createVerifier won't verify properly with RS256 about fast-jwt

[simoneb]

We have several tests covering RS512 and some seem to be also using RS256 (together with another algorithm so I'm not sure if RS256 is the one actually being tested). Can you see if you spot something in the tests that suggest that your case is different?

[kavishkagihan]

There seem to be a couple but not with a public key for sure.

  t.strictSame(
    verify('eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhIjoxfQ.57TF7smP9XDhIexBqPC-F1toZReYZLWb_YRU5tv0sxM', {
      noTimestamp: true,
      algorithms: ['RS256', 'HS256']
    }),
    { a: 1 }
  )

  t.strictSame(
    verify('eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhIjoxfQ.57TF7smP9XDhIexBqPC-F1toZReYZLWb_YRU5tv0sxM', {
      noTimestamp: true,
      algorithms: ['RS256', 'HS256'],
      key: 'secret'
    }),
    { a: 1 }
  )

  t.strictSame(
    verify('eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhIjoxfQ.57TF7smP9XDhIexBqPC-F1toZReYZLWb_YRU5tv0sxM', {
      noTimestamp: true,
      algorithms: [
        'RS256',
        'RS384',
        'RS512',
        'HS256',
        'HS384',
        'HS512',
        'ES256',
        'ES384',
        'ES512',
        'PS256',
        'PS384',

PS: I tried the example given in the docs and it fails with the same error.

[simoneb]

Ok thanks for reporting. Would you be so kind as to create a PR? If you don't want to work on the fix, could you at least create a failing test case?

[kavishkagihan]

Ok, so I was preparing the test case PR and noticed something. I think the verifier only works for the keys with the headers -----BEGIN PRIVATE KEY----- not -----BEGIN RSA PRIVATE KEY-----.

# with -----BEGIN PRIVATE KEY-----
eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJhIjoxLCJpYXQiOjE3MDExODQyODR9.acouVH2kUzUiBW534e-5ysLEuvBj_8U30W8nt4VXgU-avwYPjqPemNWekDKoFYRCDBYju-Ozy9ZnjTNOqrfQOuU6ezdzf1CHIlEj1D1059s_a7iEuEwlRkyXA49e9vyoP7-0Xbiiua17slZHQixJwbDrCyr3B6wezvedTJlxoK6JWv3zrSeQ0P6hTX8DtVxWLQFFwrH-4Mvibbe8oSUPZ6SH1apRH_8PF0XcoDadAtpMCc5agGf8-Y1mKhl82FFpoMa2P8w8sHmqGXDvNvG_t6PBHu-bB8KJ15_99R3C7YUu-bMWpdOs4T0TgSWGviyBUI4bjounbSKYgWUPsWDOgw
{ a: 1, iat: 1701184284 }

Then I looked at the commits and found this. I thought this was the reason why it didn't work before. But again this was implemented in v3.3.2 but yet I was testing it in v3.3.0.

The key headers were the only thing that was different from my previous test.

Although, as per this advisory, both headers should work in versions which are < 3.3.1

[simoneb]

I'm not sure what to make of this though. The relevant line is this, which shows that BEGIN RSA PRIVATE KEY should be supported. 15a6e92#diff-0ea128c6a526ed8106ac0088dc7d2f94c0d351cc8edd06e24e79b8e5ae4c44a4R28

[kavishkagihan]

At this point, I am pretty sure that is the root cause. Just not sure why that would happen.

┌──(kali__kali)-[~/NEW]
└─$ cat public_key.pem|head
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoxxtE32WroZX5LpgGDQ6
B/LmBBpSAjeQ3ak4t8f1jVCuvfk3RoIGD4nOznGXL1SjKo1exYIpG/EnaWkIXo37
MUlZ/StEmXRWwDZtbrrNJrdj/4qam7527jwjhFESigj95bQ4ndMNqwIfptLt3mm2
t5QdTADy0eHdPdZ7fUuYeGj3BN9fKOnqXZkBRq7C2yB9RoWB0IU7hzHsf11ODbK7
Om4v3dlBm9fiH2dTMbJAxTloeIrMd1OXu/PM5d7qgDjC2TyDmqPgLKGvlfm18LTU
9w+r52qCjAUV0EIK3Ai/ACx4hLfwnb478ZvZfdXDgUhFOrKx92Jp+oejuHqWxPRE
xQIDAQAB
-----END PUBLIC KEY-----


┌──(kali__kali)-[~/NEW]
└─$ node test.js
eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJhIjoxfQ.dvQmAf8QruptEU1nqwuIHjuE90gftfKNnkOP6i0ErVByjwCij99WLM_6Xbq__OUVjJXwdGYlP71j6-pTrqr6ue8vT6KE-1oPChnc5WyCKZBvpjAuAHG8jF-M899CcHuYUFDQ-UJV0eaRf26ilvngIQE6RMKtdavsFoR3XpiUCXobMJbgZDNvzG5j36M10FccB68C-6Y4F75sid47jfKHKSEYiqJHo6jqSredLVjNNEbVAo3ee4oafLByzEDW6F1-MA3vJZZl522EwXFBv7MnFwvP5QJVOMGxL1R5tmbbOvLKy25v6uAO_VXKPciw4ZCr-BBzeUhuFzSsCauoDZJBhA
{ a: 1 }

┌──(kali__kali)-[~/NEW]
└─$ cat public_key.pem|head
-----BEGIN RSA PUBLIC KEY-----
MIIBCgKCAQEApNkAKU4ap1AWiQaeDvPXbLNcd8UElPIK9hYLoTUDD8CCx1YSs8Rr
ACSDlyRtFkwEiplsIvlh8wj/BvkUE9lgQOzO6mcMx7bcqJ2GKaANANBCI/T+r7+D
jeq9jH0pv49eMZzO4Ye5TapVkJEiq4SR/FkLigRVP1lM16IQGqxpjDr4/nHhZ7SF
98F8TC0Suh/F4wgZaN4qrzUaBJJ5ysA3DySLlQkraJpfje5bXFbH3flys8m2SNZf
otRjrMwBrzIvW0kz9qKkbkTUJX2k8hcGkWN6GeoKABx6+v3QXARap740u8lfFYVh
skeeAXg/WhrTIr6EHAIbnJlCWqzLFh9hNQIDAQAB
-----END RSA PUBLIC KEY-----

┌──(kali__kali)-[~/NEW]
└─$ node test.js
eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJhIjoxfQ.H-e_0TykHbQZfy91O-1CNo4DCIYnCpv2WEP_KPLAfsLKTY3-h27WxO6B2HS1MI23IipAFF5dBHjPTGyUx2GZUDKBqtny9D95DhAQOUYlBK3Z4B3Pg-YBTHWge--Iv0xyNCEHZuSHi7_vDlGl2dEqYH78m88Dh4PPinK22CUbn8WvWhdkGPAFbYmXMSKkypwiazmuAPG_rdltjNxRFBZeNg3-iRqrdFTTG64ZAVHE31v78V_hTyJj-4z8A5mGglMaGrf2WntXpR6vp5SWIFYG3-jrBoeZHpV0rIJQlzhvzobtmuJytMoPQTnUX6yoCc-qgkVCUou1369WUiXFe17gnA
/home/kali/NEW/node_modules/fast-jwt/src/verifier.js:322
      throw cacheSet(cacheContext, e)
      ^

TokenError: The token algorithm is invalid.

Also, it seems you had no problems with this before because the ssh-keygen commands you have mentioned in the advisory are the same ones I used to create mine (with -----BEGIN RSA PUBLIC KEY----- header ).

[simoneb]

@kavishkagihan can you please check if #415 fixes the issue for you?

[github-actions]

🎉 This issue has been resolved in version 3.3.3 🎉

The release is available on:

• npm package
• GitHub release

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