Hi Anthony, that makes definitely sense for me. I encrypt data from pdf so I got the whole 292 bytes at one go.
Thank you for your patience! Rudy Anthony Gabrielson-4 wrote: > > Hi Rudy, > I added call when needed because EncryptUpdate can be called more than > once, as long as EncryptFinal hasn't already been called. Once > EncryptFinal has been called your saying you have all the data you expect > for that iteration. So if your 292 bytes were coming in an iterations of > N bytes you would just keep calling EncryptUpdate every N bytes once the > final iteration came in you would finalize with EncryptFinal and move on > to the next step in your code. By your codes description, and my example, > each is only needed once since all the data is already there. > > That make sense? > > Anthony > > On Jul 16, 2010, at 3:10 AM, Rudy1 wrote: > >> >> Hello Anthony, >> >> thank you for you fast reply. I visited your blog and analyzed your >> example. >> There is one >> question left. You added the comment "Call when needed" to your function >> EVP_EncryptUpdate(). >> What does that mean? In my case I want to encrypt a string containing 292 >> bytes. After calling >> EVP_EncryptUpdate_ex() the variable out_len = 288. Do I have to call >> EVP_EncryptUpdate_ex() again >> to encrypt the remaining 4 bytes? I thought the remaining bytes will be >> encrypted by calling EVP_EncryptFinal_ex() >> >> Rudy1 >> >> >> Anthony Gabrielson-4 wrote: >>> >>> Hello, >>> This seems to be a pretty typical question that gets posted often. I >>> have >>> a simple example that I think hits it. Anyway, its the first entry into >>> a >>> blog that I'm starting to building up. If your interested the code and >>> (a >>> brief) explanation is available here: >>> >>> http://agabrielson.wordpress.com/2010/07/15/openssl-an-example-from-the-command-line/#more-4 >>> >>> >>> One note - I didn't use the ex function; I used the older version. It >>> should give you a slightly easier place to start from. >>> >>> Anthony >>> >>> ----- Original Message ----- >>> From: "Rudy1" <r...@compumatica.eu> >>> To: openssl-users@openssl.org >>> Sent: Thursday, July 15, 2010 5:37:38 AM >>> Subject: AES128 CBC >>> >>> I'm using the openssl crypto lib first time and I don't know how to >>> encrypt text larger than blocksize (16 byte) . For example I want to >>> encrypt a string of size 292 bytes. I call EVP_EncryptUpdate () one time >>> and 288 bytes will be encrypted and finally I call >>> EVP_EncryptFinal_ex(). >>> Do I really encrypt the whole string correctly? Or do I have to call >>> EVP_EncryptUpdate () for every blocksize chunk of my string? How large >>> is >>> the encrypted string? I would expect 304 bytes (288 + 16). Is this >>> correct? Rudy1 >>> >>> View this message in context: AES128 CBC >>> Sent from the OpenSSL - User mailing list archive at Nabble.com. >>> >>> >> >> -- >> View this message in context: >> http://old.nabble.com/AES128-CBC-tp29170995p29180726.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 > > ______________________________________________________________________ > 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://old.nabble.com/AES128-CBC-tp29170995p29217239.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
