Decoding base64 in batch

Question

I am trying to make an installer using batch  Of course  an installer needs to consist of files that will be installed  so I m thinking of encoding the files in base64  and simply decode them and write them to their destination   Of course  my work would be very easy if Windows had something like the base64 tool that Linux boxes contain  However  since it s simply not there  is there any way to decode base64 content completely using batch files  And how would I accomplish this   Any help is appreciated    It s just an experiment  so I m not worried about inefficiency and the like

User · Accepted Answer

Actually Windows does have a utility that encodes and decodes base64 - CERTUTIL

I'm not sure what version of Windows introduced this command.

To encode a file:

certutil -encode inputFileName encodedOutputFileName

To decode a file:

certutil -decode encodedInputFileName decodedOutputFileName

There are a number of available verbs and options available to CERTUTIL.

To get a list of nearly all available verbs:

certutil -?

To get help on a particular verb (-encode for example):

certutil -encode -?

To get complete help for nearly all verbs:

certutil -v -?

Mysteriously, the -encodehex verb is not listed with certutil -? or certutil -v -?. But it is described using certutil -encodehex -?. It is another handy function :-)

Update

Regarding David Morales' comment, there is a poorly documented type option to the -encodehex verb that allows creation of base64 strings without header or footer lines.

certutil [Options] -encodehex inFile outFile [type]

A type of 1 will yield base64 without the header or footer lines.

See https://www.dostips.com/forum/viewtopic.php?f=3&t=8521#p56536 for a brief listing of the available type formats. And for a more in depth look at the available formats, see https://www.dostips.com/forum/viewtopic.php?f=3&t=8521#p57918.

Not investigated, but the -decodehex verb also has an optional trailing type argument.

User · Answer

Here s a batch file  called base64encode bat  that encodes base64    echo off if not   1        goto  arg1exists echo usage  base64encode input-file  output-file  goto  eof  arg1exists set base64out  2 if   base64out         set base64out con      set base64tmp base64 tmp   certutil -encode   1   base64tmp   gt  nul   findstr  v  c -  base64tmp    erase  base64tmp     gt   base64out

[windows] Decoding base64 in batch

Update

Examples related to windows

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