Tag Archives: public key

OpenSSL PEM_read_RSA_PUBKEY vs PEM_read_RSAPublicKey

Posted by KarlP on 17 August, 2011 None comments

File this in the “Everybody hates OpenSSL’s API” category. From the expansive documentation:

The RSAPublicKey functions process an RSA public key using an RSA structure. The public key is encoded using a PKCS#1 RSAPublicKey structure.

The RSA_PUBKEY functions also process an RSA public key using an RSA structure. However the public key is encoded using a SubjectPublicKeyInfo structure and an error occurs if the public key is not RSA.

Seeing as I’m in the “PEM” functions, so at least in theory, I’m using methods for processing files that look like this:

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAxKMFS0eoDxn6YltlCM4P
uIHK1bp3+7Lt0aWZ9rimjd4uvx49ZYT1DKrUZi96rUkzdJuCqtYbFtUVAy0V5AtZ
EtQGRoZBN5JQ9u80I8NNS4jhtHZU2i6CY9Aeb6KHY790ceD+lMCbXCgrtl1yPUVE
s8pFwEwO2Vqjim2pO0iVsAzUJAyppjn/7FjxyqOHZHL+OPi7vNule1V9OdVrb9m3
mHVy3u9LWdA+3Ch/YJe8FgenRncQEVrDbA/0wHlRE5fH+nQ9OwPTDYP6A6pphAbk
ZUhc9VjIDKrTCQP2o4RDLz0OKyBs5xZc7vjGXpHG+kL3OVpHxpSrK9EVGIX65ofN
9QIDAQAB
-----END PUBLIC KEY-----

I’ve got no idea where the PKCS#1 vs SubjectPublicKeyInfo comes into it when I’m just trying to load that file. Regardless, the only one that works is PEM_read_RSA_PUBKEY()