can't pass password via stdin during decrypt

[rdslw]

Environment

• OS: Linux 6.9.11
• age version: 1.2.0

PROBLEM

Currently (afaik) it's not possible to pass passphrase to age via stdin, like:
echo -n "$passphrase" | age -d -o output_file input_file

Here, age knows that stdin is NOT used for data, because I specified input file explicitly.

This also does not work with:
some_cli_password_manager | age -d -i - -o output_file input_file

Rationale:

1. passphrase is eventually read from stdin
2. sometimes you must use passswords (can't use keys) in script & automation
3. most cli tools allows it (cryptsetup etc.)
4. also Reading pasted armored input from a terminal clashes with password prompt #364

[Gunni]

what if you pass it in like age ... <(echo -n "$passphrase") ...? Note that I didn't test, just aware of that shell feature.

[rdslw]

what if you pass it in like age ... <(echo -n "$passphrase") ...? Note that I didn't test, just aware of that shell feature.

Any method which is using stdin (like <( cmd ) here) will not work, due to the age not supporting passphrase via stdin during decryption. This is what I'm actually asking for :)

[Gunni]

But the command I provided does not use stdin? It makes a pipe kind of file and returns the path to it to the command.

[rdslw]

But the command I provided does not use stdin? It makes a pipe kind of file and returns the path to it to the command.

That will not work because age --decrypt does not take passphrase as an command line argument (see below age --help).

The problem is that INPUT may (but not must) be used by age for content of encrypt/decrypt operation, hence age must distinguish such mode (content on stdin) from password on stdin scenario, in two ways:

• either implictly (user provided input as filename) hence if stdin is attached it must be key/passphrase material,
• either explicitly (by using some kind of option plus stdin).

$ age --help  
Usage:
    age [--encrypt] (-r RECIPIENT | -R PATH)... [--armor] [-o OUTPUT] [INPUT]
    age [--encrypt] --passphrase [--armor] [-o OUTPUT] [INPUT]
    age --decrypt [-i PATH]... [-o OUTPUT] [INPUT]