BLOCK_CIPHER_func_cfb
BLOCK_CIPHER_func_cfb(idea, IDEA, 64, EVP_IDEA_KEY, ks)
BLOCK_CIPHER_func_cfb(cname, cprefix, cbits, kstruct, ksched) \
BLOCK_CIPHER_func_cfb(cipher##_##keysize, cprefix, cbits, kstruct, ksched) \