Hello David, Can you show me exactly how to break up my example code to make my example work? I tried removing the EVP_DecryptFinal_ex from my DecryptMessage function and just seeing if the first part would just decrypt the first 7 bytes, but it got thrown into my catch statement. I am really confused.
Thanks, Christina Penn On Tue, May 4, 2010 at 6:42 PM, David Schwartz <dav...@webmaster.com> wrote: > > Christina Penn wrote: > > > Here is some example code of me trying to decrypt a partial AES message. > > It doesn't work.. is there a way I can do something like this? It only > works > > if I call DecryptMessage() with the entire encrypted string. Why? > > Your DecryptMessage function is specifically designed to require the entire > encrypted string: > > if(!EVP_DecryptFinal_ex(&deCTX, plaintext+p_len, &f_len)) > cerr << "ERROR in EVP_DecryptFinal_ex" << endl; > > See how it calls EVP_DecryptFinal_ex? > > As EVP_DecryptInit should only be called at the very start to initialize a > message, so EVP_DecryptFinal_ex should only be called at the very end to > finish a complete message. In the middle, you should only be using > EVP_DecryptUpdate. > > DS > > ______________________________________________________________________ > OpenSSL Project http://www.openssl.org > User Support Mailing List openssl-users@openssl.org > Automated List Manager majord...@openssl.org >
