Current key not working with version 45.0.2

[vinod-seshadri-TA]

Existing key that was working with cryptography version 44.0.3 no longer works with 45.0.2 (basically 45.0.0 and above)

serialization.load_pem_private_key(..) returns Unknown Key Encryption Algorithm : 1.2.840.113549.1.5.3

[reaperhulk]

Thanks for the report, it appears you have an encrypted private key using pbeWithMD5AndDES-CBC. Could you share how you generated this? (Please do not share the actual key of course)

[vinod-seshadri-TA]

Here is the command used to generate the key

openssl genrsa 2048 | openssl pkcs8 -topk8 -v1 PBE-MD5-DES -inform PEM -out <private file key name>.p8

I do understand this is considered insecure , but this issue was to see if there is an explicit removal of support for this algorithm, in the latest version , if not could it be fixed if yes, then can that be added in the changelog

[alexscott-ff]

This also popped up for us and broke our Snowflake connection, although I'm not sure the exact command that was used. It worked on 44.0.3.

[reaperhulk]

@alexscott-ff with the same OID and not a different one? Just want to make sure that if we add this algorithm back that it resolves your issue (although you should separately upgrade the encryption wrapping your key! Single DES with MD5 is not good!)

[vinod-seshadri-TA]

I was able to independently verify that a key generated with

openssl genrsa 2048 | openssl pkcs8 -topk8 -v2 des3 -inform PEM -out <private_key>.p8

works fine with the same version. so specifically an issue with the algorithm

[alexscott-ff]

@reaperhulk I believe so but I'm not sure; I think we're going to "fix forward" and re-generate the key, as you suggest :)

[fojtasek]

@alexscott-ff with the same OID and not a different one? Just want to make sure that if we add this algorithm back that it resolves your issue (although you should separately upgrade the encryption wrapping your key! Single DES with MD5 is not good!)

I work with @alexscott-ff and can confirm both that it's the same OID and that we're upgrading the encryption

[alex]

Hi all,

Thanks for the reports, we appreciate them! I want to make sure I'm following correctly:

1. Everyone who has hit this error has gotten it with 1.2.840.113549.1.5.3
2. No one is quite sure which tool/command was used to produce their key with it? (I know we can reproduce it with -v1 PBE-MD5-DES, but it sounds like no one is sure if that's what they used, and if so why)?

[lukpueh]

Thanks for the discussion! I get the same error for rsa and ecdsa test keys, which I created with LibreSSL 3.3.6, which still seems to be the default openssl on macOS.

Here's a reproducer:

$ /usr/bin/openssl version
LibreSSL 3.3.6
$ /usr/bin/openssl genrsa 2048 | /usr/bin/openssl pkcs8 -inform PEM -topk8 -passout pass:hunter2 -out key.p8
$ python <<EOF
from cryptography.hazmat.primitives.serialization import load_pem_private_key
with open("key.p8", "rb") as f:
    data = f.read()
load_pem_private_key(data, b'hunter2')
EOF
Traceback (most recent call last):
  File "<stdin>", line 4, in <module>
ValueError: Unknown key encryption algorithm: 1.2.840.113549.1.5.3

[reaperhulk]

@lukpueh Thanks, I can reproduce this on latest macOS, but I can also reproduce it on LibreSSL 4.1.0. So I think there are two action items here. First, we'll be adding support back for this OID despite its decrepit nature. Second, we'll be reaching out to the LibreSSL folks to get them to change this default 😄

[alex]

Ok, #12956 adds a test vector, next up we'll add an implementation, after we ping the LibreSSL folks.

[botovq]

I know... (closely related) We should really fix this. PKCS8 and PKCS12 are just something we don't use in the OS and I myself have only ever touched them when somebody reported a bug.

I'll happily flip the defaults to something saner but I'll have to look into what makes sense. I filed an issue that should remind me of it.

Sorry about that.