getinfo: provide info which auth was used for HTTP and proxy

CURLINFO_HTTPAUTH_USED and CURLINFO_PROXYAUTH_USED

Tested in 590 and 694

Ref: #12668
Idea-by: Ganesh Viswanathan
Closes #15450

docs/libcurl/curl_easy_getinfo.md

@@ -146,6 +146,10 @@ Number of bytes of all headers received. See CURLINFO_HEADER_SIZE(3)
 
 Available HTTP authentication methods. See CURLINFO_HTTPAUTH_AVAIL(3)
 
+## CURLINFO_HTTPAUTH_USED
+
+Used HTTP authentication method. See CURLINFO_HTTPAUTH_USED(3)
+
 ## CURLINFO_HTTP_CONNECTCODE
 
 Last proxy CONNECT response code. See CURLINFO_HTTP_CONNECTCODE(3)
@@ -225,6 +229,10 @@ CURLINFO_PROTOCOL(3)
 
 Available HTTP proxy authentication methods. See CURLINFO_PROXYAUTH_AVAIL(3)
 
+## CURLINFO_PROXYAUTH_USED
+
+Used HTTP proxy authentication methods. See CURLINFO_PROXYAUTH_USED(3)
+
 ## CURLINFO_PROXY_ERROR
 
 Detailed proxy error. See CURLINFO_PROXY_ERROR(3)

docs/libcurl/opts/CURLINFO_HTTPAUTH_USED.md

@@ -0,0 +1,76 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLINFO_HTTPAUTH_USED
+Section: 3
+Source: libcurl
+See-also:
+  - CURLINFO_PROXYAUTH_USED (3)
+  - CURLINFO_HTTPAUTH_AVAIL (3)
+  - CURLOPT_HTTPAUTH (3)
+Protocol:
+  - HTTP
+Added-in: 8.12.0
+---
+
+# NAME
+
+CURLINFO_HTTPAUTH_USED - get used HTTP authentication method
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_HTTPAUTH_USED, long *authp);
+~~~
+
+# DESCRIPTION
+
+Pass a pointer to a long to receive a bitmask indicating the authentication
+method that was used in the previous HTTP request. The meaning of the possible
+bits is explained in the CURLOPT_HTTPAUTH(3) option for curl_easy_setopt(3).
+
+The returned value has zero or one bit set.
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+int main(void)
+{
+  CURL *curl = curl_easy_init();
+  if(curl) {
+    CURLcode res;
+    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
+    curl_easy_setopt(curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC | CURLAUTH_DIGEST);
+    curl_easy_setopt(curl, CURLOPT_USERNAME, "shrek");
+    curl_easy_setopt(curl, CURLOPT_PASSWORD, "swamp");
+
+    res = curl_easy_perform(curl);
+
+    if(!res) {
+      long auth;
+      res = curl_easy_getinfo(curl, CURLINFO_HTTPAUTH_USED, &auth);
+      if(!res) {
+        if(!auth)
+          printf("No auth used\n");
+        else {
+          if(auth == CURLAUTH_DIGEST)
+            printf("Used Digest authentication\n");
+          else
+            printf("Used Basic authentication\n");
+        }
+      }
+    }
+    curl_easy_cleanup(curl);
+  }
+}
+~~~
+
+# %AVAILABILITY%
+
+# RETURN VALUE
+
+Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

docs/libcurl/opts/CURLINFO_PROXYAUTH_USED.md

@@ -0,0 +1,79 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLINFO_PROXYAUTH_USED
+Section: 3
+Source: libcurl
+See-also:
+  - CURLINFO_HTTPAUTH_USED (3)
+  - CURLINFO_PROXYAUTH_AVAIL (3)
+  - CURLOPT_HTTPAUTH (3)
+Protocol:
+  - HTTP
+Added-in: 8.12.0
+---
+
+# NAME
+
+CURLINFO_PROXYAUTH_USED - get used HTTP proxy authentication method
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_PROXYAUTH_USED, long *authp);
+~~~
+
+# DESCRIPTION
+
+Pass a pointer to a long to receive a bitmask indicating the authentication
+method that was used in the previous request done over an HTTP proxy. The
+meaning of the possible bits is explained in the CURLOPT_HTTPAUTH(3) option
+for curl_easy_setopt(3).
+
+The returned value has zero or one bit set.
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+int main(void)
+{
+  CURL *curl = curl_easy_init();
+  if(curl) {
+    CURLcode res;
+    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
+    curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy.example.com");
+    curl_easy_setopt(curl, CURLOPT_PROXYAUTH,
+                     CURLAUTH_BASIC | CURLAUTH_DIGEST);
+    curl_easy_setopt(curl, CURLOPT_PROXYUSERNAME, "shrek");
+    curl_easy_setopt(curl, CURLOPT_PROXYPASSWORD, "swamp");
+
+    res = curl_easy_perform(curl);
+
+    if(!res) {
+      long auth;
+      res = curl_easy_getinfo(curl, CURLINFO_PROXYAUTH_USED, &auth);
+      if(!res) {
+        if(!auth)
+          printf("No auth used\n");
+        else {
+          if(auth == CURLAUTH_DIGEST)
+            printf("Used Digest proxy authentication\n");
+          else
+            printf("Used Basic proxy authentication\n");
+        }
+      }
+    }
+    curl_easy_cleanup(curl);
+  }
+}
+~~~
+
+# %AVAILABILITY%
+
+# RETURN VALUE
+
+Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

docs/libcurl/opts/Makefile.inc

@@ -50,6 +50,7 @@ man_MANS =                                      \
   CURLINFO_HTTP_CONNECTCODE.3                   \
   CURLINFO_HTTP_VERSION.3                       \
   CURLINFO_HTTPAUTH_AVAIL.3                     \
+  CURLINFO_HTTPAUTH_USED.3                      \
   CURLINFO_LASTSOCKET.3                         \
   CURLINFO_LOCAL_IP.3                           \
   CURLINFO_LOCAL_PORT.3                         \
@@ -67,6 +68,7 @@ man_MANS =                                      \
   CURLINFO_PROXY_ERROR.3                        \
   CURLINFO_PROXY_SSL_VERIFYRESULT.3             \
   CURLINFO_PROXYAUTH_AVAIL.3                    \
+  CURLINFO_PROXYAUTH_USED.3                     \
   CURLINFO_QUEUE_TIME_T.3                       \
   CURLINFO_REDIRECT_COUNT.3                     \
   CURLINFO_REDIRECT_TIME.3                      \

docs/libcurl/symbols-in-versions

@@ -449,6 +449,7 @@ CURLINFO_HTTP_CODE              7.4.1         7.10.8
 CURLINFO_HTTP_CONNECTCODE       7.10.7
 CURLINFO_HTTP_VERSION           7.50.0
 CURLINFO_HTTPAUTH_AVAIL         7.10.8
+CURLINFO_HTTPAUTH_USED          8.12.0
 CURLINFO_LASTONE                7.4.1
 CURLINFO_LASTSOCKET             7.15.2        7.45.0
 CURLINFO_LOCAL_IP               7.21.0
@@ -471,6 +472,7 @@ CURLINFO_PROTOCOL               7.52.0        7.85.0
 CURLINFO_PROXY_ERROR            7.73.0
 CURLINFO_PROXY_SSL_VERIFYRESULT 7.52.0
 CURLINFO_PROXYAUTH_AVAIL        7.10.8
+CURLINFO_PROXYAUTH_USED         8.12.0
 CURLINFO_PTR                    7.54.1
 CURLINFO_QUEUE_TIME_T           8.6.0
 CURLINFO_REDIRECT_COUNT         7.9.7