calculate and expose data length for non-partial LiteralData packets

open-keychain · Feb 17, 2015 · 939914d · 939914d
1 parent 26c232f
commit 939914d
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Showing 3 changed files with 49 additions and 0 deletions.
diff --git a/pg/src/main/java/org/spongycastle/bcpg/BCPGInputStream.java b/pg/src/main/java/org/spongycastle/bcpg/BCPGInputStream.java
@@ -276,6 +276,19 @@ public void close()
         in.close();
     }
 
+    /**
+     * Return the length of the contained data packet, if available. Returns null if the
+     * length is not available, which is the case for a BCPGInputStream which is not inside
+     * a parsed Packet, and partial data packets.
+     */
+    public Long getBodyLengthIfAvailable() {
+        if (in instanceof PartialInputStream) {
+            long length = ((PartialInputStream) in).getBodyLength();
+            return length == 0 ? null : length;
+        }
+        return null;
+    }
+
     /**
      * a stream that overlays our input stream, allowing the user to only read a segment of it.
      *
@@ -286,6 +299,7 @@ private static class PartialInputStream
     {
         private BCPGInputStream     in;
         private boolean             partial;
+        private long                totalDataLength;
         private int                 dataLength;
 
         PartialInputStream(
@@ -295,6 +309,8 @@ private static class PartialInputStream
         {
             this.in = in;
             this.partial = partial;
+            // widen negative integer range to long
+            this.totalDataLength = dataLength & 0x00000000ffffffffL;
             this.dataLength = dataLength;
         }
 
@@ -317,6 +333,10 @@ public int available()
             }
         }
 
+        private long getBodyLength() {
+            return partial ? 0L : totalDataLength;
+        }
+
         private int loadDataLength()
             throws IOException
         {

diff --git a/pg/src/main/java/org/spongycastle/bcpg/LiteralDataPacket.java b/pg/src/main/java/org/spongycastle/bcpg/LiteralDataPacket.java
@@ -14,6 +14,7 @@ public class LiteralDataPacket
     int     format;
     byte[]  fileName;
     long    modDate;
+    Long    literalLength;
 
     LiteralDataPacket(
         BCPGInputStream    in)
@@ -31,6 +32,17 @@ public class LiteralDataPacket
         }
 
         modDate = ((long)in.read() << 24) | (in.read() << 16) | (in.read() << 8) | in.read();
+
+        literalLength = in.getBodyLengthIfAvailable();
+        if (literalLength != null) {
+            // length of literal data is length of the packet...
+            // ...minus 1 byte format, 1 byte filename length
+            literalLength -= 2;
+            // ...minus length of the filename
+            literalLength -= l;
+            // ...minus two bytes timestamp
+            literalLength -= 4;
+        }
     }
 
     /**
@@ -64,4 +76,12 @@ public byte[] getRawFileName()
     {
         return Arrays.clone(fileName);
     }
+
+    /**
+     * Return the length of the contained literal data, if available. Returns null if the
+     * length is not available, which is the case for partial data packets.
+     */
+    public Long getDataLengthIfAvailable() {
+        return literalLength;
+    }
 }
diff --git a/pg/src/main/java/org/spongycastle/openpgp/PGPLiteralData.java b/pg/src/main/java/org/spongycastle/openpgp/PGPLiteralData.java
@@ -71,6 +71,15 @@ public Date getModificationTime()
         return new Date(data.getModificationTime());
     }
 
+    /**
+     * Return the length of the contained literal data, if available. Returns null if the
+     * length is not available, which is the case for partial data packets.
+     */
+    public Long getDataLengthIfAvailable()
+    {
+        return data.getDataLengthIfAvailable();
+    }
+
     /**
      * Return the raw input stream for the data packet.
      */