json: Generalize chunking and getmore

* src/gpgme-json.c (MIN_REPLY_CHUNK_SIZE): Lower value to
new real minimum.
(DEF_REPLY_CHUNK_SIZE): Don't chunk by default.
(pending_data): Remove type and base64.
(make_data_object): Remove chunksize handling as this is now
generic.
(encode_and_chunk): Setup the pending_data buffer for chunking
if required.
(op_getmore): Changed to generically work on a response.
(hlp_getmore): Update accordingly.
(hlp_help): Document chunksize as generic parameter for all commands.
(process_request): Use encode_and_chunk on the response.
(hlp_encrypt, op_encrypt, hlp_decrypt, op_decrypt),
(hlp_verify, op_verify, hlp_sign, op_sign),
(op_keylist, hlp_keylist, hlp_export, op_export): Update accordingly.

--
To include handling for json properties e.g. in a keylist in
the chunk mechanism the mechanism is now more general.

If the chunksize property is provided the response will
always look exactly like a "getmore" response. E.g.

e.g.:
{
    "op": "keylist",
    "chunksize": 64
}
Results in:
{
   "more": true,
   "base64": true,
   "response": "ewoJImtleXMiOglbewoJCQkicmV2b2tlZCI6"
}

For simplicity this is even true if the chunksize is larger
then the response.

The client has to combine all "response" chunks and base64
decode them to get valid json.

The complete response (including json) is never larger then
the chunksize but might be smaller. Except for interactive
use due to additional format characters.
This commit is contained in:
Andre Heinecke 2018-06-07 17:48:55 +02:00
parent e48f4a18f8
commit af8510fb7f
No known key found for this signature in database
GPG Key ID: 2978E9D40CBABA5C

View File

@ -48,14 +48,13 @@ int main (void){fputs ("Build with Libgpg-error >= 1.28!\n", stderr);return 1;}
/* 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)
/* Minimal chunk size for returned data.*/
#define MIN_REPLY_CHUNK_SIZE 30
/* If no chunksize is provided we print everything. Changing
* this to a positive value will result in all messages beeing
* chunked. */
#define DEF_REPLY_CHUNK_SIZE 0
#define MAX_REPLY_CHUNK_SIZE (10 * 1024 * 1024)
@ -67,6 +66,7 @@ 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);
static char *process_request (const char *request);
/* True if interactive mode is active. */
@ -80,8 +80,6 @@ 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;
@ -1336,29 +1334,20 @@ get_string_data (cjson_t request, cjson_t result, const char *name,
}
/*
* Implementation of the commands.
*/
/* Create a "data" object and the "type", "base64" and "more" flags
/* Create a "data" object and the "type" and "base64" flags
* from DATA and append them to RESULT. Ownership of 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 taken as true or false. Note that
* op_getmore has similar code but works on PENDING_DATA which is set
* here. */
* If BASE64 is -1 the need for base64 encoding is determined
* by the content of DATA, all other values are taken as true
* or false. */
static gpg_error_t
make_data_object (cjson_t result, gpgme_data_t data, size_t chunksize,
make_data_object (cjson_t result, gpgme_data_t data,
const char *type, int base64)
{
gpg_error_t err;
char *buffer;
const char *s;
size_t buflen, n;
int c;
if (!base64 || base64 == -1) /* Make sure that we really have a string. */
gpgme_data_write (data, "", 1);
@ -1390,41 +1379,13 @@ make_data_object (cjson_t result, gpgme_data_t data, size_t chunksize,
}
}
/* 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);
@ -1432,7 +1393,84 @@ make_data_object (cjson_t result, gpgme_data_t data, size_t chunksize,
}
/* Encode and chunk response.
*
* If neccessary this base64 encodes and chunks the repsonse
* for getmore so that we always return valid json independent
* of the chunksize.
*
* A chunked repsonse contains the base64 encoded chunk
* as a string and a boolean if there is still more data
* available for getmore like:
* {
* chunk: "SGVsbG8gV29ybGQK"
* more: true
* }
*
* Chunking is only done if the response is larger then the
* chunksize.
*
* caller has to xfree the return value.
*/
static char *
encode_and_chunk (cjson_t request, cjson_t response)
{
char *data;
gpg_error_t err = 0;
size_t chunksize;
char *getmore_request = NULL;
if (opt_interactive)
data = cJSON_Print (response);
else
data = cJSON_PrintUnformatted (response);
if (!data)
goto leave;
if ((err = get_chunksize (request, &chunksize)))
goto leave;
if (!chunksize)
goto leave;
pending_data.buffer = data;
/* Data should already be encoded so that it does not
contain 0.*/
pending_data.length = strlen (data);
pending_data.written = 0;
if (gpgrt_asprintf (&getmore_request,
"{ \"op\":\"getmore\", \"chunksize\": %i }",
(int) chunksize) == -1)
{
err = gpg_error_from_syserror ();
goto leave;
}
data = process_request (getmore_request);
leave:
xfree (getmore_request);
if (err)
{
cjson_t err_obj = gpg_error_object (NULL, err,
"Encode and chunk failed: %s",
gpgme_strerror (err));
if (opt_interactive)
return cJSON_Print (err_obj);
return cJSON_PrintUnformatted (err_obj);
}
return data;
}
/*
* Implementation of the commands.
*/
static const char hlp_encrypt[] =
"op: \"encrypt\"\n"
"keys: Array of strings with the fingerprints or user-ids\n"
@ -1442,7 +1480,6 @@ static const char hlp_encrypt[] =
"\n"
"Optional parameters:\n"
"protocol: Either \"openpgp\" (default) or \"cms\".\n"
"chunksize: Max number of bytes in the resulting \"data\".\n"
"signing_keys: Similar to the keys parameter for added signing.\n"
" (openpgp only)"
"\n"
@ -1462,8 +1499,7 @@ static const char hlp_encrypt[] =
"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.";
"base64: Boolean indicating whether data is base64 encoded.";
static gpg_error_t
op_encrypt (cjson_t request, cjson_t result)
{
@ -1471,7 +1507,6 @@ op_encrypt (cjson_t request, cjson_t result)
gpgme_ctx_t ctx = NULL;
gpgme_protocol_t protocol;
char **signing_patterns = NULL;
size_t chunksize;
int opt_mime;
char *keystring = NULL;
gpgme_data_t input = NULL;
@ -1484,8 +1519,6 @@ op_encrypt (cjson_t request, cjson_t 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, "mime", 0, &opt_mime)))
goto leave;
@ -1599,7 +1632,7 @@ op_encrypt (cjson_t request, cjson_t result)
input = NULL;
/* We need to base64 if armoring has not been requested. */
err = make_data_object (result, output, chunksize,
err = make_data_object (result, output,
"ciphertext", !gpgme_get_armor (ctx));
output = NULL;
@ -1623,7 +1656,6 @@ static const char hlp_decrypt[] =
"\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"
@ -1678,15 +1710,13 @@ static const char hlp_decrypt[] =
" name\n"
" value\n"
" Number values:\n"
" flags\n"
"more: Optional boolean indicating that \"getmore\" is required.";
" flags\n";
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;
gpgme_data_t input = NULL;
gpgme_data_t output = NULL;
gpgme_decrypt_result_t decrypt_result;
@ -1695,8 +1725,6 @@ op_decrypt (cjson_t request, cjson_t result)
if ((err = get_protocol (request, &protocol)))
goto leave;
ctx = get_context (protocol);
if ((err = get_chunksize (request, &chunksize)))
goto leave;
if ((err = get_string_data (request, result, "data", &input)))
goto leave;
@ -1734,7 +1762,7 @@ op_decrypt (cjson_t request, cjson_t result)
verify_result_to_json (verify_result));
}
err = make_data_object (result, output, chunksize, "plaintext", -1);
err = make_data_object (result, output, "plaintext", -1);
output = NULL;
if (err)
@ -1761,7 +1789,6 @@ static const char hlp_sign[] =
"\n"
"Optional parameters:\n"
"protocol: Either \"openpgp\" (default) or \"cms\".\n"
"chunksize: Max number of bytes in the resulting \"data\".\n"
"sender: The mail address of the sender.\n"
"mode: A string with the signing mode can be:\n"
" detached (default)\n"
@ -1777,15 +1804,13 @@ static const char hlp_sign[] =
"data: Unless armor mode is used a Base64 encoded binary\n"
" signature. 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.";
"base64: Boolean indicating whether data is base64 encoded.\n";
static gpg_error_t
op_sign (cjson_t request, cjson_t result)
{
gpg_error_t err;
gpgme_ctx_t ctx = NULL;
gpgme_protocol_t protocol;
size_t chunksize;
char **patterns = NULL;
gpgme_data_t input = NULL;
gpgme_data_t output = NULL;
@ -1798,8 +1823,6 @@ op_sign (cjson_t request, cjson_t 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, "armor", 0, &abool)))
goto leave;
@ -1881,7 +1904,7 @@ op_sign (cjson_t request, cjson_t result)
input = NULL;
/* We need to base64 if armoring has not been requested. */
err = make_data_object (result, output, chunksize,
err = make_data_object (result, output,
"signature", !gpgme_get_armor (ctx));
output = NULL;
@ -1904,7 +1927,6 @@ static const char hlp_verify[] =
"\n"
"Optional parameters:\n"
"protocol: Either \"openpgp\" (default) or \"cms\".\n"
"chunksize: Max number of bytes in the resulting \"data\".\n"
"signature: A detached signature. If missing opaque is assumed.\n"
"\n"
"Optional boolean flags (default is false):\n"
@ -1959,15 +1981,13 @@ static const char hlp_verify[] =
" name\n"
" value\n"
" Number values:\n"
" flags\n"
"more: Optional boolean indicating that \"getmore\" is required.";
" flags\n";
static gpg_error_t
op_verify (cjson_t request, cjson_t result)
{
gpg_error_t err;
gpgme_ctx_t ctx = NULL;
gpgme_protocol_t protocol;
size_t chunksize;
gpgme_data_t input = NULL;
gpgme_data_t signature = NULL;
gpgme_data_t output = NULL;
@ -1976,8 +1996,6 @@ op_verify (cjson_t request, cjson_t result)
if ((err = get_protocol (request, &protocol)))
goto leave;
ctx = get_context (protocol);
if ((err = get_chunksize (request, &chunksize)))
goto leave;
if ((err = get_string_data (request, result, "data", &input)))
goto leave;
@ -2022,7 +2040,7 @@ op_verify (cjson_t request, cjson_t result)
verify_result_to_json (verify_result));
}
err = make_data_object (result, output, chunksize, "plaintext", -1);
err = make_data_object (result, output, "plaintext", -1);
output = NULL;
if (err)
@ -2097,7 +2115,6 @@ static const char hlp_keylist[] =
" For a single key a String may be used instead of an array.\n"
" default lists all keys.\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"
"secret: List secret keys.\n"
@ -2215,16 +2232,13 @@ static const char hlp_keylist[] =
" signfirst\n"
" signlast\n"
" encrfirst\n"
" encrlast\n"
"more: Optional boolean indicating that \"getmore\" is required.\n"
" (not implemented)";
" encrlast\n";
static gpg_error_t
op_keylist (cjson_t request, cjson_t result)
{
gpg_error_t err;
gpgme_ctx_t ctx = NULL;
gpgme_protocol_t protocol;
size_t chunksize;
char **patterns = NULL;
int abool;
gpgme_keylist_mode_t mode = 0;
@ -2234,8 +2248,6 @@ op_keylist (cjson_t request, cjson_t result)
if ((err = get_protocol (request, &protocol)))
goto leave;
ctx = get_context (protocol);
if ((err = get_chunksize (request, &chunksize)))
goto leave;
/* Handle the various keylist mode bools. */
if ((err = get_boolean_flag (request, "secret", 0, &abool)))
@ -2406,7 +2418,6 @@ static const char hlp_export[] =
" For a single key a String may be used instead of an array.\n"
" default exports all keys.\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"
"armor: Request output in armored format.\n"
@ -2420,15 +2431,13 @@ static const char hlp_export[] =
"data: Unless armor mode is used a Base64 encoded binary.\n"
" In armor mode a string with an armored\n"
" OpenPGP or a PEM / PKCS12 key.\n"
"base64: Boolean indicating whether data is base64 encoded.\n"
"more: Optional boolean indicating that \"getmore\" is required.";
"base64: Boolean indicating whether data is base64 encoded.\n";
static gpg_error_t
op_export (cjson_t request, cjson_t result)
{
gpg_error_t err;
gpgme_ctx_t ctx = NULL;
gpgme_protocol_t protocol;
size_t chunksize;
char **patterns = NULL;
int abool;
gpgme_export_mode_t mode = 0;
@ -2437,8 +2446,6 @@ op_export (cjson_t request, cjson_t 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, "armor", 0, &abool)))
goto leave;
@ -2495,7 +2502,7 @@ op_export (cjson_t request, cjson_t result)
}
/* We need to base64 if armoring has not been requested. */
err = make_data_object (result, output, chunksize,
err = make_data_object (result, output,
"keys", !gpgme_get_armor (ctx));
output = NULL;
@ -2765,14 +2772,10 @@ leave:
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\".";
"response: base64 encoded json response.\n"
"more: Another getmore is required.\n"
"base64: boolean if the response is base64 encoded.\n";
static gpg_error_t
op_getmore (cjson_t request, cjson_t result)
{
@ -2784,8 +2787,11 @@ op_getmore (cjson_t request, cjson_t result)
if ((err = get_chunksize (request, &chunksize)))
goto leave;
/* Adjust the chunksize if we need to do base64 conversion. */
if (pending_data.base64)
/* For the meta data we need 41 bytes:
{"more":true,"base64":true,"response":""} */
chunksize -= 41;
/* Adjust the chunksize for the base64 conversion. */
chunksize = (chunksize / 4) * 3;
/* Do we have anything pending? */
@ -2797,8 +2803,8 @@ op_getmore (cjson_t request, cjson_t result)
goto leave;
}
xjson_AddStringToObject (result, "type", pending_data.type);
xjson_AddBoolToObject (result, "base64", pending_data.base64);
/* We currently always use base64 encoding for simplicity. */
xjson_AddBoolToObject (result, "base64", 1);
if (pending_data.written >= pending_data.length)
{
@ -2807,7 +2813,7 @@ op_getmore (cjson_t request, cjson_t result)
gpgme_free (pending_data.buffer);
pending_data.buffer = NULL;
xjson_AddBoolToObject (result, "more", 0);
err = cjson_AddStringToObject (result, "data", "");
err = cjson_AddStringToObject (result, "response", "");
}
else
{
@ -2822,21 +2828,16 @@ op_getmore (cjson_t request, cjson_t result)
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",
err = add_base64_to_object (result, "response",
(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);
xfree (pending_data.buffer);
pending_data.buffer = NULL;
}
}
@ -2866,8 +2867,15 @@ static const char hlp_help[] =
" sign Sign data.\n"
" verify Verify data.\n"
" version Get engine information.\n"
" getmore Retrieve remaining data.\n"
" help Help overview.";
" getmore Retrieve remaining data if chunksize was used.\n"
" help Help overview.\n"
"\n"
"If the data needs to be transferred in smaller chunks the\n"
"property \"chunksize\" with an integer value can be added.\n"
"When \"chunksize\" is set the response (including json) will\n"
"not be larger then \"chunksize\" but might be smaller.\n"
"The chunked result will be transferred in base64 encoded chunks\n"
"using the \"getmore\" operation. See help getmore for more info.";
static gpg_error_t
op_help (cjson_t request, cjson_t result)
{
@ -2924,6 +2932,7 @@ process_request (const char *request)
cjson_t j_tmp, j_op;
cjson_t response;
int helpmode;
int is_getmore = 0;
const char *op;
char *res;
int idx;
@ -2969,7 +2978,7 @@ process_request (const char *request)
else
{
gpg_error_t err;
is_getmore = optbl[idx].handler == op_getmore;
/* 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)
@ -3001,13 +3010,20 @@ process_request (const char *request)
}
leave:
cJSON_Delete (json);
if (is_getmore)
{
/* For getmore we bypass the encode_and_chunk. */
if (opt_interactive)
res = cJSON_Print (response);
else
res = cJSON_PrintUnformatted (response);
}
else
res = encode_and_chunk (json, response);
if (!res)
log_error ("Printing JSON data failed\n");
cJSON_Delete (json);
cJSON_Delete (response);
return res;
}