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#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;
const char *index;
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;
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) {
int fd = open(container->index, O_RDONLY);
struct stat sb;
fstat(fd, &sb);
char html[sb.st_size + 1];
read(fd, html, sb.st_size);
close(fd);
const size_t index_len = sb.st_size - strlen("%s") * 4
+ api_key_len + host_len + app_url_len * 2;
char index[index_len + 1];
sprintf(index, html, api_key, host, app_url, app_url);
res = MHD_create_response_from_buffer(index_len, index,
MHD_RESPMEM_MUST_COPY);
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, const char *index, 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,
index,
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);
}
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