Encrypt/Decrypt not working (maybe wrong usage?)

[andreixk]

I created a simple xml file, generated a self-signed certificate and key:

openssl req -x509 -nodes -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365

then tried to encrypt it and then decrypt the encrypted data:

from wsse import encryption
plain = open('plain.xml','rb').read()
encr = encryption.encrypt(plain,'test/cert.pem')
print(encryption.decrypt(envelope=encr,keyfile='test/key.pem'))

The result is this error:

Traceback (most recent call last):
  File "/private/var/www/html/apps/moh/test.py", line 9, in <module>
    print(encryption.decrypt(envelope=encrd,keyfile='test/key.pem'))
  File "/private/var/www/html/apps/moh/wsse/encryption.py", line 196, in decrypt
    )[0]
IndexError: list index out of range

plain.xml:

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns0="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://hcv.health.ontario.ca/" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
	<SOAP-ENV:Header>
		<wsse:Security mustUnderstand="true">
			<wsse:UsernameToken>
				<wsse:Username>test_user</wsse:Username>
				<wsse:Password>test_pass</wsse:Password>
			</wsse:UsernameToken>
			<wsu:Timestamp>
				<wsu:Created>2017-07-18T01:32:47.577170+00:00</wsu:Created>
				<wsu:Expires>2017-07-18T01:34:17.577170+00:00</wsu:Expires>
			</wsu:Timestamp>
		</wsse:Security>
	</SOAP-ENV:Header>
	<ns0:Body>
		<ns1:validate>
			<requests>
				<hcvRequest>
					<healthNumber>9999999999</healthNumber>
					<versionCode>YX</versionCode>
				</hcvRequest>
			</requests>
			<locale>en</locale>
		</ns1:validate>
	</ns0:Body>
</SOAP-ENV:Envelope>

[kentwongg]

Did you ever figure this out? I know the index out of range error is being caused by a bad xpath query.

[wilmer05]

Helllo,

I had the same problem, the reason this is not working is because the Id attribute is preceded by a namespace which is WSU_NS, so you have to change the code from the decrypt function from

enc_data = doc.xpath( "//enc:EncryptedData[@Id='%s']" % referenced_id, namespaces={'enc': ENC_NS}, )[0]

to

enc_data = doc.xpath( "//enc:EncryptedData[@ns0:Id='%s']" % referenced_id, namespaces={'enc': ENC_NS, 'ns0': WSU_NS}, )[0]

After this there is another error arising and is that after encryption with this library the EncryptedData Element doesn't have any KeyInfo element inside, so the decrypt function will fail here

https://github.com/orcasgit/py-wsse/blob/master/wsse/encryption.py#L204

since the variable key_info is None