sha256crack.1

.Dd 11/28/10
.Dt sha256crack 1
.Os Darwin
.Sh NAME
.Nm sha256crack
.Nd crack passwords hashed with SHA-256 using OpenCL.
.Sh SYNOPSIS
.Nm
.Op Fl h | -help
.Op options
.Op Ar hash
.Sh DESCRIPTION
.Nm
cracks passwords hashed with the SHA-256 algorithm via
brute force hash calculation.
It calculates hashes for all possible strings in a given range of length
composed of characters in a given character set.
.Pp
Depending on options passed,
.Nm
may run on the host CPU or an OpenCL device, such as the GPU.
.Sh OPTIONS
.Bl -tag -width -indent
.It Fl h, -help
Output a brief help message.
.It Fl H, -host
Run without OpenCL, use the host CPU to perform the calculation.
.It Fl C, -cpu
Run with OpenCL, use the CPU device.
.It Fl G, -gpu
Run with OpenCL, use the GPU device.
.It Fl d Ar DEV , Fl -device Ar DEV
Run with OpenCL, use device specified by
.Ar DEV .
Permissible devices include:
.Bl -tag -width -indent
.It 0
no device, equivalent to
.Fl -host
.It 1
CPU
.It 2
GPU (default)
.It 4
Accelerator
.El
.It Fl i Ar MIN , Fl -min-length Ar MIN
Set minimum password length to
.Ar MIN .
Defaults to 3.
.It Fl a Ar MAX , Fl -max-length Ar MAX
Set maximum password length to
.Ar MAX .
Defaults to 5.
.It Fl c Ar SET , Fl -charset Ar SET
Set the password character set to
.Ar SET .
The default set is composed of small letters of the English alphabet.
.It Fl k Ar S , Fl -chunk-size Ar S
Set the OpenCL chunk size to
.Ar S .
Defaults to 1000000.
Passing 0 as the chunk size will prevent
.Nm
from splitting the calculation into chunks.
.It Fl s, -silent
Do not print verbose information.
This will cause
.Nm
to only output the password, if a match is found.
If no match is found,
.Nm
will produce no output.
.Pp
.It Ar hash
The hash to crack.
If no
.Ar hash
is specified,
.Nm
will use the hash for the "hello" password.
.El
.Pp
.\" .Sh ENVIRONMENT
.\" .Sh FILES
.\" .Sh DIAGNOSTICS
.\" .Sh SEE ALSO
.\" .Sh BUGS
.\" .Sh HISTORY