DOKK / manpages / debian 12 / sha1cdsum / sha1cdsum.1.en
SHA1CDSUM(1) User Commands SHA1CDSUM(1)

sha1cdsum - SHA-1 digests with collision detection

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

sha1cdsum [FLAGS] [files]...

read in binary mode
read SHA1 sums from the FILEs and check them
Prints help information
create a BSD-style checksum
read in text mode
Prints version information
end each output line with NUL, not newline, and disable file name escaping
don't fail or report status for missing files
don't print OK for each successfully verified file
don't output anything, status code shows success
exit non-zero for improperly formatted checksum lines
warn about improperly formatted checksum lines

<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.

https://shattered.io/

https://sha-mbles.github.io/

https://gitlab.com/sequoia-pgp/sha1collisiondetection

December 2020 sha1cdsum 0.2.3