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nginx/csp: make blank.html CSP completely restrictive #1479

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Merged
alxndrsn merged 6 commits into from
Nov 20, 2025
Merged

nginx/csp: make blank.html CSP completely restrictive #1479

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fb679c9
nginx/csp: make blank.html CSP completely restrictive
Nov 5, 2025
354077e
add config
Nov 5, 2025
96a562a
Merge branch 'next' into blank-csp
alxndrsn Nov 19, 2025
3ecb4e2
update test to treat paths serving blank.html identically
Nov 19, 2025
d070473
Implement routes
Nov 19, 2025
18aed8d
whitespace: join related blocks
Nov 19, 2025
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14 changes: 12 additions & 2 deletions files/nginx/odk.conf.template
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Original file line number Diff line number Diff line change
Expand Up @@ -130,8 +130,7 @@ server {
}
# To read single submission cookies
location = /-/single/check-submitted {
alias /usr/share/nginx/html/blank.html;
default_type text/html;
try_files $uri @blank.html;
}

# For that iframe to work, we'll need another path prefix (enketo-passthrough) under which we can
Expand Down Expand Up @@ -166,6 +165,17 @@ server {
proxy_read_timeout 2m;
}

location @blank.html {
root /usr/share/nginx/html;
try_files /blank.html =404;

add_header Content-Security-Policy-Report-Only "default-src 'none'";
include /usr/share/odk/nginx/common-headers.conf;
}
location = /blank.html {
try_files $uri @blank.html;
}

location / {
root /usr/share/nginx/html;
try_files $uri $uri/ /index.html;
Expand Down
36 changes: 23 additions & 13 deletions test/nginx/test-nginx.js
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ const none = `'none'`;
const self = `'self'`;
const unsafeInline = `'unsafe-inline'`;
const contentSecurityPolicies = {
'restrictive': {
'backend-default': {
'default-src': none,
'connect-src': [
'https://translate.google.com',
Expand Down Expand Up @@ -37,6 +37,9 @@ const contentSecurityPolicies = {
'worker-src': 'data:',
'report-uri': '/csp-report',
},
'disallow-all': {
'default-src': none,
},
enketo: {
'default-src': none,
'connect-src': [
Expand Down Expand Up @@ -183,7 +186,6 @@ describe('nginx config', () => {
[
[ '/index.html', /<div id="app"><\/div>/ ],
[ '/version.txt', /^versions:/ ],
[ '/blank.html', /^\n$/ ],
[ '/favicon.ico', /^\n$/ ],
].forEach(([ path, expectedContent ]) => {
it(`${path} file should serve expected content`, async () => {
Expand Down Expand Up @@ -317,15 +319,23 @@ describe('nginx config', () => {
});
});

it('should serve blank page on /-/single/check-submitted', async () => {
// when
const res = await fetchHttps('/-/single/check-submitted');
describe('blank.html', () => {
[
'/blank.html',
'/-/single/check-submitted',
].forEach(path => {
it(`should serve blank page on ${path}`, async () => {
// when
const res = await fetchHttps(path);

// then
assert.equal(res.status, 200);
assert.isEmpty((await res.text()).trim());
assertSecurityHeaders(res, { csp:'restrictive' });
await assertEnketoReceivedNoRequests();
// then
assert.equal(res.status, 200);
assert.isEmpty((await res.text()).trim());
assert.equal(res.headers.get('Content-Type'), 'text/html');
assertSecurityHeaders(res, { csp:'disallow-all' });
await assertEnketoReceivedNoRequests();
});
});
});

it('/v1/... should forward to backend', async () => {
Expand All @@ -335,7 +345,7 @@ describe('nginx config', () => {
// then
assert.equal(res.status, 200);
assert.equal(await res.text(), 'OK');
assertSecurityHeaders(res, { csp:'restrictive' });
assertSecurityHeaders(res, { csp:'backend-default' });
// and
await assertBackendReceived(
{ method:'GET', path:'/v1/some/central-backend/path' },
Expand All @@ -347,7 +357,7 @@ describe('nginx config', () => {
const res = await fetchHttps('/v1/reflect-headers');
// then
assert.equal(res.status, 200);
assertSecurityHeaders(res, { csp:'restrictive' });
assertSecurityHeaders(res, { csp:'backend-default' });

// when
const body = await res.json();
Expand All @@ -365,7 +375,7 @@ describe('nginx config', () => {
// then
assert.equal(res.status, 200);
// and
assertSecurityHeaders(res, { csp:'restrictive' });
assertSecurityHeaders(res, { csp:'backend-default' });

// when
const body = await res.json();
Expand Down