diff options
| -rw-r--r-- | src/main/java/org/openslx/imagemaster/crcchecker/CRCFile.java | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/src/main/java/org/openslx/imagemaster/crcchecker/CRCFile.java b/src/main/java/org/openslx/imagemaster/crcchecker/CRCFile.java index a096bf6..807aac1 100644 --- a/src/main/java/org/openslx/imagemaster/crcchecker/CRCFile.java +++ b/src/main/java/org/openslx/imagemaster/crcchecker/CRCFile.java @@ -71,19 +71,16 @@ public class CRCFile { if ( listOfCrcSums == null || listOfCrcSums.isEmpty() ) return false; - int masterSum = listOfCrcSums.remove( 0 ); - byte[] bytesOfInt; + + int masterSum = listOfCrcSums.get( 0 ); // don't use the first sum for the calculation because it is the sum over the other sums int size = listOfCrcSums.size(); - byte[] bytes = new byte[ size * Integer.SIZE / 8 ]; - for ( int i = 0; i < size; i++ ) { - bytesOfInt = ByteBuffer.allocate( 4 ).putInt( listOfCrcSums.remove( 0 ) ).array(); // get the bytes of this integer - bytes[4 * i] = bytesOfInt[0]; - bytes[4 * i + 1] = bytesOfInt[1]; - bytes[4 * i + 2] = bytesOfInt[2]; - bytes[4 * i + 3] = bytesOfInt[3]; - } + CRC32 crcCalc = new CRC32(); - crcCalc.update( bytes ); + + for ( int i = 1; i < size; i++ ) { + crcCalc.update( ByteBuffer.allocate( 4 ).putInt( listOfCrcSums.get( i ) ).array() ); // update the crc calculator with the next 4 bytes of the integer + } + return ( masterSum == Integer.reverseBytes( (int)crcCalc.getValue() ) ); } @@ -150,7 +147,7 @@ public class CRCFile } dis.close(); } - + public int getMasterSum() throws IOException { if ( crcSums == null ) |