sql(postgres): honour PGSSLMODE=verify-ca/verify-full next to a TLS_* connection URL

[robobun]

Problem

• With the URL in TLS_DATABASE_URL or TLS_POSTGRES_DATABASE_URL, PGSSLMODE=verify-ca or verify-full has no effect. new Bun.SQL().options.sslMode stays 2 (require), which does not check the server certificate. The same URL in DATABASE_URL gives 3 or 4.
• Cause: src/js/internal/sql/shared.ts:1864 read PGSSLMODE only while the mode was disable. A TLS_* variable name sets require first. Found by code inspection.

Fix

• parseOptions reads PGSSLMODE for every postgres connection and keeps the stricter mode. The TLS_* name is a floor of require.
• Correct because only the environment default changes. A URL ?sslmode= and the tls/ssl options apply later and still override it.
• Verified: test/js/sql/adapter-env-var-precedence.test.ts (20 new cases fail on main) and test/js/sql/postgres-pgsslmode-env.test.ts (2 fail on main). Also ran adapter-override.test.ts and sql-tls-ip-literal-host.test.ts.
• Self-reviewed: 13 concerns raised, 12 addressed. Rejected: a merge of the alias pairs PG_SSLMODE/PGSSLMODE and tls/ssl (see Notes).

Background

• sslMode is 0 disable, 1 prefer, 2 require, 3 verify-ca, 4 verify-full. The Postgres handshake checks the certificate only for 3 and 4.
• Designs weighed: a floor at the end of parseOptions also overrides a URL ?sslmode=. The environment lookup does not know the adapter.

Downsides

• New failures on a TLS_* URL. With PGSSLMODE=verify-ca or verify-full, the handshake fails when the certificate does not verify. An invalid PGSSLMODE (no-verify included) throws ERR_INVALID_ARG_VALUE, as next to DATABASE_URL.
• On a TLS_* URL, PGSSLMODE=verify-ca with tls.ca or rejectUnauthorized: true resolves verify-ca, not verify-full: main checked the hostname there. DATABASE_URL already does.
• Cost: +25 bytes of builtin source. A postgres TLS_* URL reads 2 more Bun.env properties per new SQL().

Notes

Measurements, main against this PR

• builtin internal/sql/shared.js: +25 bytes minified (45,611 to 45,636, the release-mode output of src/codegen/bundle-modules.ts).
• parseOptions: 963 -> 963 instructions (4879 -> 4880 bytes). Instructions executed in the changed region per new SQL(): postgres 17 -> 15, mysql and mariadb 9 -> 5, sqlite 0 -> 0, postgres with PGSSLMODE set 21 -> 22, postgres with a TLS_* URL 4 -> 14 with +2 Bun.env reads. Source: BUN_JSC_dumpGeneratedBytecodes=1 on the release-mode bundle, loaded from disk by a debug build.
• allocating opcodes in parseOptions + normalizeSSLMode: 2 -> 2.
• rows changed: 975 of 29,952 (raised 2->3: 57, raised 2->4: 114, new ERR_INVALID_ARG_VALUE: 792, 4->3: 12, off a postgres TLS_* source: 0). The matrix is 12 URL sources x 13 URL queries x 12 PGSSLMODE/PG_SSLMODE settings x 16 option shapes. options.tls is the same in every changed row that does not throw. The 792 new throws are PGSSLMODE=bogus (396 rows) and PGSSLMODE=no-verify (396 rows).
• The numbers are from main at f4d755a. shared.ts is the same blob on the current base.

Not changed here

• PG_SSLMODE shadows PGSSLMODE: PG_SSLMODE=prefer PGSSLMODE=verify-full resolves prefer. Every PG_X || PGX pair in this file is first-wins, and sql(postgres): honour PGSSLMODE from the environment #36840 kept this pair that way. A stricter-of rule changes rows for callers that have no TLS_* URL.
• options.tls || options.ssl: { tls: true, ssl: "verify-full" } resolves require on all three adapters (shared.ts:2062). ssl is the deprecated alias of tls, and the first truthy key wins.
• PGSSLMODE=no-verify and ?sslmode=no-verify (the node-postgres value for TLS without a certificate check) throw ERR_INVALID_ARG_VALUE on every path. A draft of this PR mapped the value to require. The self-review removed that arm: it changes 3,901 of the 29,952 rows, and 3,116 of them have no TLS_* URL.
• An environment verify-ca stops tls.ca and rejectUnauthorized: true from lifting the mode to verify-full, on every URL source. This PR brings TLS_* URLs in line with that rule. A lift for an environment verify-ca is a separate decision: it changes DATABASE_URL + PGSSLMODE=verify-ca + tls.ca from 3 to 4.
• An empty ?sslmode= maps to disable.
• getConnectionDetailsFromEnvironment still returns SSLMode.require | null. A boolean says more, and it can follow sql: do not read the environment connection URL when options name a target #41586, which rewrites the caller.

Related open PRs

• sql: do not read the environment connection URL when options name a target #41586 stops a TLS_* variable from forcing require onto a target that the options name. sql: a verify-ca or verify-full sslmode always verifies the certificate #41589 makes verify-ca and verify-full always set rejectUnauthorized. Both are independent of this PR.
• The new option tests assert tls with toMatchObject, so sql: a verify-ca or verify-full sslmode always verifies the certificate #41589 can add rejectUnauthorized to it.
• sql: a verify-ca or verify-full sslmode always verifies the certificate #41589 adds a selfSignedTlsServer helper to the same test file. The second PR to land keeps one of the two.

Tests

• Fail-before on main: 20 cases in adapter-env-var-precedence.test.ts and 2 in postgres-pgsslmode-env.test.ts. In those 2, the client connects to a self-signed server and sends the startup packet.
• The wire-level tests use a mock and not the postgres_tls container. They assert that no StartupMessage reaches the server, and a real server cannot report that.

Other designs

• Carry the TLS_* name as a boolean: the same resolved rows, a larger diff, and a conflict with sql: do not read the environment connection URL when options name a target #41586.
• Read PGSSLMODE after the URL loop: it changes which invalid values throw for DATABASE_URL callers.
• One fold over all sources: it adds calls to every construction.

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no test proof · iteration 0 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/sql/adapter-env-var-precedence.test.ts

[robobun]

Reproduction, on bun 1.4.3-canary (367d939) and on main:

env -i PATH=$PATH TLS_DATABASE_URL=postgres://u@h:5432/db PGSSLMODE=verify-full \
  bun -e 'console.log(new Bun.SQL().options.sslMode)'
# 2 (require). Expected: 4 (verify-full).

env -i PATH=$PATH DATABASE_URL=postgres://u@h:5432/db PGSSLMODE=verify-full \
  bun -e 'console.log(new Bun.SQL().options.sslMode)'
# 4

TLS_POSTGRES_DATABASE_URL behaves the same as TLS_DATABASE_URL. With this PR, the first command prints 4.

State:

• CI on 02f364c (build 123085): 180 jobs passed and 1 failed. The failure is test/js/bun/spawn/spawn.test.ts on debian 13 x64-asan, which this PR does not touch. Both SQL test files passed on every lane.
• ed11597 changes one docs paragraph and one line of test environment setup. Its build (123138) has no failed job so far. The tests that failed once passed on a retry, and none is in this diff.
• One review thread is open for a maintainer decision: sql(postgres): honour PGSSLMODE=verify-ca/verify-full next to a TLS_* connection URL #44498 (comment). Next to a TLS_* URL, PGSSLMODE=verify-ca with tls.ca or rejectUnauthorized: true resolves verify-ca, as DATABASE_URL already does on main. Main resolved verify-full there.

[coderabbitai]

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Walkthrough

The PostgreSQL option parser now applies PG_SSLMODE and PGSSLMODE as a minimum SSL mode for PostgreSQL TLS URLs. Tests cover environment and URL precedence, certificate verification, and non-PostgreSQL adapters.

Changes

PostgreSQL SSL mode

Layer / File(s)	Summary
Resolve PostgreSQL SSL mode precedence src/js/internal/sql/shared.ts, test/js/sql/adapter-env-var-precedence.test.ts, docs/runtime/sql.mdx	The parser raises the SSL mode when the PostgreSQL environment value exceeds the current mode. Tests cover TLS URL defaults, overrides, invalid values, and non-PostgreSQL adapters. The documentation describes the precedence.
Test TLS URL connection behavior test/js/sql/postgres-pgsslmode-env.test.ts	A mock PostgreSQL server records whether startup messages arrive over TLS or plaintext. Tests cover connections without certificate verification, certificate verification failures, and an explicit URL override.

Suggested reviewers: jarred-sumner

Priority: ➖ Normal

Merge Risk: 🔵 Low · up to 02f36

Clarify the SSL override rules so users do not mistake PGSSLMODE=verify-full for a guarantee. This documentation gap is bounded and does not otherwise block merging.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the main change: honoring PostgreSQL PGSSLMODE settings with TLS_* connection URLs.
Description check	✅ Passed	The description explains the problem and fix, and it lists the tests used to verify the change. It covers both required template topics, although it uses different section headings.

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[coderabbitai]

Actionable comments posted: 1

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Inline comments:
Review comments at @docs/runtime/sql.mdx:
- Around line 591-592: Update the SSL precedence wording in the documentation
paragraph containing PGSSLMODE: clarify that URL sslmode, ssl, and tls
parameters can override the URL variable’s SSL mode and PGSSLMODE, and that
explicit tls/ssl options set to false or a mode string can override the selected
mode. State that true and TLS option objects do not lower a stricter mode.

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• docs/runtime/sql.mdx
• src/js/internal/sql/shared.ts
• test/js/sql/adapter-env-var-precedence.test.ts
• test/js/sql/postgres-pgsslmode-env.test.ts

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[robobun]

^{Updated 10:37 PM PT - Oct 2nd, 2026}

✅ @robobun, your commit ed11597cbc12c67ac770a8d3def7e69653558126 passed in Build #123138! 🎉

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🧪   To try this PR locally:

bunx bun-pr 44498

That installs a local version of the PR into your bun-44498 executable, so you can run:

bun-44498 --bun

[claude]

Nothing blocking. The comments below are optional suggestions. There is no need to push a fix for them before merging.

[claude]

🔴 Apps passing tls.ca or rejectUnauthorized: true next to a TLS_* URL lose hostname verification when the environment has PGSSLMODE=verify-ca; the base verified the name. shared.ts:1870 raises sslMode to 3 first, so the sslMode < SSLMode.verify_ca guard at shared.ts:2158 skips the promotion to verify_full the base made from require. Fix: an env-derived mode must never lower what explicit tls options resolve to, e.g. apply the PGSSLMODE floor after the shared.ts:2158 upgrade, and change the expectation at adapter-env-var-precedence.test.ts:490. The PR lists this as a downside; for TLS_* users it is a 4->3 downgrade from base.

Why this was flagged

Environment has TLS_DATABASE_URL (or TLS_POSTGRES_DATABASE_URL) set to a postgres URL and PGSSLMODE=verify-ca, and the program calls new SQL({ tls: { ca: bundle } }) or new SQL({ tls: { rejectUnauthorized: true } }). On the base branch shared.ts:1864 skipped the env read because sslMode was already require (2); then shared.ts:2158-2161 saw $isObject(tls) && sslMode < SSLMode.verify_ca with tls.ca or rejectUnauthorized === true and set sslMode = SSLMode.verify_full (4). After this change shared.ts:1866-1870 sets sslMode = 3 before that block, the sslMode < SSLMode.verify_ca guard is false, and sslMode stays verify_ca (3). In src/sql_jsc/postgres/PostgresSQLConnection.rs:893-896 native_identity_hostname returns None unless ssl_mode == SSLMode::VerifyFull, so PostgresSQLConnection.rs:906-931 checks only the chain and never the server name. With rejectUnauthorized: true and no ca, any publicly trusted certificate for any host now passes. The new test at test/js/sql/adapter-env-var-precedence.test.ts:490-496 locks the 3 in.

Verification: After the change shared.ts:1864-1870 reads the env and sets sslMode=3; the promotion at shared.ts:2158-2161 is now skipped by the < verify_ca guard, so sslMode stays 3. src/sql_jsc/postgres/PostgresSQLConnection.rs:893-896 native_identity_hostname returns a hostname only when ssl_mode == SSLMode::VerifyFull, so a certificate from the trusted CA issued for a different host is now accepted where the base rejected it.

[robobun]

The facts are right. In this one shape the resolved mode goes from 4 to 3 next to a TLS_* URL, and the hostname check is lost. The PR lists it under Downsides. I kept it because it is the rule that main applies on every other URL source:

• DATABASE_URL + PGSSLMODE=verify-ca + tls: { ca } resolves 3 on main and on 1.4.2. So does tls: { rejectUnauthorized: true }. A verify-ca that something names is kept, and the options supply the CA.
• Base resolved 4 next to a TLS_* URL only because it never read PGSSLMODE there. That is the bug.

The suggested fix does not hold as written. A PGSSLMODE floor after the upgrade at shared.ts:2158 also raises the mode again after a URL ?sslmode= or after tls: false. The URL and the options then no longer override the environment, and the "URL ?sslmode= overrides PGSSLMODE" tests pin that order.

Two changes keep 4 in this shape. Each one is a decision for a maintainer:

1. Let the tls options lift an environment verify-ca to verify-full on every URL source. That changes DATABASE_URL + PGSSLMODE=verify-ca + tls.ca from 3 to 4, and a deployment whose certificate name does not match the host stops connecting.
2. Do that only next to a TLS_* URL. That needs a flag that five later assignments clear, and the same environment then resolves differently by URL variable.

I left this thread open for that decision.

[Jarred-Sumner]

Superseded by #44618, which consolidates the open TLS pull requests. This fix and its tests are in there, either as written, rewritten smaller, or merged with the other PRs that patched the same cause (see the "By area" list in that PR). Closing in favor of it.