From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Tue, 12 Jun 2018 18:07:38 +0000 (+0300)
Subject: lib-dcrypt: istream-decrypt - Fix memory leak when stream is seeked backwards
X-Git-Tag: 2.3.9~1697
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=73cd1c05d13d09f4958e9acda117fb043e8fe4ea;p=thirdparty%2Fdovecot%2Fcore.git

lib-dcrypt: istream-decrypt - Fix memory leak when stream is seeked backwards

The key already exists in memory at that time.
---

diff --git a/src/lib-dcrypt/istream-decrypt.c b/src/lib-dcrypt/istream-decrypt.c
index 537f489fef..db0ea708eb 100644
--- a/src/lib-dcrypt/istream-decrypt.c
+++ b/src/lib-dcrypt/istream-decrypt.c
@@ -340,13 +340,7 @@ i_stream_decrypt_key(struct decrypt_istream *stream, const char *malg,
 	keys = *data++;
 
 	/* if we have a key, prefab the digest */
-	if (stream->key_callback == NULL) {
-		if (stream->priv_key == NULL) {	
-			io_stream_set_error(&stream->istream.iostream,
-					    "Decryption error: "
-					    "no private key available");
-			return -1;
-		}
+	if (stream->priv_key != NULL) {
 		buffer_create_from_data(&buf, dgst, sizeof(dgst));
 		if (!dcrypt_key_id_private(stream->priv_key, "sha256", &buf,
 					   &error)) {
@@ -356,6 +350,11 @@ i_stream_decrypt_key(struct decrypt_istream *stream, const char *malg,
 					    error);
 			return -1;
 		}
+	} else if (stream->key_callback == NULL) {
+		io_stream_set_error(&stream->istream.iostream,
+				    "Decryption error: "
+				    "no private key available");
+		return -1;
 	}
 
 	/* for each key */
@@ -364,9 +363,17 @@ i_stream_decrypt_key(struct decrypt_istream *stream, const char *malg,
 			return 0;
 		ktype = *data++;
 
-		if (stream->key_callback != NULL) {
+		if (stream->priv_key != NULL) {
+			/* see if key matches to the one we have */
+			if (memcmp(dgst, data, sizeof(dgst)) == 0) {
+				have_key = TRUE;
+				break;
+			}
+		} else if (stream->key_callback != NULL) {
 			const char *hexdgst = /* digest length */
 				binary_to_hex(data, sizeof(dgst));
+			if (stream->priv_key != NULL)
+				dcrypt_key_unref_private(&stream->priv_key);
 			/* hope you going to give us right key.. */
 			int ret = stream->key_callback(hexdgst,
 				&stream->priv_key, &error, stream->key_context);
@@ -380,12 +387,6 @@ i_stream_decrypt_key(struct decrypt_istream *stream, const char *malg,
 				have_key = TRUE;
 				break;
 			}
-		} else {
-			/* see if key matches to the one we have */
-			if (memcmp(dgst, data, sizeof(dgst)) == 0) {
-			      	have_key = TRUE;
-				break;
-			}
 		}
 		data += sizeof(dgst);