store payment requests even if M2Crypto is not available

lib/paymentrequest.py

@@ -14,15 +14,15 @@ except:
     print "protoc --proto_path=lib/ --python_out=lib/ lib/paymentrequest.proto"
     raise Exception()
 
-import urlparse
-import requests
-from M2Crypto import X509
+try:
+    import requests
+except ImportError:
+    sys.exit("Error: requests does not seem to be installed. Try 'sudo pip install requests'")
 
-import bitcoin
-from bitcoin import is_valid
 import urlparse
 
 
+import bitcoin
 import util
 import transaction
 
@@ -39,10 +39,24 @@ PR_PAID    = 3     # send and propagated
 
 
 
-ca_path = os.path.expanduser("~/.electrum/ca/ca-bundle.crt")
 ca_list = {}
-try:
-    with open(ca_path, 'r') as ca_f:
+
+def load_certificates():
+    try:
+        from M2Crypto import X509
+    except:
+        print_error("ERROR: Could not import M2Crypto")
+        return False
+
+    ca_path = os.path.expanduser("~/.electrum/ca/ca-bundle.crt")
+    try:
+        ca_f = open(ca_path, 'r')
+    except Exception:
+        print "ERROR: Could not open %s"%ca_path
+        print "ca-bundle.crt file should be placed in ~/.electrum/ca/ca-bundle.crt"
+        print "Documentation on how to download or create the file here: http://curl.haxx.se/docs/caextract.html"
+        print "Payment will continue with manual verification."
+        return False
     c = ""
     for line in ca_f:
         if line == "-----BEGIN CERTIFICATE-----\n":
@@ -52,16 +66,13 @@ try:
         if line == "-----END CERTIFICATE-----\n":
             x = X509.load_cert_string(c)
             ca_list[x.get_fingerprint()] = x
-except Exception:
-    print "ERROR: Could not open %s"%ca_path
-    print "ca-bundle.crt file should be placed in ~/.electrum/ca/ca-bundle.crt"
-    print "Documentation on how to download or create the file here: http://curl.haxx.se/docs/caextract.html"
-    print "Payment will continue with manual verification."
-    raise Exception()
+    ca_f.close()
+    return True
 
+load_certificates()
 
-class PaymentRequest:
 
+class PaymentRequest:
     def __init__(self, config):
         self.config = config
         self.outputs = []
@@ -72,7 +83,6 @@ class PaymentRequest:
 
         u = urlparse.urlparse(url)
         self.domain = u.netloc
-
         try:
             connection = httplib.HTTPConnection(u.netloc) if u.scheme == 'http' else httplib.HTTPSConnection(u.netloc)
             connection.request("GET",u.geturl(), headers=REQUEST_HEADERS)
@@ -107,6 +117,16 @@ class PaymentRequest:
 
 
     def verify(self):
+        try:
+            from M2Crypto import X509
+        except:
+            self.error = "cannot import M2Crypto"
+            return False
+
+        if not ca_list:
+            self.error = "Trusted certificate authorities list not found"
+            return False
+
         paymntreq = self.data
         sig = paymntreq.signature
         if not sig: