EVP_MD_block_size
int EVP_MD_block_size(const EVP_MD *md);
#define EVP_MD_CTX_block_size(e) EVP_MD_block_size(EVP_MD_CTX_md(e))
LCRYPTO_ALIAS(EVP_MD_block_size);
LCRYPTO_USED(EVP_MD_block_size);
if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md)))
if (!EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md)))
j = EVP_MD_block_size(md);
if ((v = EVP_MD_block_size(md_type)) <= 0)