Migrated from: https://gitlab.com/m2crypto/m2crypto/-/issues/204
Created by: Sonu Kumar (@sonus21)
Created at: 2018-03-01T18:28:20.601Z
import M2Crypto
import hashlib
rsa = M2Crypto.RSA.load_key("privkey.pem")
msg = "This is a secret"
digest = hashlib.new('sha1', msg).digest()
signature = rsa.sign(digest, "sha1")
rsa = M2Crypto.RSA.load_pub_key( "pubkey.pem" )
rsa.verify(signature, digest)
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.exceptions import InvalidSignature
with open( "pubkey.pem", "rb" ) as key_file:
pub = serialization.load_pem_public_key(
key_file.read(), backend=default_backend() )
pub.verify(signature, digest,padding.PKCS1v15(),hashes.SHA1() )
Unfortunately, verification always fails when called in crytography module, with following error _OpenSSLError(code=67702888L, lib=4, func=145, reason=104)
After digging further down the line, it looks different module make different API calls, for example, M2Crypto calls RSA_verify whereas cryptograph module calls EVP_PKEY_verify function.
Cryptography Version: 1.5.3
M2Crypto Version: 0.21.1
NOTE: I've raised a similar issue to cryptography at https://github.com/pyca/cryptography/issues/4125
Changed on 2018-04-17T20:27:04.993Z by Matěj Cepl:
changed milestone to 0.30
On 2018-04-17T20:28:33.946Z, Matěj Cepl wrote:
From other bug:
I suspect the m2crypto code in this example does raw (aka textbook) RSA. We don’t support that at this time as it is extremely insecure.
Changed on 2018-04-24T08:43:34.624Z by Matěj Cepl:
changed milestone to 0.31
On 2018-04-24T08:44:38.157Z, Matěj Cepl wrote:
@t8m Do we do something wrong here? Should we change? Would we break API? Should we?
On 2018-04-24T09:52:07.482Z, Tomáš Mráz wrote:
I think the best way would be to deprecate rsa.sign/rsa.verify completely. We cannot change the signature format as that would break the existing callers anyway.
If you would like to support proper RSA sign/verify there would have to be a way to specify the padding used - i.e. PKCS1v1.5 or PSS.
On 2018-04-25T08:33:09.842Z, Matěj Cepl wrote:
Well, but not-breaking-API and supporting ancient programs is raison d'être of M2Crypto.
On 2018-04-25T10:48:21.571Z, Hubert Kario (@mention me if you need reply) wrote:
raw RSA signing is how you can get RSA-PSS out of even OpenSSL 0.9.8, so yes, it should stay, but likely be documented that it is not something you should be doing
On 2018-05-02T15:28:50.771Z, Matěj Cepl wrote:
See https://stackoverflow.com/questions/2536307/how-do-i-deprecate-python-functions and https://github.com/vrcmarcos/python-deprecated/blob/master/deprecated/__init__.py for illustration, how to do it.
def deprecated(reason): # type: (Optional[str, Callable, Type]) -> Callable """ :param reason: Reason message (or function/class/method to decorate). """ if isinstance(reason, six.string_types): # The @deprecated is used with a 'reason'. # # .. code-block:: python # # @deprecated("please, use another function") # def old_function(x, y): # pass def decorator(func1): if inspect.isclass(func1): fmt1 = "Call to deprecated class {name} ({reason})." else: fmt1 = "Call to deprecated function {name} ({reason})." @functools.wraps(func1) def new_func1(*args, **kwargs): warnings.simplefilter('always', DeprecationWarning) warnings.warn( fmt1.format(name=func1.__name__, reason=reason), category=DeprecationWarning, stacklevel=2 ) warnings.simplefilter('default', DeprecationWarning) return func1(*args, **kwargs) return new_func1 return decorator elif inspect.isclass(reason) or inspect.isfunction(reason): # The @deprecated is used without any 'reason'. # # .. code-block:: python # # @deprecated # def old_function(x, y): # pass func2 = reason if inspect.isclass(func2): fmt2 = "Call to deprecated class {name}." else: fmt2 = "Call to deprecated function {name}." @functools.wraps(func2) def new_func2(*args, **kwargs): warnings.simplefilter('always', DeprecationWarning) warnings.warn( fmt2.format(name=func2.__name__), category=DeprecationWarning, stacklevel=2 ) warnings.simplefilter('default', DeprecationWarning) return func2(*args, **kwargs) return new_func2 else: raise TypeError(repr(type(reason)))(Last edited at 2018-05-02T15:29:10.510Z.)
On 2018-05-03T15:53:32.353Z, Matěj Cepl wrote:
raw RSA signing is how you can get RSA-PSS out of even OpenSSL 0.9.8, so yes, it should stay, but likely be documented that it is not something you should be doing
@tomato42 except we have OpenSSL 1.0.1e as the minimal supported version.
I guess we have to create
RSA2module (or something in that style), which would do the things properly and deprecateM2Crypto.RSA?Which all methods of
M2Crypto.RSAshould be rewritten in your opinion?
Changed on 2018-05-28T05:13:42.846Z by Matěj Cepl:
mentioned in issue #217
On 2018-06-29T16:52:19.708Z, Hubert Kario (@mention me if you need reply) wrote:
OpenSSL 1.0.1e as the minimal supported version.
and rsa-pss was introduced in 1.0.2...
I guess we have to create RSA2 module (or something in that style), which would do the things properly and deprecate M2Crypto.RSA?
I'm not sure if it is worth the effort
On 2018-06-30T09:44:30.879Z, Matěj Cepl wrote:
raw RSA signing is how you can get RSA-PSS out of even OpenSSL 0.9.8, so yes, it should stay, but likely be documented that it is not something you should be doing
OK, I will plead stupidity here. Could somebody point me to some documentation what's RSA-PSS is, or (even better) provide pull request how would you like to see old ways deprecated and news introduced (at least some kind of draft, where I could fill in the gaps)?
(Last edited at 2018-06-30T09:44:56.882Z.)
On 2018-06-30T10:06:05.689Z, Matěj Cepl wrote:
Some more resources for me to study:
On 2018-07-09T11:58:49.066Z, Matěj Cepl wrote:
I'm not sure if it is worth the effort
Could you elaborate on this one, please?
Changed on 2018-10-02T11:53:27.513Z by Matěj Cepl:
changed milestone to 0.32
Changed on 2019-03-05T07:59:23.641Z by Matěj Cepl:
changed milestone to 0.33
Changed on 2019-04-26T14:30:13.984Z by Matěj Cepl:
changed milestone to 0.34
Changed on 2019-05-30T19:58:18.167Z by Matěj Cepl:
changed milestone to 0.35
(Last edited at 2019-05-30T19:58:18.171Z.)
Changed on 2019-06-08T06:32:44.520Z by Matěj Cepl:
changed milestone to 0.36
(Last edited at 2019-06-08T06:32:44.523Z.)