why pgp ask passphrase at the first time after I use --passphrase-fd

Question

please see my batch file:

cd C:\Program Files (x86)\Gpg4win\bin
echo "my passphrase"|gpg  --always-trust --recipient [email protected] --batch  --passphrase-fd 0  --output D:\pgptest\a.txt --decrypt "d:\pgptest\b.txt"

It keeps asking me to input the passphrase even though I add it in batch file. Once I input the passphrase, it works well, but I want to my batch file running at silent mode.Please help me.

C:\Program Files (x86)\Gpg4win\bin>gpg --version

gpg (GnuPG) 2.2.4
libgcrypt 1.8.2
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: C:/Users/xxx/AppData/Roaming/gnupg
Supported algorithms:
Pubkey: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
        CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2

Andre Heinecke Andre Heinecke · Accepted Answer · 2018-03-27T09:56:09

Short Answer: Add "--pinentry-mode loopback" to your command line

As noted on: https://wiki.gnupg.org/TroubleShooting#Passphrase_on_the_command_line

If you put the passphrase in a batch file anyway it usually does not make much sense to have a passphrase on your key at all. (Use gpg --passwd to remove it.) If you want to supply it on the command line you have to add the pinentry-mode argument.

Btw. "--always-trust --recipient [email protected]" arguments are unused / make no sense together with --decrypt.

why pgp ask passphrase at the first time after I use --passphrase-fd

1 Answers