Never heard about binary specification of the RSA* private key. Can you give more more information about that please.
David Schwartz wrote: > > >> Hi! >> >> I am doing a SHA256 on a RSA* private key. I used the result as a >> symmetric >> key for AES encryption. > > Do you have a specification for how to do this? What ensures that the RSA > private key has the same binary representation each time? > > For example, "3" and "03" represent the same number, so does "3.0". But > they > will each have a different binary representation and hance a different > SHA256 hash. So if you were to write a standard that expected the same > output each time, you would need to specify a particular binary > representation for the RSA key. Did you do that? > >> ////////////////////////////////////////////////////////////////// >> ///////////////////////// >> int length = RSA_size(rsaPrivateKey); > >> SHA256_CTX sha256ctx; >> SHA256_Init(&sha256ctx); >> SHA256_Update(&sha256ctx, rsaPrivateKey, length); >> >> unsigned char* hash = new unsigned char[SHA256_DIGEST_LENGTH]; >> >> SHA256_Final(hash, &sha256ctx); >> ////////////////////////////////////////////////////////////////// >> ///////////////////////// >> >> If I execute this code couples of time in the same process execution, >> hash >> variable is always the same value (this is normal!!). >> But, each time I restart the application, hash value is different. > > You forgot to: > > 1) create a specification > > 2) implement it > >> In the past I used the same pattern, with SHA512 instead of >> SHA256, and with >> a char* instead of a RSA* and I dit not have this problem. >> >> Any idea what's going on ? > > You forgot to create a specification for the binary format of the RSA key > such that the same RSA key will always have the same binary format. You > forgot to convert the RSA key to this format and take the hash of the > converted key. > > If you do not have a specification, you can only be right by accident. And > even if you are right, you can never prove it. > > DS > > > ______________________________________________________________________ > OpenSSL Project http://www.openssl.org > User Support Mailing List openssl-users@openssl.org > Automated List Manager majord...@openssl.org > > -- View this message in context: http://www.nabble.com/Question-about-SHA256-on-a-RSA*-key-tp21093222p21101565.html Sent from the OpenSSL - User mailing list archive at Nabble.com. ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org
