MD5(1) FreeBSD General Commands Manual MD5(1)
NAME
md5, sha1, sha224, sha256, sha384, sha512, sha512t224, sha512t256,
rmd160, skein256, skein512, skein1024, md5sum, sha1sum, sha224sum,
sha256sum, sha384sum, sha512sum, sha512t224sum, sha512t256sum, rmd160sum,
skein256sum, skein512sum, skein1024sum, shasum - calculate a message-
digest fingerprint (checksum) for a file
SYNOPSIS
md5 [-pqrtx] [-c string] [-s string] [file ...]
md5sum [-bctwz] [--binary] [--check] [--help] [--ignore-missing]
[--quiet] [--status] [--strict] [--tag] [--text] [--version]
[--warn] [--zero] [file ...]
(All other hashes have the same options and usage.)
shasum [-0bchqstUvw] [--01] [-a | --algorithm alg] [--binary] [--check]
[--help] [--ignore-missing] [--quiet] [--status] [--strict]
[--tag] [--text] [--UNIVERSAL] [--version] [--warn] [file ...]
DESCRIPTION
The md5, sha1, sha224, sha256, sha384, sha512, sha512t224, sha512t256,
rmd160, skein256, skein512, and skein1024 utilities take as input a
message of arbitrary length and produce as output a "fingerprint" or
"message digest" of the input.
The md5sum, sha1sum, sha224sum, sha256sum, sha384sum, sha512sum,
sha512t224sum, sha512t256sum, rmd160sum, skein256sum, skein512sum, and
skein1024sum utilities do the same, but with command-line options and an
output format that match those of their similary named GNU utilities.
The shasum utility does the same, but with command-line options and an
output format that match those of the similarly named utility that ships
with Perl.
In all cases, each file listed on the command line is processed
separately. If no files are listed on the command line, or a file name
is given as -, input is taken from stdin instead.
The utility's different modes have different output formats, but in all
cases, filenames containing unprintable characters are encoded as
described in vis(3) using the VIS_CSTYLE | VIS_OCTAL style.
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 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 "compressed"
in a secure manner before being encrypted with a private (secret) key
under a public-key cryptosystem such as RSA.
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.
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.
SHA-512t224 is identical to SHA-512t256, but with the digest truncated to
224 bits.
It is recommended that all new applications use SHA-512 or SKEIN-512
instead of one of the other hash functions.
BSD OPTIONS
The following options are available in BSD mode, i.e. when the program is
invoked with a name that does not end in "sum":
-c string, --check=string
Compare the digest of the file against this string. If combined
with the -q or --quiet option, the calculated digest is printed
in addition to the exit status being set. (Note that this option
is not yet useful if multiple files are specified.)
-p, --passthrough
Echo stdin to stdout and append the checksum to stdout. In this
mode, any files specified on the command line are silently
ignored.
-q, --quiet
Quiet mode -- only the checksum is printed out. Overrides the -r
or --reverse option.
-r, --reverse
Reverses the format of the output. This helps with visual diffs.
Does nothing when combined with the -ptx options.
-s string, --string=string
Print a checksum of the given string. In this mode, any files
specified on the command line are silently ignored.
-t, --time-trial
Run a built-in time trial. For the -sum versions, this is a nop
for compatibility with coreutils.
-x, --self-test
Run a built-in test script.
GNU OPTIONS
The following options are available in GNU mode, i.e. when the program is
invoked with a name that ends in "sum":
-b, --binary
Read files in binary mode.
-c, --check
The file passed as arguments must contain digest lines generated
by the same digest algorithm in either classical BSD format or in
GNU coreutils format. A line with the file name followed by a
colon ":" and either OK or FAILED is written for each well-formed
line in the digest file. If applicable, the number of failed
comparisons and the number of lines that were skipped since they
were not well-formed are printed at the end. The --quiet option
can be used to quiesce the output unless there are mismatched
entries in the digest.
--help Print a usage message and exit.
--ignore-missing
When verifying checksums, ignore files for which checksums are
given but which aren't found on disk.
--quiet
When verifying checksums, do not print anything unless the
verification fails.
--status
When verifying checksums, do not print anything at all. The exit
code will reflect whether verification succeeded.
--strict
When verifying checksums, fail if the input is malformed.
--tag Produce BSD-style output.
-t, --text
Read files in text mode. This is the default. Note that this
implementation does not differentiate between binary and text
mode.
--version
Print version information and exit.
-w, --warn
When verifying checksums, warn about malformed input.
-z, --zero
Terminate output lines with NUL rather than with newline.
PERL OPTIONS
The following options are available in Perl mode, i.e. when the program
is invoked with the name "shasum":
-0, --01
Read files in bits mode: ASCII `0' and `1' characters correspond
to 0 and 1 bits, respectively, and all other characters are
ignored. See BUGS.
-a alg, --algorithm alg
Use the specified algorithm: "1" for SHA-1 (default), "xxx" for
xxx-bit SHA-2 (e.g. "256" for SHA-256) or "xxxyyy" for xxx-bit
SHA-2 truncated to yyy bits (e.g. "512224" for SHA-512/224).
-b, --binary
Read files in binary mode.
-c, --check
The file passed as arguments must contain digest lines generated
by the same digest algorithm in either classical BSD format or in
GNU coreutils format. A line with the file name followed by a
colon ":" and either OK or FAILED is written for each well-formed
line in the digest file. If applicable, the number of failed
comparisons and the number of lines that were skipped since they
were not well-formed are printed at the end. The --quiet option
can be used to quiesce the output unless there are mismatched
entries in the digest.
--help Print a usage message and exit.
--ignore-missing
When verifying checksums, ignore files for which checksums are
given but which aren't found on disk.
--quiet
When verifying checksums, do not print anything unless the
verification fails.
--status
When verifying checksums, do not print anything at all. The exit
code will reflect whether verification succeeded.
--strict
When verifying checksums, fail if the input is malformed.
--tag Produce BSD-style output.
-t, --text
Read files in text mode. This is the default. Note that this
implementation does not differentiate between binary and text
mode.
-U, --UNIVERSAL
Read files in universal mode: any CR-LF pair, as well as any CR
not followed by LF, is translated to LF before the digest is
computed.
--version
Print version information and exit.
-w, --warn
When verifying checksums, warn about malformed input.
EXIT STATUS
The md5, sha1, sha224, sha256, sha384, sha512, sha512t224, sha512t256,
rmd160, skein256, skein512, and skein1024 utilities exit 0 on success, 1
if at least one of the input files could not be read, and 2 if at least
one file does not have the same hash as the -c option.
The md5sum, sha1sum, sha224sum, sha256sum, sha384sum, sha512sum,
sha512t224sum, sha512t256sum, rmd160, skein256, skein512, skein1024 and
shasum utilities exit 0 on success and 1 if at least one of the input
files could not be read or, when verifying checksums, does not have the
expected checksum.
EXAMPLES
Calculate the MD5 checksum of the string "Hello".
$ 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
This is almost but not quite identical to the output from GNU mode:
$ md5sum /boot/loader.conf /etc/rc.conf
ada5f60f23af88ff95b8091d6d67bef6 /boot/loader.conf
d80bf36c332dc0fdc479366ec3fa44cd /etc/rc.conf
Note the two spaces between hash and file name. If binary mode is
requested, they are instead separated by a space and an asterisk:
$ md5sum -b /boot/loader.conf /etc/rc.conf
ada5f60f23af88ff95b8091d6d67bef6 */boot/loader.conf
d80bf36c332dc0fdc479366ec3fa44cd */etc/rc.conf
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 ]
In GNU mode, the -c option does not compare against a hash string passed
as parameter. Instead, it expects a digest file, as created under the
name digest for /boot/loader.conf in the example above.
$ md5sum -c digest
/boot/loader.conf: OK
The digest file may contain any number of lines in the format generated
in either BSD or GNU mode. If a hash value does not match the file,
"FAILED" is printed instead of "OK".
SEE ALSO
cksum(1), md5(3), ripemd(3), sha(3), sha256(3), sha384(3), sha512(3),
skein(3), vis(3)
R. Rivest, The MD5 Message-Digest Algorithm, RFC1321.
J. Burrows, The Secure Hash Standard, FIPS PUB 180-2.
D. Eastlake and P. Jones, US Secure Hash Algorithm 1, RFC 3174.
RIPEMD-160 is part of the ISO draft standard "ISO/IEC DIS 10118-3" on
dedicated hash functions.
Secure Hash Standard (SHS):
https://www.nist.gov/publications/secure-hash-standard-shs
The RIPEMD-160 page:
https://homes.esat.kuleuven.be/~bosselae/ripemd160.html
CAVEATS
The encoding used for file names containing non-printable characters is
incompatible with that used by GNU coreutils. The encoding used by GNU
coreutils is non-reversible, in that certain non-printable characters are
encoded while others are simply omitted. The encoding used by this
utility, on the other hand, is fully reversible.
If interoperability with GNU coreutils is required, it is recommended to
ensure that all file names contain only printable characters.
BUGS
In bits mode, the original shasum script is capable of processing inputs
of arbitrary length. This implementation is not, and will issue an error
if the input length is not a multiple of eight bits.
ACKNOWLEDGMENTS
This utility was originally derived from a program which was placed in
the public domain for free general use by RSA Data Security.
Support for SHA-1 and RIPEMD-160 was added by Oliver Eikemeier
<eik@FreeBSD.org>.
Support for SHA-2 was added by Colin Percival <cperciva@FreeBSD.org> and
Allan Jude <allanjude@FreeBSD.org>.
Support for SKEIN was added by Allan Jude <allanjude@FreeBSD.org>.
Compatibility with GNU coreutils was added by Warner Losh
<imp@FreeBSD.org> and much expanded by Dag-Erling Smorgrav
<des@FreeBSD.org>, who also added Perl compatibility.
FreeBSD 15.1-STABLE-HBSD April 6, 2026 MD5(1)