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pythonpyopenssl

How do I get the value of OpenSSL._util.lib.X509_verify_cert_error_string as a python string

I am trying to print out the error that is input to the certificate verification callback function[I am using pyopenssl]:

def verify_cb(context, certificate, errornum, depth, ok):
       if (lib.X509_V_OK == errornum):
           print lib.X509_verify_cert_error_string(errornum)

I thought the above code would print ok. However it returns <cdata 'char *' 0x7fff8b400f0f>. Debugging this in pdb I get the following:

(Pdb) lp=lib.X509_verify_cert_error_string(errnum)
(Pdb) type(lp)
<type '_cffi_backend.CData'>
(Pdb) lp[0]
'o'
(Pdb) lp[1]
'k'
(Pdb) lp[2]
'\x00'

Does anyone know how I can get the value of this as a python string other that iterating through this till I get a \x00 character? Thank you.

Solution

  • Ok I figured it out. The following gets it to work:

    from OpenSSL._util import ffi
ffi.string(lib.X509_verify_cert_error_string(errornum))