sha1cdsum(1)

SHA-1 digests with collision detection

Section 1 sha1cdsum bookworm source

Description

SHA1CDSUM

NAME

sha1cdsum - SHA-1 digests with collision detection

DESCRIPTION

sha1cdsum 0.2.3 Print or check SHA1 (160-bit) checksums with collision detection.

USAGE:

sha1cdsum [FLAGS] [files]...

FLAGS:

-b, --binary

read in binary mode

-c, --check

read SHA1 sums from the FILEs and check them

-h, --help

Prints help information

--tag

create a BSD-style checksum

-t, --text

read in text mode

-V, --version

Prints version information

-z, --zero

end each output line with NUL, not newline, and disable file name escaping

--ignore-missing

don’t fail or report status for missing files

--quiet

don’t print OK for each successfully verified file

--status

don’t output anything, status code shows success

--strict

exit non-zero for improperly formatted checksum lines

-w, --warn

warn about improperly formatted checksum lines

ARGS:

<files>...

Input file(s). With no FILE, or when FILE is -, read standard input

The last five options are useful only when verifying checksums.

The sums are computed using Marc Stevens’ modified SHA1 that detects collision attacks. When checking, the input should be a former output of this program. The default mode is to print a line with checksum, a space, a character indicating input mode (’*’ for binary, ’ ’ for text or where binary is insignificant), and name for each FILE.

If a collision is detected, ’*coll*’ is printed in front of the file name.

Note: There is no difference between binary mode and text mode on GNU systems.

This program implements the same interface as coreutils’ sha1sum, modulo error messages printed to stderr, handling of non-UTF8 filenames, and bugs.