[PATCH v2 15/21] crypto: record whether an actual decryption attempt happened

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

In our consolidation of _notmuch_crypto_decrypt, the callers lost
track a little bit of whether any actual decryption was attempted.

Now that we have the more-subtle "auto" policy, it's possible that
_notmuch_crypto_decrypt could be called without having any actual
decryption take place.

This change lets the callers be a little bit smarter about whether or
not any decryption was actually attempted.
---
 lib/index.cc  | 17 ++++++++++++-----
 mime-node.c   |  4 ++--
 util/crypto.c |  7 ++++++-
 util/crypto.h |  3 ++-
 4 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/lib/index.cc b/lib/index.cc
index af999bd3..3914012a 100644
--- a/lib/index.cc
+++ b/lib/index.cc
@@ -548,12 +548,19 @@ _index_encrypted_mime_part (notmuch_message_t *message,
 	}
     }
 #endif
-    clear = _notmuch_crypto_decrypt (notmuch_indexopts_get_decrypt_policy (indexopts),
+    bool attempted = false;
+    clear = _notmuch_crypto_decrypt (&attempted, notmuch_indexopts_get_decrypt_policy (indexopts),
 				     message, crypto_ctx, encrypted_data, NULL, &err);
-    if (err) {
-	_notmuch_database_log (notmuch, "Failed to decrypt during indexing. (%d:%d) [%s]\n",
-			       err->domain, err->code, err->message);
-	g_error_free(err);
+    if (!attempted)
+	return;
+    if (err || !clear) {
+	if (err) {
+	    _notmuch_database_log (notmuch, "Failed to decrypt during indexing. (%d:%d) [%s]\n",
+				   err->domain, err->code, err->message);
+	    g_error_free(err);
+	} else {
+	    _notmuch_database_log (notmuch, "Failed to decrypt during indexing. (unknown error)\n");
+	}
 	/* Indicate that we failed to decrypt during indexing */
 	status = notmuch_message_add_property (message, "index.decryption", "failure");
 	if (status)
diff --git a/mime-node.c b/mime-node.c
index 49d668fe..11df082b 100644
--- a/mime-node.c
+++ b/mime-node.c
@@ -204,8 +204,8 @@ node_decrypt_and_verify (mime_node_t *node, GMimeObject *part,
 	    if (parent->envelope_file)
 		break;
 
-	node->decrypt_attempted = true;
-	node->decrypted_child = _notmuch_crypto_decrypt (node->ctx->crypto->decrypt,
+	node->decrypted_child = _notmuch_crypto_decrypt (&node->decrypt_attempted,
+							 node->ctx->crypto->decrypt,
 							 parent ? parent->envelope_file : NULL,
 							 cryptoctx, encrypteddata, &decrypt_result, &err);
     }
diff --git a/util/crypto.c b/util/crypto.c
index bb587571..338f1d5d 100644
--- a/util/crypto.c
+++ b/util/crypto.c
@@ -140,7 +140,8 @@ void _notmuch_crypto_cleanup (unused(_notmuch_crypto_t *crypto))
 #endif
 
 GMimeObject *
-_notmuch_crypto_decrypt (notmuch_decryption_policy_t decrypt,
+_notmuch_crypto_decrypt (bool *attempted,
+			 notmuch_decryption_policy_t decrypt,
 			 notmuch_message_t *message,
 			 g_mime_3_unused(GMimeCryptoContext* crypto_ctx),
 			 GMimeMultipartEncrypted *part,
@@ -162,6 +163,8 @@ _notmuch_crypto_decrypt (notmuch_decryption_policy_t decrypt,
 		g_error_free (*err);
 		*err = NULL;
 	    }
+	    if (attempted)
+		*attempted = true;
 #if (GMIME_MAJOR_VERSION < 3)
 	    ret = g_mime_multipart_encrypted_decrypt_session (part,
 							      crypto_ctx,
@@ -191,6 +194,8 @@ _notmuch_crypto_decrypt (notmuch_decryption_policy_t decrypt,
     if (decrypt == NOTMUCH_DECRYPT_AUTO)
 	return ret;
 
+    if (attempted)
+	*attempted = true;
 #if (GMIME_MAJOR_VERSION < 3)
     ret = g_mime_multipart_encrypted_decrypt(part, crypto_ctx,
 					     decrypt_result, err);
diff --git a/util/crypto.h b/util/crypto.h
index dc95b4ca..c384601c 100644
--- a/util/crypto.h
+++ b/util/crypto.h
@@ -16,7 +16,8 @@ typedef struct _notmuch_crypto {
 } _notmuch_crypto_t;
 
 GMimeObject *
-_notmuch_crypto_decrypt (notmuch_decryption_policy_t decrypt,
+_notmuch_crypto_decrypt (bool *attempted,
+			 notmuch_decryption_policy_t decrypt,
 			 notmuch_message_t *message,
 			 GMimeCryptoContext* crypto_ctx,
 			 GMimeMultipartEncrypted *part,
-- 
2.15.0