SHA1(1) BSD Reference Manual SHA1(1)NAMEsha1 - calculate a message-digest fingerprint (checksum) for a file
SYNOPSISsha1 [-b] [-p | -s string | file ...]
sha1-G [file ...]
sha1-t | -x | -c [checklist ...]
sha1sum [-b | -t] [file ...]
DESCRIPTIONsha1 takes as input a message of arbitrary length and produces as output
a 160-bit "fingerprint" or "message digest" of the input. It is conjec-
tured that it is computationally infeasible to produce two messages hav-
ing the same message digest, or to produce any message having a given
prespecified target message digest.
The SHA-1 algorithm is intended for digital signature applications, where
a large file must be "compressed" in a secure manner before being en-
crypted with a private (secret) key under a public-key cryptosystem such
as RSA. However, recently the SHA family's (SHA-0, SHA-1, SHA-2 (SHA-384
and SHA-512) all share the same design) weakness has been proven in re-
duced versions of SHA-1 and partially SHA-2 and collisions for SHA-1 can
be found. The use of other hash functions is encouraged; however, as
RIPEMD-160 is only little more secure, combining hashes from different
families or, better, different approaches (Tiger, Whirlpool) is recom-
mended.
The options are as follows:
-b Print the checksum as binary to stdout. Ignored in GNU mode.
-c [checklist ...]
Compares all checksums contained in the file checklist with newly
computed checksums for the corresponding files. Output consists
of the digest used, the file name, and an OK or FAILED for the
result of the comparison. This will validate any of the supported
checksums (see cksum(1)). If no file is given, stdin is used.
-G Enable GNU md5sum compatible output mode. Can also be enabled by
calling this programme as sha1sum.
-p Echoes stdin to stdout and appends the SHA-1 sum to stdout.
-s string
Prints a checksum of the given string.
-t Runs a built-in time trial. Ignored in GNU mode.
-x Runs a built-in test script.
The SHA-1 sum of each file listed on the command line is printed after
the options are processed.
The sha1 command is shorthand for
cksum -asha1
The cksum(1) command can also be used to compute digests from the SHA-2
family: sha256, sha384 and sha512.
SEE ALSOcksum(1), md5(1), rmd160(1)
J. Burrows, The Secure Hash Standard, FIPS PUB 180-1.
D. Eastlake and P. Jones, US Secure Hash Algorithm 1, RFC 3174.
MirOS BSD #10-current November 17, 2009 1
