Avoid caches to get the most recent copy of the key. This is bug #1061

5 files changed, 105 insertions, 5 deletions

diff --git a/keyserver/ChangeLog b/keyserver/ChangeLog
index 26abf0fba..2b69ccd56 100644
--- a/keyserver/ChangeLog
+++ b/keyserver/ChangeLog
@@ -1,3 +1,15 @@
+2009-05-28  David Shaw  <dshaw@jabberwocky.com>
+
+	From 1.4:
+
+	* curl-shim.c (curl_slist_append, curl_slist_free_all): New.
+	Simple wrappers around strlist_t to emulate the curl way of doing
+	string lists.
+	(curl_easy_setopt): Handle the curl HTTPHEADER option.
+
+	* gpgkeys_curl.c, gpgkeys_hkp.c (main): Avoid caches to get the
+	most recent copy of the key.  This is bug #1061.
+
 2009-05-27  David Shaw  <dshaw@jabberwocky.com>
 
 	From 1.4:
diff --git a/keyserver/curl-shim.c b/keyserver/curl-shim.c
index 98b5b24c7..500d9f562 100644
--- a/keyserver/curl-shim.c
+++ b/keyserver/curl-shim.c
@@ -1,7 +1,7 @@
 /* curl-shim.c - Implement a small subset of the curl API in terms of
  * the iobuf HTTP API
  *
- * Copyright (C) 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ * Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
  *
  * This file is part of GnuPG.
  *
@@ -26,8 +26,8 @@
 #include <stdio.h>
 #include <errno.h>
 
-#include "http.h"
 #include "util.h"
+#include "http.h"
 #include "ksutil.h"
 #include "curl-shim.h"
 
@@ -156,6 +156,9 @@ curl_easy_setopt(CURL *curl,CURLoption option,...)
     case CURLOPT_STDERR:
       curl->errors=va_arg(ap,FILE *);
       break;
+    case CURLOPT_HTTPHEADER:
+      curl->headers=va_arg(ap,struct curl_slist *);
+      break;
     default:
       /* We ignore the huge majority of curl options */
       break;
@@ -196,7 +199,8 @@ curl_easy_perform(CURL *curl)
   if(curl->flags.post)
     {
       rc = http_open (&curl->hd, HTTP_REQ_POST, curl->url, curl->auth,
-                      0, proxy, NULL, curl->srvtag);
+                      0, proxy, NULL, curl->srvtag,
+		      curl->headers?curl->headers->list:NULL);
       if (!rc)
 	{
 	  unsigned int post_len = strlen(curl->postfields);
@@ -219,7 +223,8 @@ curl_easy_perform(CURL *curl)
   else
     {
       rc = http_open (&curl->hd, HTTP_REQ_GET, curl->url, curl->auth,
-                      0, proxy, NULL, curl->srvtag);
+                      0, proxy, NULL, curl->srvtag,
+		      curl->headers?curl->headers->list:NULL);
       if (!rc)
 	{
 	  rc = http_wait_response (curl->hd);
@@ -350,3 +355,28 @@ curl_version_info(int type)
 
   return &data;
 }
+
+struct curl_slist *
+curl_slist_append(struct curl_slist *list,const char *string)
+{
+  if(!list)
+    {
+      list=calloc(1,sizeof(*list));
+      if(!list)
+	return NULL;
+    }
+
+  add_to_strlist(&list->list,string);
+
+  return list;
+}
+
+void
+curl_slist_free_all(struct curl_slist *list)
+{
+  if(list)
+    {
+      free_strlist(list->list);
+      free(list);
+    }
+}
diff --git a/keyserver/curl-shim.h b/keyserver/curl-shim.h
index 793d484b9..e37d81675 100644
--- a/keyserver/curl-shim.h
+++ b/keyserver/curl-shim.h
@@ -1,5 +1,5 @@
 /* curl-shim.h
- * Copyright (C) 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ * Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
  *
  * This file is part of GNUPG.
  *
@@ -20,6 +20,7 @@
 #ifndef _CURL_SHIM_H_
 #define _CURL_SHIM_H_
 
+#include "util.h"
 #include "http.h"
 
 typedef enum
@@ -49,6 +50,7 @@ typedef enum
     CURLOPT_POST,
     CURLOPT_POSTFIELDS,
     CURLOPT_FAILONERROR,
+    CURLOPT_HTTPHEADER,
     CURLOPT_SRVTAG_GPG_HACK
   } CURLoption;
 
@@ -67,6 +69,7 @@ typedef struct
   char *srvtag;
   unsigned int status;
   FILE *errors;
+  struct curl_slist *headers;
   struct
   {
     unsigned int post:1;
@@ -96,4 +99,13 @@ char *curl_escape(char *str,int len);
 #define curl_version() "GnuPG curl-shim"
 curl_version_info_data *curl_version_info(int type);
 
+struct curl_slist
+{
+  strlist_t list;
+};
+
+struct curl_slist *curl_slist_append(struct curl_slist *list,
+				     const char *string);
+void curl_slist_free_all(struct curl_slist *list);
+
 #endif /* !_CURL_SHIM_H_ */
diff --git a/keyserver/gpgkeys_curl.c b/keyserver/gpgkeys_curl.c
index 6183556e7..28ec69822 100644
--- a/keyserver/gpgkeys_curl.c
+++ b/keyserver/gpgkeys_curl.c
@@ -117,6 +117,7 @@ main(int argc,char *argv[])
   long follow_redirects=5;
   char *proxy=NULL;
   curl_version_info_data *curldata;
+  struct curl_slist *headers=NULL;
 
   console=stderr;
 
@@ -305,6 +306,26 @@ main(int argc,char *argv[])
   curl_easy_setopt(curl,CURLOPT_SSL_VERIFYPEER,(long)opt->flags.check_cert);
   curl_easy_setopt(curl,CURLOPT_CAINFO,opt->ca_cert_file);
 
+  /* Avoid caches to get the most recent copy of the key.  This is bug
+     #1061.  In pre-curl versions of the code, we didn't do it.  Then
+     we did do it (as a curl default) until curl changed the default.
+     Now we're doing it again, but in such a way that changing
+     defaults in the future won't impact us.  We set both the Pragma
+     and Cache-Control versions of the header, so we're good with both
+     HTTP 1.0 and 1.1. */
+  headers=curl_slist_append(headers,"Pragma: no-cache");
+  if(headers)
+    headers=curl_slist_append(headers,"Cache-Control: no-cache");
+
+  if(!headers)
+    {
+      fprintf(console,"gpgkeys: out of memory when building HTTP headers\n");
+      ret=KEYSERVER_NO_MEMORY;
+      goto fail;
+    }
+
+  curl_easy_setopt(curl,CURLOPT_HTTPHEADER,headers);
+
   if(proxy)
     curl_easy_setopt(curl,CURLOPT_PROXY,proxy);
 
@@ -385,6 +406,8 @@ main(int argc,char *argv[])
 
   free_ks_options(opt);
 
+  curl_slist_free_all(headers);
+
   if(curl)
     curl_easy_cleanup(curl);
 
diff --git a/keyserver/gpgkeys_hkp.c b/keyserver/gpgkeys_hkp.c
index 0764fe2ac..2e7f8078a 100644
--- a/keyserver/gpgkeys_hkp.c
+++ b/keyserver/gpgkeys_hkp.c
@@ -547,6 +547,7 @@ main(int argc,char *argv[])
   int failed=0;
   struct keylist *keylist=NULL,*keyptr=NULL;
   char *proxy=NULL;
+  struct curl_slist *headers=NULL;
 
   console=stderr;
 
@@ -742,6 +743,26 @@ main(int argc,char *argv[])
   curl_easy_setopt(curl,CURLOPT_SSL_VERIFYPEER,(long)opt->flags.check_cert);
   curl_easy_setopt(curl,CURLOPT_CAINFO,opt->ca_cert_file);
 
+  /* Avoid caches to get the most recent copy of the key.  This is bug
+     #1061.  In pre-curl versions of the code, we didn't do it.  Then
+     we did do it (as a curl default) until curl changed the default.
+     Now we're doing it again, but in such a way that changing
+     defaults in the future won't impact us.  We set both the Pragma
+     and Cache-Control versions of the header, so we're good with both
+     HTTP 1.0 and 1.1. */
+  headers=curl_slist_append(headers,"Pragma: no-cache");
+  if(headers)
+    headers=curl_slist_append(headers,"Cache-Control: no-cache");
+
+  if(!headers)
+    {
+      fprintf(console,"gpgkeys: out of memory when building HTTP headers\n");
+      ret=KEYSERVER_NO_MEMORY;
+      goto fail;
+    }
+
+  curl_easy_setopt(curl,CURLOPT_HTTPHEADER,headers);
+
   if(proxy)
     curl_easy_setopt(curl,CURLOPT_PROXY,proxy);
 
@@ -919,6 +940,8 @@ main(int argc,char *argv[])
 
   free_ks_options(opt);
 
+  curl_slist_free_all(headers);
+
   if(curl)
     curl_easy_cleanup(curl);