|MD5(1)||General Commands Manual||MD5(1)|
calculate a message digest (checksum) for a file
These utilities take as input a message of arbitrary length and produce as output a message digest (checksum) of the input. It is conjectured that it is computationally infeasible to produce two messages having the same message digest (a collision), or to produce any message having a given prespecified target message digest. The algorithm (MD5, SHA-1, SHA-256, SHA-512) is determined by the name used to invoke the utility.
Collisions have now been produced for MD5, and are theorized for SHA-1, so their use is deprecated.
The options for use with each command are as follows:
-tmultiple times results in the number of rounds being multiplied by 10 for each additional flag.
These utilities exit 0 on success, and >0 if an error occurs.
R. Rivest, The MD5 Message-Digest Algorithm, RFC 1321, April 1992. J. Burrows, The Secure Hash Standard, FIPS PUB 180-1.
D. Eastlake and P. Jones, US Secure Hash Algorithm 1 (SHA1), RFC 3174, September 2001. Secure Hash Standard, FIPS PUB 180-2.
Since collisions have been found for MD5, the use of
sha256 is recommended instead.
|December 4, 2014||OpenBSD-5.7|