Extract content in p7m

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- [val-p7m] utility to extract p7m content
 - [val-core] XmlValidator for simple xml doc type validation
 - [val] P7MValidator in full validator facade
 - [playground-quarkus] P7MValidator in validator feature

fj-doc-val-p7m/src/main/java/org/fugerit/java/doc/val/p7m/P7MUtils.java

@@ -0,0 +1,28 @@
+package org.fugerit.java.doc.val.p7m;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.bouncycastle.cms.CMSException;
+import org.bouncycastle.cms.CMSProcessable;
+import org.bouncycastle.cms.CMSSignedData;
+import org.fugerit.java.core.io.StreamIO;
+
+public class P7MUtils {
+
+	private P7MUtils() {}
+
+	public static void extractContent( InputStream p7mContent, OutputStream contentStream ) throws CMSException, IOException  {
+		CMSSignedData csd = new CMSSignedData( p7mContent );
+		CMSProcessable cmsContent = csd.getSignedContent();
+		if ( cmsContent != null ) {
+			byte[] content = (byte[])cmsContent.getContent();
+			try ( ByteArrayInputStream is = new ByteArrayInputStream( content ) ) {
+				StreamIO.pipeStream(is, contentStream, StreamIO.MODE_CLOSE_BOTH);
+			}
+		}
+	}
+
+}

fj-doc-val-p7m/src/test/java/test/org/fugerit/java/doc/val/p7m/TestExtractContentP7M.java

@@ -0,0 +1,50 @@
+package test.org.fugerit.java.doc.val.p7m;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+
+import org.bouncycastle.cms.CMSException;
+import org.fugerit.java.core.function.SafeFunction;
+import org.fugerit.java.core.io.FileIO;
+import org.fugerit.java.doc.val.p7m.P7MUtils;
+import org.junit.Assert;
+import org.junit.Test;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class TestExtractContentP7M {
+
+	@Test
+	public void testP7MKo() {
+		Assert.assertThrows( CMSException.class , () -> {
+			String path = "src/test/resources/sample/png_as_p7m.p7m";
+			File testP7M = new File( path );
+			log.info( "test extract ko : {}", testP7M.getCanonicalPath() );
+			try ( FileInputStream is = new FileInputStream( testP7M );
+					ByteArrayOutputStream os = new ByteArrayOutputStream() ) {
+				P7MUtils.extractContent(is, os);
+			}
+		}) ;
+	}
+
+	@Test
+	public void testP7MOk() {
+		SafeFunction.apply( () -> {
+			String path = "src/test/resources/sample/pdf_as_pdf.p7m";
+			File testP7M = new File( path );
+			log.info( "test extract : {}", testP7M.getCanonicalPath() );
+			File outputBase = new File( "target" );
+			File outputContent = new File( outputBase, "content.pdf" );
+			outputContent.delete();
+			try ( FileInputStream is = new FileInputStream( testP7M );
+					ByteArrayOutputStream os = new ByteArrayOutputStream() ) {
+				P7MUtils.extractContent(is, os);
+				FileIO.writeBytes( os.toByteArray() , outputContent );
+			}
+			Assert.assertTrue( outputContent.exists() );
+		} );
+	}
+
+}