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tdepim/libkdenetwork/libgpgme-copy/gpgme/decrypt.c

341 lines
7.3 KiB

/* decrypt.c - Decrypt function.
Copyright (C) 2000 Werner Koch (dd9jn)
Copyright (C) 2001, 2002, 2003, 2004 g10 Code GmbH
This file is part of GPGME.
GPGME is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of
the License, or (at your option) any later version.
GPGME is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#if HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "gpgme.h"
#include "util.h"
#include "context.h"
#include "ops.h"
typedef struct
{
struct _gpgme_op_decrypt_result result;
int okay;
int failed;
/* A pointer to the next pointer of the last recipient in the list.
This makes appending new invalid signers painless while
preserving the order. */
gpgme_recipient_t *last_recipient_p;
} *op_data_t;
static void
release_op_data (void *hook)
{
op_data_t opd = (op_data_t) hook;
if (opd->result.unsupported_algorithm)
free (opd->result.unsupported_algorithm);
if (opd->result.file_name)
free (opd->result.file_name);
}
gpgme_decrypt_result_t
gpgme_op_decrypt_result (gpgme_ctx_t ctx)
{
void *hook;
op_data_t opd;
gpgme_error_t err;
err = _gpgme_op_data_lookup (ctx, OPDATA_DECRYPT, &hook, -1, NULL);
opd = hook;
if (err || !opd)
return NULL;
return &opd->result;
}
static gpgme_error_t
parse_enc_to (char *args, gpgme_recipient_t *recp)
{
gpgme_recipient_t rec;
char *tail;
int i;
rec = malloc (sizeof (*rec));
if (!rec)
return gpg_error_from_errno (errno);
rec->next = NULL;
rec->keyid = rec->_keyid;
rec->status = 0;
for (i = 0; i < sizeof (rec->_keyid) - 1; i++)
{
if (args[i] == '\0' || args[i] == ' ')
break;
rec->_keyid[i] = args[i];
}
rec->_keyid[i] = '\0';
args = &args[i];
if (*args != '\0' && *args != ' ')
{
free (rec);
return gpg_error (GPG_ERR_INV_ENGINE);
}
while (*args == ' ')
args++;
if (*args)
{
errno = 0;
rec->pubkey_algo = strtol (args, &tail, 0);
if (errno || args == tail || *tail != ' ')
{
/* The crypto backend does not behave. */
free (rec);
return gpg_error (GPG_ERR_INV_ENGINE);
}
}
/* FIXME: The key length is always 0 right now, so no need to parse
it. */
*recp = rec;
return 0;
}
gpgme_error_t
_gpgme_decrypt_status_handler (void *priv, gpgme_status_code_t code,
char *args)
{
gpgme_ctx_t ctx = (gpgme_ctx_t) priv;
gpgme_error_t err;
void *hook;
op_data_t opd;
err = _gpgme_passphrase_status_handler (priv, code, args);
if (err)
return err;
err = _gpgme_op_data_lookup (ctx, OPDATA_DECRYPT, &hook, -1, NULL);
opd = hook;
if (err)
return err;
switch (code)
{
case GPGME_STATUS_EOF:
/* FIXME: These error values should probably be attributed to
the underlying crypto engine (as error source). */
if (opd->failed)
return gpg_error (GPG_ERR_DECRYPT_FAILED);
else if (!opd->okay)
return gpg_error (GPG_ERR_NO_DATA);
break;
case GPGME_STATUS_DECRYPTION_OKAY:
opd->okay = 1;
break;
case GPGME_STATUS_DECRYPTION_FAILED:
opd->failed = 1;
break;
case GPGME_STATUS_ERROR:
/* Note that this is an informational status code which should
not lead to an error return unless it is something not
related to the backend. */
{
const char d_alg[] = "decrypt.algorithm";
const char u_alg[] = "Unsupported_Algorithm";
const char k_alg[] = "decrypt.keyusage";
if (!strncmp (args, d_alg, sizeof (d_alg) - 1))
{
args += sizeof (d_alg) - 1;
while (*args == ' ')
args++;
if (!strncmp (args, u_alg, sizeof (u_alg) - 1))
{
char *end;
args += sizeof (u_alg) - 1;
while (*args == ' ')
args++;
end = strchr (args, ' ');
if (end)
*end = '\0';
if (!(*args == '?' && *(args + 1) == '\0'))
{
opd->result.unsupported_algorithm = strdup (args);
if (!opd->result.unsupported_algorithm)
return gpg_error_from_errno (errno);
}
}
}
else if (!strncmp (args, k_alg, sizeof (k_alg) - 1))
{
args += sizeof (k_alg) - 1;
while (*args == ' ')
args++;
err = _gpgme_map_gnupg_error (args);
if (gpg_err_code (err) == GPG_ERR_WRONG_KEY_USAGE)
opd->result.wrong_key_usage = 1;
}
}
break;
case GPGME_STATUS_ENC_TO:
err = parse_enc_to (args, opd->last_recipient_p);
if (err)
return err;
opd->last_recipient_p = &(*opd->last_recipient_p)->next;
break;
case GPGME_STATUS_NO_SECKEY:
{
gpgme_recipient_t rec = opd->result.recipients;
while (rec)
{
if (!strcmp (rec->keyid, args))
{
rec->status = gpg_error (GPG_ERR_NO_SECKEY);
break;
}
rec = rec->next;
}
/* FIXME: Is this ok? */
if (!rec)
return gpg_error (GPG_ERR_INV_ENGINE);
}
break;
case GPGME_STATUS_PLAINTEXT:
err = _gpgme_parse_plaintext (args, &opd->result.file_name);
if (err)
return err;
default:
break;
}
return 0;
}
static gpgme_error_t
decrypt_status_handler (void *priv, gpgme_status_code_t code, char *args)
{
gpgme_error_t err;
err = _gpgme_progress_status_handler (priv, code, args);
if (!err)
err = _gpgme_decrypt_status_handler (priv, code, args);
return err;
}
gpgme_error_t
_gpgme_op_decrypt_init_result (gpgme_ctx_t ctx)
{
gpgme_error_t err;
void *hook;
op_data_t opd;
err = _gpgme_op_data_lookup (ctx, OPDATA_DECRYPT, &hook,
sizeof (*opd), release_op_data);
opd = hook;
if (err)
return err;
opd->last_recipient_p = &opd->result.recipients;
return 0;
}
static gpgme_error_t
decrypt_start (gpgme_ctx_t ctx, int synchronous,
gpgme_data_t cipher, gpgme_data_t plain)
{
gpgme_error_t err;
err = _gpgme_op_reset (ctx, synchronous);
if (err)
return err;
err = _gpgme_op_decrypt_init_result (ctx);
if (err)
return err;
if (!cipher)
return gpg_error (GPG_ERR_NO_DATA);
if (!plain)
return gpg_error (GPG_ERR_INV_VALUE);
if (err)
return err;
if (ctx->passphrase_cb)
{
err = _gpgme_engine_set_command_handler
(ctx->engine, _gpgme_passphrase_command_handler, ctx, NULL);
if (err)
return err;
}
_gpgme_engine_set_status_handler (ctx->engine, decrypt_status_handler, ctx);
return _gpgme_engine_op_decrypt (ctx->engine, cipher, plain);
}
gpgme_error_t
gpgme_op_decrypt_start (gpgme_ctx_t ctx, gpgme_data_t cipher,
gpgme_data_t plain)
{
return decrypt_start (ctx, 0, cipher, plain);
}
/* Decrypt ciphertext CIPHER within CTX and store the resulting
plaintext in PLAIN. */
gpgme_error_t
gpgme_op_decrypt (gpgme_ctx_t ctx, gpgme_data_t cipher, gpgme_data_t plain)
{
gpgme_error_t err = decrypt_start (ctx, 1, cipher, plain);
if (!err)
err = _gpgme_wait_one (ctx);
return err;
}