In evp.h, BytesToKey() generates the key from the passhphrase, IV and the MD5 digest in order to decrypt information used by the public/private keypair generation using AES-256-CBC. I am trying to isolate all the EVP_* functions into a standalone implementation for an embedded system. Does anyone have the actual function or what exactly it does?
KEY DERIVATION ALGORITHM The key and IV is derived by concatenating D_1, D_2, etc until enough data is available for the key and IV. D_i is defined as:
D_i = HASH^count(D_(i-1) || data || salt)
