Re: [PATCH v2 1/2] http: add client cert for HTTPS proxies.

> You may copy around your ~/.gitconfig to multiple hosts, some may
> have newer and others may have older versions of libcurl, so it
> would be OK for a version of Git built with older libcurl to at
> least see and parse configurations meant for newer one, if only
> to ignore and discard.
> The only two effects these #if/#endif have are (1) they save a tiny
> bit of memory, code and runtime cycle on an older platform and (2)
> they make the resuting code ugly and harder to read.  I do not think
> that the tradeoff is worth it.

>  This part is more or less straight-forward.
> This is a minor tangent, but I see many "var != NULL" instances used
> as the condition to if statements, which we tend to frown upon
> (instead just say "if (var) ...").  I know there are already many in
> the existing code in this file, but this patch is making it even
> worse.

>
> "Jorge Lopez Silva via GitGitGadget" <gitgitgadget@gmail.com>
> writes:
>
> > +#if LIBCURL_VERSION_NUM >= 0x073400
> > +static const char *http_proxy_ssl_cert;
> > +static const char *http_proxy_ssl_key;
> > +static const char *http_proxy_ssl_keypasswd;
> > +#endif
> > +static const char *http_proxy_ssl_ca_info;
> > +
> >  static struct {
> >       const char *name;
> >       long curlauth_param;
> > @@ -365,6 +373,20 @@ static int http_options(const char *var, const char *value, void *cb)
> >       if (!strcmp("http.proxyauthmethod", var))
> >               return git_config_string(&http_proxy_authmethod, var, value);
> >
> > +#if LIBCURL_VERSION_NUM >= 0x073400
> > +     if (!strcmp("http.proxycert", var))
> > +             return git_config_string(&http_proxy_ssl_cert, var, value);
> > +
> > +     if (!strcmp("http.proxykey", var))
> > +             return git_config_string(&http_proxy_ssl_key, var, value);
> > +
> > +     if (!strcmp("http.proxykeypass", var))
> > +             return git_config_string(&http_proxy_ssl_keypasswd, var, value);
> > +
> > +     if (!strcmp("http.proxycainfo", var))
> > +             return git_config_string(&http_proxy_ssl_ca_info, var, value);
> > +#endif
>
> You may copy around your ~/.gitconfig to multiple hosts, some may
> have newer and others may have older versions of libcurl, so it
> would be OK for a version of Git built with older libcurl to at
> least see and parse configurations meant for newer one, if only
> to ignore and discard.
>
> The only two effects these #if/#endif have are (1) they save a tiny
> bit of memory, code and runtime cycle on an older platform and (2)
> they make the resuting code ugly and harder to read.  I do not think
> that the tradeoff is worth it.
>
> >       if (!strcmp("http.cookiefile", var))
> >               return git_config_pathname(&curl_cookie_file, var, value);
> >       if (!strcmp("http.savecookies", var)) {
> > @@ -924,8 +946,14 @@ static CURL *get_curl_handle(void)
> >  #if LIBCURL_VERSION_NUM >= 0x073400
> >               curl_easy_setopt(result, CURLOPT_PROXY_CAINFO, NULL);
> >  #endif
> > -     } else if (ssl_cainfo != NULL)
> > -             curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
> > +     } else if (ssl_cainfo != NULL || http_proxy_ssl_ca_info != NULL) {
> > +             if (ssl_cainfo != NULL)
> > +                     curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
> > +#if LIBCURL_VERSION_NUM >= 0x073400
> > +             if (http_proxy_ssl_ca_info != NULL)
> > +                     curl_easy_setopt(result, CURLOPT_PROXY_CAINFO, http_proxy_ssl_ca_info);
> > +#endif
> > +     }
>
> On this codepath, unlike the config and variable definitions,
> #if/#endif is absolutely necessary.
>
> In any case, the code around here is messy, but it is mostly due to
> the fact that the existing #if/#endif with if/elseif/... cascade was
> messy.  The general idea is
>
>  * We want to honor ssl_cainfo and http_proxy_ssl_ca_info, and use
>    CAINFO when set, but
>
>  * When http_schannel_use_ssl_cainfo is not in effect and
>    http_ssl_backend is schannel, ssl_cainfo/http_proxy_ssl_ca_info
>    business is completely skipped, and these two CAINFO are cleared
>    instead.
>
> I do not know if the above is the best code structure to express
> that, but at least the way this patch adds code is the least noisy,
> I guess.
>
> > @@ -1018,9 +1046,19 @@ static CURL *get_curl_handle(void)
> >                               CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
> >  #endif
> >  #if LIBCURL_VERSION_NUM >= 0x073400
> > -             else if (starts_with(curl_http_proxy, "https"))
> > -                     curl_easy_setopt(result,
> > -                             CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
> > +             else if (starts_with(curl_http_proxy, "https")) {
> > +                     curl_easy_setopt(result, CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
> > +
> > +                     if (http_proxy_ssl_cert != NULL)
> > +                             curl_easy_setopt(result, CURLOPT_PROXY_SSLCERT, http_proxy_ssl_cert);
> > +
> > +                     if (http_proxy_ssl_key != NULL)
> > +                             curl_easy_setopt(result, CURLOPT_PROXY_SSLKEY, http_proxy_ssl_key);
> > +
> > +                     if (http_proxy_ssl_keypasswd != NULL)
> > +                             curl_easy_setopt(result, CURLOPT_PROXY_KEYPASSWD, http_proxy_ssl_keypasswd);
>
> This part is more or less straight-forward.
>
> This is a minor tangent, but I see many "var != NULL" instances used
> as the condition to if statements, which we tend to frown upon
> (instead just say "if (var) ...").  I know there are already many in
> the existing code in this file, but this patch is making it even
> worse.
>
> > +             }
> >  #endif
> >               if (strstr(curl_http_proxy, "://"))
> >                       credential_from_url(&proxy_auth, curl_http_proxy);