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The Captcha response was sent in the header instead of using the payload #139

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The Captcha response was sent in the header instead of using the payload #139

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6 changes: 3 additions & 3 deletions assets/hCaptcha.html
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Original file line number Diff line number Diff line change
Expand Up @@ -14,11 +14,11 @@
</style>
<script>
function onSubmit(token) {
let reqBody = "h-captcha-response=" + token;
let httpRequest = new XMLHttpRequest();
httpRequest.open("POST", "/captcha");
httpRequest.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
httpRequest.send(reqBody);
httpRequest.setRequestHeader("h-captcha-response", token);
httpRequest.send(null);
httpRequest.onreadystatechange = () => {
if (httpRequest.readyState == 4 && httpRequest.status == 200) {
let text = httpRequest.responseText;
Expand All @@ -43,7 +43,7 @@
<body>
<h1>Please complete the captcha.</h1>
<h1>请完成验证码</h1>
<div class="h-captcha" data-sitekey="********your_site_key********" data-callback="onSubmit"></div>
<div class="h-captcha" data-sitekey="%V" data-callback="onSubmit"></div>
</body>

</html>
2 changes: 1 addition & 1 deletion inc/ngx_http_waf_module_data.h
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@
extern unsigned char ngx_http_waf_data_html_under_attack[555];


extern unsigned char ngx_http_waf_data_html_template_hCaptcha[1548];
extern unsigned char ngx_http_waf_data_html_template_hCaptcha[1635];


extern unsigned char ngx_http_waf_data_html_template_reCAPTCHAv2_checkbox[1550];
Expand Down
97 changes: 60 additions & 37 deletions src/ngx_http_waf_module_captcha.c
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Original file line number Diff line number Diff line change
Expand Up @@ -530,6 +530,44 @@ static ngx_int_t _verify_cookies(ngx_http_request_t* r) {
return NGX_HTTP_WAF_SUCCESS;
}

static char* ngx_waf_get_captcha_response_token(ngx_http_request_t* r, ngx_str_t header_str) {

ngx_int_t need_to_continue = NGX_HTTP_WAF_TRUE;

ngx_list_part_t *part;
ngx_table_elt_t *header;
ngx_uint_t i;
char * response_token = NULL;

part = &r->headers_in.headers.part;
header = part->elts;

for (i = 0; /* void */; i++) {
if (need_to_continue == NGX_HTTP_WAF_FALSE)
break;
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
header = part->elts;
i = 0;
}
if (ngx_strcmp(header[i].key.data, header_str.data) == 0) {
if (header[i].value.len > 0 ) {
char * buf = ngx_pnalloc (r->pool, header[i].value.len + 1);
if (buf != NULL) {
ngx_memcpy(buf, header[i].value.data, header[i].value.len);
buf[header[i].value.len] = '\0';
response_token = buf;
}
}
need_to_continue = NGX_HTTP_WAF_FALSE;
}
}

return response_token;
}

static ngx_int_t _verify_captcha_dispatcher(ngx_http_request_t* r) {
ngx_http_waf_dp_func_end(r);
Expand Down Expand Up @@ -591,9 +629,9 @@ static ngx_int_t _verify_hCaptcha(ngx_http_request_t* r) {
ngx_http_waf_loc_conf_t* loc_conf = NULL;
ngx_http_waf_get_ctx_and_conf(r, &loc_conf, &ctx);

ngx_str_t response_key = ngx_string("h-captcha-response");
ngx_str_t response_header = ngx_string("h-captcha-response");
ngx_int_t ret = _verfiy_reCAPTCHA_compatible(r,
response_key,
response_header,
loc_conf->waf_captcha_hCaptcha_secret,
loc_conf->waf_captcha_api,
NGX_HTTP_WAF_FALSE,
Expand All @@ -611,9 +649,9 @@ static ngx_int_t _verify_reCAPTCHAv2(ngx_http_request_t* r) {
ngx_http_waf_loc_conf_t* loc_conf = NULL;
ngx_http_waf_get_ctx_and_conf(r, &loc_conf, &ctx);

ngx_str_t response_key = ngx_string("g-recaptcha-response");
ngx_str_t response_header = ngx_string("g-recaptcha-response");
ngx_int_t ret = _verfiy_reCAPTCHA_compatible(r,
response_key,
response_header,
loc_conf->waf_captcha_reCAPTCHAv2_secret,
loc_conf->waf_captcha_api,
NGX_HTTP_WAF_FALSE,
Expand All @@ -631,9 +669,9 @@ static ngx_int_t _verify_reCAPTCHAv3(ngx_http_request_t* r) {
ngx_http_waf_loc_conf_t* loc_conf = NULL;
ngx_http_waf_get_ctx_and_conf(r, &loc_conf, &ctx);

ngx_str_t response_key = ngx_string("g-recaptcha-response");
ngx_str_t response_header = ngx_string("g-recaptcha-response");
ngx_int_t ret = _verfiy_reCAPTCHA_compatible(r,
response_key,
response_header,
loc_conf->waf_captcha_reCAPTCHAv3_secret,
loc_conf->waf_captcha_api,
NGX_HTTP_WAF_TRUE,
Expand All @@ -645,7 +683,7 @@ static ngx_int_t _verify_reCAPTCHAv3(ngx_http_request_t* r) {


static ngx_int_t _verfiy_reCAPTCHA_compatible(ngx_http_request_t* r,
ngx_str_t response_key,
ngx_str_t response_header,
ngx_str_t secret,
ngx_str_t url,
ngx_int_t is_reCAPTCHA_v3,
Expand All @@ -655,36 +693,30 @@ static ngx_int_t _verfiy_reCAPTCHA_compatible(ngx_http_request_t* r,
ngx_http_waf_ctx_t* ctx = NULL;
ngx_http_waf_loc_conf_t* loc_conf = NULL;
ngx_http_waf_get_ctx_and_conf(r, &loc_conf, &ctx);
ngx_int_t ret = NGX_HTTP_WAF_SUCCESS;

ngx_str_t body = { ctx->req_body.last - ctx->req_body.pos, ctx->req_body.pos };
key_value_t* kvs = NULL;
ngx_http_waf_dpf(r, "parsing form %V", &body);
ngx_int_t ret = ngx_http_waf_parse_form_string(&body, &kvs);
if (ret != NGX_HTTP_WAF_SUCCESS) {
goto hash_map_free;
}
ngx_http_waf_dp(r, "success");

ngx_http_waf_dpf(r, "getting %V", &response_key);
key_value_t* captcha_response = NULL;
HASH_FIND(hh, kvs, response_key.data, response_key.len, captcha_response);
if (captcha_response == NULL) {
char * captcha_token = NULL;
captcha_token = ngx_waf_get_captcha_response_token(r, response_header);
if (captcha_token == NULL) {
ngx_http_waf_dp(r, "failed ... releasing resources");
ret = NGX_HTTP_WAF_FAIL;
goto hash_map_free;
goto _verify_recaptcha_compatible_error;
}
ngx_http_waf_dpf(r, "success(%V)", &captcha_response->value);

ngx_str_t captcha_response = ngx_null_string;
captcha_response.data = (u_char*)captcha_token;
captcha_response.len = strlen(captcha_token);

char* json_str = NULL;
ngx_http_waf_dpf(r, "using serect %V", &secret);

ngx_http_waf_dp(r, "gererating request body for verification");
char* in = ngx_pnalloc(r->pool, captcha_response->value.len + secret.len + 64);
char* in = ngx_pnalloc(r->pool, captcha_response.len + secret.len + 64);
if (in == NULL) {
ngx_http_waf_dp(r, "no memory ... releasing resources");
goto hash_map_free;
goto _verify_recaptcha_compatible_error;
}
sprintf(in, "response=%s&secret=%s", (char*)(captcha_response->value.data), (char*)(secret.data));
sprintf(in, "response=%s&secret=%s", (char*)(captcha_response.data), (char*)(secret.data));
ngx_http_waf_dpf(r, "success(%s)", in);

ngx_http_waf_dpf(r, "sending a request to %V", &url);
Expand All @@ -699,7 +731,7 @@ static ngx_int_t _verfiy_reCAPTCHA_compatible(ngx_http_request_t* r,
}

ngx_http_waf_dp(r, "releasing resources");
goto hash_map_free;
goto _verify_recaptcha_compatible_error;
}
ngx_http_waf_dpf(r, "success(%s)", json_str);

Expand All @@ -709,7 +741,7 @@ static ngx_int_t _verfiy_reCAPTCHA_compatible(ngx_http_request_t* r,
if (json_obj == NULL) {
ngx_http_waf_dp(r, "failed ... releasing resources");
ret = NGX_HTTP_WAF_FAIL;
goto hash_map_free;
goto _verify_recaptcha_compatible_error;
}
ngx_http_waf_dp(r, "success");

Expand Down Expand Up @@ -756,16 +788,7 @@ static ngx_int_t _verfiy_reCAPTCHA_compatible(ngx_http_request_t* r,
// json_free:
cJSON_Delete(json_obj);

hash_map_free:
{
key_value_t *temp0 = NULL, *temp1 = NULL;
HASH_ITER(hh, kvs, temp0, temp1) {
HASH_DEL(kvs, temp0);
free(temp0->key.data);
free(temp0->value.data);
free(temp0);
}
}
_verify_recaptcha_compatible_error:

ngx_http_waf_dp_func_end(r);
return ret;
Expand Down
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