Generating a SHA-256 hash from the Linux command line

Question

I know the string \"foobar\" generates the SHA-256 hash c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2 using http://hash.online-convert.com/sh

Answer 1

echo will normally output a newline, which is suppressed with -n. Try this:

echo -n foobar | sha256sum

Answer 2

For the sha256 hash in base64, use:

echo -n foo | openssl dgst -binary -sha1 | openssl base64

Example

echo -n foo | openssl dgst -binary -sha1 | openssl base64
C+7Hteo/D9vJXQ3UfzxbwnXaijM=

Answer 3

I believe that echo outputs a trailing newline. Try using -n as a parameter to echo to skip the newline.

Answer 4

If you have installed openssl, you can use:

echo -n "foobar" | openssl dgst -sha256

For other algorithms you can replace -sha256 with -md4, -md5, -ripemd160, -sha, -sha1, -sha224, -sha384, -sha512 or -whirlpool.

Answer 5

echo -n works and is unlikely to ever disappear due to massive historical usage, however per recent versions of the POSIX standard, new conforming applications are "encouraged to use printf".

Answer 6

echo produces a trailing newline character which is hashed too. Try:

/bin/echo -n foobar | sha256sum