ChaCha20 (without Poly1305) block counter

Hi, I am trying to use ChaCha20 (without Poly1305) >From RFC 7539: One of the inputs to ChaCha20 is: "A 32-bit initial counter." However I cannot find the function to set this. where should I input this? Thanks, Jerry

Regarding the use of EVP_aes_256_cbc_hmac_sha256, EVP_rc4_hmac_md5 and AES_encrypt

First question: How should AAD data be supplied to ciphers like EVP_aes_256_cbc_hmac_sha256() and EVP_rc4_hmac_md5()? If I understand correctly, these are AEAD ciphers (the EVP_CIPH_FLAG_AEAD_CIPHER flag is set), so it should be possible to provide AAD data? The following seems to work for AEAD

Re: rand interface while upgrading openssl

Thanks Michael, I am using *ssleay_rand_add* function which was present in earlier version of openssl https://code.woboq.org/crypto/openssl/crypto/rand/md_rand.c.html#ssleay_rand_add I don't find this file or function in latest version of openssl. As I understood recommended way is to use engine