Index: head/sbin/md5/md5.1 =================================================================== --- head/sbin/md5/md5.1 +++ head/sbin/md5/md5.1 @@ -1,5 +1,5 @@ .\" $FreeBSD$ -.Dd July 9, 2018 +.Dd June 15, 2020 .Dt MD5 1 .Os .Sh NAME @@ -16,8 +16,8 @@ (All other hashes have the same options and usage.) .Sh DESCRIPTION The -.Nm md5 , sha1 , sha224 , sha256 , sha384 , sha512, sha512t256, rmd160, -.Nm skein256, skein512, +.Nm md5 , sha1 , sha224 , sha256 , sha384 , sha512 , sha512t256 , rmd160 , +.Nm skein256 , skein512 , and .Nm skein1024 utilities take as input a message of arbitrary length and produce as @@ -29,43 +29,29 @@ It is conjectured that it is computationally infeasible to produce two messages having the same message digest, or to produce any message having a given prespecified target message digest. -The -.Tn SHA-224 , SHA-256 , SHA-384 , SHA-512, RIPEMD-160, -and -.Tn SKEIN +The SHA-224 , SHA-256 , SHA-384 , SHA-512, RIPEMD-160, +and SKEIN algorithms are intended for digital signature applications, where a large file must be .Dq compressed in a secure manner before being encrypted with a private (secret) -key under a public-key cryptosystem such as -.Tn RSA . +key under a public-key cryptosystem such as RSA. .Pp -The -.Tn MD5 -and -.Tn SHA-1 -algorithms have been proven to be vulnerable to practical collision -attacks and should not be relied upon to produce unique outputs, +The MD5 and SHA-1 algorithms have been proven to be vulnerable to practical +collision attacks and should not be relied upon to produce unique outputs, .Em nor should they be used as part of a cryptographic signature scheme. As of 2017-03-02, there is no publicly known method to .Em reverse -either algorithm, i.e. to find an input that produces a specific +either algorithm, i.e., to find an input that produces a specific output. .Pp -.Tn SHA-512t256 -is a version of -.Tn SHA-512 -truncated to only 256 bits. -On 64-bit hardware, this algorithm is approximately 50% faster than -.Tn SHA-256 -but with the same level of security. +SHA-512t256 is a version of SHA-512 truncated to only 256 bits. +On 64-bit hardware, this algorithm is approximately 50% faster than SHA-256 but +with the same level of security. The hashes are not interchangeable. .Pp -It is recommended that all new applications use -.Tn SHA-512 -or -.Tn SKEIN-512 +It is recommended that all new applications use SHA-512 or SKEIN-512 instead of one of the other hash functions. .Pp The following options may be used in any combination and must @@ -101,7 +87,7 @@ .Sh EXIT STATUS The .Nm md5 , sha1 , sha224 , sha256 , sha512 , sha512t256 , rmd160 , -.Nm skein256 , skein512, +.Nm skein256 , skein512 , and .Nm skein1024 utilities exit 0 on success, @@ -114,7 +100,6 @@ .Xr md5 3 , .Xr ripemd 3 , .Xr sha 3 , -.Xr sha224 3 , .Xr sha256 3 , .Xr sha384 3 , .Xr sha512 3 ,