fix: 702 - parsing decrypted file (#723)

spring/src/main/java/com/cra/service/DecryptService.java

@@ -2,92 +2,38 @@
 
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
+
 import javax.mail.Part;
 import javax.mail.internet.MimeBodyPart;
+
 import org.springframework.stereotype.Service;
 
 import com.entrust.toolkit.User;
 import iaik.smime.SMimeEncrypted;
 import iaik.smime.SMimeSigned;
 import iaik.smime.SMimeCompressed;
-import iaik.asn1.DerInputStream;
-import iaik.asn1.SEQUENCE;
-import iaik.asn1.CON_SPEC;
-import iaik.asn1.OCTET_STRING;
 
 @Service
 public class DecryptService {
 
     public String decrypt(User user, byte[] data) throws Exception {
-        InputStream inputStream = new ByteArrayInputStream(data);
-        SMimeEncrypted sMimeEncrypted = new SMimeEncrypted(inputStream);
-        sMimeEncrypted.decryptSymmetricKey(user);
+        Part p;
+        InputStream contentStream;
 
-        Part p = (Part) new MimeBodyPart(sMimeEncrypted.getInputStream());
-        InputStream contentStream = (InputStream) p.getContent();
+        contentStream = new ByteArrayInputStream(data);
+        SMimeEncrypted encrypted = new SMimeEncrypted(contentStream);
+        encrypted.decryptSymmetricKey(user);
+        p = new MimeBodyPart(encrypted.getInputStream());
+        contentStream = (InputStream) p.getContent();
 
-        // the line below reads the signature part from the message into a SMimeSigned
-        // object:
         SMimeSigned signed = new SMimeSigned(contentStream);
-        System.out
-                .println("number of signers associated with file we're decrypting: " + signed.getSignerInfos().length);
-        // todo: see if there are signers using "signed.getSignerInfos().length"; if so,
-        // check the signature
-
-        // now we take the unread part of content:
-        Part q = (Part) new MimeBodyPart(contentStream);
-        InputStream refinedContentStream = (InputStream) q.getContent();
-
-        DerInputStream dis = new DerInputStream(refinedContentStream);
-        // next tag may be 4, meaning octet string
-        // after that is 16, which means sequence
-        // after that is 6, which means object id
-        // after that is 0, which means we've reached the end
-        // let's read the sequence, which is of type CMS compressedData
-        // to do so, we have to read the octet string first, if present:
-        if (dis.nextTag() == 4) {
-            dis.readOctetString();
-        }
-
-        // SMimeCompressed reads from dis where we left off, which is the sequence
-        SMimeCompressed sMimeCompressed = new SMimeCompressed(dis);
-
-        // if we write SMimeCompressed to a file right now, we get the headers at the
-        // top, e.g.:
-        // MIME-Version: 1.0
-        // Content-Type: text/plain;
-        // charset="US-ASCII";
-        // name=ABCVR00085
-        // Content-Transfer-Encoding: 7bit
-        // Content-Disposition: attachment;
-        // filename=ABCVR00085
-
-        // have to find a way to remove this...
-        // try:
-
-        // calling toASN1Object decompresses the data (I think...)
-        SEQUENCE sequence = (SEQUENCE) sMimeCompressed.toASN1Object();
-        // there are 2 components
-        // the first component is an object id, second is con_spec:
-        CON_SPEC a = (CON_SPEC) sequence.getComponentAt(1);
-        // a has exactly one component:
-        SEQUENCE b = (SEQUENCE) a.getComponentAt(0);
-        // b has 3 components:
-        // b's first component is an integer, 2nd and 3rd are sequences
-        // let's look at the third one:
-        SEQUENCE c = (SEQUENCE) b.getComponentAt(2);
-        // c has two components:
-        // first is object id, second is CON_SPEC:
-        CON_SPEC d = (CON_SPEC) c.getComponentAt(1);
-        // d has exactly one component, and it is an octet_string:
-        OCTET_STRING e = (OCTET_STRING) d.getComponentAt(0);
-        byte[] value = e.getWholeValue();
-        InputStream resultStream = new ByteArrayInputStream(value);
+        p = new MimeBodyPart(signed.getInputStream());
+        contentStream = (InputStream) p.getContent();
 
-        // WILL THE FILES WE RECEIVE ALWAYS HAVE THIS STRUCTURE???
+        SMimeCompressed compressed = new SMimeCompressed(contentStream);
+        p = new MimeBodyPart(compressed.getInputStream());
+        String result = (String) p.getContent();
 
-        Part r = (Part) new MimeBodyPart(resultStream);
-        String text = (String) r.getContent();
-        return text;
+        return result;
     }
 }