Thanks Matt. On that note, do we have support for OCB mode in openssl. Where can i find the documentation for all the modes supported by openssl??
Regards, Rohit Bansal On Mon, Jan 14, 2013 at 1:16 PM, Matt Caswell <fr...@baggins.org> wrote: > The EVP API is documented here: > https://www.openssl.org/docs/crypto/EVP_EncryptInit.html# > > There is some example code there too. It doesn't use AES or CTR, but the > principle is the same. Just replace EVP_bf_cbc() with EVP_aes_256_ctr(), > and ensure you use an appropriately sized key and IV. > > Matt > > > > On 14 January 2013 20:44, Rohit Bansal <banr...@gmail.com> wrote: > >> Thanks Matt. Is there a sample code i can look into? >> >> In my case the key is unique across different messages, so having same IV >> across messages should not lead me into problem >> >> Thanks, >> Rohit Bansal >> >> >> On Mon, Jan 14, 2013 at 12:22 PM, Matt Caswell <fr...@baggins.org> wrote: >> >>> Yes, you can use CTR mode for AES-256: use the EVP interface with the >>> EVP_CIPHER of EVP_aes_256_ctr(). >>> >>> However it is a fundamental requirement of CTR mode that the IV must be >>> unique across messages. If you reuse the IV then your messages can be >>> broken quite trivially. Therefore, if by a fixed IV, you mean that it is >>> fixed across multiple messages then CTR mode is not suitable for you. >>> >>> Matt >>> >>> >>> On 14 January 2013 19:25, Rohit Bansal <banr...@gmail.com> wrote: >>> >>>> Hi, >>>> >>>> Can somebody help me if CTR mode is supported in openssl for AES-256 >>>> encryption? >>>> >>>> I dont want to use CBC and i have a fixed IV. >>>> >>>> Thanks, >>>> Rohit >>>> >>> >>> >> >> >> -- >> Rohit Bansal >> > > -- Rohit Bansal
