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Diffstat (limited to 'src/bin/md5/cksum.1')
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diff --git a/src/bin/md5/cksum.1 b/src/bin/md5/cksum.1 new file mode 100644 index 0000000..452007a --- /dev/null +++ b/src/bin/md5/cksum.1 @@ -0,0 +1,191 @@ +.\" $OpenBSD: cksum.1,v 1.38 2014/03/20 22:06:21 tedu Exp $ +.\" +.\" Copyright (c) 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" This code is derived from software contributed to Berkeley by +.\" the Institute of Electrical and Electronics Engineers, Inc. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)cksum.1 8.2 (Berkeley) 4/28/95 +.\" +.Dd $Mdocdate: March 20 2014 $ +.Dt CKSUM 1 +.Os +.Sh NAME +.Nm cksum +.Nd display file checksums and block counts +.Sh SYNOPSIS +.Nm cksum +.Bk -words +.Op Fl bcpqrtx +.Op Fl a Ar algorithms +.Op Fl C Ar checklist +.Op Fl h Ar hashfile +.Op Fl s Ar string +.Op Ar +.Ek +.Sh DESCRIPTION +The +.Nm cksum +utility writes to the standard output a single line for each input file. +The format of this line varies with the algorithm being used as follows: +.Bl -tag -width allxothers +.It cksum +The output line consists of three whitespace separated fields: +a CRC checksum, the number of octets in the input, +and name of the file or string. +If no file name is specified, the standard input is used and no file name +is written. +.It all others +The output line consists of four whitespace separated fields: +the name of the algorithm used, the name of the file or string in +parentheses, an equals sign, and the cryptographic hash of the input. +If no file name is specified, the standard input is used and only +the cryptographic hash is output. +.El +.Pp +The options are as follows: +.Bl -tag -width Ds +.It Fl a Ar algorithms +Use the specified algorithm(s) instead of the default (cksum). +Supported algorithms include cksum, md5, rmd160, sha1, +sha224, sha256, sha384, and sha512. +Multiple algorithms may be specified, separated by a comma or whitespace. +Additionally, multiple +.Fl a +options may be specified on the command line. +Case is ignored when matching algorithms. +The output format may be specified on a per-algorithm basis +by using a single-character suffix, e.g.\& +.Dq sha256b . +If the algorithm has a +.Sq b +suffix, the checksum will be output in base64 format. +If the algorithm has an +.Sq x +suffix, the checksum will be output in hex format. +If an algorithm with the same output format is repeated, +only the first instance is used. +Note that output format suffixes are not supported +for the cksum algorithm. +.It Fl b +Output checksums in base64 notation, not hexadecimal by +default. +A +.Sq b +or +.Sq x +suffix on the algorithm will override this default. +This option is ignored for the cksum algorithm. +.It Fl C Ar checklist +Compare the checksum of each +.Ar file +against the checksums in the +.Ar checklist . +Any specified +.Ar file +that is not listed in the +.Ar checklist +will generate an error. +.It Fl c +If this option is specified, the +.Ar file +options become checklists. +Each checklist should contain hash results in the normal format, +which will be verified against the specified paths. +Output consists of the digest used, the file name, +and an OK, FAILED, or MISSING for the result of the comparison. +This will validate any of the supported checksums. +If no file is given, stdin is used. +The +.Fl c +option may not be used in conjunction with more than a single +.Fl a +option. +.It Fl h Ar hashfile +Place the checksum into +.Ar hashfile +instead of stdout. +.It Fl p +Echoes stdin to stdout and appends the +checksum to stdout. +.It Fl q +Only print the checksum (quiet mode) or if used in conjunction with the +.Fl c +flag, only print the failed cases. +.It Fl r +Reverse the format of the hash algorithm output, making +it match the checksum output format. +.It Fl s Ar string +Prints a checksum of the given +.Ar string . +.It Fl t +Runs a built-in time trial. +Specifying +.Fl t +multiple times results in the number of rounds being multiplied +by 10 for each additional flag. +.It Fl x +Runs a built-in test script. +.El +.Pp +The default CRC used is based on the polynomial used for CRC error checking +in the networking standard +ISO/IEC 8802-3:1996. +The other available algorithms are described in their respective +man pages in section 3 of the manual. +.Sh EXIT STATUS +.Ex -std cksum +.Sh SEE ALSO +.Xr md5 1 +.Pp +The default calculation is identical to that given in pseudo-code +in the following ACM article: +.Rs +.%T "Computation of Cyclic Redundancy Checks Via Table Lookup" +.%A Dilip V. Sarwate +.%J "Communications of the ACM" +.%D "August 1988" +.Re +.Sh STANDARDS +The +.Nm +utility is compliant with the +.St -p1003.1-2008 +specification. +.Pp +All the flags are extensions to that specification. +.Sh HISTORY +The +.Nm cksum +utility appeared in +.Bx 4.4 . +.Sh CAVEATS +Do not use the cksum or md5 algorithms to verify file integrity. +An attacker can trivially produce modified payload that +has the same checksum as the original version. +Use a cryptographic checksum instead. |