1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
|
#include <stdbool.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <microhttpd.h>
#include "shopify.h"
#include "crypt.h"
#include "base64.h"
#include "regex.h"
#include "config.h"
#include "request.h"
#include "accesstoken.h"
#include "sessiontoken.h"
#define AUTH_URL \
"https://%s/oauth/authorize?client_id=%s&scope=%s&redirect_uri=%s%s"\
"&state=%s"
#define AUTH_URL_LEN strlen(AUTH_URL) - strlen("%s") * 6
#define REDIR_PAGE \
"<!DOCTYPE html>\n"\
"<html lang=\"en\">\n"\
"\t<head>\n"\
"\t\t<meta charset=\"utf-8\"/>\n"\
"\t</head>\n"\
"\t<body>\n"\
"\t\t<script src=\"https://unpkg.com/@shopify/app-bridge@3\">\n"\
"\t\t</script>\n"\
"\t\t<script>\n"\
"\t\t\tvar AppBridge = window['app-bridge'];\n"\
"\t\t\tvar Redirect = AppBridge.actions.Redirect;\n"\
"\t\t\tRedirect.create(AppBridge.createApp({\n"\
"\t\t\t\tapiKey: '%s',\n"\
"\t\t\t\thost: '%s'\n"\
"\t\t\t})).dispatch(Redirect.Action.REMOTE, '%s');\n"\
"\t\t</script>\n"\
"\t</body>\n"\
"</html>\n"
#define REDIR_PAGE_LEN strlen(REDIR_PAGE) - strlen("%s") * 3
#define EMBEDDED_HEADER "frame-ancestors https://%s https://admin.shopify.com;"
#define EMBEDDED_HEADER_LEN strlen(EMBEDDED_HEADER) - strlen("%s")
#define EMBEDDED_URL "https://%s/apps/%s/"
#define EMBEDDED_URL_LEN strlen(EMBEDDED_URL) - strlen("%s") * 2
extern inline void crypt_init();
extern inline bool crypt_macmatch(const char *, const char *, const char *);
extern inline void crypt_getnonce(char [], const size_t);
extern inline bool regex_match(const char *);
extern inline void base64_getdecoded(const char *, char **);
extern inline void config_getscopes(const char *, char **);
extern inline void request_init();
extern inline void request_gettoken(const char *, const char *, const char *,
const char *, char **);
extern inline void request_graphql(const char *, const struct shopify_session *,
char **);
extern inline void request_cleanup();
extern inline void accesstoken_parse(const char *, struct shopify_session *);
extern inline bool sessiontoken_isvalid(const char *, const char *,
const char *, const char *);
struct parameter {
char *key;
char *val;
};
struct container {
const char *api_key;
const char *api_secret_key;
const char *app_url;
const char *redir_url;
const char *app_id;
const char *scopes;
char *(*html)(const char *);
const char *js_dir;
const struct shopify_api *apis;
struct shopify_session *sessions;
};
static enum MHD_Result iterate(void *cls, enum MHD_ValueKind kind,
const char *key, const char *val)
{
switch (kind) {
case MHD_GET_ARGUMENT_KIND:
;
struct parameter **params = cls;
int nparams = 0;
while ((*params)[nparams].key)
nparams++;
*params = realloc(*params, sizeof(struct parameter)
* (nparams + 2));
(*params)[nparams].key = malloc(strlen(key) + 1);
strcpy((*params)[nparams].key, key);
(*params)[nparams].val = malloc(strlen(val) + 1);
strcpy((*params)[nparams].val, val);
(*params)[nparams + 1].key = NULL;
break;
case MHD_HEADER_KIND:
;
char ***array = cls;
if (!strcmp(key, "Authorization")) {
static const char *schema = "Bearer ";
const size_t schema_len = strlen(schema);
const int token_len = strlen(val) - schema_len;
if (token_len < 0)
break;
*array[0] = malloc(token_len + 1);
strcpy(*array[0], &val[schema_len]);
} else if (!strcmp(key, "Referer")) {
*array[1] = malloc(strlen(val) + 1);
strcpy(*array[1], val);
}
break;
default:
break;
}
return MHD_YES;
}
static inline void clear(const struct parameter params[])
{
int i = 0;
while (params[i].key) {
free(params[i].val);
free(params[i++].key);
}
}
static int keycmp(const void *struct1, const void *struct2)
{
return strcmp(*(char **)struct1, *(char **)struct2);
}
static inline int redirect(const char *host, const char *id,
struct MHD_Connection *con, struct MHD_Response **res)
{
char url[EMBEDDED_URL_LEN + strlen(host) + strlen(id) + 1];
sprintf(url, EMBEDDED_URL, host, id);
*res = MHD_create_response_from_buffer(0, "", MHD_RESPMEM_PERSISTENT);
MHD_add_response_header(*res, "Location", url);
return MHD_queue_response(con, MHD_HTTP_PERMANENT_REDIRECT, *res);
}
static enum MHD_Result handle_request(void *cls, struct MHD_Connection *con,
const char *url, const char *method, const char *version,
const char *upload_data, size_t *upload_data_size,
void **con_cls)
{
struct parameter *params = *con_cls;
if (!params) {
params = malloc(sizeof(struct parameter));
params[0].key = NULL;
*con_cls = params;
return MHD_YES;
}
struct container *container = cls;
struct MHD_Response *res = NULL;
enum MHD_Result ret = MHD_NO;
char *dot = strrchr(url, '.');
if (dot && !strcmp(method, "GET")
&& (!strcmp(dot, ".js") || !strcmp(dot, ".wasm")
|| !strcmp(dot, ".data"))) {
char path[strlen(container->js_dir) + strlen(url) + 1];
sprintf(path, "%s%s", container->js_dir, url);
int fd = open(path, O_RDONLY);
if (fd == -1) {
close(fd);
static char *notfound = "Not Found";
res = MHD_create_response_from_buffer(strlen(notfound),
notfound, MHD_RESPMEM_PERSISTENT);
ret = MHD_queue_response(con, MHD_HTTP_NOT_FOUND, res);
} else {
struct stat sb;
fstat(fd, &sb);
char file[sb.st_size + 1];
read(fd, file, sb.st_size);
close(fd);
res = MHD_create_response_from_buffer(sb.st_size, file,
MHD_RESPMEM_MUST_COPY);
static const char *js_type = "application/javascript";
static const char *wasm_type = "application/wasm";
static const char *data_type = "text/html";
const char *type = NULL;
if (!strcmp(dot, ".js"))
type = js_type;
else if (!strcmp(dot, ".wasm"))
type = wasm_type;
else if (!strcmp(dot, ".data"))
type = data_type;
MHD_add_response_header(res, "Content-Type", type);
ret = MHD_queue_response(con, MHD_HTTP_OK, res);
}
return ret;
}
MHD_get_connection_values(con, MHD_GET_ARGUMENT_KIND, iterate, ¶ms);
const char *api_key = container->api_key;
const size_t api_key_len = strlen(api_key);
const char *api_secret_key = container->api_secret_key;
const char *app_url = container->app_url;
const size_t app_url_len = strlen(app_url);
const char *redir_url = container->redir_url;
struct shopify_session *sessions = container->sessions;
int nsessions = 0;
while (sessions[nsessions].shop)
nsessions++;
qsort(sessions, nsessions, sizeof(struct shopify_session), keycmp);
char *shop = NULL;
size_t shop_len = 0;
char *session_token = NULL;
struct parameter *param = NULL;
int nparams = 0;
while (params[nparams].key)
nparams++;
if (nparams) {
qsort(params, nparams, sizeof(struct parameter), keycmp);
if ((param = bsearch(&(struct parameter){ "shop" }, params,
nparams,
sizeof(struct parameter),
keycmp)))
shop = param->val;
if (!shop || !regex_match(shop)) {
clear(params);
free(params);
return MHD_NO;
}
shop_len = strlen(shop);
char *query = NULL;
for (int i = 0; i < nparams; i++) {
const char *key = params[i].key;
const char *val = params[i].val;
if (strcmp(key, "hmac")) {
size_t query_len = query ? strlen(query) : 0;
bool ampersand_len = i != nparams - 1;
query = realloc(query, query_len + strlen(key)
+ strlen("=") + strlen(val)
+ ampersand_len + 1);
query[query_len] = '\0';
sprintf(query, "%s%s=%s%s", query, key, val,
ampersand_len ? "&" : "");
}
}
char *hmac = NULL;
if ((param = bsearch(&(struct parameter){ "hmac" }, params,
nparams,
sizeof(struct parameter),
keycmp)))
hmac = param->val;
if (!hmac || !crypt_macmatch(api_secret_key, query, hmac)) {
free(query);
clear(params);
free(params);
return MHD_NO;
}
free(query);
if (!strcmp(url, redir_url)
&& strcmp(((struct parameter *)bsearch(
&(struct parameter)
{ "state" }, params,
nparams,
sizeof(struct parameter),
keycmp))->val,
((struct shopify_session *)bsearch(
&(struct shopify_session)
{ shop }, sessions, nsessions,
sizeof(struct shopify_session),
keycmp))->nonce)) {
clear(params);
free(params);
return MHD_NO;
}
} else {
free(params);
params = NULL;
char *referer = NULL;
MHD_get_connection_values(con, MHD_HEADER_KIND, iterate,
(char **[]){ &session_token, &referer });
if (!session_token || !referer
|| strncmp(referer, app_url, app_url_len)
|| referer[app_url_len] != '?'
|| !&referer[app_url_len + 1]) {
if (session_token)
free(session_token);
if (referer)
free(referer);
return MHD_NO;
}
referer = &referer[app_url_len + 1];
char *tofree = referer;
char *pair = NULL;
static const char *key = "shop=";
const size_t key_len = strlen(key);
while ((pair = strsep(&referer, "&")))
if (!strncmp(pair, key, key_len))
break;
if (!pair || !&pair[key_len]) {
free(session_token);
free(tofree);
return MHD_NO;
}
pair = &pair[key_len];
shop_len = (strchrnul(pair, '&') - pair) * sizeof(char);
shop = malloc(shop_len + 1);
strlcpy(shop, pair, shop_len + 1);
free(tofree);
if (!regex_match(shop) || !sessiontoken_isvalid(session_token,
api_key, api_secret_key, shop)) {
free(session_token);
free(shop);
return MHD_NO;
}
}
char *host = NULL;
size_t host_len = 0;
bool embedded = false;
char *dec_host = NULL;
if (params) {
host = ((struct parameter *)bsearch(&(struct parameter)
{ "host" }, params, nparams,
sizeof(struct parameter), keycmp))->val;
host_len = strlen(host);
param = bsearch(&(struct parameter){ "embedded" }, params,
nparams, sizeof(struct parameter), keycmp);
embedded = param && !strcmp(param->val, "1");
base64_getdecoded(host, &dec_host);
}
const char *app_id = container->app_id;
char header[EMBEDDED_HEADER_LEN + shop_len + 1];
sprintf(header, EMBEDDED_HEADER, shop);
struct shopify_session *session = bsearch(&(struct shopify_session)
{ shop }, sessions, nsessions,
sizeof(struct shopify_session), keycmp);
if (!strcmp(url, redir_url)) {
const char *code = ((struct parameter *)bsearch(
&(struct parameter){ "code" }, params,
nparams, sizeof(struct parameter),
keycmp))->val;
char *access_token = NULL;
request_gettoken(dec_host, api_key, api_secret_key, code,
&access_token);
accesstoken_parse(access_token, session);
free(access_token);
ret = redirect(dec_host, app_id, con, &res);
} else if (session_token) {
free(session_token);
free(shop);
int i = 0;
const struct shopify_api *api;
while ((api = &(container->apis[i++])))
if (!strcmp(url, api->url)
&& !strcmp(method, api->method)) {
char *json = NULL;
if (!strcmp(method, "POST")
&& upload_data_size) {
api->cb(upload_data, session, &json);
*upload_data_size = 0;
} else
api->cb(api->arg, session, &json);
res = MHD_create_response_from_buffer(
strlen(json), json,
MHD_RESPMEM_MUST_FREE);
MHD_add_response_header(res,
"Content-Security-Policy",
header);
MHD_add_response_header(res, "Content-Type",
"application/json");
ret = MHD_queue_response(con, MHD_HTTP_OK, res);
break;
}
} else if (session && session->access_token) {
if (embedded) {
char *html = container->html(host);
res = MHD_create_response_from_buffer(strlen(html),
html, MHD_RESPMEM_MUST_FREE);
MHD_add_response_header(res, "Content-Security-Policy",
header);
ret = MHD_queue_response(con, MHD_HTTP_OK, res);
} else
ret = redirect(dec_host, app_id, con, &res);
} else {
const size_t dec_host_len = strlen(dec_host);
char *scopes = NULL;
config_getscopes(container->scopes, &scopes);
const size_t scopes_len = strlen(scopes);
static const size_t nonce_len = 64;
char nonce[nonce_len + 1];
crypt_getnonce(nonce, nonce_len);
const size_t auth_url_len = AUTH_URL_LEN + dec_host_len
+ api_key_len + scopes_len + app_url_len
+ strlen(redir_url) + nonce_len;
char auth_url[auth_url_len + 1];
sprintf(auth_url, AUTH_URL, dec_host, api_key, scopes, app_url,
redir_url, nonce);
free(scopes);
sessions = realloc(sessions, sizeof(struct shopify_session)
* (nsessions + 2));
sessions[nsessions].shop = malloc(shop_len + 1);
strcpy(sessions[nsessions].shop, shop);
sessions[nsessions].nonce = malloc(nonce_len + 1);
strcpy(sessions[nsessions].nonce, nonce);
sessions[nsessions + 1].shop = NULL;
container->sessions = sessions;
if (embedded) {
const size_t page_len = REDIR_PAGE_LEN + api_key_len
+ host_len + auth_url_len;
char page[page_len + 1];
sprintf(page, REDIR_PAGE, api_key, host, auth_url);
res = MHD_create_response_from_buffer(page_len,
page, MHD_RESPMEM_MUST_COPY);
MHD_add_response_header(res, "Content-Security-Policy",
header);
ret = MHD_queue_response(con, MHD_HTTP_OK, res);
} else {
res = MHD_create_response_from_buffer(0, "",
MHD_RESPMEM_PERSISTENT);
MHD_add_response_header(res, "Location", auth_url);
ret = MHD_queue_response(con,
MHD_HTTP_TEMPORARY_REDIRECT, res);
}
}
if (params) {
free(dec_host);
clear(params);
free(params);
}
return ret;
}
void shopify_app(const char *api_key, const char *api_secret_key,
const char *app_url, const char *redir_url, const char *app_id,
const char *scopes, char *(*html)(const char *host),
const char *js_dir, const struct shopify_api apis[])
{
crypt_init();
request_init();
struct shopify_session *sessions
= malloc(sizeof(struct shopify_session));
sessions[0].shop = NULL;
struct MHD_Daemon *daemon
= MHD_start_daemon(MHD_USE_INTERNAL_POLLING_THREAD, 3000, NULL,
NULL, &handle_request, &(struct container){
api_key,
api_secret_key,
app_url,
redir_url,
app_id,
scopes,
html,
js_dir,
apis,
sessions
}, MHD_OPTION_END);
getchar();
MHD_stop_daemon(daemon);
int i = 0;
while (sessions[i].shop) {
if (sessions[i].scopes)
free(sessions[i].scopes);
if (sessions[i].access_token)
free(sessions[i].access_token);
free(sessions[i].nonce);
free(sessions[i++].shop);
}
free(sessions);
request_cleanup();
}
void shopify_graphql(const char *query, const struct shopify_session *session,
char **json)
{
request_graphql(query, session, json);
}
|
