How to decode a bytes SSL certificate?-CodePudding

I have the following certificate, as returned by ssl.enum_certificates:

import ssl

cert = ssl.enum_certificates("MY")[1][0]
print(cert)

Result:

b'0\x82\x02\xa60\x82\x01\x8e\xa0\x03\x02\x01\x02\x02\x11\x00\xff\xe1C\xed\x8c\xa5UA\xad\x870"\x0f\xc3 \xc30\r\x06\t*\x86H\x86\xf7\r\x01\x01\x0b\x05\x000&1$0"\x06\x03U\x04\x03\x13\x1bXBL Client IPsec Issuing CA0\x1e\x17\r211013223833Z\x17\r211014223833Z0\x1b1\x190\x17\x06\x03U\x04\x03\x0c\x10F900E607B75850AE0\x81\x9f0\r\x06\t*\x86H\x86\xf7\r\x01\x01\x01\x05\x00\x03\x81\x8d\x000\x81\x89\x02\x81\x81\x00\xb8\xaeE\x04\x9c\x02\xe7\xe1\xe7g\xd9\xad\xfc\xbeg\x83\xbc\x7f\xd7\xcc\xc7m\x1d\x02\xe3\xff\x93\xe3\x81\xe9%\x8b\xdc]%\xd2\x8b!!;\xd0^\xdc\\\xd47\x07\x05g\xe2\xdeR\x8d\xc8\xea\xd4\xc5\xdc\x1c]\xa7L\xab\x92\x1f9\x02\x0f\x83\x12\x99\xd1^\xe2\xfdm\xcfU_8N\x94T\x92\x94\x8e\xa3\xe9\xa3\xc3\xf6\x04\xd9\x1b\xa1\xa5\t\xce\xa6~_\xc9\xc1DH\xd0j\x95\x84\x8e\xef\xd9o\xd7\xfe\x91Yz\x1a\xa2\xbe\xc5\x06Y\x9bc\x8bU\x02\x03\x01\x00\x01\xa3^0\\0\x0e\x06\x03U\x1d\x0f\x01\x01\xff\x04\x04\x03\x02\x01\xa60)\x06\x03U\x1d%\x04"0 \x06\x08 \x06\x01\x05\x05\x07\x03\x02\x06\x08 \x06\x01\x05\x05\x07\x03\x05\x06\n \x06\x01\x04\x01\x827x\x04\x040\x1f\x06\x03U\x1d#\x04\x180\x16\x80\x14\xc1\xfe7p|Z9\x12&\xec\xc0\x94\xcd\x80\x94\xb1\xa8u\xe4\xd80\r\x06\t*\x86H\x86\xf7\r\x01\x01\x0b\x05\x00\x03\x82\x01\x01\x00.\xaakE7h\x95\xc7\xa8\x17\xce\x1d\xf2\xc5\x9d[y8g\xb44\x12\xcd\xbb\xdak\xdbF9\r\xef\xb8\x15\x01W[\xa0 \xcf\xa8\x19ML\xa5\x12\x00\xcaF\xb1\xa8\x91\xd9\xde\xc6\xe1.\xe4\xa0\xfe\\\xde\x90\x0c@\xaf\x7fS\x13\xd0\xde\xd9Q\xe2\xa6J\x98\x0f\xfd\x11\x7f\xf7\xed\xf8\xfeI-\x89o\x1b\xc1\xfeF\xbb\x05\x8d\xd0{\x9fc2\xc9\xcf\xcfe\x04\x1e .\xbe\x1b\x90<~@@\xa00\xa4\\1`\xd3\x84\x14\xf2\xe5\x16"\xda\x80\xa9\x90d\x92\xf5\x82\xc9\x87\xdf\xc4x\xc6\xde \x17\x10\xc5j\x96\xed\x8e\xdfp\xb3\x04\x9e\xeb\xc6\xe6{\x1ee\x1c\xeeN\xad\xe4K7xb\xd5\x99\xb9\xf4pb{\x13\xa1\xa4:\x1cF\xef\xe7Hf*\x96!k\x0c\xda\x08*x\x13`\xd9Ju`e\xd8W\xf1;B\xa4\xb8B\xe5Y\xa5\n\x9a\xdb\xc7\xb5\xee \xfe~\xac\xc1\x85\xfex\x1d\x8f\xc3s\xbc\xdd\xab\x1bo\xe0a\x98\xba\xa5\x98z\x03\xee}c[\xe1\xcb8\x1a\xb4\x80'

How to convert this output to a human-readable format? (dict preferred).

This is pretty much the same question as this one, but here I have the certificate in bytes format. I could call ssl.DER_cert_to_PEM_cert and try to go from there, but I'd rather avoid this additional step.

CodePudding user response：

There is a library called cryptography which can do exactly this:

pip install cryptography

Then you can create an x509 certificate object and print whatever results you are after:

import ssl
from cryptography import x509

cert = ssl.enum_certificates("MY")[1][0]
decoded_cert = x509.load_der_x509_certificate(cert)
print(decoded_cert.subject)

Sometimes you just have to add additional steps/libraries to your code. It's not a reasonable expectation to only use native functionality or be expected to reinvent the wheel.