Search for encrypted objects Metadata signatures

GroupDocs.Signature provides ability to search for embedded objects in Metadata signatures with standard or custom encryption. Standard encryption is implemented over class SymmetricEncryption class. Creation of this object expects 3 arguments like encryption algorithm enumeration SymmetricAlgorithmType with one of following values (DES, TripleDES, RC2, Rijndael), string value key and string value salt.

Here are the steps to search for embedded Metadata signature with standard encryption with GroupDocs.Signature:

- Create new instance of Signature class and pass source document path or stream as a constructor parameter.
- Compose object of SymmetricEncryption class with same parameters as secured QR-code was signed with.
- Create objects of MetadataSearchOptions class and setup property setDataEncryption with object of SymmetricEncryption
- Call Search method of Signature class instance and pass MetadataSearchOptions to it.
- Call method getData of encrypted MetadataSignature object to retrieve object of type Type

Definition of class

This example shows how to define custom class with serialization and encryption properties and setup Format attributes for properties.

public static class DocumentSignatureData
{
    public String getID(){ return ID; }
    public void setID(String value){ ID = value; }
    @FormatAttribute(propertyName = "SignID")
    public String ID;
 
 
    public final String getAuthor(){ return Author; }
    public final void setAuthor(String value){ Author = value; }
    @FormatAttribute(propertyName = "SAuth")
    public String Author;
    //JAVA-added public wrapper for internalized property accessor
 
    public final java.util.Date getSigned() {  return Signed; }
    public final void setSigned(java.util.Date value) { Signed = value; }
    @FormatAttribute (propertyName = "SDate",propertyFormat = "yyyy-MM-dd")
    public java.util.Date Signed = new java.util.Date();
 
 
    public final java.math.BigDecimal getDataFactor() { return DataFactor; }
    public final void setDataFactor(java.math.BigDecimal value) { DataFactor = value; }
    @FormatAttribute (propertyName = "SDFact",propertyFormat = "N2")
    public java.math.BigDecimal DataFactor = new java.math.BigDecimal(0.01);
}

Search for embedded object in Metadata signatures

This example shows how to search for embedded objects in Metadata signatures.

Signature signature = new Signature("MetadataEncryptedObject.docx");
// setup key and passphrase
String key = "1234567890";
String salt = "1234567890";
// create data encryption
IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
 
MetadataSearchOptions options = new MetadataSearchOptions();
options.setDataEncryption(encryption);
 
// search for signatures in document
List<WordProcessingMetadataSignature> signatures = signature.search(WordProcessingMetadataSignature.class,options);
System.out.print("\nSource document contains following signatures.");
 
// get required metadata signatures
WordProcessingMetadataSignature wordSignature = null;
for (WordProcessingMetadataSignature mdSign : signatures) {
    if (mdSign.getName().equals("Signature")) {
        wordSignature = mdSign;
        break;
    }
}
if (wordSignature != null)
{
    DocumentSignatureData documentSignatureData = wordSignature.getData(DocumentSignatureData.class);
    if (documentSignatureData != null)
    {
        System.out.print("Signature has DocumentSignatureData object:\n ID = " + documentSignatureData.getID() + ", Author = " + documentSignatureData.getAuthor() + ", Signed = " + documentSignatureData.getSigned() + ", DataFactor " + documentSignatureData.getDataFactor());
    }
}
// get required metadata signatures
WordProcessingMetadataSignature mdAuthor = null;
for (WordProcessingMetadataSignature mdSign : signatures) {
    if (mdSign.getName().equals("Author")) {
        mdAuthor = mdSign;
        break;
    }
}
if (mdAuthor != null)
{
    System.out.print("Metadata signature found. Name : " + mdAuthor.getName() + ". Value: " + mdAuthor.getData(String.class));
}
// get required metadata signatures
WordProcessingMetadataSignature mdDocId = null;
for (WordProcessingMetadataSignature mdSign : signatures) {
    if (mdSign.getName().equals("DocumentId")) {
        mdDocId = mdSign;
        break;
    }
}
if (mdDocId != null)
{
    System.out.print("Metadata signature found. Name : " + mdDocId.getName() + ". Value: " + mdDocId.getData(String.class));
}

More resources

GitHub Examples

You may easily run the code above and see the feature in action in our GitHub examples:

Free Online App

Along with full-featured .NET library we provide simple, but powerful free Apps.
You are welcome to eSign PDF, Word, Excel, PowerPoint documents with free to use online GroupDocs Signature App.

Search for embedded object with custom serialization of Metadata signatures Search for encrypted text in Metadata signatures