From ca295709d5bb59793e747487bcb562c4b055c2b9 Mon Sep 17 00:00:00 2001 From: Noah Crocker Date: Tue, 2 Jun 2015 21:20:53 -0400 Subject: [PATCH] Fix parsing of long frame lengths --- src/ch/blinkenlights/bastp/ID3v2File.java | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/src/ch/blinkenlights/bastp/ID3v2File.java b/src/ch/blinkenlights/bastp/ID3v2File.java index d0a10bed..8b97dfc8 100644 --- a/src/ch/blinkenlights/bastp/ID3v2File.java +++ b/src/ch/blinkenlights/bastp/ID3v2File.java @@ -45,10 +45,7 @@ public class ID3v2File extends Common { int id3v = ((b2be32(v2hdr,0))) & 0xFF; // swapped ID3\04 -> ver. ist the first byte int v3len = ((b2be32(v2hdr,6))); // total size EXCLUDING the this 10 byte header - v3len = ((v3len & 0x7f000000) >> 3) | // for some funky reason, this is encoded as 7*4 bits - ((v3len & 0x007f0000) >> 2) | - ((v3len & 0x00007f00) >> 1) | - ((v3len & 0x0000007f) >> 0) ; + v3len = unsyncsafe(v3len); // debug(">> tag version ID3v2."+id3v); // debug(">> LEN= "+v3len+" // "+v3len); @@ -59,6 +56,17 @@ public class ID3v2File extends Common { tags.put("_hdrlen", v3len+v2hdr_len); return tags; } + + /* + ** converts syncsafe integer to Java integer + */ + private int unsyncsafe(int x) { + x = ((x & 0x7f000000) >> 3) | + ((x & 0x007f0000) >> 2) | + ((x & 0x00007f00) >> 1) | + ((x & 0x0000007f) >> 0) ; + return x; + } /* Parses all ID3v2 frames at the current position up until payload_len ** bytes were read @@ -72,6 +80,7 @@ public class ID3v2File extends Common { bread += s.read(frame); String framename = new String(frame, 0, 4); int slen = b2be32(frame, 4); + slen = unsyncsafe(slen); /* Abort on silly sizes */ if(slen < 1 || slen > 524288)