/* 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 .
* 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
#include
#include
#include
#include
#ifdef HAVE_LOCALE_H
#include
#endif
#include
#include
#define GPGRT_ENABLE_ES_MACROS 1
#define GPGRT_ENABLE_LOG_MACROS 1
#define GPGRT_ENABLE_ARGPARSE_MACROS 1
#include "gpgme.h"
#include "cJSON.h"
#if GPGRT_VERSION_NUMBER < 0x011c00 /* 1.28 */
int main (void){fputs ("Build with Libgpg-error >= 1.28!\n", stderr);return 1;}
#else /* libgpg-error >= 1.28 */
/* We don't allow a request with more than 64 MiB. */
#define MAX_REQUEST_SIZE (64 * 1024 * 1024)
/* Minimal, default and maximum chunk size for returned data. The
* first chunk is returned directly. If the "more" flag is also
* returned, a "getmore" command needs to be used to get the next
* chunk. Right now this value covers just the value of the "data"
* element; so to cover for the other returned objects this values
* needs to be lower than the maximum allowed size of the browser. */
#define MIN_REPLY_CHUNK_SIZE 512
#define DEF_REPLY_CHUNK_SIZE (512 * 1024)
#define MAX_REPLY_CHUNK_SIZE (10 * 1024 * 1024)
static void xoutofcore (const char *type) GPGRT_ATTR_NORETURN;
static cjson_t error_object_v (cjson_t json, const char *message,
va_list arg_ptr) GPGRT_ATTR_PRINTF(2,0);
static cjson_t error_object (cjson_t json, const char *message,
...) GPGRT_ATTR_PRINTF(2,3);
static char *error_object_string (const char *message,
...) GPGRT_ATTR_PRINTF(1,2);
/* True if interactive mode is active. */
static int opt_interactive;
/* True is debug mode is active. */
static int opt_debug;
/* Pending data to be returned by a getmore command. */
static struct
{
char *buffer; /* Malloced data or NULL if not used. */
size_t length; /* Length of that data. */
size_t written; /* # of already written bytes from BUFFER. */
const char *type;/* The "type" of the data. */
int base64; /* The "base64" flag of the data. */
} pending_data;
/*
* Helper functions and macros
*/
#define xtrymalloc(a) gpgrt_malloc ((a))
#define xtrystrdup(a) gpgrt_strdup ((a))
#define xmalloc(a) ({ \
void *_r = gpgrt_malloc ((a)); \
if (!_r) \
xoutofcore ("malloc"); \
_r; })
#define xcalloc(a,b) ({ \
void *_r = gpgrt_calloc ((a), (b)); \
if (!_r) \
xoutofcore ("calloc"); \
_r; })
#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 new 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");
}
/* Wrapper around cJSON_AddBoolToObject which terminates the process
* in case of an error. */
static void
xjson_AddBoolToObject (cjson_t object, const char *name, int abool)
{
if (!cJSON_AddBoolToObject (object, name, abool))
xoutofcore ("cJSON_AddStringToObject");
return ;
}
/* This is similar to cJSON_AddStringToObject but takes (DATA,
* DATALEN) and adds it under NAME as a base 64 encoded string to
* OBJECT. */
static gpg_error_t
add_base64_to_object (cjson_t object, const char *name,
const void *data, size_t datalen)
{
#if GPGRT_VERSION_NUMBER < 0x011d00 /* 1.29 */
return gpg_error (GPG_ERR_NOT_SUPPORTED);
#else
gpg_err_code_t err;
estream_t fp = NULL;
gpgrt_b64state_t state = NULL;
cjson_t j_str = NULL;
void *buffer = NULL;
fp = es_fopenmem (0, "rwb");
if (!fp)
{
err = gpg_err_code_from_syserror ();
goto leave;
}
state = gpgrt_b64enc_start (fp, "");
if (!state)
{
err = gpg_err_code_from_syserror ();
goto leave;
}
err = gpgrt_b64enc_write (state, data, datalen);
if (err)
goto leave;
err = gpgrt_b64enc_finish (state);
state = NULL;
if (err)
return err;
es_fputc (0, fp);
if (es_fclose_snatch (fp, &buffer, NULL))
{
fp = NULL;
err = gpg_error_from_syserror ();
goto leave;
}
fp = NULL;
j_str = cJSON_CreateStringConvey (buffer);
if (!j_str)
{
err = gpg_error_from_syserror ();
goto leave;
}
buffer = NULL;
if (!cJSON_AddItemToObject (object, name, j_str))
{
err = gpg_error_from_syserror ();
cJSON_Delete (j_str);
j_str = NULL;
goto leave;
}
j_str = NULL;
leave:
xfree (buffer);
cJSON_Delete (j_str);
gpgrt_b64enc_finish (state);
es_fclose (fp);
return err;
#endif
}
/* Create a JSON error object. If JSON is not NULL the error message
* is appended to that object. An existing "type" item will be replaced. */
static cjson_t
error_object_v (cjson_t json, const char *message, va_list arg_ptr)
{
cjson_t response, j_tmp;
char *msg;
msg = gpgrt_vbsprintf (message, arg_ptr);
if (!msg)
xoutofcore ("error_object");
response = json? json : xjson_CreateObject ();
if (!(j_tmp = cJSON_GetObjectItem (response, "type")))
xjson_AddStringToObject (response, "type", "error");
else /* Replace existing "type". */
{
j_tmp = cJSON_CreateString ("error");
if (!j_tmp)
xoutofcore ("cJSON_CreateString");
cJSON_ReplaceItemInObject (response, "type", j_tmp);
}
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 (cjson_t json, const char *message, ...)
{
cjson_t response;
va_list arg_ptr;
va_start (arg_ptr, message);
response = error_object_v (json, 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 (NULL, message, arg_ptr);
va_end (arg_ptr);
msg = xjson_Print (response);
cJSON_Delete (response);
return msg;
}
/* Get the boolean property NAME from the JSON object and store true
* or valse at R_VALUE. If the name is unknown the value of DEF_VALUE
* is returned. If the type of the value is not boolean,
* GPG_ERR_INV_VALUE is returned and R_VALUE set to DEF_VALUE. */
static gpg_error_t
get_boolean_flag (cjson_t json, const char *name, int def_value, int *r_value)
{
cjson_t j_item;
j_item = cJSON_GetObjectItem (json, name);
if (!j_item)
*r_value = def_value;
else if (cjson_is_true (j_item))
*r_value = 1;
else if (cjson_is_false (j_item))
*r_value = 0;
else
{
*r_value = def_value;
return gpg_error (GPG_ERR_INV_VALUE);
}
return 0;
}
/* Get the boolean property PROTOCOL from the JSON object and store
* its value at R_PROTOCOL. The default is OpenPGP. */
static gpg_error_t
get_protocol (cjson_t json, gpgme_protocol_t *r_protocol)
{
cjson_t j_item;
*r_protocol = GPGME_PROTOCOL_OpenPGP;
j_item = cJSON_GetObjectItem (json, "protocol");
if (!j_item)
;
else if (!cjson_is_string (j_item))
return gpg_error (GPG_ERR_INV_VALUE);
else if (!strcmp(j_item->valuestring, "openpgp"))
;
else if (!strcmp(j_item->valuestring, "cms"))
*r_protocol = GPGME_PROTOCOL_CMS;
else
return gpg_error (GPG_ERR_UNSUPPORTED_PROTOCOL);
return 0;
}
/* Get the chunksize from JSON and store it at R_CHUNKSIZE. */
static gpg_error_t
get_chunksize (cjson_t json, size_t *r_chunksize)
{
cjson_t j_item;
*r_chunksize = DEF_REPLY_CHUNK_SIZE;
j_item = cJSON_GetObjectItem (json, "chunksize");
if (!j_item)
;
else if (!cjson_is_number (j_item))
return gpg_error (GPG_ERR_INV_VALUE);
else if ((size_t)j_item->valueint < MIN_REPLY_CHUNK_SIZE)
*r_chunksize = MIN_REPLY_CHUNK_SIZE;
else if ((size_t)j_item->valueint > MAX_REPLY_CHUNK_SIZE)
*r_chunksize = MAX_REPLY_CHUNK_SIZE;
else
*r_chunksize = (size_t)j_item->valueint;
return 0;
}
/* Extract the keys from the "keys" array in the JSON object. On
* success a string with the keys identifiers is stored at R_KEYS.
* The keys in that string are LF delimited. On failure an error code
* is returned. */
static gpg_error_t
get_keys (cjson_t json, char **r_keystring)
{
cjson_t j_keys, j_item;
int i, nkeys;
char *p;
size_t length;
*r_keystring = NULL;
j_keys = cJSON_GetObjectItem (json, "keys");
if (!j_keys)
return gpg_error (GPG_ERR_NO_KEY);
if (!cjson_is_array (j_keys) && !cjson_is_string (j_keys))
return gpg_error (GPG_ERR_INV_VALUE);
/* Fixme: We should better use a membuf like thing. */
length = 1; /* For the EOS. */
if (cjson_is_string (j_keys))
{
nkeys = 1;
length += strlen (j_keys->valuestring);
if (strchr (j_keys->valuestring, '\n'))
return gpg_error (GPG_ERR_INV_USER_ID);
}
else
{
nkeys = cJSON_GetArraySize (j_keys);
if (!nkeys)
return gpg_error (GPG_ERR_NO_KEY);
for (i=0; i < nkeys; i++)
{
j_item = cJSON_GetArrayItem (j_keys, i);
if (!j_item || !cjson_is_string (j_item))
return gpg_error (GPG_ERR_INV_VALUE);
if (i)
length++; /* Space for delimiter. */
length += strlen (j_item->valuestring);
if (strchr (j_item->valuestring, '\n'))
return gpg_error (GPG_ERR_INV_USER_ID);
}
}
p = *r_keystring = xtrymalloc (length);
if (!p)
return gpg_error_from_syserror ();
if (cjson_is_string (j_keys))
{
strcpy (p, j_keys->valuestring);
}
else
{
for (i=0; i < nkeys; i++)
{
j_item = cJSON_GetArrayItem (j_keys, i);
if (i)
*p++ = '\n'; /* Add delimiter. */
p = stpcpy (p, j_item->valuestring);
}
}
return 0;
}
/*
* GPGME support functions.
*/
/* Helper for get_context. */
static gpgme_ctx_t
_create_new_context (gpgme_protocol_t proto)
{
gpg_error_t err;
gpgme_ctx_t ctx;
err = gpgme_new (&ctx);
if (err)
log_fatal ("error creating GPGME context: %s\n", gpg_strerror (err));
gpgme_set_protocol (ctx, proto);
gpgme_set_ctx_flag (ctx, "request-origin", "browser");
return ctx;
}
/* Return a context object for protocol PROTO. This is currently a
* statuically allocated context initialized for PROTO. Termnates
* process on failure. */
static gpgme_ctx_t
get_context (gpgme_protocol_t proto)
{
static gpgme_ctx_t ctx_openpgp, ctx_cms;
if (proto == GPGME_PROTOCOL_OpenPGP)
{
if (!ctx_openpgp)
ctx_openpgp = _create_new_context (proto);
return ctx_openpgp;
}
else if (proto == GPGME_PROTOCOL_CMS)
{
if (!ctx_cms)
ctx_cms = _create_new_context (proto);
return ctx_cms;
}
else
log_bug ("invalid protocol %d requested\n", proto);
}
/* Free context object retrieved by get_context. */
static void
release_context (gpgme_ctx_t ctx)
{
/* Nothing to do right now. */
(void)ctx;
}
/* Given a Base-64 encoded string object in JSON return a gpgme data
* object at R_DATA. */
static gpg_error_t
data_from_base64_string (gpgme_data_t *r_data, cjson_t json)
{
#if GPGRT_VERSION_NUMBER < 0x011d00 /* 1.29 */
*r_data = NULL;
return gpg_error (GPG_ERR_NOT_SUPPORTED);
#else
gpg_error_t err;
size_t len;
char *buf = NULL;
gpgrt_b64state_t state = NULL;
gpgme_data_t data = NULL;
*r_data = NULL;
/* A quick check on the JSON. */
if (!cjson_is_string (json))
{
err = gpg_error (GPG_ERR_INV_VALUE);
goto leave;
}
state = gpgrt_b64dec_start (NULL);
if (!state)
{
err = gpg_err_code_from_syserror ();
goto leave;
}
/* Fixme: Data duplication - we should see how to snatch the memory
* from the json object. */
len = strlen (json->valuestring);
buf = xtrystrdup (json->valuestring);
if (!buf)
{
err = gpg_error_from_syserror ();
goto leave;
}
err = gpgrt_b64dec_proc (state, buf, len, &len);
if (err)
goto leave;
err = gpgrt_b64dec_finish (state);
state = NULL;
if (err)
goto leave;
err = gpgme_data_new_from_mem (&data, buf, len, 1);
if (err)
goto leave;
*r_data = data;
data = NULL;
leave:
xfree (data);
xfree (buf);
gpgrt_b64dec_finish (state);
return err;
#endif
}
/*
* Implementation of the commands.
*/
/* Create a "data" object and the "type", "base64" and "more" flags
* from DATA and append them to RESULT. Ownership if DATA is
* transferred to this function. TYPE must be a fixed string.
* CHUNKSIZE is the chunksize requested from the caller. If BASE64 is
* -1 the need for base64 encoding is determined by the content of
* DATA, all other values are take as rtue or false. Note that
* op_getmore has similar code but works on PENDING_DATA which is set
* here. */
static gpg_error_t
make_data_object (cjson_t result, gpgme_data_t data, size_t chunksize,
const char *type, int base64)
{
gpg_error_t err;
char *buffer;
size_t buflen;
int c;
if (!base64 || base64 == -1) /* Make sure that we really have a string. */
gpgme_data_write (data, "", 1);
buffer = gpgme_data_release_and_get_mem (data, &buflen);
data = NULL;
if (!buffer)
{
err = gpg_error_from_syserror ();
goto leave;
}
if (base64 == -1)
{
base64 = 0;
if (!buflen)
log_fatal ("Appended Nul byte got lost\n");
if (memchr (buffer, 0, buflen-1))
{
buflen--; /* Adjust for the extra nul byte. */
base64 = 1;
}
/* Fixme: We might want to do more advanced heuristics than to
* only look for a Nul. */
}
/* Adjust the chunksize if we need to do base64 conversion. */
if (base64)
chunksize = (chunksize / 4) * 3;
xjson_AddStringToObject (result, "type", type);
xjson_AddBoolToObject (result, "base64", base64);
if (buflen > chunksize)
{
xjson_AddBoolToObject (result, "more", 1);
c = buffer[chunksize];
buffer[chunksize] = 0;
if (base64)
err = add_base64_to_object (result, "data", buffer, chunksize);
else
err = cjson_AddStringToObject (result, "data", buffer);
buffer[chunksize] = c;
if (err)
goto leave;
pending_data.buffer = buffer;
buffer = NULL;
pending_data.length = buflen;
pending_data.written = chunksize;
pending_data.type = type;
pending_data.base64 = base64;
}
else
{
if (base64)
err = add_base64_to_object (result, "data", buffer, buflen);
else
err = cjson_AddStringToObject (result, "data", buffer);
}
leave:
gpgme_free (buffer);
return err;
}
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: Input data. \n"
"\n"
"Optional parameters:\n"
"protocol: Either \"openpgp\" (default) or \"cms\".\n"
"chunksize: Max number of bytes in the resulting \"data\".\n"
"\n"
"Optional boolean flags (default is false):\n"
"base64: Input data is base64 encoded.\n"
"mime: Indicate that data is a MIME object.\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"
"want-address: Require that the keys include a mail address.\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.\n"
"more: Optional boolean indicating that \"getmore\" is required.";
static gpg_error_t
op_encrypt (cjson_t request, cjson_t result)
{
gpg_error_t err;
gpgme_ctx_t ctx = NULL;
gpgme_protocol_t protocol;
size_t chunksize;
int opt_base64;
int opt_mime;
char *keystring = NULL;
cjson_t j_input;
gpgme_data_t input = NULL;
gpgme_data_t output = NULL;
int abool;
gpgme_encrypt_flags_t encrypt_flags = 0;
if ((err = get_protocol (request, &protocol)))
goto leave;
ctx = get_context (protocol);
if ((err = get_chunksize (request, &chunksize)))
goto leave;
if ((err = get_boolean_flag (request, "base64", 0, &opt_base64)))
goto leave;
if ((err = get_boolean_flag (request, "mime", 0, &opt_mime)))
goto leave;
if ((err = get_boolean_flag (request, "armor", 0, &abool)))
goto leave;
gpgme_set_armor (ctx, abool);
if ((err = get_boolean_flag (request, "always-trust", 0, &abool)))
goto leave;
if (abool)
encrypt_flags |= GPGME_ENCRYPT_ALWAYS_TRUST;
if ((err = get_boolean_flag (request, "no-encrypt-to", 0,&abool)))
goto leave;
if (abool)
encrypt_flags |= GPGME_ENCRYPT_NO_ENCRYPT_TO;
if ((err = get_boolean_flag (request, "no-compress", 0, &abool)))
goto leave;
if (abool)
encrypt_flags |= GPGME_ENCRYPT_NO_COMPRESS;
if ((err = get_boolean_flag (request, "throw-keyids", 0, &abool)))
goto leave;
if (abool)
encrypt_flags |= GPGME_ENCRYPT_THROW_KEYIDS;
if ((err = get_boolean_flag (request, "wrap", 0, &abool)))
goto leave;
if (abool)
encrypt_flags |= GPGME_ENCRYPT_WRAP;
if ((err = get_boolean_flag (request, "want-address", 0, &abool)))
goto leave;
if (abool)
encrypt_flags |= GPGME_ENCRYPT_WANT_ADDRESS;
/* Get the keys. */
err = get_keys (request, &keystring);
if (err)
{
/* Provide a custom error response. */
error_object (result, "Error getting keys: %s", gpg_strerror (err));
goto leave;
}
/* Get the data. Note that INPUT is a shallow data object with the
* storage hold in REQUEST. */
j_input = cJSON_GetObjectItem (request, "data");
if (!j_input)
{
err = gpg_error (GPG_ERR_NO_DATA);
goto leave;
}
if (!cjson_is_string (j_input))
{
err = gpg_error (GPG_ERR_INV_VALUE);
goto leave;
}
if (opt_base64)
{
err = data_from_base64_string (&input, j_input);
if (err)
{
error_object (result, "Error decoding Base-64 encoded 'data': %s",
gpg_strerror (err));
goto leave;
}
}
else
{
err = gpgme_data_new_from_mem (&input, j_input->valuestring,
strlen (j_input->valuestring), 0);
if (err)
{
error_object (result, "Error getting 'data': %s", gpg_strerror (err));
goto leave;
}
}
if (opt_mime)
gpgme_data_set_encoding (input, GPGME_DATA_ENCODING_MIME);
/* Create an output data object. */
err = gpgme_data_new (&output);
if (err)
{
error_object (result, "Error creating output data object: %s",
gpg_strerror (err));
goto leave;
}
/* Encrypt. */
err = gpgme_op_encrypt_ext (ctx, NULL, keystring, encrypt_flags,
input, output);
/* encrypt_result = gpgme_op_encrypt_result (ctx); */
if (err)
{
error_object (result, "Encryption failed: %s", gpg_strerror (err));
goto leave;
}
gpgme_data_release (input);
input = NULL;
/* We need to base64 if armoring has not been requested. */
err = make_data_object (result, output, chunksize,
"ciphertext", !gpgme_get_armor (ctx));
output = NULL;
leave:
xfree (keystring);
release_context (ctx);
gpgme_data_release (input);
gpgme_data_release (output);
return err;
}
static const char hlp_decrypt[] =
"op: \"decrypt\"\n"
"data: The encrypted data.\n"
"\n"
"Optional parameters:\n"
"protocol: Either \"openpgp\" (default) or \"cms\".\n"
"chunksize: Max number of bytes in the resulting \"data\".\n"
"\n"
"Optional boolean flags (default is false):\n"
"base64: Input data is base64 encoded.\n"
"\n"
"Response on success:\n"
"type: \"plaintext\"\n"
"data: The decrypted data. This may be base64 encoded.\n"
"base64: Boolean indicating whether data is base64 encoded.\n"
"mime: A Boolean indicating whether the data is a MIME object.\n"
"info: An optional object with extra information.\n"
"more: Optional boolean indicating that \"getmore\" is required.";
static gpg_error_t
op_decrypt (cjson_t request, cjson_t result)
{
gpg_error_t err;
gpgme_ctx_t ctx = NULL;
gpgme_protocol_t protocol;
size_t chunksize;
int opt_base64;
cjson_t j_input;
gpgme_data_t input = NULL;
gpgme_data_t output = NULL;
gpgme_decrypt_result_t decrypt_result;
if ((err = get_protocol (request, &protocol)))
goto leave;
ctx = get_context (protocol);
if ((err = get_chunksize (request, &chunksize)))
goto leave;
if ((err = get_boolean_flag (request, "base64", 0, &opt_base64)))
goto leave;
/* Get the data. Note that INPUT is a shallow data object with the
* storage hold in REQUEST. */
j_input = cJSON_GetObjectItem (request, "data");
if (!j_input)
{
err = gpg_error (GPG_ERR_NO_DATA);
goto leave;
}
if (!cjson_is_string (j_input))
{
err = gpg_error (GPG_ERR_INV_VALUE);
goto leave;
}
if (opt_base64)
{
err = data_from_base64_string (&input, j_input);
if (err)
{
error_object (result, "Error decoding Base-64 encoded 'data': %s",
gpg_strerror (err));
goto leave;
}
}
else
{
err = gpgme_data_new_from_mem (&input, j_input->valuestring,
strlen (j_input->valuestring), 0);
if (err)
{
error_object (result, "Error getting 'data': %s", gpg_strerror (err));
goto leave;
}
}
/* Create an output data object. */
err = gpgme_data_new (&output);
if (err)
{
error_object (result, "Error creating output data object: %s",
gpg_strerror (err));
goto leave;
}
/* Decrypt. */
err = gpgme_op_decrypt_ext (ctx, GPGME_DECRYPT_VERIFY,
input, output);
decrypt_result = gpgme_op_decrypt_result (ctx);
if (err)
{
error_object (result, "Decryption failed: %s", gpg_strerror (err));
goto leave;
}
gpgme_data_release (input);
input = NULL;
if (decrypt_result->is_mime)
xjson_AddBoolToObject (result, "mime", 1);
err = make_data_object (result, output, chunksize, "plaintext", -1);
output = NULL;
leave:
release_context (ctx);
gpgme_data_release (input);
gpgme_data_release (output);
return err;
}
static const char hlp_getmore[] =
"op: \"getmore\"\n"
"\n"
"Optional parameters:\n"
"chunksize: Max number of bytes in the \"data\" object.\n"
"\n"
"Response on success:\n"
"type: Type of the pending data\n"
"data: The next chunk of data\n"
"base64: Boolean indicating whether data is base64 encoded\n"
"more: Optional boolean requesting another \"getmore\".";
static gpg_error_t
op_getmore (cjson_t request, cjson_t result)
{
gpg_error_t err;
int c;
size_t n;
size_t chunksize;
if ((err = get_chunksize (request, &chunksize)))
goto leave;
/* Adjust the chunksize if we need to do base64 conversion. */
if (pending_data.base64)
chunksize = (chunksize / 4) * 3;
/* Do we have anything pending? */
if (!pending_data.buffer)
{
err = gpg_error (GPG_ERR_NO_DATA);
error_object (result, "Operation not possible: %s", gpg_strerror (err));
goto leave;
}
xjson_AddStringToObject (result, "type", pending_data.type);
xjson_AddBoolToObject (result, "base64", pending_data.base64);
if (pending_data.written >= pending_data.length)
{
/* EOF reached. This should not happen but we return an empty
* string once in case of client errors. */
gpgme_free (pending_data.buffer);
pending_data.buffer = NULL;
xjson_AddBoolToObject (result, "more", 0);
err = cjson_AddStringToObject (result, "data", "");
}
else
{
n = pending_data.length - pending_data.written;
if (n > chunksize)
{
n = chunksize;
xjson_AddBoolToObject (result, "more", 1);
}
else
xjson_AddBoolToObject (result, "more", 0);
c = pending_data.buffer[pending_data.written + n];
pending_data.buffer[pending_data.written + n] = 0;
if (pending_data.base64)
err = add_base64_to_object (result, "data",
(pending_data.buffer
+ pending_data.written), n);
else
err = cjson_AddStringToObject (result, "data",
(pending_data.buffer
+ pending_data.written));
pending_data.buffer[pending_data.written + n] = c;
if (!err)
{
pending_data.written += n;
if (pending_data.written >= pending_data.length)
{
gpgme_free (pending_data.buffer);
pending_data.buffer = NULL;
}
}
}
leave:
return err;
}
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"
" getmore Retrieve remaining data.\n"
" help Help overview.";
static gpg_error_t
op_help (cjson_t request, cjson_t result)
{
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;
xjson_AddStringToObject (result, "type", "help");
xjson_AddStringToObject (result, "msg", msg);
xfree (buffer);
return 0;
}
/*
* Dispatcher
*/
/* Process a request and return the response. The response is a newly
* allocated string 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 result);
const char * const helpstr;
} optbl[] = {
{ "encrypt", op_encrypt, hlp_encrypt },
{ "decrypt", op_decrypt, hlp_decrypt },
{ "getmore", op_getmore, hlp_getmore },
{ "help", op_help, hlp_help },
{ NULL }
};
size_t erroff;
cjson_t json;
cjson_t j_tmp, j_op;
cjson_t response;
int helpmode;
const char *op;
char *res;
int idx;
response = xjson_CreateObject ();
json = cJSON_Parse (request, &erroff);
if (!json)
{
log_string (GPGRT_LOGLVL_INFO, request);
log_info ("invalid JSON object at offset %zu\n", erroff);
error_object (response, "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)
{
error_object (response, "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"))
{
xjson_AddStringToObject (response, "type", "help");
xjson_AddStringToObject (response, "op", op);
xjson_AddStringToObject (response, "msg", optbl[idx].helpstr);
}
else
{
gpg_error_t err;
/* If this is not the "getmore" command and we have any
* pending data release that data. */
if (pending_data.buffer && optbl[idx].handler != op_getmore)
{
gpgme_free (pending_data.buffer);
pending_data.buffer = NULL;
}
err = optbl[idx].handler (json, response);
if (err)
{
if (!(j_tmp = cJSON_GetObjectItem (response, "type"))
|| !cjson_is_string (j_tmp)
|| strcmp (j_tmp->valuestring, "error"))
{
/* No error type response - provide a generic one. */
error_object (response, "Operation failed: %s",
gpg_strerror (err));
}
xjson_AddStringToObject (response, "op", op);
}
}
}
else /* Operation not supported. */
{
error_object (response, "Unknown operation '%s'", op);
xjson_AddStringToObject (response, "op", op);
}
leave:
cJSON_Delete (json);
if (opt_interactive)
res = cJSON_Print (response);
else
res = cJSON_PrintUnformatted (response);
if (!res)
log_error ("Printing JSON data failed\n");
cJSON_Delete (response);
return res;
}
/*
* Driver code
*/
static char *
get_file (const char *fname)
{
gpg_error_t err;
estream_t fp;
struct stat st;
char *buf;
size_t buflen;
fp = es_fopen (fname, "r");
if (!fp)
{
err = gpg_error_from_syserror ();
log_error ("can't open '%s': %s\n", fname, gpg_strerror (err));
return NULL;
}
if (fstat (es_fileno(fp), &st))
{
err = gpg_error_from_syserror ();
log_error ("can't stat '%s': %s\n", fname, gpg_strerror (err));
es_fclose (fp);
return NULL;
}
buflen = st.st_size;
buf = xmalloc (buflen+1);
if (es_fread (buf, buflen, 1, fp) != 1)
{
err = gpg_error_from_syserror ();
log_error ("error reading '%s': %s\n", fname, gpg_strerror (err));
es_fclose (fp);
xfree (buf);
return NULL;
}
buf[buflen] = 0;
es_fclose (fp);
return buf;
}
/* 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]))
{
if (request[4])
{
char *buf = xstrconcat ("{ \"help\":true, \"op\":\"", request+5,
"\" }", NULL);
result = process_request (buf);
xfree (buf);
}
else
result = process_request ("{ \"op\": \"help\","
" \"interactive_help\": "
"\"\\nMeta commands:\\n"
" ,read FNAME Process data from FILE\\n"
" ,help CMD Print help for a command\\n"
" ,quit Terminate process\""
"}");
}
else if (!strncmp (request, "quit", 4) && (spacep (request+4) || !request[4]))
exit (0);
else if (!strncmp (request, "read", 4) && (spacep (request+4) || !request[4]))
{
if (!request[4])
log_info ("usage: ,read FILENAME\n");
else
{
char *buffer = get_file (request + 5);
if (buffer)
{
result = process_request (buffer);
xfree (buffer);
}
}
}
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);
#if GPGRT_VERSION_NUMBER >= 0x011d00 /* 1.29 */
es_fprintf (es_stderr, "%s %s ready (enter \",help\" for help)\n",
gpgrt_strusage (11), gpgrt_strusage (13));
#endif
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 a single 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);
es_setbuf (es_stdin, NULL); /* stdin needs to be unbuffered! */
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 to 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 */
{
if (opt_debug)
log_debug ("request='%s'\n", request);
xfree (response);
response = process_request (request);
if (opt_debug)
log_debug ("response='%s'\n", response);
}
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 9: p = "LGPL-2.1-or-later"; break;
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[])
{
#if GPGRT_VERSION_NUMBER < 0x011d00 /* 1.29 */
fprintf (stderr, "WARNING: Old libgpg-error - using limited mode\n");
native_messaging_repl ();
#else /* This is a modern libgp-error. */
enum { CMD_DEFAULT = 0,
CMD_INTERACTIVE = 'i',
CMD_SINGLE = 's',
CMD_LIBVERSION = 501,
} cmd = CMD_DEFAULT;
enum {
OPT_DEBUG = 600
};
static gpgrt_opt_t 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_s_n(OPT_DEBUG, "debug", "Flyswatter"),
ARGPARSE_end()
};
gpgrt_argparse_t pargs = { &argc, &argv};
gpgrt_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 (gpgrt_argparse (NULL, &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;
case OPT_DEBUG: opt_debug = 1; break;
default:
pargs.err = ARGPARSE_PRINT_WARNING;
break;
}
}
gpgrt_argparse (NULL, &pargs, NULL);
if (!opt_debug)
{
const char *s = getenv ("GPGME_JSON_DEBUG");
if (s && atoi (s) > 0)
opt_debug = 1;
}
if (opt_debug)
{
const char *home = getenv ("HOME");
char *file = xstrconcat ("socket://",
home? home:"/tmp",
"/.gnupg/S.gpgme-json.log", NULL);
log_set_file (file);
xfree (file);
}
if (opt_debug)
{ int i;
for (i=0; argv[i]; i++)
log_debug ("argv[%d]='%s'\n", i, argv[i]);
}
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;
}
if (opt_debug)
log_debug ("ready");
#endif /* This is a modern libgp-error. */
return 0;
}
#endif /* libgpg-error >= 1.28 */