Stephen Sprunk wrote: > > Can someone help me implement the EVP macros for AES 128-bit CFB and > OFB modes? It's too messy for me to figure out. > > I've got non-EVP versions written, but it appears the EVP macros do > their own implementation of the various modes and only call the base > ECB function. > > I've also got a trial implementation of CTR mode, but I don't see > where that would fit into EVP or the ASN.1 stuff. >
The ASN.1 stuff you can largely ignore. Most of the existing CFB and OFB modes do and nothing really uses the ASN.1 stuff with those modes. The macros can also be ignored and you can populate the EVP_CIPHER structure manually if you wish. The reason for the macros was that when the EVP layer was being revised it was an absolute nightmare to change anything. IIRC at one point I had to add an additional field to the EVP_CIPHER structure. I then spent the next couple of hours modifying lots of almost identical EVP_CIPHER definitions spread over zillions of little files. So I rewrote the files to use macros so that any future changes could largely be handled by just changing the macros and the odd exception manually. Steve. -- Dr Stephen N. Henson. http://www.drh-consultancy.demon.co.uk/ Personal Email: [EMAIL PROTECTED] Senior crypto engineer, Gemplus: http://www.gemplus.com/ Core developer of the OpenSSL project: http://www.openssl.org/ Business Email: [EMAIL PROTECTED] PGP key: via homepage. ______________________________________________________________________ OpenSSL Project http://www.openssl.org Development Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
