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|
#include <fcntl.h>
#include <sys/stat.h>
#define PCRE2_CODE_UNIT_WIDTH 8
#include <pcre2.h>
#include <gcrypt.h>
#include <gnutls/gnutls.h>
#include <toml.h>
#include <curl/curl.h>
#include <json.h>
#include <l8w8jwt/decode.h>
#include <microhttpd.h>
#include "shopify.h"
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 compare(const void *struct1, const void *struct2)
{
return strcmp(*(char **)struct1, *(char **)struct2);
}
static inline _Bool match(const char *shop)
{
pcre2_code *re = pcre2_compile((PCRE2_SPTR)
"^[a-zA-Z0-9][a-zA-Z0-9\\-]*\\.myshopify\\.com",
PCRE2_ZERO_TERMINATED, 0, &(int){ 0 },
&(PCRE2_SIZE){ 0 }, NULL);
pcre2_match_data *match_data
= pcre2_match_data_create_from_pattern(re, NULL);
int rc = pcre2_match(re, (PCRE2_SPTR)shop, strlen(shop), 0, 0,
match_data, NULL);
pcre2_match_data_free(match_data);
pcre2_code_free(re);
return rc >= 0;
}
static size_t append(char *data, size_t size, size_t nmemb, char **res)
{
size_t realsize = size * nmemb;
size_t res_len = *res ? strlen(*res) : 0;
*res = realloc(*res, res_len + realsize + 1);
strlcpy(&(*res)[res_len], data, realsize + 1);
return realsize;
}
static inline int redirect(const char *host, const char *id,
struct MHD_Connection *con, struct MHD_Response **res)
{
static const char *tmpl = "https://%s/apps/%s/";
char url[strlen(tmpl) - strlen("%s") * 2 + strlen(host) + strlen(id)
+ 1];
sprintf(url, tmpl, 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), compare);
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), compare);
if ((param = bsearch(&(struct parameter){ "shop" }, params,
nparams,
sizeof(struct parameter),
compare)))
shop = param->val;
if (!shop || !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),
compare)))
hmac = param->val;
if (!hmac) {
free(query);
clear(params);
free(params);
return MHD_NO;
}
gcry_mac_hd_t hd;
gcry_mac_open(&hd, GCRY_MAC_HMAC_SHA256, GCRY_MAC_FLAG_SECURE,
NULL);
gcry_mac_setkey(hd, api_secret_key, strlen(api_secret_key));
gcry_mac_write(hd, query, strlen(query));
static size_t hmacsha256_len = 32;
unsigned char hmacsha256[hmacsha256_len];
gcry_mac_read(hd, hmacsha256, &hmacsha256_len);
gcry_mac_close(hd);
char hmacsha256_str[hmacsha256_len * 2 + 1];
hmacsha256_str[0] ='\0';
for (int i = 0; i < hmacsha256_len; i++)
sprintf(hmacsha256_str, "%s%02x", hmacsha256_str,
hmacsha256[i]);
if (strcmp(hmac, hmacsha256_str)) {
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),
compare))->val,
((struct shopify_session *)bsearch(
&(struct shopify_session)
{ shop }, sessions, nsessions,
sizeof(struct shopify_session),
compare))->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;
shop = malloc(shop_len + 1);
strlcpy(shop, pair, shop_len + 1);
free(tofree);
if (!match(shop)) {
free(session_token);
free(shop);
return MHD_NO;
}
struct l8w8jwt_decoding_params params;
l8w8jwt_decoding_params_init(¶ms);
params.alg = L8W8JWT_ALG_HS256;
params.jwt = (char *)session_token;
params.jwt_length = strlen(session_token);
params.verification_key = (unsigned char *)api_secret_key;
params.verification_key_length = strlen(api_secret_key);
params.validate_exp = 1;
params.validate_nbf = 1;
params.validate_aud = (char *)api_key;
enum l8w8jwt_validation_result validation;
struct l8w8jwt_claim *claims;
size_t claims_len;
int decode = l8w8jwt_decode(¶ms, &validation, &claims,
&claims_len);
if (validation != L8W8JWT_NBF_FAILURE)
printf("JWT payload nbf is invalid.\n");
struct l8w8jwt_claim *dest
= l8w8jwt_get_claim(claims, claims_len, "dest", 4);
_Bool iss_valid = !strncmp( l8w8jwt_get_claim(claims,
claims_len, "iss", 3)->value,
dest->value, dest->value_length);
printf("JWT payload sub: %s\n", l8w8jwt_get_claim(claims,
claims_len, "sub", 3)->value);
l8w8jwt_free_claims(claims, claims_len);
if (decode != L8W8JWT_SUCCESS
|| validation != L8W8JWT_VALID
&& validation != L8W8JWT_NBF_FAILURE
|| !iss_valid) {
free(session_token);
free(shop);
return MHD_NO;
}
}
char *host = NULL;
size_t host_len = 0;
_Bool embedded = 0;
char *dec_host = NULL;
size_t dec_host_len = 0;
if (params) {
host = ((struct parameter *)bsearch(&(struct parameter)
{ "host" }, params, nparams,
sizeof(struct parameter), compare))->val;
host_len = strlen(host);
param = bsearch(&(struct parameter){ "embedded" }, params,
nparams, sizeof(struct parameter), compare);
embedded = param && !strcmp(param->val, "1");
gnutls_datum_t result;
gnutls_base64_decode2(&(gnutls_datum_t){
(unsigned char *)host,
host_len
}, &result);
dec_host_len = result.size;
dec_host = malloc(dec_host_len + 1);
strlcpy(dec_host, (const char *)result.data, dec_host_len + 1);
gnutls_free(result.data);
}
static const char *header_tmpl
= "frame-ancestors https://%s https://admin.shopify.com;";
char header[strlen(header_tmpl) - strlen("%s") + shop_len + 1];
sprintf(header, header_tmpl, shop);
struct shopify_session *session = bsearch(&(struct shopify_session)
{ shop }, sessions, nsessions,
sizeof(struct shopify_session), compare);
const char *app_id = container->app_id;
if (!strcmp(url, redir_url)) {
const char *code = ((struct parameter *)bsearch(
&(struct parameter){ "code" }, params,
nparams, sizeof(struct parameter),
compare))->val;
CURL *curl = curl_easy_init();
char *json = NULL;
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &json);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, append);
static const char *url_tmpl = "https://%s/oauth/access_token";
char url[strlen(url_tmpl) - strlen("%s") + dec_host_len + 1];
sprintf(url, url_tmpl, dec_host);
curl_easy_setopt(curl, CURLOPT_URL, url);
static const char *post_tmpl
= "client_id=%s&client_secret=%s&code=%s";
char post[strlen(post_tmpl) - strlen("%s") * 3 + strlen(api_key)
+ strlen(api_secret_key) + strlen(code) + 1];
sprintf(post, post_tmpl, api_key, api_secret_key, code);
curl_easy_setopt(curl, CURLOPT_POSTFIELDS, post);
curl_easy_perform(curl);
curl_easy_cleanup(curl);
json_tokener *tokener = json_tokener_new();
json_object *obj = json_tokener_parse_ex(tokener, json,
strlen(json));
struct json_object_iterator iter = json_object_iter_begin(obj);
struct json_object_iterator iter_end
= json_object_iter_end(obj);
while (!json_object_iter_equal(&iter, &iter_end)) {
json_object *val = json_object_iter_peek_value(&iter);
if (!strcmp(json_object_iter_peek_name(&iter),
"access_token")) {
const char *str = json_object_get_string(val);
session->access_token = malloc(strlen(str) + 1);
strcpy(session->access_token, str);
} else if (!strcmp(json_object_iter_peek_name(&iter),
"scope")) {
const char *str = json_object_get_string(val);
session->scopes = malloc(strlen(str) + 1);
strcpy(session->scopes, str);
}
json_object_iter_next(&iter);
}
json_tokener_free(tokener);
free(json);
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 {
FILE *fp = fopen(container->scopes, "r");
toml_table_t* toml = toml_parse_file(fp, NULL, 0);
fclose(fp);
char *scopes = toml_string_in(toml, "scopes").u.s;
toml_free(toml);
static const size_t nonce_len = 64;
char nonce[nonce_len + 1];
nonce[0] = '\0';
const size_t hex_len = nonce_len / 2;
unsigned char hex[hex_len];
gcry_create_nonce(hex, hex_len);
for (int i = 0; i < hex_len; i++)
sprintf(nonce, "%s%02x", nonce, hex[i]);
static const char *tmpl = "https://%s/oauth/authorize"
"?client_id=%s&scope=%s&redirect_uri=%s%s&state=%s";
const size_t auth_url_len = strlen(tmpl) - strlen("%s") * 6
+ dec_host_len + api_key_len + strlen(scopes)
+ app_url_len + strlen(redir_url) + nonce_len;
char auth_url[auth_url_len + 1];
sprintf(auth_url, tmpl, 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) {
static const char *tmpl =
"<!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";
const size_t page_len = strlen(tmpl) - strlen("%s") * 3
+ api_key_len + host_len + auth_url_len;
char page[page_len + 1];
sprintf(page, tmpl, 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[])
{
gcry_check_version("1.9.4");
curl_global_init(CURL_GLOBAL_DEFAULT);
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);
curl_global_cleanup();
}
void shopify_graphql(const char *query, const struct shopify_session *session,
char **json)
{
CURL *curl = curl_easy_init();
curl_easy_setopt(curl, CURLOPT_POSTFIELDS, query);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, json);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, append);
static const char *url_tmpl
= "https://%s/admin/api/2022-07/graphql.json";
char url[strlen(url_tmpl) - strlen("%s") + strlen(session->shop) + 1];
sprintf(url, url_tmpl, session->shop);
curl_easy_setopt(curl, CURLOPT_URL, url);
static const char *hdr_tmpl = "X-Shopify-Access-Token: %s";
char header[strlen(hdr_tmpl) - strlen("%s")
+ strlen(session->access_token) + 1];
sprintf(header, hdr_tmpl, session->access_token);
struct curl_slist *list = NULL;
list = curl_slist_append(list, header);
list = curl_slist_append(list, "Content-Type: application/graphql");
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, list);
curl_easy_perform(curl);
curl_slist_free_all(list);
curl_easy_cleanup(curl);
}
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