jpadilla
commented
9 years ago @mark-adams would you happen to know what might be going on here?
Closed buzzrick closed 9 years ago
jpadilla
commented
9 years ago @mark-adams would you happen to know what might be going on here?
mark-adams
commented
9 years ago I'll take a look today
mark-adams
commented
9 years ago @buzzrick Can you provide an example JWT?
mark-adams
commented
9 years ago @buzzrick It looks like the test is failing because the key is not in a valid format. We have tests that cover both types (PEM & SSH) of public key. Can you attach the public key that is being used to verify so that we can see why its failing?
buzzrick
commented
9 years ago I have sent an email to mark-adams with an example JWT and certificate (I'm not sure whether it is a good idea to paste the details in public here).
mark-adams
commented
9 years ago Thanks @buzzrick. Generally speaking, it is safe to share the RSA public key publicly (hence the name) as long as you don't share the RSA private key. I've had a chance to look over what you sent me and I think I've figured out where the issue lies.
PyJWT's documentation talks about accepting two kinds of RSA public keys: PEM and SSH format. PEM keys start with "-----BEGIN PUBLIC KEY-----" and SSH format keys start with "ssh-rsa". The file you sent me starts with "-----BEGIN CERTIFICATE-----" indicating that it is a x509 certificate in PEM format. A certificate is actually a public key accompanied by certain statements about that key (who owns it, how long it is valid, etc.) that are together digitally signed by a third-party authority who is vouching for its authenticity. However, an x509 certificate is not exactly an RSA key in PEM format... even though it does actually contain the RSA public key. That is why you are getting an error.
I was curious so I went back to v0.3.2 (cd32cf25) and ran the following:
>>> cert = open('certificate.cer', 'r').read()
>>> import jwt
>>> jwt.prepare_RS_key(cert)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "jwt/__init__.py", line 105, in prepare_RS_key
key = RSA.importKey(key)
File "/home/mark/.venv/pyjwt/local/lib/python2.7/site-packages/Crypto/PublicKey/RSA.py", line 665, in importKey
return self._importKeyDER(der)
File "/home/mark/.venv/pyjwt/local/lib/python2.7/site-packages/Crypto/PublicKey/RSA.py", line 588, in _importKeyDER
raise ValueError("RSA key format is not supported")
ValueError: RSA key format is not supportedIt seems like the v0.3.2 also rejects x509 certificates so I'm not sure how it was working before unless something changed with regards to how you were generating your keys. At any point in time did you change from generating PEM public keys to generating PEM x509 certificates?
The good news is... there are some easy workarounds to solve this problem since the RSA public key can be extracted from the x509 certificate.
First, OpenSSL can extract the key for you in PEM format by running the following command:
openssl x509 -in certificate.cer -noout -pubkey > public_key.pemYou can then read public_key.pem in and use it as the key in PyJWT.
Second, if you like doing things in Python, cryptography can help you extract the public key from the certificate:
from cryptography.x509 import load_pem_x509_certificate
from cryptography.hazmat.backends import default_backend
certificate_text = open('certificate.cer', 'r').read()
certificate = load_pem_x509_certificate(certificate_text, default_backend())
publickey = certificate.public_key()The publickey variable can then be passed in as the key to verify().
I hope that helps! I'm sorry I can't help explain why you didn't seem to run into this problem with v0.3.2 but it appears that the older version couldn't import x509 certificates either.
Also, one last recommendation: most people consider 1024-bit RSA keys to be risky now as computers have gotten better and better at being able to brute-force them. Generally, most people have begun transitioning to 2048-bit (or higher) keys. Just something to consider. :-)
cc: @jpadilla
buzzrick
commented
9 years ago Darn, sorry, i should have mentioned that we do decode the certificate, and extract the public key component of it, which we use to verify the signature.
I didn't post the public key, because it is a binary blob, not a string.
we use the following code snippet to do extract the public key:
lines = certificates[certKey].replace(" ",'').split()
der = a2b_base64(''.join(lines[1:-1]))
# Extract subjectPublicKeyInfo field from X.509 certificate (see RFC3280)
cert = DerSequence()
cert.decode(der)
tbsCertificate = DerSequence()
tbsCertificate.decode(cert[0])
subjectPublicKeyInfo = tbsCertificate[6]How are you extracting the public key? Is it possible for you to try one of the methods above? Maybe the format you're extracting into was accidentally readable by the old version but not the new? I know that the docs have always said PEM and SSH and that's what we did when we ported over from PyCrypto to cryptography but its possible maybe another format was allowed by PyCrypto.
buzzrick
commented
9 years ago I'm getting the public key as per my updated comment above. I've had a quick attempt at using the following method
from cryptography.x509 import load_pem_x509_certificate
from cryptography.hazmat.backends import default_backend
certificate_text = open('certificate.cer', 'r').read()
certificate = load_pem_x509_certificate(certificate_text, default_backend())
publickey = certificate.public_key()Unfortunately, our cert is stored as a string in a database, not in a file, so i'm getting an initializer for ctype 'char[]' must be a str or list or tuple, not unicode error. I'll have another shot at it this afternoon once i've finished some other pressing tasks, and get back to you.
buzzrick
commented
9 years ago Yay. I have managed to decode the public key from the certificate string as follows:
certBytes = list(unicodeCertString.encode())
certificate = load_pem_x509_certificate(certBytes, default_backend())
publicKey = certificate.public_key()PyJWT v0.4.1 does work with this instance of the key.
Interestingly this code does NOT work with PyJWT v0.3.2. The issue just seems to be a difference in the way that the cryptography/PyCrypto dependancy works.
Thanks Mark for your assistance.
mark-adams
commented
9 years ago Yea, PyCrypto and cryptography have two totally different representations of the RSA key so the example code using load_pem_x509_certificate would definitely not work with any pre-cryptography versions (like 0.3.2)
I'm glad the workaround is working for you! Thanks for reaching out!
jpadilla
commented
9 years ago @mark-adams thanks again for stepping and helping out!
ghost
commented
8 years ago Should this be fixed? I am getting the same error:
ValueError: Could not unserialize key data.
Following packages installed:
PyJWT==1.4.0 cryptography==1.4
Running:
encoded = jwt.encode({'some': 'payload'}, 'secret', algorithm='RS256')
mark-adams
commented
8 years ago @kevart You must use an actual RSA key as the secret= argument. When the algorithm is specified as 'RS256', PyJWT tries to convert the argument into a crytography RSA key object. If the value you are passing in is not an RSA key, you'll receive a ValueErrro.
In your case, if you're literally using the string 'secret' as the value, it won't work because the word 'secret' is not a valid RSA key.
ghost
commented
8 years ago Thanks for the explanation. I would recommend to indicate this in the example, e.g. sth. like:
encoded = jwt.encode({'header': '<jwt header>', 'claim_set': '<jwt claim set>'}, '<rsa key>', algorithm='HS256')
DylanVerstraete
commented
8 years ago @buzzrick I'm getting initializer for ctype 'char' must be a bytes of length 1, not int
when using
cert = "-----BEGIN PUBLIC KEY-----MHYwEAYHKoZIzj0CAQ...."
certBytes = list(cert.encode())
certificate = load_pem_x509_certificate(certBytes, default_backend())
publicKey = certificate.public_key()
print(jwt.decode(jsonWt, publicKey, algorithms=["ES384"]))
wild3r
commented
7 years ago from signxml import * from xml.etree import ElementTree import base64 from lxml import etree
Good day to all friends, I want to convert .pen to base64 and I sell the following error, thanks for the help
codigo:
f = open('/home/carlos/invoice/certifica/20600995805-01-FF11-00000027.xml', 'rb') xml_content = f.read() cert = open('/home/carlos/invoice/certifica/CERTIFICADO.pem').read() key = open('/home/carlos/invoice/certifica/CERTIFICADO.key').read()
cert = base64.decodestring(cert) key = base64.b64decode(key)
error;
File "example.py", line 14, in
fbartolom
commented
7 years ago I have this code:
import jwt
import time
from hyper import HTTPConnection
ALGORITHM = 'ES256'
APNS_KEY_ID = 'H6Q3X7RYZG'
APNS_AUTH_KEY = 'APNsAuthKey_H6Q3X7RYZG.p8'
TEAM_ID = 'GF9PQ87F68'
REGISTRATION_ID = '713d3a9f4d932ac824caf9373a2f182b2dfa710fb7b6214e3bd405ae1e32d0aa'
BUNDLE_ID = 'com.meditation.iPujaPro'
f = open(APNS_AUTH_KEY)
secret = f.read()
token = jwt.encode(
{
'iss': TEAM_ID,
'iat': time.time()
},
secret,
algorithm= ALGORITHM,
headers={
'alg': ALGORITHM,
'kid': APNS_KEY_ID,
}
)
and I am getting error:
Traceback (most recent call last):
File "simpleNotification.py", line 24, in
mark-adams
commented
7 years ago Your key is in the wrong format. PyJWT expects an RSA key to be in PEM format. If you convert your key to PEM format, that should resolve the issue.
fbartolom
commented
7 years ago Good to know, thanks. But how do I modify my python code in order to do what you suggest? I am no crypto expert and I just copied the script without much understanding of what it did.
fbartolom
commented
7 years ago If I execute: openssl pkcs8 -inform DER -nocrypt -in APNsAuthKey_H6Q3X7RYZG.p8 -out APNsAuthKey_H6Q3X7RYZG.pem I get: Error decrypting key 139845397403552:error:0D0680A8:asn1 encoding routines:ASN1_CHECK_TLEN:wrong tag:tasn_dec.c:1343: 139845397403552:error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 error:tasn_dec.c:393:Type=PKCS8_PRIV_KEY_INFO
tema85
commented
6 years ago I had the Cryptography error, I've installed cryptography with command "easy_install cryptography" now I have this error:
Traceback (most recent call last):
File "D:/ITIS/Thesis/Token/pyjwt-master/Run-token.py", line 22, in
thanks for your helps in advance
pavelsuk
commented
5 years ago I tried the example from https://github.com/jpadilla/pyjwt/issues/82#issuecomment-71396019 and it requires little bugfix - the file should be opened as binary:
certificate_text = open('certificate.cer', 'rb').read()So complete code is:
from cryptography.x509 import load_pem_x509_certificate from cryptography.hazmat.backends import default_backend certificate_text = open('certificate.cer', 'rb').read() certificate = load_pem_x509_certificate(certificate_text, default_backend()) publickey = certificate.public_key()
Since updating PyJWT to v4.1 (from v3.2) we are no longer able to verify RS256 signed messages.
I now get a "Could not unserialize key data" ValueError exception. This stack trace shows the relevant place that the error occurs:
I'm not sure exactly which version this stopped working, but I assume it was when the crypto library dependancy switched from PyCrypto to cryptography
If there's anything else relevant that I can provide, then please ask. Cheers Buzzrick