ANNOUNCING AFFLIB 3.0 I'm happy to announce the release of AFFLIB 3.0. You can download it from the standard location at http://www.afflib.org/ Version 3.0 is a significant upgrade to AFFLIB which introduces the following features: * STRONG ENCRYPTION FOR AFF FILES. * STRONG DIGITAL SIGNATURES WITH X.509 CERTIFICATES * SIGNED BILL-OF-MATERIALS AND CHAIN OF CUSTODY * SIGNED ISO FILES * PARITY PAGES ALLOW RECONSTRUCTION OF DAMAGED DISK IMAGES * STRONG ENCRYPTION FOR AFF FILES. With Version 3.0 we are introducing the ability to encrypt AFF evidence files with the AES-256 algorithm, the strongest encryption algorithm available today. Each AFF 3.0 file can be encrypted with a unique AES-256 key. This key is can then itself be encrypted using a passphrase provided by the user, or using an X.509 public key. Because of this two-step process, the passphraseor public key can be changed in just a few seconds without having to decrypt and re-encrypt the entire disk image. Whereas some other forensic programs provide the ability to put a "password" on an evidence file, those passwords can be disregarded by non-conformant programs. (For example, GetData claims that it's MountImage Pro program can "open EnCase password protected image files without the password.) AFF 3.0 uses true encryption: if you do not know the correct decryption key, the only way to access the evidence is to brute-force the encryption passphrase (if there is one). THERE IS NO BACK DOOR. * STRONG DIGITAL SIGNATURES WITH X.509 CERTIFICATES Version 3.0 introduces strong digital signatures (SHA-256) signed with X.509 certificates. Digital signatures represents a significant improvement for evidence integrity over today's standard practice of recording the MD5 or SHA-1 of an imaged disk in an investigator's notebook. AFF Digital Signatures, signatures are written for the entire disk image, all of the disk's metadata, and every 16-megabyte AFF "page." Because digital signatures are written after each "page" is acquired, the integrity of these pages can be established in court even if the entire disk cannot be images (for example, because the device is fault, or because there is insufficient time). AFF Digital Signatures complement existing integrity measures. Because the signature is stored in its own metadata segment, the signature does not change the content of the acquired disk image. Signatures can be written with either self-signed certificates or with X.509 certificates that are issued as part of an organization's PKI. Using X.509 certificates means that AFF can support RSA or DSA algorithms with 1024, 2048 or larger keys. * SIGNED BILL-OF-MATERIALS AND CHAIN OF CUSTODY Version 3.0 introduces a special XML structure that contains a list of every AFF segment in the file, a signature for each segment, a set of "notes," and a public key. This structure is called an "AFF Bill Of Materials" (AFFBOM). When an AFF image is created with AIMAGE, the AFFBOM is created and signed with the private key belonging to the person who did the acquisiton. Thereafter, each time a signed AFF file is copied, a new AFFBOM can be created which includes a new AFFBOM which covers all of the original segments and all of the previous AFFBOMs. In this manner the sequence of signed bill-of-materials becomes a custody chain, showing who has copied the image and verifying that no evidentuary segments have been added, deleted, or modified. * SIGNED ISO FILES AFF's "AFM" format allows a disk image to be stored in an uncompressed raw file (eg "file.iso") and the associated metadata to be stored in a ".afm" file. The AFM format can also handle raw data stored as a series of "split" raw files (eg "file.001", "file.002", "file.003" etc.) Beacuse AFF tools operating on named segments that are independent of the underlying storage container, the AFM format allows any ISO-file to be signed using the "afsign" command. When filename.iso is signed, the afsign create a new file called filename.afm which contains the signatures, the signed bill of materials, and other metadata. Although it is also possible sign ISO files using existing tools such as PGP with detached signatures, afsign has several advantages: - afsign will sign every 16-megabytes chunk of the ISO file. In this way, if the file is corrupted, you will be able to pinpoint what data is invalid and what data is still good. - Unlike PGP, afsign allows you to add arbitrary metadata and maintain chain-of-custody information. - You can sign with X.509 certificates * PARITY PAGES ALLOW RECONSTRUCTION OF DAMAGED DISK IMAGES Because every 16-megabyte chunk of an AFF or AFM file is signed, it is easy to detect when a page has been modified or accidently corrupted. The BoM allows missing pages to be detected. Similar to RAID5 on hard drives, an AFF parity page makes possible to reconstruct damaged or missing AFF data segments. Once repaired or reconstructed, the signature (which is stored in a differnet location) can be used to determine if the reconstruction is correct. Partiy Pages are automatically created when an image is signed with afsign. The rewritten aimage that will be part of AFFLIB 3.1 will create parity pages as the drive is imaged. ================================================================ AVAILABILITY AFFLIB 3.0.0 is available now. ================================================================ NEW AND MODIFIED TOOLS IN AFF 3.0: The following tools have been aded for AFF 3.0: * afsign - signs an AFF file. * afverify - verifies the signature and chain-of-custody segments of an AFF file. * afcrypto - manipulates the cryptographic properties of an AFF file. - Can change the passphrase The following tools have been modified: * afcopy - If you provide a signing key, a signed bill-of-materials will be added to extend the chain-of-custody. Other changes in AFF3.0: * A few bugs have been fixed which caused difficulties in testing. (No users reported problems with them.) ================================================================ COMING IN AFFLIB 3.1: I've pushed out Version 3.0 so that people can start to experiment with it now. Meanwhile, I'm now working on the following features which, I'm hoping, will make it into Version 3.1: * Public key encryption (so agents in the field can encrypt to a public key, and the images can only be decrypted in the lab.) * Dramatically improved performance when opening AFF files with signed bill-of-materials. (The BOM will be used as a table-of-contents so that large AFF files do not need to be scanned from end-to-end.) * A rewrite of aimage: - The ability to image raw and AFF files at the same time will be removed (since AFF can now write raw files directly). - page-at-a-time imaging, resulting in more compact AFF files (less wasted space) and easier implementation of novel data recovery algorithms. - Calculation of parity pages while the image is written, rather than afterwards.