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Openssl how to find out what size of a public key bit in an X509 certificate

If I have X509*one that openssl provided is the best way to find out the bitness of the RSA public key in a certificate? I can’t figure it out. I am sure that if I go back to verifying the SSL certificate certificate, I can get ptr with x509 using

X509 * cert = X509_STORE_CTX_get_current_cert(the_x509_store_ctx);

and I would suggest that I get a public key, like this

EVP_PKEY *public_key = X509_get_pubkey(cert);

and then I need to check if this is an RSA, presumably?

if (public_key && (EVP_PKEY_RSA == public_key->type))

and as soon as I find out that I received the public key and that it is RSA, I would like to do this:

int key_length = BN_num_bits(public_key->pkey.rsa->n);

but I found that although it works pretty well on openssl 0.9.8, in 1.0.1h it segfaults on Windows. BIGNUM 'n' doesn't seem to be valid - the ptr data in it has a pointer to garbage.

Any idea what is wrong?

+4
1

, RSA ( " "...), :

EVP_PKEY * public_key = X509_get_pubkey(cert);
RSA *rsa_key = EVP_PKEY_get1_RSA(public_key);
int key_length = RSA_size(rsa_key);
...
RSA_free(rsa_key);
+6

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