luo980/curl
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

url: fall back to http/https proxy env-variable if ws/wss not set

Browse Source 
Reported-by: Craig Andrews
Fixes #12031
Closes #12058
This commit is contained in:
Daniel Stenberg 2023-10-07 21:13:04 +02:00
parent b9c78eeac1
commit 43215842f2
No known key found for this signature in database
GPG Key ID: 5CC908FDB71E12C2
2 changed files with 36 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
docs/libcurl/libcurl-env.3
View File

@ -30,16 +30,20 @@ controls and changes behaviors. This is the full list of variables to set and
description of what they do. Also note that curl, the command line tool,
supports a set of additional environment variables independently of this.
.IP "[scheme]_proxy"
When libcurl is given a URL to use in a transfer, it first extracts the
"scheme" part from the URL and checks if there is a given proxy set for that
in its corresponding environment variable. A URL like "https://example.com"
makes libcurl use the "http_proxy" variable, while a URL like
"ftp://example.com" uses the "ftp_proxy" variable.
When libcurl is given a URL to use in a transfer, it first extracts the scheme
part from the URL and checks if there is a given proxy set for that in its
corresponding environment variable. A URL like https://example.com makes
libcurl use the \fBhttp_proxy\fP variable, while a URL like ftp://example.com
uses the \fBftp_proxy\fP variable.
These proxy variables are also checked for in their uppercase versions, except
the "http_proxy" one which is only used lowercase. Note also that some systems
actually have a case insensitive handling of environment variables and then of
course "HTTP_PROXY" still works.
the \fBhttp_proxy\fP one which is only used lowercase. Note also that some
systems actually have a case insensitive handling of environment variables and
then of course \fBHTTP_PROXY\fP still works.
An exception exists for the WebSocket \fBws\fP and \fBwss\fP URL schemes,
where libcurl first checks \fBws_proxy\fP or \fBwss_proxy\fP but if they are
not set, it will fall back and try the http and https versions instead if set.
.IP ALL_PROXY
This is a setting to set proxy for all URLs, independently of what scheme is
being used. Note that the scheme specific variables overrides this one if set.

37
lib/url.c
View File

@ -2076,7 +2076,6 @@ static char *detect_proxy(struct Curl_easy *data,
char proxy_env[128];
const char *protop = conn->handler->scheme;
char *envp = proxy_env;
char *prox;
#ifdef CURL_DISABLE_VERBOSE_STRINGS
(void)data;
#endif
@ -2089,7 +2088,7 @@ static char *detect_proxy(struct Curl_easy *data,
strcpy(envp, "_proxy");
/* read the protocol proxy: */
prox = curl_getenv(proxy_env);
proxy = curl_getenv(proxy_env);
/*
* We don't try the uppercase version of HTTP_PROXY because of
@ -2103,23 +2102,35 @@ static char *detect_proxy(struct Curl_easy *data,
* This can cause 'internal' http/ftp requests to be
* arbitrarily redirected by any external attacker.
*/
if(!prox && !strcasecompare("http_proxy", proxy_env)) {
if(!proxy && !strcasecompare("http_proxy", proxy_env)) {
/* There was no lowercase variable, try the uppercase version: */
Curl_strntoupper(proxy_env, proxy_env, sizeof(proxy_env));
prox = curl_getenv(proxy_env);
proxy = curl_getenv(proxy_env);
}
envp = proxy_env;
if(prox) {
proxy = prox; /* use this */
}
else {
envp = (char *)"all_proxy";
proxy = curl_getenv(envp); /* default proxy to use */
if(!proxy) {
envp = (char *)"ALL_PROXY";
proxy = curl_getenv(envp);
if(!proxy) {
#ifdef USE_WEBSOCKETS
/* websocket proxy fallbacks */
if(strcasecompare("ws_proxy", proxy_env)) {
proxy = curl_getenv("http_proxy");
}
else if(strcasecompare("wss_proxy", proxy_env)) {
proxy = curl_getenv("https_proxy");
if(!proxy)
proxy = curl_getenv("HTTPS_PROXY");
}
if(!proxy) {
#endif
envp = (char *)"all_proxy";
proxy = curl_getenv(envp); /* default proxy to use */
if(!proxy) {
envp = (char *)"ALL_PROXY";
proxy = curl_getenv(envp);
}
#ifdef USE_WEBSOCKETS
}
#endif
}
if(proxy)
infof(data, "Uses proxy env variable %s == '%s'", envp, proxy);