No, as far as I know, there is no support for OCB. For the documentation on which modes are supported check evp.h!!! :-)
Matt On 16 January 2013 02:57, Rohit Bansal <[email protected]> wrote: > 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 <[email protected]> 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 <[email protected]> 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 <[email protected]>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 <[email protected]> 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 >
