checkisomd5(1) [centos man page]

CHECKISOMD5(1)						      General Commands Manual						    CHECKISOMD5(1)

NAME

       checkisomd5 -- check an MD5 checksum implanted by implantisomd5

SYNOPSIS

       checkisomd5 [--md5sumonly]  [--verbose]	[--gauge]  [isofilename  | blockdevice ]

DESCRIPTION

       This  manual  page  documents  briefly the checkisomd5 command.	checkisomd5 is a program that checks an embedded MD5 checksum in a ISO9660
       image (.iso), or block device.  The checksum is embedded by the corresponding implantisomd5 command.

       The check can be aborted by pressing Esc key.

EXIT STATUS

       Program returns exit status 0 if the checksum is correct, 1 if the checksum is incorrect or non-existent, or 2 if the check was aborted.

OPTIONS

       --md5sumonly
		 Do not check the target.  Instead, output human-readable information about the target's checksums.

       --verbose Display human-readable progress as the target is checked.  Without this option, nothing is outputted except errors.

       --gauge	 Display a series of numbers from 0 to 100, corresponding to check progress.  This output can be piped to  dialog  --gauge  for  a
		 user-friendly progress bar.

SEE ALSO

       implantisomd5 (1).

																    CHECKISOMD5(1)

MD5(1)							    BSD General Commands Manual 						    MD5(1)

NAME

     md5 -- calculate a message-digest fingerprint (checksum) for a file

SYNOPSIS

     md5 [-pqrtx] [-s string] [file ...]

DESCRIPTION

     The md5 utility takes as input a message of arbitrary length and produces as output a ``fingerprint'' or ``message digest'' of the input.	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 MD5 algorithm is intended for digital signature applications, where a large file must be
     ``compressed'' in a secure manner before being encrypted with a private (secret) key under a public-key cryptosystem such as RSA.

     MD5's designer Ron Rivest has stated "md5 and sha1 are both clearly broken (in terms of collision-resistance)".  So MD5 should be avoided
     when creating new protocols, or implementing protocols with better options.  SHA256 and SHA512 are better options as they have been more
     resilient to attacks (as of 2009).

     The following options may be used in any combination and must precede any files named on the command line.  The hexadecimal checksum of each
     file listed on the command line is printed after the options are processed.

     -s string
	     Print a checksum of the given string.

     -p      Echo stdin to stdout and append the checksum to stdout.

     -q      Quiet mode - only the checksum is printed out.  Overrides the -r option.

     -r      Reverses the format of the output.  This helps with visual diffs.	Does nothing when combined with the -ptx options.

     -t      Run a built-in time trial.

     -x      Run a built-in test script.

EXIT STATUS

     The md5 utility exits 0 on success, and 1 if at least one of the input files could not be read.

SEE ALSO

     cksum(1), md5(3), ripemd(3), sha(3), CC_SHA256_Init(3)

     Vlastimil Klima, Finding MD5 Collisions - a Toy For a Notebook, Cryptology ePrint Archive: Report 2005/075.

ACKNOWLEDGMENTS

     This program is placed in the public domain for free general use by RSA Data Security.

BSD
								   June 6, 2004 							       BSD