Difference between revisions of "Encase hash files"
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[[Category:Forensics File ]]
Latest revision as of 19:19, 17 December 2010
The EnCase forensics suite uses a proprietary file format to store sets of known hashes called the EnCase hash file format. The format stores a set of MD5 hashes and metadata about the set as a whole. That is, individual hashes do not contain any information specific to them, but the set as a whole can contain some information. In particular, the filename corresponding to each hash is not stored.
Version 3 of EnCase used a slightly different format than versions 4 and 5. Both versions start with the header, in hexadecimal:
48 41 53 48 0d 0a ff 00
In ASCII, this looks like HASH followed by a newline.
The hashes begin at offset 0x480 in the file.
A quick look at a hash file created by Encase 220.127.116.11 revealed the following structure (to be verified):
A header that consists of the following 16 bytes:
48 41 53 48 0D 0A FF 00 02 00 00 00 01 00 00 00
Count: The number of MD5 sums contained in this file, written as a 4 byte integer in Intel litle endian format (i.e. least significant byte first).
The range from 0x0014 to 0x0407 is filled by zero-bytes. The purpose of this area is unknown.
HashSet: The text that EnCase shows in its column "Hash Set". The maximum string length is 39 characters. Characters are stored in Unicode. (Based on hash file form EnCase v. 6.17)
Category: The text that Encase shows in its column "category". The maximum string length is 19 characters. Each character is written as a 2-byte-Unicode-number. Examples:The latin letter A is represented by the 2 bytes
41 00The cyrillic letter Д is represented by the 2 bytes
Again, Intel little endian format is used. The unused space is filled up by zero-bytes.
Start of the hash entries. Each entry occupies 18 bytes: The hash value itself (16 bytes) followed by 2 zero-bytes. The next entry follows immediately.
The file ends with the last hash entry.