Dave Dribin made libcurl understand and handle cases when the server

(wrongly) sends *two* WWW-Authenticate headers for Digest. While this should
never happen in a sane world, libcurl previously got into an infinite loop
when this occurred. Dave added test 273 to verify this.

CHANGES

@@ -9,6 +9,11 @@
 
 
 Daniel (20 October 2005)
+- Dave Dribin made libcurl understand and handle cases when the server
+  (wrongly) sends *two* WWW-Authenticate headers for Digest. While this should
+  never happen in a sane world, libcurl previously got into an infinite loop
+  when this occurred. Dave added test 273 to verify this.
+
 - Temprimus improved the MSVC makefile: "makes a build option available so if
   you set rtlibcfg=static for the make, then it would build with /MT. The
   default behaviour is /MD (the original)."

RELEASE-NOTES

@@ -15,6 +15,7 @@ This release includes the following changes:
 
 This release includes the following bugfixes:
 
+ o double WWW-Authenticate Digest headers are now handled
  o curl-config --vernum fixed
 
 Other curl-related news since the previous public release:

lib/http.c

@@ -621,6 +621,10 @@ CURLcode Curl_http_input_auth(struct connectdata *conn,
 #endif
 #ifndef CURL_DISABLE_CRYPTO_AUTH
       if(checkprefix("Digest", start)) {
+        if((authp->avail & CURLAUTH_DIGEST) != 0) {
+          infof(data, "Ignoring duplicate digest auth header.\n");
+        }
+        else {
           CURLdigest dig;
           *availp |= CURLAUTH_DIGEST;
           authp->avail |= CURLAUTH_DIGEST;
@@ -635,6 +639,7 @@ CURLcode Curl_http_input_auth(struct connectdata *conn,
             data->state.authproblem = TRUE;
           }
         }
+      }
       else
 #endif
       if(checkprefix("Basic", start)) {

tests/data/Makefile.am

@@ -33,4 +33,4 @@ EXTRA_DIST = test1 test108 test117 test127 test20 test27 test34 test46	   \
  test237 test238 test239 test243 test245 test246 test247 test248 test249   \
  test250 test251 test252 test253 test254 test255 test521 test522 test523   \
  test256 test257 test258 test259 test260 test261 test262 test263 test264   \
- test265 test266 test267 test268 test269 test270 test271 test272
+ test265 test266 test267 test268 test269 test270 test271 test272 test273

tests/data/test273

@@ -0,0 +1,76 @@
+<info>
+<keywords>
+HTTP
+HTTP GET
+HTTP Digest auth
+</keywords>
+</info>
+# Server-side
+<reply>
+<data>
+HTTP/1.1 401 Authorization Required swsclose
+Server: Apache/1.3.27 (Darwin) PHP/4.1.2
+WWW-Authenticate: Digest realm="testrealm", nonce="1053604145"
+WWW-Authenticate: Digest realm="testrealm", nonce="1053604145"
+Content-Type: text/html; charset=iso-8859-1
+
+This is not the real page
+</data>
+
+# This is supposed to be returned when the server gets a
+# Authorization: Digest line passed-in from the client
+<data1000>
+HTTP/1.1 200 OK swsclose
+Server: Apache/1.3.27 (Darwin) PHP/4.1.2
+Content-Type: text/html; charset=iso-8859-1
+
+This IS the real page!
+</data1000>
+
+<datacheck>
+HTTP/1.1 401 Authorization Required swsclose
+Server: Apache/1.3.27 (Darwin) PHP/4.1.2
+WWW-Authenticate: Digest realm="testrealm", nonce="1053604145"
+WWW-Authenticate: Digest realm="testrealm", nonce="1053604145"
+Content-Type: text/html; charset=iso-8859-1
+
+HTTP/1.1 200 OK swsclose
+Server: Apache/1.3.27 (Darwin) PHP/4.1.2
+Content-Type: text/html; charset=iso-8859-1
+
+This IS the real page!
+</datacheck>
+
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+ <name>
+HTTP with two Digest authorization headers
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/273 -u testuser:testpass --digest
+</command>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<protocol>
+GET /273 HTTP/1.1
+Host: 127.0.0.1:%HTTPPORT
+Accept: */*
+
+GET /273 HTTP/1.1
+Authorization: Digest username="testuser", realm="testrealm", nonce="1053604145", uri="/273", response="576ae57b1db0039f8c0de43ef58e49e3"
+User-Agent: curl/7.10.5 (i686-pc-linux-gnu) libcurl/7.10.5 OpenSSL/0.9.7a ipv6 zlib/1.1.3
+Host: 127.0.0.1:%HTTPPORT
+Accept: */*
+
+</protocol>
+</verify>