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(All other hashes have the same options and usage.)
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, nor should they be used as part of a cryptographic signature scheme. As of 2017-03-02, there is no publicly known method to reverse either algorithm, i.e. to find an input that produces a specific output.
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.
It is recommended that all new applications use SHA-512 or SKEIN-512 instead of one of the other hash functions.
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.
|Make the -sum programs separate hash and digest with a blank followed by an asterisk instead of by 2 blank characters for full compatibility with the output generated by the coreutils versions of these programs.|
|If the program was called with a name that does not end in sum, compare the digest of the file against this string. (Note that this option is not yet useful if multiple files are specified.)|
If the program was called with a name that does end in
the file passed as argument must contain digest lines generated by the same
digest algorithm with or without the
|Print a checksum of the given string.|
|Echo stdin to stdout and append the checksum to stdout.|
Quiet mode — only the checksum is printed out.
Reverses the format of the output.
This helps with visual diffs.
when combined with the
|Run a built-in time trial. For the -sum versions, this is a nop for compatibility with coreutils.|
|Run a built-in test script.|
$ md5 -s Hello MD5 ("Hello") = 8b1a9953c4611296a827abf8c47804d7
Same as above, but note the absence of the newline character in the input string:
$ echo -n Hello | md5 8b1a9953c4611296a827abf8c47804d7
Calculate the checksum of multiple files reversing the output:
$ md5 -r /boot/loader.conf /etc/rc.conf ada5f60f23af88ff95b8091d6d67bef6 /boot/loader.conf d80bf36c332dc0fdc479366ec3fa44cd /etc/rc.conf
.Pd The -sum variants put 2 blank characters between hash and file name for full compatibility with the coreutils versions of these commands.
Write the digest for /boot/loader.conf in a file named digest. Then calculate the checksum again and validate it against the checksum string extracted from the digest file:
$ md5 /boot/loader.conf > digest && md5 -c $(cut -f2 -d= digest) /boot/loader.conf MD5 (/boot/loader.conf) = ada5f60f23af88ff95b8091d6d67bef6
Same as above but comparing the digest against an invalid string ("randomstring"), which results in a failure.
$ md5 -c randomstring /boot/loader.conf MD5 (/boot/loader.conf) = ada5f60f23af88ff95b8091d6d67bef6 [ Failed ]
If invoked with a name ending in
$ md5 -c digest /boot/loader.conf /boot/loader.conf: OK
The digest file may contain any number of lines in the format generated with or without the
RFC1321, The MD5 Message-Digest Algorithm,,
FIPS PUB 180-2, The Secure Hash Standard,,
RFC 3174, US Secure Hash Algorithm 1,,
RIPEMD-160 is part of the ISO draft standard "ISO/IEC DIS 10118-3" on dedicated hash functions.
Secure Hash Standard (SHS): http://csrc.nist.gov/cryptval/shs.html.
The RIPEMD-160 page: http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html.
Support for SHA-1 and RIPEMD-160 has been added by Oliver Eikemeier <Mt eik@FreeBSD.org>.
|MD5 (1)||July 9, 2018|
|Main index||Section 1||Options|
|“||I define UNIX as “30 definitions of regular expressions living under one roof.”||”|
|— Donald Knuth|