mirror of git://git.gnupg.org/gnupg.git
281 lines
8.2 KiB
C
281 lines
8.2 KiB
C
/* assuan-client.c - client functions
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* Copyright (C) 2001, 2002 Free Software Foundation, Inc.
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* Copyright (C) 2005 Free Software Foundation, Inc.
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*
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* This file is part of Assuan.
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*
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* Assuan is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation; either version 2.1 of
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* the License, or (at your option) any later version.
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*
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* Assuan is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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/* Please note that this is a stripped down and modified version of
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the orginal Assuan code from libassuan. */
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#include <config.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <errno.h>
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#include <unistd.h>
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#include <assert.h>
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#include <string.h>
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#include "assuan-defs.h"
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#define xtoi_1(p) (*(p) <= '9'? (*(p)- '0'): \
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*(p) <= 'F'? (*(p)-'A'+10):(*(p)-'a'+10))
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#define xtoi_2(p) ((xtoi_1(p) * 16) + xtoi_1((p)+1))
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assuan_error_t
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_assuan_read_from_server (assuan_context_t ctx, int *okay, int *off)
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{
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char *line;
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int linelen;
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assuan_error_t rc;
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*okay = 0;
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*off = 0;
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do
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{
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rc = _assuan_read_line (ctx);
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if (rc)
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return rc;
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line = ctx->inbound.line;
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linelen = ctx->inbound.linelen;
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}
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while (*line == '#' || !linelen);
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if (linelen >= 1
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&& line[0] == 'D' && line[1] == ' ')
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{
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*okay = 2; /* data line */
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*off = 2;
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}
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else if (linelen >= 1
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&& line[0] == 'S'
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&& (line[1] == '\0' || line[1] == ' '))
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{
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*okay = 4;
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*off = 1;
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while (line[*off] == ' ')
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++*off;
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}
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else if (linelen >= 2
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&& line[0] == 'O' && line[1] == 'K'
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&& (line[2] == '\0' || line[2] == ' '))
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{
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*okay = 1;
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*off = 2;
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while (line[*off] == ' ')
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++*off;
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}
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else if (linelen >= 3
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&& line[0] == 'E' && line[1] == 'R' && line[2] == 'R'
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&& (line[3] == '\0' || line[3] == ' '))
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{
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*okay = 0;
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*off = 3;
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while (line[*off] == ' ')
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++*off;
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}
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else if (linelen >= 7
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&& line[0] == 'I' && line[1] == 'N' && line[2] == 'Q'
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&& line[3] == 'U' && line[4] == 'I' && line[5] == 'R'
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&& line[6] == 'E'
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&& (line[7] == '\0' || line[7] == ' '))
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{
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*okay = 3;
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*off = 7;
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while (line[*off] == ' ')
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++*off;
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}
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else if (linelen >= 3
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&& line[0] == 'E' && line[1] == 'N' && line[2] == 'D'
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&& (line[3] == '\0' || line[3] == ' '))
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{
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*okay = 5; /* end line */
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*off = 3;
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}
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else
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rc = ASSUAN_Invalid_Response;
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return rc;
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}
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assuan_error_t
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assuan_transact (assuan_context_t ctx,
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const char *command,
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assuan_error_t (*data_cb)(void *, const void *, size_t),
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void *data_cb_arg,
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assuan_error_t (*inquire_cb)(void*, const char *),
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void *inquire_cb_arg,
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assuan_error_t (*status_cb)(void*, const char *),
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void *status_cb_arg)
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{
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return assuan_transact2 (ctx, command,
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data_cb, data_cb_arg,
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inquire_cb, inquire_cb_arg,
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status_cb, status_cb_arg,
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NULL, NULL);
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}
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/**
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* assuan_transact2:
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* @ctx: The Assuan context
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* @command: Coimmand line to be send to server
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* @data_cb: Callback function for data lines
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* @data_cb_arg: first argument passed to @data_cb
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* @inquire_cb: Callback function for a inquire response
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* @inquire_cb_arg: first argument passed to @inquire_cb
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* @status_cb: Callback function for a status response
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* @status_cb_arg: first argument passed to @status_cb
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* @okay_cb: Callback function for the final OK response
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* @okay_cb_arg: first argument passed to @okay_cb
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*
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* FIXME: Write documentation
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*
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* Return value: 0 on success or error code. The error code may be
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* the one one returned by the server in error lines or from the
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* callback functions.
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**/
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assuan_error_t
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assuan_transact2 (assuan_context_t ctx,
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const char *command,
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assuan_error_t (*data_cb)(void *, const void *, size_t),
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void *data_cb_arg,
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assuan_error_t (*inquire_cb)(void*, const char *),
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void *inquire_cb_arg,
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assuan_error_t (*status_cb)(void*, const char *),
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void *status_cb_arg,
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assuan_error_t (*okay_cb)(void*, const char *),
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void *okay_cb_arg)
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{
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int rc, okay, off;
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unsigned char *line;
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int linelen;
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rc = assuan_write_line (ctx, command);
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if (rc)
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return rc;
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if (*command == '#' || !*command)
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return 0; /* Don't expect a response for a comment line. */
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again:
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rc = _assuan_read_from_server (ctx, &okay, &off);
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if (rc)
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return rc; /* error reading from server */
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line = ctx->inbound.line + off;
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linelen = ctx->inbound.linelen - off;
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if (!okay)
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{
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rc = atoi (line);
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if (rc < 100)
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rc = ASSUAN_Server_Fault;
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}
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else if (okay == 1) /* Received OK. */
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{
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if (okay_cb)
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{
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rc = okay_cb (okay_cb_arg, line);
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/* We better wipe out the buffer after processing it. This
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is no real guarantee that it won't get swapped out but at
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least for the standard cases we can make sure that a
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passphrase returned with the OK line is rendered
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unreadable. In fact the current Assuan interface suffers
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from the problem that it is not possible to do assuan I/O
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through secure memory. There is no easy solution given
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the current implementation but we need to address it
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sooner or later. The problem was introduced with
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gpg-agent's GET_PASPHRASE command but it might also make
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sense to have a way to convey sessions keys through
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secured memory. Note that the old implementation in gpg
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for accessing the passphrase in fact used secure memory
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but had the drawback of using a limited and not fully
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conforming Assuan implementation - given that pinentry
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and gpg-agent neither use secured memory for Assuan I/O,
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it is negligible to drop the old implementation in gpg's
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passphrase.c and use the wipememory workaround here. */
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memset (line, 0, strlen (line));
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}
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}
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else if (okay == 2)
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{
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if (!data_cb)
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rc = ASSUAN_No_Data_Callback;
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else
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{
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unsigned char *s, *d;
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for (s=d=line; linelen; linelen--)
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{
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if (*s == '%' && linelen > 2)
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{ /* handle escaping */
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s++;
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*d++ = xtoi_2 (s);
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s += 2;
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linelen -= 2;
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}
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else
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*d++ = *s++;
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}
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*d = 0; /* add a hidden string terminator */
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rc = data_cb (data_cb_arg, line, d - line);
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if (!rc)
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goto again;
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}
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}
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else if (okay == 3)
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{
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if (!inquire_cb)
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{
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assuan_write_line (ctx, "END"); /* get out of inquire mode */
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_assuan_read_from_server (ctx, &okay, &off); /* dummy read */
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rc = ASSUAN_No_Inquire_Callback;
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}
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else
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{
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rc = inquire_cb (inquire_cb_arg, line);
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if (!rc)
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rc = assuan_send_data (ctx, NULL, 0); /* flush and send END */
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if (!rc)
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goto again;
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}
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}
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else if (okay == 4)
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{
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if (status_cb)
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rc = status_cb (status_cb_arg, line);
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if (!rc)
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goto again;
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}
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else if (okay == 5)
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{
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if (!data_cb)
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rc = ASSUAN_No_Data_Callback;
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else
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{
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rc = data_cb (data_cb_arg, NULL, 0);
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if (!rc)
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goto again;
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}
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}
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return rc;
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}
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