Implemented PDF Document permission check

2 files changed, 100 insertions, 84 deletions

diff --git a/pdf-as-common/src/main/java/at/gv/egiz/pdfas/common/exceptions/PdfAsValidationException.java b/pdf-as-common/src/main/java/at/gv/egiz/pdfas/common/exceptions/PdfAsValidationException.java
index b8a5fc62..95380794 100644
--- a/pdf-as-common/src/main/java/at/gv/egiz/pdfas/common/exceptions/PdfAsValidationException.java
+++ b/pdf-as-common/src/main/java/at/gv/egiz/pdfas/common/exceptions/PdfAsValidationException.java
@@ -16,6 +16,11 @@ public class PdfAsValidationException extends PdfAsException {
 		this.parameter = parameter;
 	}
 	
+	public PdfAsValidationException(String msgId, String parameter, Throwable e) {
+		super(msgId, e);
+		this.parameter = parameter;
+	}
+	
 	@Override
 	protected String localizeMessage(String msgId) {
 		if(parameter != null) {
diff --git a/pdf-as-common/src/main/java/at/gv/egiz/pdfas/common/utils/PDFUtils.java b/pdf-as-common/src/main/java/at/gv/egiz/pdfas/common/utils/PDFUtils.java
index 155f9cfb..8b649034 100644
--- a/pdf-as-common/src/main/java/at/gv/egiz/pdfas/common/utils/PDFUtils.java
+++ b/pdf-as-common/src/main/java/at/gv/egiz/pdfas/common/utils/PDFUtils.java
@@ -1,94 +1,105 @@
 package at.gv.egiz.pdfas.common.utils;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.encryption.AccessPermission;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.ArrayList;
-import java.util.List;
-
+import at.gv.egiz.pdfas.common.exceptions.PdfAsValidationException;
 
 public class PDFUtils {
 
-    private static final Logger logger = LoggerFactory.getLogger(PDFUtils.class);
-
-
-    private static final byte[] signature_pattern = new byte[] {
-            (byte) 0x0A, (byte) 0x2F, (byte) 0x43, (byte) 0x6F,   // ./Co
-            (byte) 0x6E, (byte) 0x74, (byte) 0x65, (byte) 0x6E,   // nten
-            (byte) 0x74, (byte) 0x73, (byte) 0x20, (byte) 0x0A,   // ts .
-            (byte) 0x2F, (byte) 0x42, (byte) 0x79, (byte) 0x74,   // /Byt
-            (byte) 0x65, (byte) 0x52, (byte) 0x61, (byte) 0x6E,   // eRan
-            (byte) 0x67, (byte) 0x65, (byte) 0x20, (byte) 0x5B,   // ge [
-
-    };
-
-    private static final byte range_seperation = (byte) 0x20;
-    private static final byte range_end = (byte) 0x5D;
-
-    private static int extractASCIIInteger(byte[] data, int offset) {
-       int nextsepp = nextSeperator(data, offset);
-
-        if(nextsepp < offset) {
-            return -1;
-        }
-
-        String asciiString = new String(data, offset, nextsepp - offset);
-
-        logger.debug("Extracted " + asciiString);
-
-        return Integer.parseInt(asciiString);
-    }
-
-    private static int nextSeperator(byte[] data, int offset) {
-        for(int i = offset; i < data.length; i++) {
-            if(data[i] == range_seperation) {
-                return i;
-            } else if(data[i] == range_end) {
-                return i;
-            }
-        }
-        return -2;
-    }
-
-    public static int[] extractSignatureByteRange(byte[] rawPdfData) {
-        int i = 0;
-        for(i = rawPdfData.length - 1; i >= 0; i--) {
-            if(rawPdfData[i] == signature_pattern[0] &&
-                    i+signature_pattern.length < rawPdfData.length) {
-                boolean match = true;
-                for(int j = 0; j < signature_pattern.length; j++) {
-
-                    if(rawPdfData[i+j] != signature_pattern[j]) {
-                        match = false;
-                        break;
-                    }
-                }
-
-                if(match) {
-
-                    int offset = i + signature_pattern.length;
-                    List<Integer> byteRange = new ArrayList<Integer>();
-                    while(offset > 0) {
-                        byteRange.add(extractASCIIInteger(rawPdfData, offset));
-                        offset = nextSeperator(rawPdfData, offset);
-                        if(rawPdfData[offset] == range_end) {
-                            break;
-                        }
-                        offset++;
-                    }
-                    int[] range = new int[byteRange.size()];
-                    for(int j = 0; j < byteRange.size(); j++) {
-                        range[j] = byteRange.get(j);
-                    }
-                    return range;
-                }
-            }
-        }
-        return null;
-    }
-
-    public static void checkPDFPermissions(PDDocument doc) {
-        // TODO: Check permission for document
-    }
+	private static final Logger logger = LoggerFactory
+			.getLogger(PDFUtils.class);
+
+	private static final byte[] signature_pattern = new byte[] { (byte) 0x0A,
+			(byte) 0x2F, (byte) 0x43, (byte) 0x6F, // ./Co
+			(byte) 0x6E, (byte) 0x74, (byte) 0x65, (byte) 0x6E, // nten
+			(byte) 0x74, (byte) 0x73, (byte) 0x20, (byte) 0x0A, // ts .
+			(byte) 0x2F, (byte) 0x42, (byte) 0x79, (byte) 0x74, // /Byt
+			(byte) 0x65, (byte) 0x52, (byte) 0x61, (byte) 0x6E, // eRan
+			(byte) 0x67, (byte) 0x65, (byte) 0x20, (byte) 0x5B, // ge [
+
+	};
+
+	private static final byte range_seperation = (byte) 0x20;
+	private static final byte range_end = (byte) 0x5D;
+
+	private static int extractASCIIInteger(byte[] data, int offset) {
+		int nextsepp = nextSeperator(data, offset);
+
+		if (nextsepp < offset) {
+			return -1;
+		}
+
+		String asciiString = new String(data, offset, nextsepp - offset);
+
+		logger.debug("Extracted " + asciiString);
+
+		return Integer.parseInt(asciiString);
+	}
+
+	private static int nextSeperator(byte[] data, int offset) {
+		for (int i = offset; i < data.length; i++) {
+			if (data[i] == range_seperation) {
+				return i;
+			} else if (data[i] == range_end) {
+				return i;
+			}
+		}
+		return -2;
+	}
+
+	public static int[] extractSignatureByteRange(byte[] rawPdfData) {
+		int i = 0;
+		for (i = rawPdfData.length - 1; i >= 0; i--) {
+			if (rawPdfData[i] == signature_pattern[0]
+					&& i + signature_pattern.length < rawPdfData.length) {
+				boolean match = true;
+				for (int j = 0; j < signature_pattern.length; j++) {
+
+					if (rawPdfData[i + j] != signature_pattern[j]) {
+						match = false;
+						break;
+					}
+				}
+
+				if (match) {
+
+					int offset = i + signature_pattern.length;
+					List<Integer> byteRange = new ArrayList<Integer>();
+					while (offset > 0) {
+						byteRange.add(extractASCIIInteger(rawPdfData, offset));
+						offset = nextSeperator(rawPdfData, offset);
+						if (rawPdfData[offset] == range_end) {
+							break;
+						}
+						offset++;
+					}
+					int[] range = new int[byteRange.size()];
+					for (int j = 0; j < byteRange.size(); j++) {
+						range[j] = byteRange.get(j);
+					}
+					return range;
+				}
+			}
+		}
+		return null;
+	}
+
+	public static void checkPDFPermissions(PDDocument doc) throws PdfAsValidationException {
+
+		AccessPermission accessPermission = doc.getCurrentAccessPermission();
+		if (doc.isEncrypted()) {
+			throw new PdfAsValidationException("error.pdf.sig.12", null);
+		}
+
+		if (!accessPermission.isOwnerPermission()) {
+			throw new PdfAsValidationException("error.pdf.sig.12", null);
+		}
+
+	}
 }