gpgme/src/revsig.c

/* revsig.c - Revoke signature helpers.
 * Copyright (C) 2020 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, see <https://gnu.org/licenses/>.
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#if HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>

#include "gpgme.h"
#include "debug.h"
#include "context.h"
#include "ops.h"


typedef struct
{
  /* The error code from a FAILURE status line or 0.  */
  gpg_error_t failure_code;

  /* The error code from certain ERROR status lines or 0.  */
  gpg_error_t error_code;

} *op_data_t;


/* Parse an error status line.  Return the error location and the
   error code.  The function may modify ARGS. */
static char *
parse_error (char *args, gpg_error_t *r_err)
{
  char *where = strchr (args, ' ');
  char *which;

  if (where)
    {
      *where = '\0';
      which = where + 1;

      where = strchr (which, ' ');
      if (where)
	*where = '\0';

      where = args;
    }
  else
    {
      *r_err = trace_gpg_error (GPG_ERR_INV_ENGINE);
      return NULL;
    }

  *r_err = atoi (which);

  return where;
}


static gpgme_error_t
revsig_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;
  char *loc;

  /* Pipe the status code through the progress status handler.  */
  err = _gpgme_progress_status_handler (ctx, code, args);
  if (err)
    return err;

  err = _gpgme_op_data_lookup (ctx, OPDATA_REVSIG, &hook, -1, NULL);
  opd = hook;
  if (err)
    return err;

  switch (code)
    {
    case GPGME_STATUS_ERROR:
      loc = parse_error (args, &err);
      if (!loc)
        return err;
      if (!opd->error_code)
        opd->error_code = err;
      break;

    case GPGME_STATUS_FAILURE:
      if (!opd->failure_code
          || gpg_err_code (opd->failure_code) == GPG_ERR_GENERAL)
        opd->failure_code = _gpgme_parse_failure (args);
      break;

    case GPGME_STATUS_EOF:
      if (opd->error_code)
        return opd->error_code;
      else if (opd->failure_code)
        return opd->failure_code;
      break;

    case GPGME_STATUS_INQUIRE_MAXLEN:
      if (ctx->status_cb && !ctx->full_status)
        {
          err = ctx->status_cb (ctx->status_cb_value, "INQUIRE_MAXLEN", args);
          if (err)
            return err;
        }
      break;

    default:
      break;
    }
  return 0;
}


/* Revoke the signature(s) on USERID of KEY made with SIGNING_KEY.
 * If USERID is NULL, revoke signatures on all user ids.  To put several
 * user ids into USERID, separate them by LF and set the flag
 * GPGME_REVSIG_LFSEP.  */
static gpgme_error_t
revsig_start (gpgme_ctx_t ctx, int synchronous,
              gpgme_key_t key, gpgme_key_t signing_key,
              const char *userid, unsigned int flags)
{
  gpgme_error_t err;
  void *hook;
  op_data_t opd;

  if (!ctx)
    return gpg_error (GPG_ERR_INV_ARG);

  if (ctx->protocol != GPGME_PROTOCOL_OPENPGP)
    return gpgme_error (GPG_ERR_UNSUPPORTED_PROTOCOL);

  if (!key)
    return gpg_error (GPG_ERR_INV_ARG);

  err = _gpgme_op_reset (ctx, synchronous);
  if (err)
    return err;

  err = _gpgme_op_data_lookup (ctx, OPDATA_REVSIG, &hook, sizeof (*opd),
                               NULL);
  opd = hook;
  if (err)
    return err;

  _gpgme_engine_set_status_handler (ctx->engine, revsig_status_handler, ctx);

  if (ctx->passphrase_cb)
    {
      err = _gpgme_engine_set_command_handler
        (ctx->engine, _gpgme_passphrase_command_handler, ctx);
      if (err)
        return err;
    }

  return _gpgme_engine_op_revsig (ctx->engine, key, signing_key, userid, flags);
}


gpgme_error_t
gpgme_op_revsig_start (gpgme_ctx_t ctx, gpgme_key_t key, gpgme_key_t signing_key,
                       const char *userid, unsigned int flags)
{
  gpgme_error_t err;

  TRACE_BEG  (DEBUG_CTX, "gpgme_op_revsig_start", ctx,
	      "key=%p, uid='%s' flags=0x%x", key, userid, flags);

  err = revsig_start (ctx, 0, key, signing_key, userid, flags);
  return TRACE_ERR (err);
}


gpgme_error_t
gpgme_op_revsig (gpgme_ctx_t ctx, gpgme_key_t key, gpgme_key_t signing_key,
                 const char *userid, unsigned int flags)
{
  gpgme_error_t err;

  TRACE_BEG  (DEBUG_CTX, "gpgme_op_revsig", ctx,
	      "key=%p, uid='%s' flags=0x%x", key, userid, flags);

  err = revsig_start (ctx, 1, key, signing_key, userid, flags);
  if (!err)
    err = _gpgme_wait_one (ctx);
  return TRACE_ERR (err);
}