First take on the low-level assuan interface.

1 files changed, 744 insertions, 0 deletions

diff --git a/src/engine-assuan.c b/src/engine-assuan.c
new file mode 100644
index 00000000..fb748689
--- /dev/null
+++ b/src/engine-assuan.c
@@ -0,0 +1,744 @@
+/* engine-assuan.c - Low-level Assuan protocol engine
+ * Copyright (C) 2009 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 <http://www.gnu.org/licenses/>.
+ */
+
+/*
+   Note: This engine requires a modern Assuan server which uses
+   gpg-error codes.  In particular there is no backward compatible
+   mapping of old Assuan error codes implemented.
+*/
+
+
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <assert.h>
+#include <unistd.h>
+#include <locale.h>
+#include <errno.h>
+
+#include "gpgme.h"
+#include "util.h"
+#include "ops.h"
+#include "wait.h"
+#include "priv-io.h"
+#include "sema.h"
+
+#include "assuan.h"
+#include "debug.h"
+
+#include "engine-backend.h"
+
+
+typedef struct
+{
+  int fd;	/* FD we talk about.  */
+  int server_fd;/* Server FD for this connection.  */
+  int dir;	/* Inbound/Outbound, maybe given implicit?  */
+  void *data;	/* Handler-specific data.  */
+  void *tag;	/* ID from the user for gpgme_remove_io_callback.  */
+} iocb_data_t;
+
+/* Engine instance data.  */
+struct engine_llass
+{
+  assuan_context_t assuan_ctx;
+
+  int lc_ctype_set;
+  int lc_messages_set;
+
+  iocb_data_t status_cb;
+
+  struct gpgme_io_cbs io_cbs;
+
+  /* Internal callbacks.  */
+  engine_assuan_result_cb_t result_cb;
+  void *result_cb_value; 
+
+  /* User provided callbacks.  */
+  struct {
+    gpgme_assuan_data_cb_t data_cb;
+    void *data_cb_value;
+
+    gpgme_assuan_inquire_cb_t inq_cb;
+    void *inq_cb_value;
+
+    gpgme_assuan_status_cb_t status_cb;
+    void *status_cb_value;
+  } user;
+
+  /* Option flags.  */
+  struct {
+    int gpg_agent:1;  /* Assume this is a gpg-agent connection.  */
+  } opt;
+
+};
+typedef struct engine_llass *engine_llass_t;
+
+/* Helper to pass data to a callback.  */
+struct _gpgme_assuan_sendfnc_ctx
+{
+  assuan_context_t assuan_ctx;
+};
+
+
+
+/* Prototypes.  */
+static void llass_io_event (void *engine,
+                            gpgme_event_io_t type, void *type_data);
+
+
+
+
+
+/* return the default home directory.  */
+static const char *
+llass_get_home_dir (void)
+{
+  /* For this engine the home directory is not a filename but a string
+     used to convey options.  The exclamation mark is a marker to show
+     that this is not a directory name. Options are strings delimited
+     by a space.  The only option defined for now is GPG_AGENT to
+     enable GPG_AGENT specific commands to send to the server at
+     connection startup.  */
+  return "!GPG_AGENT";
+}
+
+static char *
+llass_get_version (const char *file_name)
+{
+  return strdup ("1.0");
+}
+
+
+static const char *
+llass_get_req_version (void)
+{
+  return "1.0";
+}
+
+
+static void
+close_notify_handler (int fd, void *opaque)
+{
+  engine_llass_t llass = opaque;
+
+  assert (fd != -1);
+  if (llass->status_cb.fd == fd)
+    {
+      if (llass->status_cb.tag)
+	llass->io_cbs.remove (llass->status_cb.tag);
+      llass->status_cb.fd = -1;
+      llass->status_cb.tag = NULL;
+    }
+}
+
+
+
+static gpgme_error_t
+llass_cancel (void *engine)
+{
+  engine_llass_t llass = engine;
+
+  if (!llass)
+    return gpg_error (GPG_ERR_INV_VALUE);
+
+  if (llass->status_cb.fd != -1)
+    _gpgme_io_close (llass->status_cb.fd);
+
+  if (llass->assuan_ctx)
+    {
+      assuan_disconnect (llass->assuan_ctx);
+      llass->assuan_ctx = NULL;
+    }
+
+  return 0;
+}
+
+
+static void
+llass_release (void *engine)
+{
+  engine_llass_t llass = engine;
+
+  if (!llass)
+    return;
+
+  llass_cancel (engine);
+
+  free (llass);
+}
+
+
+/* Create a new instance. If HOME_DIR is NULL standard options for use
+   with gpg-agent are issued.  */  
+static gpgme_error_t
+llass_new (void **engine, const char *file_name, const char *home_dir)
+{
+  gpgme_error_t err = 0;
+  engine_llass_t llass;
+  char *optstr;
+
+  llass = calloc (1, sizeof *llass);
+  if (!llass)
+    return gpg_error_from_syserror ();
+
+  llass->status_cb.fd = -1;
+  llass->status_cb.dir = 1;
+  llass->status_cb.tag = 0;
+  llass->status_cb.data = llass;
+
+  /* Parse_options.  */
+  if (home_dir && *home_dir == '!')
+    {
+      home_dir++;
+      /* Very simple parser only working for the one option we support.  */
+      if (!strncmp (home_dir, "GPG_AGENT", 9) 
+          && (!home_dir[9] || home_dir[9] == ' '))
+        llass->opt.gpg_agent = 1;
+    }
+
+  err = assuan_socket_connect (&llass->assuan_ctx, file_name, 0);
+  if (err)
+    goto leave;
+
+  if (llass->opt.gpg_agent)
+    {
+      char *dft_display = NULL;
+
+      err = _gpgme_getenv ("DISPLAY", &dft_display);
+      if (err)
+        goto leave;
+      if (dft_display)
+        {
+          if (asprintf (&optstr, "OPTION display=%s", dft_display) < 0)
+            {
+              err = gpg_error_from_syserror ();
+              free (dft_display);
+              goto leave;
+            }
+          free (dft_display);
+
+          err = assuan_transact (llass->assuan_ctx, optstr, NULL, NULL, NULL,
+                                 NULL, NULL, NULL);
+          free (optstr);
+          if (err)
+            goto leave;
+        }
+    }
+
+  if (llass->opt.gpg_agent && isatty (1))
+    {
+      int rc;
+      char dft_ttyname[64];
+      char *dft_ttytype = NULL;
+
+      rc = ttyname_r (1, dft_ttyname, sizeof (dft_ttyname));
+      if (rc)
+	{
+	  err = gpg_error_from_errno (rc);
+	  goto leave;
+	}
+      else
+	{
+	  if (asprintf (&optstr, "OPTION ttyname=%s", dft_ttyname) < 0)
+	    {
+	      err = gpg_error_from_syserror ();
+	      goto leave;
+	    }
+	  err = assuan_transact (llass->assuan_ctx, optstr, NULL, NULL, NULL,
+				 NULL, NULL, NULL);
+	  free (optstr);
+	  if (err)
+            goto leave;
+
+	  err = _gpgme_getenv ("TERM", &dft_ttytype);
+	  if (err)
+	    goto leave;
+	  if (dft_ttytype)
+	    {
+	      if (asprintf (&optstr, "OPTION ttytype=%s", dft_ttytype) < 0)
+		{
+		  err = gpg_error_from_syserror ();
+		  free (dft_ttytype);
+		  goto leave;
+		}
+	      free (dft_ttytype);
+              
+	      err = assuan_transact (llass->assuan_ctx, optstr, NULL, NULL,
+				     NULL, NULL, NULL, NULL);
+	      free (optstr);
+	      if (err)
+                goto leave;
+	    }
+	}
+    }
+
+
+#ifdef HAVE_W32_SYSTEM
+  /* Under Windows we need to use AllowSetForegroundWindow.  Tell
+     llass to tell us when it needs it.  */
+  if (!err && llass->opt.gpg_agent)
+    {
+      err = assuan_transact (llass->assuan_ctx, "OPTION allow-pinentry-notify",
+                             NULL, NULL, NULL, NULL, NULL, NULL);
+      if (gpg_err_code (err) == GPG_ERR_UNKNOWN_OPTION)
+        err = 0; /* This work only with recent gpg-agents.  */
+    }
+#endif /*HAVE_W32_SYSTEM*/
+
+
+ leave:
+  /* Close the server ends of the pipes (because of this, we must use
+     the stored server_fd_str in the function start).  Our ends are
+     closed in llass_release().  */
+
+  if (err)
+    llass_release (llass);
+  else
+    *engine = llass;
+
+  return err;
+}
+
+
+static gpgme_error_t
+llass_set_locale (void *engine, int category, const char *value)
+{
+  gpgme_error_t err;
+  engine_llass_t llass = engine;
+  char *optstr;
+  char *catstr;
+
+  if (!llass->opt.gpg_agent)
+    return 0;
+
+  /* FIXME: If value is NULL, we need to reset the option to default.
+     But we can't do this.  So we error out here.  gpg-agent needs
+     support for this.  */
+  if (category == LC_CTYPE)
+    {
+      catstr = "lc-ctype";
+      if (!value && llass->lc_ctype_set)
+	return gpg_error (GPG_ERR_INV_VALUE);
+      if (value)
+	llass->lc_ctype_set = 1;
+    }
+#ifdef LC_MESSAGES
+  else if (category == LC_MESSAGES)
+    {
+      catstr = "lc-messages";
+      if (!value && llass->lc_messages_set)
+	return gpg_error (GPG_ERR_INV_VALUE);
+      if (value)
+	llass->lc_messages_set = 1;
+    }
+#endif /* LC_MESSAGES */
+  else
+    return gpg_error (GPG_ERR_INV_VALUE);
+
+  /* FIXME: Reset value to default.  */
+  if (!value)
+    return 0;
+
+  if (asprintf (&optstr, "OPTION %s=%s", catstr, value) < 0)
+    err = gpg_error_from_errno (errno);
+  else
+    {
+      err = assuan_transact (llass->assuan_ctx, optstr, NULL, NULL,
+			     NULL, NULL, NULL, NULL);
+      free (optstr);
+    }
+  return err;
+}
+
+
+
+static gpgme_error_t
+inquire_cb_sendfnc (gpgme_assuan_sendfnc_ctx_t ctx,
+                    const void *data, size_t datalen)
+{
+  if (data && datalen)
+    return assuan_send_data (ctx->assuan_ctx, data, datalen);
+  else
+    return 0;  /* Don't allow an inquire to send a flush.  */
+}
+
+
+/* This is the inquiry callback.  It handles stuff which ee need to
+   handle here and passes everything on to the user callback.  */
+static gpgme_error_t
+inquire_cb (engine_llass_t llass, const char *keyword, const char *args)
+{
+  gpg_error_t err;
+
+  if (llass->opt.gpg_agent && !strcmp (keyword, "PINENTRY_LAUNCHED"))
+    {
+      _gpgme_allow_set_foregound_window ((pid_t)strtoul (args, NULL, 10));
+    }
+
+  if (llass->user.inq_cb)
+    {
+      struct _gpgme_assuan_sendfnc_ctx sendfnc_ctx;
+
+      sendfnc_ctx.assuan_ctx = llass->assuan_ctx;
+      err = llass->user.inq_cb (llass->user.inq_cb_value,
+                                keyword, args,
+                                inquire_cb_sendfnc, &sendfnc_ctx);
+    }
+  else
+    err = 0;
+
+  return err;
+}
+
+
+static gpgme_error_t
+llass_status_handler (void *opaque, int fd)
+{
+  gpgme_error_t err = 0;
+  engine_llass_t llass = opaque;
+  char *line;
+  size_t linelen;
+
+  do
+    {
+      err = assuan_read_line (llass->assuan_ctx, &line, &linelen);
+      if (err)
+	{
+          TRACE2 (DEBUG_CTX, "gpgme:llass_status_handler", llass,
+		  "fd 0x%x: error reading assuan line: %s",
+                  fd, gpg_strerror (err));
+	}
+      else if (linelen >= 2 && line[0] == 'D' && line[1] == ' ')
+        {
+          char *src = line + 2;
+	  char *end = line + linelen;
+	  char *dst = src;
+
+          linelen = 0;
+          while (src < end)
+            {
+              if (*src == '%' && src + 2 < end)
+                {
+                  /* Handle escaped characters.  */
+                  ++src;
+                  *dst++ = _gpgme_hextobyte (src);
+                  src += 2;
+                }
+              else
+                *dst++ = *src++;
+
+              linelen++;
+            }
+
+          src = line + 2;
+          if (linelen && llass->user.data_cb)
+            err = llass->user.data_cb (llass->user.data_cb_value,
+                                       src, linelen);
+          else
+            err = 0;
+
+          TRACE2 (DEBUG_CTX, "gpgme:llass_status_handler", llass,
+		  "fd 0x%x: D inlinedata; status from cb: %s",
+                  fd, (llass->user.data_cb ?
+                       (err? gpg_strerror (err):"ok"):"no callback"));
+        }
+      else if (linelen >= 3
+               && line[0] == 'E' && line[1] == 'N' && line[2] == 'D'
+               && (line[3] == '\0' || line[3] == ' '))
+        {
+          /* END received.  Tell the data callback.  */
+          if (llass->user.data_cb)
+            err = llass->user.data_cb (llass->user.data_cb_value, NULL, 0);
+          else
+            err = 0;
+
+          TRACE2 (DEBUG_CTX, "gpgme:llass_status_handler", llass,
+		  "fd 0x%x: END line; status from cb: %s",
+                  fd, (llass->user.data_cb ?
+                       (err? gpg_strerror (err):"ok"):"no callback"));
+        }
+      else if (linelen > 2 && line[0] == 'S' && line[1] == ' ')
+	{
+	  char *args;
+          char *src;
+
+          for (src=line+2; *src == ' '; src++)
+            ;
+
+	  args = strchr (src, ' ');
+	  if (!args)
+	    args = line + linelen; /* Let it point to an empty string.  */
+	  else
+	    *(args++) = 0;
+
+          while (*args == ' ')
+            args++;
+
+          if (llass->user.status_cb)
+            err = llass->user.status_cb (llass->user.status_cb_value,
+                                         src, args);
+          else
+            err = 0;
+
+          TRACE3 (DEBUG_CTX, "gpgme:llass_status_handler", llass,
+		  "fd 0x%x: S line (%s) - status from cb: %s",
+                  fd, line+2, (llass->user.status_cb ?
+                               (err? gpg_strerror (err):"ok"):"no callback"));
+	}
+      else if (linelen >= 7
+               && line[0] == 'I' && line[1] == 'N' && line[2] == 'Q'
+               && line[3] == 'U' && line[4] == 'I' && line[5] == 'R'
+               && line[6] == 'E'
+               && (line[7] == '\0' || line[7] == ' '))
+        {
+          char *src;
+	  char *args;
+
+          for (src=line+7; *src == ' '; src++)
+            ;
+
+	  args = strchr (src, ' ');
+	  if (!args)
+	    args = line + linelen; /* Let it point to an empty string.  */
+	  else
+	    *(args++) = 0;
+
+          while (*args == ' ')
+            args++;
+
+          err = inquire_cb (llass, src, args);
+          if (!err) /* Flush and send END.  */
+            err = assuan_send_data (llass->assuan_ctx, NULL, 0);
+        }
+      else if (linelen >= 3
+	       && line[0] == 'E' && line[1] == 'R' && line[2] == 'R'
+	       && (line[3] == '\0' || line[3] == ' '))
+	{
+	  if (line[3] == ' ')
+	    err = atoi (line+4);
+	  else
+	    err = gpg_error (GPG_ERR_GENERAL);
+          TRACE2 (DEBUG_CTX, "gpgme:llass_status_handler", llass,
+		  "fd 0x%x: ERR line: %s",
+                  fd, err ? gpg_strerror (err) : "ok");
+          if (llass->result_cb)
+            err = llass->result_cb (llass->result_cb_value, err);
+          else
+            err = 0;
+          if (!err)
+            {
+              _gpgme_io_close (llass->status_cb.fd);
+              return 0;
+            }
+	}
+      else if (linelen >= 2
+	       && line[0] == 'O' && line[1] == 'K'
+	       && (line[2] == '\0' || line[2] == ' '))
+	{
+          TRACE1 (DEBUG_CTX, "gpgme:llass_status_handler", llass,
+		  "fd 0x%x: OK line", fd);
+          if (llass->result_cb)
+            err = llass->result_cb (llass->result_cb_value, 0);
+          else
+            err = 0;
+          if (!err)
+            {
+              _gpgme_io_close (llass->status_cb.fd);
+              return 0;
+            }
+	}
+      else
+        {
+          /* Comment line or invalid line.  */
+        }
+
+    }
+  while (!err && assuan_pending_line (llass->assuan_ctx));
+
+  return err;
+}
+
+
+static gpgme_error_t
+add_io_cb (engine_llass_t llass, iocb_data_t *iocbd, gpgme_io_cb_t handler)
+{
+  gpgme_error_t err;
+
+  TRACE_BEG2 (DEBUG_ENGINE, "engine-assuan:add_io_cb", llass,
+              "fd %d, dir %d", iocbd->fd, iocbd->dir);
+  err = (*llass->io_cbs.add) (llass->io_cbs.add_priv,
+			      iocbd->fd, iocbd->dir,
+			      handler, iocbd->data, &iocbd->tag);
+  if (err)
+    return TRACE_ERR (err);
+  if (!iocbd->dir)
+    /* FIXME Kludge around poll() problem.  */
+    err = _gpgme_io_set_nonblocking (iocbd->fd);
+  return TRACE_ERR (err);
+}
+
+
+static gpgme_error_t
+start (engine_llass_t llass, const char *command)
+{
+  gpgme_error_t err;
+  int fdlist[5];
+  int nfds;
+
+  /* We need to know the fd used by assuan for reads.  We do this by
+     using the assumption that the first returned fd from
+     assuan_get_active_fds() is always this one.  */
+  nfds = assuan_get_active_fds (llass->assuan_ctx, 0 /* read fds */,
+                                fdlist, DIM (fdlist));
+  if (nfds < 1)
+    return gpg_error (GPG_ERR_GENERAL);	/* FIXME */
+
+  /* We "duplicate" the file descriptor, so we can close it here (we
+     can't close fdlist[0], as that is closed by libassuan, and
+     closing it here might cause libassuan to close some unrelated FD
+     later).  Alternatively, we could special case status_fd and
+     register/unregister it manually as needed, but this increases
+     code duplication and is more complicated as we can not use the
+     close notifications etc.  A third alternative would be to let
+     Assuan know that we closed the FD, but that complicates the
+     Assuan interface.  */
+
+  llass->status_cb.fd = _gpgme_io_dup (fdlist[0]);
+  if (llass->status_cb.fd < 0)
+    return gpg_error_from_syserror ();
+
+  if (_gpgme_io_set_close_notify (llass->status_cb.fd,
+				  close_notify_handler, llass))
+    {
+      _gpgme_io_close (llass->status_cb.fd);
+      llass->status_cb.fd = -1;
+      return gpg_error (GPG_ERR_GENERAL);
+    }
+
+  err = add_io_cb (llass, &llass->status_cb, llass_status_handler);
+  if (!err)
+    err = assuan_write_line (llass->assuan_ctx, command);
+
+  /* FIXME: If *command == '#' no answer is expected.  */
+
+  if (!err)
+    llass_io_event (llass, GPGME_EVENT_START, NULL);
+
+  return err;
+}
+
+
+
+static gpgme_error_t
+llass_transact (void *engine,
+                const char *command,
+                engine_assuan_result_cb_t result_cb,
+                void *result_cb_value,
+                gpgme_assuan_data_cb_t data_cb,
+                void *data_cb_value,
+                gpgme_assuan_inquire_cb_t inq_cb,
+                void *inq_cb_value,
+                gpgme_assuan_status_cb_t status_cb,
+                void *status_cb_value)
+{
+  engine_llass_t llass = engine;
+  gpgme_error_t err;
+
+  if (!llass || !command || !*command)
+    return gpg_error (GPG_ERR_INV_VALUE);
+
+  llass->result_cb = result_cb;
+  llass->result_cb_value = result_cb_value;
+  llass->user.data_cb = data_cb;
+  llass->user.data_cb_value = data_cb_value;
+  llass->user.inq_cb = inq_cb;
+  llass->user.inq_cb_value = inq_cb_value;
+  llass->user.status_cb = status_cb;
+  llass->user.status_cb_value = status_cb_value;
+
+  err = start (llass, command);
+  return err;
+}
+
+
+
+static void
+llass_set_io_cbs (void *engine, gpgme_io_cbs_t io_cbs)
+{
+  engine_llass_t llass = engine;
+  llass->io_cbs = *io_cbs;
+}
+
+
+static void
+llass_io_event (void *engine, gpgme_event_io_t type, void *type_data)
+{
+  engine_llass_t llass = engine;
+
+  TRACE3 (DEBUG_ENGINE, "gpgme:llass_io_event", llass,
+          "event %p, type %d, type_data %p",
+          llass->io_cbs.event, type, type_data);
+  if (llass->io_cbs.event)
+    (*llass->io_cbs.event) (llass->io_cbs.event_priv, type, type_data);
+}
+
+
+struct engine_ops _gpgme_engine_ops_assuan =
+  {
+    /* Static functions.  */
+    _gpgme_get_default_agent_socket,
+    llass_get_home_dir,
+    llass_get_version,
+    llass_get_req_version,
+    llass_new,
+
+    /* Member functions.  */
+    llass_release,
+    NULL,		/* reset */
+    NULL,               /* set_status_handler */
+    NULL,		/* set_command_handler */
+    NULL,               /* set_colon_line_handler */
+    llass_set_locale,
+    NULL,               /* decrypt */
+    NULL,               /* delete */
+    NULL,		/* edit */
+    NULL,               /* encrypt */
+    NULL,		/* encrypt_sign */
+    NULL,               /* export */
+    NULL,               /* export_ext */
+    NULL,               /* genkey */
+    NULL,               /* import */
+    NULL,               /* keylist */
+    NULL,               /* keylist_ext */
+    NULL,               /* sign */
+    NULL,		/* trustlist */
+    NULL,               /* verify */
+    NULL,               /* getauditlog */
+    llass_transact,     /* opassuan_transact */
+    NULL,		/* conf_load */
+    NULL,		/* conf_save */
+    llass_set_io_cbs,
+    llass_io_event,
+    llass_cancel
+  };