json: Add framework for the gpgme-json tool

* src/gpgme-json.c: New.
* src/Makefile.am (bin_PROGRAMS): Add gpgme-json.
(gpgme_json_SOURCES, gpgme_json_LDADD): New.

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2018-03-16 13:55:48 +01:00
parent 81c90d0cd0
commit d2b31d8c10
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
3 changed files with 833 additions and 2 deletions

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@ -13,3 +13,4 @@ cl Common Lisp
cpp C++ cpp C++
qt Qt-Framework API qt Qt-Framework API
python Python 2 and 3 (module name: gpg) python Python 2 and 3 (module name: gpg)
javascript Native messaging client for the gpgme-json server.

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@ -26,7 +26,7 @@ m4datadir = $(datadir)/aclocal
m4data_DATA = gpgme.m4 m4data_DATA = gpgme.m4
nodist_include_HEADERS = gpgme.h nodist_include_HEADERS = gpgme.h
bin_PROGRAMS = gpgme-tool bin_PROGRAMS = gpgme-tool gpgme-json
if BUILD_W32_GLIB if BUILD_W32_GLIB
ltlib_gpgme_glib = libgpgme-glib.la ltlib_gpgme_glib = libgpgme-glib.la
@ -95,13 +95,18 @@ if BUILD_W32_GLIB
libgpgme_glib_la_SOURCES = $(main_sources) w32-glib-io.c libgpgme_glib_la_SOURCES = $(main_sources) w32-glib-io.c
endif endif
# We use a global CFLAGS setting for all library # We use a global CFLAGS setting for all libraries
# versions, because then every object file is only compiled once. # versions, because then every object file is only compiled once.
AM_CFLAGS = @LIBASSUAN_CFLAGS@ @GLIB_CFLAGS@ AM_CFLAGS = @LIBASSUAN_CFLAGS@ @GLIB_CFLAGS@
gpgme_tool_SOURCES = gpgme-tool.c argparse.c argparse.h gpgme_tool_SOURCES = gpgme-tool.c argparse.c argparse.h
gpgme_tool_LDADD = libgpgme.la @LIBASSUAN_LIBS@ gpgme_tool_LDADD = libgpgme.la @LIBASSUAN_LIBS@
gpgme_json_SOURCES = gpgme-json.c argparse.c argparse.h cJSON.c cJSON.h
gpgme_json_LDADD = -lm libgpgme.la $(GPG_ERROR_LIBS)
## We use -no-install temporary during development.
#gpgme_json_LDFLAGS = -no-install
if HAVE_W32_SYSTEM if HAVE_W32_SYSTEM
# Windows provides us with an endless stream of Tough Love. To spawn # Windows provides us with an endless stream of Tough Love. To spawn

825
src/gpgme-json.c Normal file
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@ -0,0 +1,825 @@
/* gpgme-json.c - JSON based interface to gpgme (server)
* Copyright (C) 2018 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/>.
* SPDX-License-Identifier: LGPL-2.1+
*/
/* This is tool implements the Native Messaging protocol of web
* browsers and provides the server part of it. A Javascript based
* client can be found in lang/javascript. The used data format is
* similar to the API of openpgpjs.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#include <stdint.h>
#define GPGRT_ENABLE_ES_MACROS 1
#define GPGRT_ENABLE_LOG_MACROS 1
#include "gpgme.h"
#include "argparse.h"
#include "cJSON.h"
/* We don't allow a request with more than 64 MiB. */
#define MAX_REQUEST_SIZE (64 * 1024 * 1024)
static void xoutofcore (const char *type) GPGRT_ATTR_NORETURN;
static cjson_t error_object_v (const char *message,
va_list arg_ptr) GPGRT_ATTR_PRINTF(1,0);
static cjson_t error_object (const char *message,
...) GPGRT_ATTR_PRINTF(1,2);
static char *error_object_string (const char *message,
...) GPGRT_ATTR_PRINTF(1,2);
/* True if interactive mode is active. */
static int opt_interactive;
/*
* Helper functions and macros
*/
#define xtrymalloc(a) gpgrt_malloc ((a))
#define xstrdup(a) ({ \
char *_r = gpgrt_strdup ((a)); \
if (!_r) \
xoutofcore ("strdup"); \
_r; })
#define xstrconcat(a, ...) ({ \
char *_r = gpgrt_strconcat ((a), __VA_ARGS__); \
if (!_r) \
xoutofcore ("strconcat"); \
_r; })
#define xfree(a) gpgrt_free ((a))
#define spacep(p) (*(p) == ' ' || *(p) == '\t')
static void
xoutofcore (const char *type)
{
gpg_error_t err = gpg_error_from_syserror ();
log_error ("%s failed: %s\n", type, gpg_strerror (err));
exit (2);
}
/* Call cJSON_CreateObject but terminate in case of an error. */
static cjson_t
xjson_CreateObject (void)
{
cjson_t json = cJSON_CreateObject ();
if (!json)
xoutofcore ("cJSON_CreateObject");
return json;
}
/* Wrapper around cJSON_AddStringToObject which returns an gpg-error
* code instead of the NULL or the object. */
static gpg_error_t
cjson_AddStringToObject (cjson_t object, const char *name, const char *string)
{
if (!cJSON_AddStringToObject (object, name, string))
return gpg_error_from_syserror ();
return 0;
}
/* Same as cjson_AddStringToObject but prints an error message and
* terminates. the process. */
static void
xjson_AddStringToObject (cjson_t object, const char *name, const char *string)
{
if (!cJSON_AddStringToObject (object, name, string))
xoutofcore ("cJSON_AddStringToObject");
}
/* Create a JSON error object. */
static cjson_t
error_object_v (const char *message, va_list arg_ptr)
{
cjson_t response;
char *msg;
msg = gpgrt_vbsprintf (message, arg_ptr);
if (!msg)
xoutofcore ("error_object");
response = xjson_CreateObject ();
xjson_AddStringToObject (response, "type", "error");
xjson_AddStringToObject (response, "msg", msg);
xfree (msg);
return response;
}
/* Call cJSON_Print but terminate in case of an error. */
static char *
xjson_Print (cjson_t object)
{
char *buf;
buf = cJSON_Print (object);
if (!buf)
xoutofcore ("cJSON_Print");
return buf;
}
static cjson_t
error_object (const char *message, ...)
{
cjson_t response;
va_list arg_ptr;
va_start (arg_ptr, message);
response = error_object_v (message, arg_ptr);
va_end (arg_ptr);
return response;
}
static char *
error_object_string (const char *message, ...)
{
cjson_t response;
va_list arg_ptr;
char *msg;
va_start (arg_ptr, message);
response = error_object_v (message, arg_ptr);
va_end (arg_ptr);
msg = xjson_Print (response);
cJSON_Delete (response);
return msg;
}
/*
* Implementaion of the commands.
*/
static const char hlp_encrypt[] =
"op: \"encrypt\"\n"
"keys: Array of strings with the fingerprints or user-ids\n"
" of the keys to encrypt the data. For a single key\n"
" a String may be used instead of an array.\n"
"data: Base64 encoded input data.\n"
"\n"
"Optional parameters:\n"
"protocol: Either \"openpgp\" (default) or \"cms\".\n"
"\n"
"Optional boolean flags (default is false):\n"
"armor: Request output in armored format.\n"
"always-trust: Request --always-trust option.\n"
"no-encrypt-to: Do not use a default recipient.\n"
"no-compress: Do not compress the plaintext first.\n"
"throw-keyids: Request the --throw-keyids option.\n"
"wrap: Assume the input is an OpenPGP message.\n"
"\n"
"Response on success:\n"
"type: \"ciphertext\"\n"
"data: Unless armor mode is used a Base64 encoded binary\n"
" ciphertext. In armor mode a string with an armored\n"
" OpenPGP or a PEM message.\n"
"base64: Boolean indicating whether data is base64 encoded.";
static gpg_error_t
op_encrypt (cjson_t request, cjson_t *r_result)
{
return 0;
}
static const char hlp_help[] =
"The tool expects a JSON object with the request and responds with\n"
"another JSON object. Even on error a JSON object is returned. The\n"
"property \"op\" is mandatory and its string value selects the\n"
"operation; if the property \"help\" with the value \"true\" exists, the\n"
"operation is not performned but a string with the documentation\n"
"returned. To list all operations it is allowed to leave out \"op\" in\n"
"help mode. Supported values for \"op\" are:\n\n"
" encrypt Encrypt data.\n"
" help Help overview.";
static gpg_error_t
op_help (cjson_t request, cjson_t *r_result)
{
gpg_error_t err = 0;
cjson_t result = NULL;
cjson_t j_tmp;
char *buffer = NULL;
const char *msg;
j_tmp = cJSON_GetObjectItem (request, "interactive_help");
if (opt_interactive && j_tmp && cjson_is_string (j_tmp))
msg = buffer = xstrconcat (hlp_help, "\n", j_tmp->valuestring, NULL);
else
msg = hlp_help;
result = cJSON_CreateObject ();
if (!result)
err = gpg_error_from_syserror ();
if (!err)
err = cjson_AddStringToObject (result, "type", "help");
if (!err)
err = cjson_AddStringToObject (result, "msg", msg);
xfree (buffer);
if (err)
xfree (result);
else
*r_result = result;
return err;
}
/* Process a request and return the response. The response is a newly
* allocated staring or NULL in case of an error. */
static char *
process_request (const char *request)
{
static struct {
const char *op;
gpg_error_t (*handler)(cjson_t request, cjson_t *r_result);
const char * const helpstr;
} optbl[] = {
{ "encrypt", op_encrypt, hlp_encrypt },
{ "help", op_help, hlp_help },
{ NULL }
};
gpg_error_t err = 0;
size_t erroff;
cjson_t json;
cjson_t j_tmp, j_op;
cjson_t response = NULL;
int helpmode;
const char *op;
char *res;
int idx;
json = cJSON_Parse (request, &erroff);
if (!json)
{
log_string (GPGRT_LOGLVL_INFO, request);
log_info ("invalid JSON object at offset %zu\n", erroff);
response = error_object ("invalid JSON object at offset %zu\n", erroff);
goto leave;
}
j_tmp = cJSON_GetObjectItem (json, "help");
helpmode = (j_tmp && cjson_is_true (j_tmp));
j_op = cJSON_GetObjectItem (json, "op");
if (!j_op || !cjson_is_string (j_op))
{
if (!helpmode)
{
response = error_object ("Property \"op\" missing");
goto leave;
}
op = "help"; /* Help summary. */
}
else
op = j_op->valuestring;
for (idx=0; optbl[idx].op; idx++)
if (!strcmp (op, optbl[idx].op))
break;
if (optbl[idx].op)
{
if (helpmode && strcmp (op, "help"))
{
response = cJSON_CreateObject ();
if (!response)
err = gpg_error_from_syserror ();
if (!err)
err = cjson_AddStringToObject (response, "type", "help");
if (!err)
err = cjson_AddStringToObject (response, "op", op);
if (!err)
err = cjson_AddStringToObject (response, "msg", optbl[idx].helpstr);
}
else
err = optbl[idx].handler (json, &response);
}
else /* Operation not supported. */
{
response = error_object ("Unknown operation '%s'", op);
err = cjson_AddStringToObject (response, "op", op);
}
leave:
cJSON_Delete (json);
json = NULL;
if (err)
log_error ("failed to create the response: %s\n", gpg_strerror (err));
if (response)
{
res = cJSON_Print (response);
if (!res)
log_error ("Printing JSON data failed\n");
cJSON_Delete (response);
}
else
res = NULL;
return res;
}
/*
* Driver code
*/
/* Return a malloced line or NULL on EOF. Terminate on read
* error. */
static char *
get_line (void)
{
char *line = NULL;
size_t linesize = 0;
gpg_error_t err;
size_t maxlength = 2048;
int n;
const char *s;
char *p;
again:
n = es_read_line (es_stdin, &line, &linesize, &maxlength);
if (n < 0)
{
err = gpg_error_from_syserror ();
log_error ("error reading line: %s\n", gpg_strerror (err));
exit (1);
}
if (!n)
{
xfree (line);
line = NULL;
return NULL; /* EOF */
}
if (!maxlength)
{
log_info ("line too long - skipped\n");
goto again;
}
if (memchr (line, 0, n))
log_info ("warning: line shortened due to embedded Nul character\n");
if (line[n-1] == '\n')
line[n-1] = 0;
/* Trim leading spaces. */
for (s=line; spacep (s); s++)
;
if (s != line)
{
for (p=line; *s;)
*p++ = *s++;
*p = 0;
n = p - line;
}
return line;
}
/* Process meta commands used with the standard REPL. */
static char *
process_meta_commands (const char *request)
{
char *result = NULL;
while (spacep (request))
request++;
if (!strncmp (request, "help", 4) && (spacep (request+4) || !request[4]))
result = process_request ("{ \"op\": \"help\","
" \"interactive_help\": "
"\"\\nMeta commands:\\n"
" ,help This help\\n"
" ,quit Terminate process\""
"}");
else if (!strncmp (request, "quit", 4) && (spacep (request+4) || !request[4]))
exit (0);
else
log_info ("invalid meta command\n");
return result;
}
/* If STRING has a help response, return the MSG property in a human
* readable format. */
static char *
get_help_msg (const char *string)
{
cjson_t json, j_type, j_msg;
const char *msg;
char *buffer = NULL;
char *p;
json = cJSON_Parse (string, NULL);
if (json)
{
j_type = cJSON_GetObjectItem (json, "type");
if (j_type && cjson_is_string (j_type)
&& !strcmp (j_type->valuestring, "help"))
{
j_msg = cJSON_GetObjectItem (json, "msg");
if (j_msg || cjson_is_string (j_msg))
{
msg = j_msg->valuestring;
buffer = malloc (strlen (msg)+1);
if (buffer)
{
for (p=buffer; *msg; msg++)
{
if (*msg == '\\' && msg[1] == '\n')
*p++ = '\n';
else
*p++ = *msg;
}
*p = 0;
}
}
}
cJSON_Delete (json);
}
return buffer;
}
/* An interactive standard REPL. */
static void
interactive_repl (void)
{
char *line = NULL;
char *request = NULL;
char *response = NULL;
char *p;
int first;
es_setvbuf (es_stdin, NULL, _IONBF, 0);
es_fprintf (es_stderr, "%s %s ready (enter \",help\" for help)\n",
strusage (11), strusage (13));
do
{
es_fputs ("> ", es_stderr);
es_fflush (es_stderr);
es_fflush (es_stdout);
xfree (line);
line = get_line ();
es_fflush (es_stderr);
es_fflush (es_stdout);
first = !request;
if (line && *line)
{
if (!request)
request = xstrdup (line);
else
request = xstrconcat (request, "\n", line, NULL);
}
if (!line)
es_fputs ("\n", es_stderr);
if (!line || !*line || (first && *request == ','))
{
/* Process the input. */
xfree (response);
response = NULL;
if (request && *request == ',')
{
response = process_meta_commands (request+1);
}
else if (request)
{
response = process_request (request);
}
xfree (request);
request = NULL;
if (response)
{
if (opt_interactive)
{
char *msg = get_help_msg (response);
if (msg)
{
xfree (response);
response = msg;
}
}
es_fputs ("===> ", es_stderr);
es_fflush (es_stderr);
for (p=response; *p; p++)
{
if (*p == '\n')
{
es_fflush (es_stdout);
es_fputs ("\n===> ", es_stderr);
es_fflush (es_stderr);
}
else
es_putc (*p, es_stdout);
}
es_fflush (es_stdout);
es_fputs ("\n", es_stderr);
}
}
}
while (line);
xfree (request);
xfree (response);
xfree (line);
}
/* Read and process asingle request. */
static void
read_and_process_single_request (void)
{
char *line = NULL;
char *request = NULL;
char *response = NULL;
size_t n;
for (;;)
{
xfree (line);
line = get_line ();
if (line && *line)
request = (request? xstrconcat (request, "\n", line, NULL)
/**/ : xstrdup (line));
if (!line)
{
if (request)
{
xfree (response);
response = process_request (request);
if (response)
{
es_fputs (response, es_stdout);
if ((n = strlen (response)) && response[n-1] != '\n')
es_fputc ('\n', es_stdout);
}
es_fflush (es_stdout);
}
break;
}
}
xfree (response);
xfree (request);
xfree (line);
}
/* The Native Messaging processing loop. */
static void
native_messaging_repl (void)
{
gpg_error_t err;
uint32_t nrequest, nresponse;
char *request = NULL;
char *response = NULL;
size_t n;
/* Due to the length octets we need to switch the I/O stream into
* binary mode. */
es_set_binary (es_stdin);
es_set_binary (es_stdout);
for (;;)
{
/* Read length. Note that the protocol uses native endianess.
* Is it allowed to call such a thing a well thought out
* protocol? */
if (es_read (es_stdin, &nrequest, sizeof nrequest, &n))
{
err = gpg_error_from_syserror ();
log_error ("error reading request header: %s\n", gpg_strerror (err));
break;
}
if (!n)
break; /* EOF */
if (n != sizeof nrequest)
{
log_error ("error reading request header: short read\n");
break;
}
if (nrequest > MAX_REQUEST_SIZE)
{
log_error ("error reading request: request too long (%zu MiB)\n",
(size_t)nrequest / (1024*1024));
/* Fixme: Shall we read the request t the bit bucket and
* return an error reponse or just return an error reponse
* and terminate? Needs some testing. */
break;
}
/* Read request. */
request = xtrymalloc (nrequest);
if (!request)
{
err = gpg_error_from_syserror ();
log_error ("error reading request: Not enough memory for %zu MiB)\n",
(size_t)nrequest / (1024*1024));
/* FIXME: See comment above. */
break;
}
if (es_read (es_stdin, request, nrequest, &n))
{
err = gpg_error_from_syserror ();
log_error ("error reading request: %s\n", gpg_strerror (err));
break;
}
if (n != nrequest)
{
/* That is a protocol violation. */
xfree (response);
response = error_object_string ("Invalid request:"
" short read (%zu of %zu bytes)\n",
n, (size_t)nrequest);
}
else /* Process request */
{
xfree (response);
response = process_request (request);
}
nresponse = strlen (response);
/* Write response */
if (es_write (es_stdout, &nresponse, sizeof nresponse, &n))
{
err = gpg_error_from_syserror ();
log_error ("error writing request header: %s\n", gpg_strerror (err));
break;
}
if (n != sizeof nrequest)
{
log_error ("error writing request header: short write\n");
break;
}
if (es_write (es_stdout, response, nresponse, &n))
{
err = gpg_error_from_syserror ();
log_error ("error writing request: %s\n", gpg_strerror (err));
break;
}
if (n != nresponse)
{
log_error ("error writing request: short write\n");
break;
}
if (es_fflush (es_stdout) || es_ferror (es_stdout))
{
err = gpg_error_from_syserror ();
log_error ("error writing request: %s\n", gpg_strerror (err));
break;
}
}
xfree (response);
xfree (request);
}
static const char *
my_strusage( int level )
{
const char *p;
switch (level)
{
case 11: p = "gpgme-json"; break;
case 13: p = PACKAGE_VERSION; break;
case 14: p = "Copyright (C) 2018 g10 Code GmbH"; break;
case 19: p = "Please report bugs to <" PACKAGE_BUGREPORT ">.\n"; break;
case 1:
case 40:
p = "Usage: gpgme-json [OPTIONS]";
break;
case 41:
p = "Native messaging based GPGME operations.\n";
break;
case 42:
p = "1"; /* Flag print 40 as part of 41. */
break;
default: p = NULL; break;
}
return p;
}
int
main (int argc, char *argv[])
{
enum { CMD_DEFAULT = 0,
CMD_INTERACTIVE = 'i',
CMD_SINGLE = 's',
CMD_LIBVERSION = 501
} cmd = CMD_DEFAULT;
static ARGPARSE_OPTS opts[] = {
ARGPARSE_c (CMD_INTERACTIVE, "interactive", "Interactive REPL"),
ARGPARSE_c (CMD_SINGLE, "single", "Single request mode"),
ARGPARSE_c (CMD_LIBVERSION, "lib-version", "Show library version"),
ARGPARSE_end()
};
ARGPARSE_ARGS pargs = { &argc, &argv, 0 };
set_strusage (my_strusage);
#ifdef HAVE_SETLOCALE
setlocale (LC_ALL, "");
#endif
gpgme_check_version (NULL);
#ifdef LC_CTYPE
gpgme_set_locale (NULL, LC_CTYPE, setlocale (LC_CTYPE, NULL));
#endif
#ifdef LC_MESSAGES
gpgme_set_locale (NULL, LC_MESSAGES, setlocale (LC_MESSAGES, NULL));
#endif
while (arg_parse (&pargs, opts))
{
switch (pargs.r_opt)
{
case CMD_INTERACTIVE:
opt_interactive = 1;
/* Fall trough. */
case CMD_SINGLE:
case CMD_LIBVERSION:
cmd = pargs.r_opt;
break;
default:
pargs.err = ARGPARSE_PRINT_WARNING;
break;
}
}
switch (cmd)
{
case CMD_DEFAULT:
native_messaging_repl ();
break;
case CMD_SINGLE:
read_and_process_single_request ();
break;
case CMD_INTERACTIVE:
interactive_repl ();
break;
case CMD_LIBVERSION:
printf ("Version from header: %s (0x%06x)\n",
GPGME_VERSION, GPGME_VERSION_NUMBER);
printf ("Version from binary: %s\n", gpgme_check_version (NULL));
printf ("Copyright blurb ...:%s\n", gpgme_check_version ("\x01\x01"));
break;
}
return 0;
}