"Failed to decrypt field" after upgrading to Renovate >= 37.317.0

[9numbernine9]

What would you like help with?

I think I found a bug

How are you running Renovate?

Self-hosted

If you're self-hosting Renovate, tell us which platform (GitHub, GitLab, etc) and which version of Renovate.

Bitbucket Cloud; Renovate >= 37.317.0

Please tell us more about your question or problem

Hello!

Since upgrading our self-hosted Renovate to versions >= 37.317.0, we've started noticing a difference in behaviour with respect to encryption/decryption with GPG keys. (We've tested with 37.342.2, 37.340.9, and 37.328.1). Previously the GPG keys that we were using worked perfectly fine, but after the 37.317.0 release they stopped working correctly; in our logs we would see "Failed to decrypt field password. Please re-encrypt and try again." errors, despite the keys working correctly previously.

Poking through the release notes for 37.317.0, we noticed that the PGP library was replaced with Renovate's fork of kbpgp. This release also added the RENOVATE_X_USE_OPENPGP flag, which we enabled for testing purposes and our encryption/decryption worked correctly once again. Knowing that this is an experimental flag, however, this doesn't seem like a permanent solution.

What we've observed is that kbpgp seems to treat keys that are generated with a version of GnuPG that's too new as being invalid. We tested this by generating a brand new RSA 4096-bit keypair using GnuPG 2.4.5, re-encrypting all of our secrets with this new key, disabling the RENOVATE_X_USE_OPENPGP flag, and trying again - same decryption error as before. Then, we went through the same process but we used the gpg executable inside of the renovatebot/renovate:37.342.2 image instead - which uses GnuPG 2.2.17 - re-encrypting all of our secrets again with these new keys, and everything worked fine with kbpgp decryption.

With all of that said, my questions are:

• Has anyone else run into a similar issue? (Feel free to comment on this discussion.)
• Is this a known issue? (I couldn't find anything relevant on the issue tracker.)

My concern is that anyone who's using a newer GnuPG might run into this issue, and with the recent release of Ubuntu 24.04 - which defaults to GnuPG 2.4.x - the chances of someone running into this situation are higher.

Logs (if relevant)

Logs

INFO: Repository has invalid config (repository=myorg/myrepo)
       "error": {
         "validationError": "Failed to decrypt field password. Please re-encrypt and try again.",
         "message": "config-validation",
         "stack": "Error: config-validation\n    at decryptConfig (/usr/local/renovate/lib/config/decrypt.ts:156:27)\n    at processTicksAndRejections (node:internal/process/task_queues:95:5)\n    at decryptConfig (/usr/local/renovate/lib/config/decrypt.ts:202:13)\n    at mergeRenovateConfig (/usr/local/renovate/lib/workers/repository/init/merge.ts:212:24)\n    at getRepoConfig (/usr/local/renovate/lib/workers/repository/init/config.ts:14:12)\n    at initRepo (/usr/local/renovate/lib/workers/repository/init/index.ts:55:12)\n    at Object.renovateRepository (/usr/local/renovate/lib/workers/repository/index.ts:62:14)\n    at attributes.repository (/usr/local/renovate/lib/workers/global/index.ts:217:11)\n    at start (/usr/local/renovate/lib/workers/global/index.ts:202:7)\n    at /usr/local/renovate/lib/renovate.ts:18:22"

[viceice]

• does it work with an old key and gnupg v2.4?
• doest it work with the new key and gnugp v2.2?

[viceice]

this workaround works for me:

% gpg --edit-key mykey

gpg> showpref
[ultimate] (1). mykey
     Cipher: AES256, AES192, AES, 3DES
     AEAD: OCB, EAX
     Digest: SHA512, SHA384, SHA256, SHA224, SHA1
     Compression: ZLIB, BZIP2, ZIP, Uncompressed
     Features: MDC, AEAD, Keyserver no-modify

gpg> setpref AES256 AES192 AES 3DES SHA512 SHA384 SHA256 SHA224 SHA1 ZLIB BZIP2 ZIP
Set preference list to:
     Cipher: AES256, AES192, AES, 3DES
     AEAD: 
     Digest: SHA512, SHA384, SHA256, SHA224, SHA1
     Compression: ZLIB, BZIP2, ZIP, Uncompressed
     Features: MDC, Keyserver no-modify
Really update the preferences? (y/N) y

You can only use rsa, no ecc keys.

[viceice]

ecc works too, sorry. was a typo on my tests

[viceice]

• test: add more e2e tests kbpgp#22

[9numbernine9]

@viceice @rarkins Thank you for digging into this issue further! Apologies for not responding sooner. I am indeed using RSA 4096-bit keys.

@viceice I believe your workaround is indeed the correct course of action. Removing AEAD support from my key, then re-encrypting my secret with the key and giving the non-AEAD version of my private key to Renovate made everything work just fine, regardless if I used GnuPG 2.2 or 2.4 for key generation. The only practical difference between the two is that keys generated with 2.4 appear to choose AEAD by default; now that I know what the problem is, I can see this has caused issues for others too. (Examples here and here ; Arch Wiki also recommends disabling it FWIW).

Ideally I would love to see AEAD support added to kbpgp but I realize this might be non-trivial. Perhaps for now the best solution would be to update the self-hosted documentation to explicitly mention the gotcha with AEAD?

[viceice]

Sadly kbpgp is not actively developed, so chances are bad to get it working.

I've not enough knowledge to do the implementation and the Coffeescript language is making it even more worse.

I've also not enough time to convert it to regular JavaScript or Typescript for easier development. sorry 😔

[lildadou]

I would like to take advantage of this thread to mention a problem I encountered: if your ciphertext is less than 500 characters long, you will encounter an error during decryption. This can happen when your key is 2048 bits and your secret is short.

This problem is caused by this condition :

renovate/lib/config/decrypt/kbpgp.ts

Lines 9 to 12 in 01d4d0d

	if (encryptedStr.length < 500) {
	// optimization during transition of public key -> pgp
	return null;
	}

[viceice]

It should now be possible to use AEAD with renovate v42 when setting RENOVATE_X_PGP_RUNTIME=wasm-java which will become the default on renovate v43

• feat!: use wasm-java build of bouncy castle #40678
• https://docs.renovatebot.com/self-hosted-experimental/#renovate_x_pgp_runtime