[PATCH v3 12/15] config: define new option index.try_decrypt

[Daniel Kahn Gillmor <dkg@fifthhorseman.net>]

By default, notmuch won't try to decrypt on indexing.  With this
patch, we make it possible to indicate a per-database preference using
the config variable "index.try_decrypt", which by default will be
false.
---
 doc/man1/notmuch-config.rst | 12 ++++++++++++
 lib/indexopts.c             | 18 +++++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/doc/man1/notmuch-config.rst b/doc/man1/notmuch-config.rst
index 6a51e64f..6f35d127 100644
--- a/doc/man1/notmuch-config.rst
+++ b/doc/man1/notmuch-config.rst
@@ -134,6 +134,18 @@ The available configuration items are described below.
 
         Default: ``gpg``.
 
+    **index.try_decrypt**
+
+        When indexing an encrypted e-mail message, if this variable is
+        set to true, notmuch will try to decrypt the message and index
+        the cleartext.  Be aware that the index is likely sufficient
+        to reconstruct the cleartext of the message itself, so please
+        ensure that the notmuch message index is adequately protected.
+        DO NOT USE ``index.try_decrypt=true`` without considering the
+        security of your index.
+
+        Default: ``false``.
+
     **built_with.<name>**
 
         Compile time feature <name>. Current possibilities include
diff --git a/lib/indexopts.c b/lib/indexopts.c
index cc1d6422..987d8952 100644
--- a/lib/indexopts.c
+++ b/lib/indexopts.c
@@ -23,7 +23,23 @@
 notmuch_indexopts_t *
 notmuch_database_get_default_indexopts (notmuch_database_t *db)
 {
-    return talloc_zero (db, notmuch_indexopts_t);
+    notmuch_indexopts_t *ret = talloc_zero (db, notmuch_indexopts_t);
+    if (!ret)
+	return ret;
+
+    char * try_decrypt;
+    notmuch_status_t err = notmuch_database_get_config (db, "index.try_decrypt", &try_decrypt);
+    if (err)
+	return ret;
+
+    if (try_decrypt &&
+	((!(strcasecmp(try_decrypt, "true"))) ||
+	 (!(strcasecmp(try_decrypt, "yes"))) ||
+	 (!(strcasecmp(try_decrypt, "1")))))
+	notmuch_indexopts_set_try_decrypt (ret, true);
+
+    free (try_decrypt);
+    return ret;
 }
 
 notmuch_status_t
-- 
2.14.2