Added error message if package is missing.

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>

tools/pico-hsm-tool.py

@@ -19,14 +19,24 @@
  */
 """
 
-from smartcard.CardType import AnyCardType
+import sys
-from smartcard.CardRequest import CardRequest
+try:
-from smartcard.Exceptions import CardRequestTimeoutException
+    from smartcard.CardType import AnyCardType
-from cvc.certificates import CVC
+    from smartcard.CardRequest import CardRequest
-from cvc.asn1 import ASN1
+    from smartcard.Exceptions import CardRequestTimeoutException
-from cvc.oid import oid2scheme
+    from cvc.certificates import CVC
-from cvc.utils import scheme_rsa
+except:
-from cryptography.hazmat.primitives.asymmetric import ec
+    print('ERROR: smarctard module not found! Install pyscard package.\nTry with `pip install pyscard`')
+    sys.exit(-1)
+
+try:
+    from cvc.asn1 import ASN1
+    from cvc.oid import oid2scheme
+    from cvc.utils import scheme_rsa
+    from cryptography.hazmat.primitives.asymmetric import ec
+except:
+    print('ERROR: cvc module not found! Install pycvc package.\nTry with `pip install pycvc`')
+    sys.exit(-1)
 import json
 import urllib.request
 import base64