Decryption of .asc files

[Sougata Chandra]

Hi All ,

We are evaluating the CLI tool for encryption/decryptions.
The file types we are using are .txt, .pdf, .asc , .csv etc.

We bump into an issue when using pgp on a  normal mainframe and unix ascii files - the files gets encrypted as <filename>.asc.pgp
But when we try to decrypt the encrypted files , the decrypted file is <filename> without any file extension.

This does not happen for .pdf or .txt file.

Do we need to do anything different for the .asc files to decrypt.


Thanks.

[Adam]

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[Adam]

Hi Sougata,

Thank you for your interest in PGP Command Line.  I think I see what's happening.  PGP treats the asc and pgp file extensions to mean that the file contains pgp-encrypted data.  The pgp extension means the file contains pgp-encrypted data in binary format while asc means the file is using ascii-armor to represent encrypted data.  Ascii-armor is PGP's Radix-64 format for representing data in a text-only format safe for all platforms and transmission mediums.  After decrypting a file, pgp tries to remove any extension from the file name that indicates encrypted content.  I suspect that is why .asc.pgp is removed.  There is a way forward.  PGP has an output option, -o,  that allows specifying the filename as a full or relative path.  This lets the user place the file in a new location as well as override the filename.  Here is a small shell script example (using bash on linux) that overrides the output name.

#!/bin/sh

encrypted_filename="/some/path/to/file.asc.pgp"
# trim path, could also use basename utility
base_output_name="${encrypted_filename##/*/}"
# remove .pgp from the end of base_output_name
output_filename="${base_output_name%.pgp}"

echo "encrypted filename: $encrypted_filename"
echo "   output filename: $output_filename"

The output is as follows:

encrypted filename: /some/path/to/file.asc.pgp
   output filename: file.asc

Using the logic from the example script, we can retain the .asc portion of the filename.

pgp -d "$encrypted_filename" -o "$output_filename"

My example did not include an output path in the new filename so it should be placed in the current working directory.  A production implementation may specify an output location more explicitly.

I hope this answers your question and helps you find a solution that uses PGP Command Line.

Regards,

Adam​