#50974 [Opn->Bgs]: A public key can't be extracted from a private one

ID: 50974 User updated by: willy dot weisz at univie dot ac dot at Reported By: willy dot weisz at univie dot ac dot at -Status: Open +Status: Bogus Bug Type: Documentation problem Operating System: irrelevant PHP Version: Irrelevant New Comment: I was too fast, I made a mistake: PKCS#1 as implemented by openSSL defines an RSAPrivateKey structure whose components allow the (re)construction of the public key and not only consisting of the module and the exponent of the private key, which would be sufficient for a private key. The bug report against the documentation is thus irrelevant. Previous Comments: ------------------------------------------------------------------------ [2010-02-09 16:09:57] willy dot weisz at univie dot ac dot at Description: ------------ The manual page says that the parameter "certificate" can be a private key (alternative 3). This is pure nonsense: A public key can't be extracted from a private key (nor is it possible the other way round), that would make the concept of Public Key Cryptography absurd. This is a bug report against the manual page, not the code!!! Reproduce code: --------------- --- From manual page: function.openssl-pkey-get-public#Parameters --- Expected result: ---------------- A correct manual page. Actual result: -------------- A manual page with an absurd alternative 3 for the parameter "certificate". ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=50974&edit=1