I'll grant that having variables named with "tmp" is confusing out of context, I guess. But if you're trying to start a Java-style war over this stuff, just recognize that most of the world has moved on and views names like those as perfectly fine when used within standard idioms.
To actually comprehend this function requires storing those 14 names in short-term memory, reading through the over 300 lines of remaining code, filling in bits of the meaning of those names as they become clear, and only then reading the code again with that mental map. That's the case where none of the 14 have slipped my mind by the time I get back around. That just seems like an awful lot of overhead to net something that could be as easy as reading names if they were better chosen.
Just as a demonstration, why don't you time how long it takes you to figure out what j actually is and then report back?
i = sk_X509_num(ctx->chain);
i = check_trust(ctx);
i = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain, ctx->param->flags);
class Function<T> {
public apply(T param);
}