Reject special Windows device names in ObjectChecker

If Windows rejection is enabled reject special device names like
NUL and PRN, including NUL.txt. This prevents a tree that might
be used on a Windows client from referencing a confusing name.

Change-Id: Ic700ea8fa68724509e0357d4b758a41178c4d70c

1 files changed, 66 insertions, 4 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectChecker.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectChecker.java
index 39f071c98e..260a643e66 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectChecker.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectChecker.java
@@ -410,10 +410,68 @@ public class ObjectChecker {
 			}
 		}
 
-		// Windows ignores space and dot at end of file name.
-		if (windows && (raw[end - 1] == ' ' || raw[end - 1] == '.'))
-			throw new CorruptObjectException("invalid name ends with '"
-					+ ((char) raw[end - 1]) + "'");
+		if (windows) {
+			// Windows ignores space and dot at end of file name.
+			if (raw[end - 1] == ' ' || raw[end - 1] == '.')
+				throw new CorruptObjectException("invalid name ends with '"
+						+ ((char) raw[end - 1]) + "'");
+			if (end - ptr >= 3)
+				checkNotWindowsDevice(raw, ptr, end);
+		}
+	}
+
+	private static void checkNotWindowsDevice(byte[] raw, int ptr, int end)
+			throws CorruptObjectException {
+		switch (toLower(raw[ptr])) {
+		case 'a': // AUX
+			if (end - ptr >= 3
+					&& toLower(raw[ptr + 1]) == 'u'
+					&& toLower(raw[ptr + 2]) == 'x'
+					&& (end - ptr == 3 || raw[ptr + 3] == '.'))
+				throw new CorruptObjectException("invalid name 'AUX'");
+			break;
+
+		case 'c': // CON, COM[1-9]
+			if (end - ptr >= 3
+					&& toLower(raw[ptr + 2]) == 'n'
+					&& toLower(raw[ptr + 1]) == 'o'
+					&& (end - ptr == 3 || raw[ptr + 3] == '.'))
+				throw new CorruptObjectException("invalid name 'CON'");
+			if (end - ptr >= 4
+					&& toLower(raw[ptr + 2]) == 'm'
+					&& toLower(raw[ptr + 1]) == 'o'
+					&& isPositiveDigit(raw[ptr + 3])
+					&& (end - ptr == 4 || raw[ptr + 4] == '.'))
+				throw new CorruptObjectException("invalid name 'COM"
+						+ ((char) raw[ptr + 3]) + "'");
+			break;
+
+		case 'l': // LPT[1-9]
+			if (end - ptr >= 4
+					&& toLower(raw[ptr + 1]) == 'p'
+					&& toLower(raw[ptr + 2]) == 't'
+					&& isPositiveDigit(raw[ptr + 3])
+					&& (end - ptr == 4 || raw[ptr + 4] == '.'))
+				throw new CorruptObjectException("invalid name 'LPT"
+						+ ((char) raw[ptr + 3]) + "'");
+			break;
+
+		case 'n': // NUL
+			if (end - ptr >= 3
+					&& toLower(raw[ptr + 1]) == 'u'
+					&& toLower(raw[ptr + 2]) == 'l'
+					&& (end - ptr == 3 || raw[ptr + 3] == '.'))
+				throw new CorruptObjectException("invalid name 'NUL'");
+			break;
+
+		case 'p': // PRN
+			if (end - ptr >= 3
+					&& toLower(raw[ptr + 1]) == 'r'
+					&& toLower(raw[ptr + 2]) == 'n'
+					&& (end - ptr == 3 || raw[ptr + 3] == '.'))
+				throw new CorruptObjectException("invalid name 'PRN'");
+			break;
+		}
 	}
 
 	private static boolean isInvalidOnWindows(byte c) {
@@ -446,6 +504,10 @@ public class ObjectChecker {
 		return (char) b;
 	}
 
+	private static boolean isPositiveDigit(byte b) {
+		return '1' <= b && b <= '9';
+	}
+
 	/**
 	 * Check a blob for errors.
 	 *