From fa5d1513a29708ce51496b4e248bcd91a81c17fe Mon Sep 17 00:00:00 2001
From: Werner Koch <wk@gnupg.org>
Date: Wed, 28 Jan 2004 16:19:46 +0000
Subject: [PATCH] (agent_marktrusted): Check whether the trustlist is writable.

---
 agent/ChangeLog    |  5 +++++
 agent/divert-scd.c |  2 +-
 agent/learncard.c  |  1 +
 agent/trustlist.c  | 16 ++++++++++++++++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/agent/ChangeLog b/agent/ChangeLog
index 57f9214f6..73b9c4596 100644
--- a/agent/ChangeLog
+++ b/agent/ChangeLog
@@ -1,3 +1,8 @@
+2004-01-28  Werner Koch  <wk@gnupg.org>
+
+	* trustlist.c (agent_marktrusted): Check whether the trustlist is
+	writable.
+
 2004-01-27  Werner Koch  <wk@gnupg.org>
 
 	* sexp-parse.h: Moved to ../common.
diff --git a/agent/divert-scd.c b/agent/divert-scd.c
index 69f184474..283150ad3 100644
--- a/agent/divert-scd.c
+++ b/agent/divert-scd.c
@@ -134,7 +134,7 @@ ask_for_card (CTRL ctrl, const unsigned char *shadow_info, char **r_kid)
 }
 
 
-/* Put the DIGEST into an DER encoded comtainer and return it in R_VAL. */
+/* Put the DIGEST into an DER encoded container and return it in R_VAL. */
 static int
 encode_md_for_card (const unsigned char *digest, size_t digestlen, int algo,
                     unsigned char **r_val, size_t *r_len)
diff --git a/agent/learncard.c b/agent/learncard.c
index 28a74f972..a76f2652a 100644
--- a/agent/learncard.c
+++ b/agent/learncard.c
@@ -303,6 +303,7 @@ agent_handle_learn (void *assuan_context)
     101, /* trusted */
     102, /* useful */
     100, /* regular */
+    /* We don't include 110 here because gpgsm can't handle it. */
     -1 /* end of list */
   };
 
diff --git a/agent/trustlist.c b/agent/trustlist.c
index 8575aedb0..5c3271ac0 100644
--- a/agent/trustlist.c
+++ b/agent/trustlist.c
@@ -236,6 +236,22 @@ agent_marktrusted (CTRL ctrl, const char *name, const char *fpr, int flag)
   static char key[41];
   int keyflag;
   char *desc;
+  char *fname;
+
+  /* Check whether we are at all allowed to modify the trustlist.
+     This is useful so that the trustlist may be a symlink to a global
+     trustlist with only admin priviliges to modify it.  Of course
+     this is not a secure way of denying access, but it avoids the
+     usual clicking on an Okay buttun thing most users are used to. */
+  fname = make_filename (opt.homedir, "trustlist.txt", NULL);
+  rc = access (fname, W_OK);
+  if (rc && errno != ENOENT)
+    {
+      xfree (fname);
+      return gpg_error (GPG_ERR_EPERM);
+    }    
+  xfree (fname);
+
 
   if (trustfp)
     rewind (trustfp);