Added pass plugin in order to provide completion.

More info about pass tool: http://zx2c4.com/projects/password-store/

plugins/pass/_pass

+#compdef pass
+#autoload
+
+# Copyright (C) 2012:
+#    Johan Venant <jvenant@invicem.pro>
+#    Brian Mattern <rephorm@rephorm.com>
+#    Jason A. Donenfeld <Jason@zx2c4.com>.
+#    Santiago Borrazás <sanbor@gmail.com>
+# All Rights Reserved.
+# This file is licensed under the GPLv2+. Please see COPYING for more information.
+
+
+_pass () {
+	local cmd
+	if (( CURRENT > 2)); then
+		cmd=${words[2]}
+		# Set the context for the subcommand.
+		curcontext="${curcontext%:*:*}:pass-$cmd"
+		# Narrow the range of words we are looking at to exclude `pass'
+		(( CURRENT-- ))
+		shift words
+		# Run the completion for the subcommand
+		case "${cmd}" in
+			init)
+				_arguments : \
+					"-r[re-encrypt existing passwords]" \
+					"--reencrypt[re-encrypt existing passwords]"
+				_pass_complete_keys
+				;;
+			ls|list|edit)
+				_pass_complete_entries_with_subdirs
+				;;
+			insert)
+				_arguments : \
+					"-e[echo password to console]" \
+					"--echo[echo password to console]" \
+					"-m[multiline]" \
+					"--multiline[multiline]"
+				_pass_complete_entries_with_subdirs
+				;;
+			generate)
+				_arguments : \
+					"-n[don't include symbols in password]" \
+					"--no-symbols[don't include symbols in password]" \
+					"-c[copy password to the clipboard]" \
+					"--clip[copy password to the clipboard]"
+				_pass_complete_entries_with_subdirs
+				;;
+			rm)
+				_arguments : \
+					"-f[force deletion]" \
+					"--force[force deletion]" \
+					"-r[recursively delete]" \
+					"--recursive[recursively delete]"
+					_pass_complete_entries_with_subdirs
+				;;
+			git)
+				local -a subcommands
+				subcommands=(
+					"init:Initialize git repository"
+					"push:Push to remote repository"
+					"pull:Pull from remote repository"
+					"config:Show git config"
+					"log:Show git log"
+					"reflog:Show git reflog"
+				)
+				_describe -t commands 'pass git' subcommands
+				;;
+			show|*)
+				_pass_cmd_show
+				;;
+		esac
+	else
+		local -a subcommands
+		subcommands=(
+			"init:Initialize new password storage"
+			"ls:List passwords"
+			"show:Decrypt and print a password"
+			"insert:Insert a new password"
+			"generate:Generate a new password using pwgen"
+			"edit:Edit a password with \$EDITOR"
+			"rm:Remove the password"
+			"git:Call git on the password store"
+			"version:Output version information"
+			"help:Output help message"
+		)
+		_describe -t commands 'pass' subcommands
+		_arguments : \
+			"--version[Output version information]" \
+			"--help[Output help message]"
+		_pass_cmd_show
+	fi
+}
+
+_pass_cmd_show () {
+	_arguments : \
+		"-c[put it on the clipboard]" \
+		"--clip[put it on the clipboard]"
+	_pass_complete_entries
+}
+_pass_complete_entries_helper () {
+	local IFS=$'\n'
+	local prefix="${PASSWORD_STORE_DIR:-$HOME/.password-store}"
+	_values -C 'passwords' $(find "$prefix" \( -name .git -o -name .gpg-id \) -prune -o $@ -print | sed -e "s#${prefix}.##" -e 's#\.gpg##' | sort)
+}
+
+_pass_complete_entries_with_subdirs () {
+	_pass_complete_entries_helper
+}
+
+_pass_complete_entries () {
+	_pass_complete_entries_helper -type f
+}
+
+_pass_complete_keys () {
+	local IFS=$'\n'
+	# Extract names and email addresses from gpg --list-keys
+	_values 'gpg keys' $(gpg2 --list-secret-keys --with-colons | cut -d : -f 10 | sort -u | sed '/^$/d')
+}