How to encode md5 sum into base64 in BASH

Question

I need to encode md5 hash to base 64. The problem is that if give output of md5sum command to base64 command, it is considered as a text and not as a hexadecimal data. How to manage it? Base64 command has no option to set it's input as a hexadecimal number.

Thanks for any help.

plundra · Accepted Answer · 2014-06-12T20:16:58.663

65

Use openssl dgst -md5 -binary instead of md5sum. If you want, you can use it to base64-encode as well, to only use one program for all uses.

echo -n foo | openssl dgst -md5 -binary | openssl enc -base64

(openssl md5 instead of openssl dgst -md5 works too, but I think it's better to be explicit)

edited Jun 12 '14 at 20:16

answered Jan 03 '11 at 11:30

plundra

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score 9 · Answer 2 · answered Apr 06 '13 at 18:30

9

You can also use xxd (comes with vim) to decode the hex, before passing it to base64:

(echo 0:; echo -n foo | md5sum) | xxd -rp -l 16 | base64

answered Apr 06 '13 at 18:30

BeniBela

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On CentOS8 you have to use `xxd -r -p -l 16`, joining the `-r -p` into `-rp` has the `-p` ignored and results in `xxd: sorry, cannot seek backwards.` – Hashbrown Jan 30 '22 at 05:19

score 1 · Answer 3 · answered Apr 06 '13 at 17:31

In busybox you might not be able to use for loop syntax. Below unhex() is implemented with a while loop instead:

unhex ()
{
    b=0;
    while [ $b -lt ${#1} ];
    do
        printf "\\x${1:$b:2}";
        b=$((b += 2));
    done
}

md5sum2bytes ()
{
    while read -r md5sum file; do
        unhex $md5sum;
    done
}

md5sum inputfile | md5sum2bytes | base64

score 0 · Answer 4 · answered Jan 03 '11 at 11:41

0

unhex ()
{
    for ((b=0; b<${#1}; b+=2))
    do
        printf "\\x${1:$b:2}";
    done
}

md5sum2bytes ()
{
    while read -r md5sum file; do
        unhex $md5sum;
    done
}

md5sum inputfile | md5sum2bytes | base64

answered Jan 03 '11 at 11:41

Dennis Williamson

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How to encode md5 sum into base64 in BASH

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