > 1:
 147             for i in range(cert_num - 1):
 148                 x509.append(X509.load_cert_der_string(cert.certificate[i+1]))
 149                 if x509[i].check_ca() == 0:
 150                     self.error = "ERROR: Supplied CA Certificate Error"
 151                     return
 152             for i in range(cert_num - 1):
 153                 if i == 0:
 154                     if x509_1.verify(x509[i].get_pubkey()) != 1:
 155                         self.error = "ERROR: Certificate not Signed by Provided CA Certificate Chain"
 156                         return
 157                 else:
 158                     if x509[i-1].verify(x509[i].get_pubkey()) != 1:
 159                         self.error = "ERROR: CA Certificate not Signed by Provided CA Certificate Chain"
 160                         return
 161
 162             supplied_CA_fingerprint = x509[cert_num-2].get_fingerprint()
 163             supplied_CA_CN = x509[cert_num-2].get_subject().CN
 164             CA_match = False
 165
 166             x = ca_list.get(supplied_CA_fingerprint)
 167             if x:
 168                 CA_OU = x.get_subject().OU
 169                 CA_match = True
 170                 if x.get_subject().CN != supplied_CA_CN:
 171                     print "ERROR: Trusted CA CN Mismatch; however CA has trusted fingerprint"
 172                     print "Payment will continue with manual verification."
 173             else:
 174                 print "ERROR: Supplied CA Not Found in Trusted CA Store."
 175                 print "Payment will continue with manual verification."
 176         else:
 177             self.error = "ERROR: CA Certificate Chain Not Provided by Payment Processor"
 178             return False
 179
 180         paymntreq.signature = ''
 181         s = paymntreq.SerializeToString()
 182         pubkey_1 = x509_1.get_pubkey()
 183
 184         if paymntreq.pki_type == "x509+sha256":
 185             pubkey_1.reset_context(md="sha256")
 186         elif paymntreq.pki_type == "x509+sha1":
 187             pubkey_1.reset_context(md="sha1")
 188         else:
 189             self.error = "ERROR: Unsupported PKI Type for Message Signature"
 190             return False
 191
 192         pubkey_1.verify_init()
 193         pubkey_1.verify_update(s)
 194         if pubkey_1.verify_final(sig) != 1:
 195             self.error = "ERROR: Invalid Signature for Payment Request Data"
 196             return False
 197
 198         ### SIG Verified
 199
 200         self.payment_details = pay_det = paymentrequest_pb2.PaymentDetails()
 201         pay_det.ParseFromString(paymntreq.serialized_payment_details)
 202
 203         if pay_det.expires and pay_det.expires < int(time.time()):
 204             self.error = "ERROR: Payment Request has Expired."
 205             return False
 206
 207         for o in pay_det.outputs:
 208             addr = transaction.get_address_from_output_script(o.script)[1]
 209             self.outputs.append( (addr, o.amount) )
 210
 211         self.memo = pay_det.memo
 212
 213         if CA_match:
 214             self.status = 'Signed by Trusted CA:\n' + CA_OU
 215
 216         print "payment url", pay_det.payment_url
 217         return True
 218
 219
 220     def get_amount(self):
 221         return sum(map(lambda x:x[1], self.outputs))
 222
 223     def get_domain(self):
 224         return self.domain
 225
 226     def get_id(self):
 227         return self.id
 228
 229     def send_ack(self, raw_tx, refund_addr):
 230
 231         pay_det = self.payment_details
 232         if not pay_det.payment_url:
 233             return False, "no url"
 234
 235         paymnt = paymentrequest_pb2.Payment()
 236         paymnt.merchant_data = pay_det.merchant_data
 237         paymnt.transactions.append(raw_tx)
 238
 239         ref_out = paymnt.refund_to.add()
 240         ref_out.script = transaction.Transaction.pay_script(refund_addr)
 241         paymnt.memo = "Paid using Electrum"
 242         pm = paymnt.SerializeToString()
 243
 244         payurl = urlparse.urlparse(pay_det.payment_url)
 245         try:
 246             r = requests.post(payurl.geturl(), data=pm, headers=ACK_HEADERS, verify=ca_path)
 247         except requests.exceptions.SSLError:
 248             print "Payment Message/PaymentACK verify Failed"
 249             try:
 250                 r = requests.post(payurl.geturl(), data=pm, headers=ACK_HEADERS, verify=False)
 251             except Exception as e:
 252                 print e
 253                 return False, "Payment Message/PaymentACK Failed"
 254
 255         if r.status_code >= 500:
 256             return False, r.reason
 257
 258         try:
 259             paymntack = paymentrequest_pb2.PaymentACK()
 260             paymntack.ParseFromString(r.content)
 261         except Exception:
 262             return False, "PaymentACK could not be processed. Payment was sent; please manually verify that payment was received."
 263
 264         print "PaymentACK message received: %s" % paymntack.memo
 265         return True, paymntack.memo
 266
 267
 268
 269 if __name__ == "__main__":
 270
 271     try:
 272         uri = sys.argv[1]
 273     except:
 274         print "usage: %s url"%sys.argv[0]
 275         print "example url: \"bitcoin:mpu3yTLdqA1BgGtFUwkVJmhnU3q5afaFkf?r=https%3A%2F%2Fbitcoincore.org%2F%7Egavin%2Ff.php%3Fh%3D2a828c05b8b80dc440c80a5d58890298&amount=1\""
 276         sys.exit(1)
 277
 278     address, amount, label, message, request_url, url = util.parse_url(uri)
 279     pr = PaymentRequest(request_url)
 280     if not pr.verify():
 281         sys.exit(1)
 282
 283     print 'Payment Request Verified Domain: ', pr.domain
 284     print 'outputs', pr.outputs
 285     print 'Payment Memo: ', pr.payment_details.memo
 286
 287     tx = "blah"
 288     pr.send_ack(tx, refund_addr = "1vXAXUnGitimzinpXrqDWVU4tyAAQ34RA")
 289