To check the sha1 of a file I would use
openssl sha1 <file> I'm not sure what to use to check the sha256 hash of the file however, what would you recommend?
OS X ships with a shasum command.
> which shasum /usr/bin/shasum
You can use:
> shasum -a 256 <file>
> shasum --help Usage: shasum [OPTION]... [FILE]... Print or check SHA checksums. With no FILE, or when FILE is -, read standard input. -a, --algorithm 1 (default), 224, 256, 384, 512, 512224, 512256 -b, --binary read in binary mode -c, --check read SHA sums from the FILEs and check them -t, --text read in text mode (default) -p, --portable read in portable mode produces same digest on Windows/Unix/Mac -0, --01 read in BITS mode ASCII '0' interpreted as 0-bit, ASCII '1' interpreted as 1-bit, all other characters ignored The following two options are useful only when verifying checksums: -s, --status don't output anything, status code shows success -w, --warn warn about improperly formatted checksum lines -h, --help display this help and exit -v, --version output version information and exit When verifying SHA-512/224 or SHA-512/256 checksums, indicate the algorithm explicitly using the -a option, e.g. shasum -a 512224 -c checksumfile The sums are computed as described in FIPS-180-4. When checking, the input should be a former output of this program. The default mode is to print a line with checksum, a character indicating type (`*' for binary, ` ' for text, `?' for portable, `^' for BITS), and name for each FILE. Report shasum bugs to email@example.com
To clarify @John's useful answer - which allows you to compare a given hash with its file in one command:
shasum -a 256 -c <<<,
followed by an optional space,
followed by a single tick (
followed by the hash to compare,
followed by a space,
followed by a mode character, based on how the initial hash was generated:
nothing, if the hash was created with
-tor no option (text mode, which is the default)
*), if the hash was created with
question mark (
?), if the hash was created with
^), if the hash was created with
followed by the path to the file,
followed by a closing single tick (
Like the following breakdown, with delineating parens around the hash and filepath parts, and square brackets around the optional "mode character" part. (Don't include the parens or brackets in real life - they're just here to make the parts easy to see!)
shasum -a 256 -c <<< '(hashToCompare) [mode character](filepath)'
The actual shasum command is
shasum -a 256 -c
shasumto use sha256.
shasumto "check" the provided input.
<<< is a Unix/Linux special character set, called a "redirection" operator. It's for feeding something into a prior command. By using it, we're saying we're going to provide a string of information for the
shasum command to use as input.
The string of input information must have opening and closing single ticks, such as
'some string here', or in this case, the hash, mode character, and filepath to be checked.
The hash part inside the string doesn't need anything special - but it must be followed by a space.
The mode character part can be nothing, an asterisk (
*), a question mark (
?), or a caret (
^). This tells
shasumthe mode with which the hash was generated. (Note: no character at all, representing text mode, is
The filepath part, is the actual path to the file to be checked.
So, here's a real-life example checking a particular MAMP download file against it's purported SHA-256 value. The
* mode character was required for this check to work:
shasum -a 256 -c <<< 'f05ede012b8a5d0e7c9cf17fee0fa1eb5cd8131f3c703ed14ea347f25be11a28 *MAMP_MAMP_PRO_5.2.pkg'
Note: the result of this command (for my example file) is either -
shasum: WARNING: 1 computed checksum did NOT match