From 3d091411f3290aaee37be1d0cf82dfeeea23bc15 Mon Sep 17 00:00:00 2001
From: Nick Couchman <vnick@apache.org>
Date: Sun, 1 Oct 2017 07:15:19 -0400
Subject: [PATCH] GUACAMOLE-362: Deal correctly with return value when reading
 the key.

---
 .../PrivateKeyGuacamoleProperty.java           | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/guacamole-ext/src/main/java/org/apache/guacamole/properties/PrivateKeyGuacamoleProperty.java b/guacamole-ext/src/main/java/org/apache/guacamole/properties/PrivateKeyGuacamoleProperty.java
index 174f18399..c360f4b9e 100644
--- a/guacamole-ext/src/main/java/org/apache/guacamole/properties/PrivateKeyGuacamoleProperty.java
+++ b/guacamole-ext/src/main/java/org/apache/guacamole/properties/PrivateKeyGuacamoleProperty.java
@@ -53,8 +53,22 @@ public abstract class PrivateKeyGuacamoleProperty implements GuacamoleProperty<P
             // Open and read the file specified in the configuration.
             File keyFile = new File(value);
             InputStream keyInput = new BufferedInputStream(new FileInputStream(keyFile));
-            final byte[] keyBytes = new byte[(int) keyFile.length()];
-            keyInput.read(keyBytes);
+            int keyLength = (int) keyFile.length();
+            final byte[] keyBytes = new byte[keyLength];
+            int keyRead = keyInput.read(keyBytes);
+
+            // Error reading any bytes out of the key.
+            if (keyRead == -1)
+                throw new GuacamoleServerException("Failed to get any bytes while reading key.");
+
+            // Zero-sized key
+            else if(keyRead == 0)
+                throw new GuacamoleServerException("Failed to ready key because key is empty.");
+
+            // Fewer bytes read than contained in the key
+            else if (keyRead < keyLength)
+                throw new GuacamoleServerException("Unable to read the full length of the key.");
+
             keyInput.close();
 
             // Set up decryption infrastructure