95 Rz-hash
The rz-hash tool can be used to compute checksums of files, disk devices or strings. By block or entirely using many different hash algorithms.
This tool is also capable of doing some encoding/decoding operations like base64 and xor encoding.
This is an example usage:
$ rz-hash -a md5 -s "hello world"Note that rz-hash also permits to read from files in a stream, so you don’t need 4GB of ram to compute the hash of a 4GB file.
95.1 Hashing by blocks
When doing forensics, it is useful to compute partial checksums. The reason for that is because you may want to split a huge file into small portions that are easier to identify by contents or regions in the disk.
This will spot the same hash for blocks containing the same contents. For example, if is filled with zeros.
It can also be used to find which blocks have changed between more than one sample dump.
This can be useful when analyzing ram dumps from a virtual machine for example. Use this command for this:
$ rz-hash -b 1M -B -a sha256 /bin/ls95.2 Hashing with rz-bin
The rz-bin tool parses the binary headers of the files, but it also have the ability to use the rhash plugins to compute checksum of sections in the binary.
$ rz-bin -K md5 -S /bin/ls95.3 Obtaining hashes within rizin session
To calculate a checksum of current block when running rizin, use the ph command. Pass an algorithm name to it as a parameter. An example session:
$ rizin /bin/ls
[0x08049790]> bf entry0
[0x08049790]> ph md5
d2994c75adaa58392f953a448de5fba7You can use all hashing algorithms supported by rz-hash:
[0x00000000]> ph?
algorithm license author
md4 LGPL3 deroad
md5 RSA-MD RSA Data Security, Inc.
sha1 LGPL3 deroad
sha256 BSD-3 Aaron D. Gifford
sha384 BSD-3 Aaron D. Gifford
sha512 BSD-3 Aaron D. Gifford
fletcher8 LGPL3 deroad
fletcher16 LGPL3 deroad
fletcher32 LGPL3 deroad
fletcher64 LGPL3 deroad
adler32 LGPL3 deroad
crc8smbus LGPL3 deroad
crc8cdma2000 LGPL3 deroad
crc8darc LGPL3 deroad
crc8dvbs2 LGPL3 deroad
crc8ebu LGPL3 deroad
crc8icode LGPL3 deroad
crc8itu LGPL3 deroad
crc8maxim LGPL3 deroad
crc8rohc LGPL3 deroad
crc8wcdma LGPL3 deroad
crc15can LGPL3 deroad
crc16 LGPL3 deroad
crc16citt LGPL3 deroad
crc16usb LGPL3 deroad
crc16hdlc LGPL3 deroad
crc16augccitt LGPL3 deroad
crc16buypass LGPL3 deroad
crc16cdma2000 LGPL3 deroad
crc16dds110 LGPL3 deroad
crc16dectr LGPL3 deroad
crc16dectx LGPL3 deroad
crc16dnp LGPL3 deroad
crc16en13757 LGPL3 deroad
crc16genibus LGPL3 deroad
crc16maxim LGPL3 deroad
crc16mcrf4xx LGPL3 deroad
crc16riello LGPL3 deroad
crc16t10dif LGPL3 deroad
crc16teledisk LGPL3 deroad
crc16tms37157 LGPL3 deroad
crca LGPL3 deroad
crc16kermit LGPL3 deroad
crc16modbus LGPL3 deroad
crc16x25 LGPL3 deroad
crc16xmodem LGPL3 deroad
crc24 LGPL3 deroad
crc32 LGPL3 deroad
crc32ecma267 LGPL3 deroad
crc32c LGPL3 deroad
crc32bzip2 LGPL3 deroad
crc32d LGPL3 deroad
crc32mpeg2 LGPL3 deroad
crc32posix LGPL3 deroad
crc32q LGPL3 deroad
crc32jamcrc LGPL3 deroad
crc32xfer LGPL3 deroad
crc64 LGPL3 deroad
crc64ecma182 LGPL3 deroad
crc64we LGPL3 deroad
crc64xz LGPL3 deroad
crc64iso LGPL3 deroad
xor8 LGPL3 deroad
xor16 LGPL3 deroad
xxhash32 LGPL3 deroad
parity LGPL3 deroad
entropy LGPL3 deroad
entropy_fract LGPL3 deroadThe ph command accepts an optional numeric argument to specify length of byte range to be hashed, instead of default block size. For example:
[0x08049A80]> ph md5 32
9b9012b00ef7a94b5824105b7aaad83b
[0x08049A80]> ph md5 64
a71b087d8166c99869c9781e2edcf183
[0x08049A80]> ph md5 1024
a933cc94cd705f09a41ecc80c0041def