VLTCLT-62 Fix V4 signature using proxyPath instead of original path

[nicolas2bert]

When a VaultClient has a proxyPath set (ex: /_/backbeat/iam), _signRequest() signs the request with options.path which includes the proxyPath, instead of the original path argument (/).

Vault sets the canonical URI to / (standard IAM logic), which lead to signature mismatch error = InvalidAccessKeyId.
The bug was introduced in vaultclient 8.3.18 by commit 6fd9996 (VLTCLT-37: rely on aws signer to sign requests).

Every version from 8.3.18 onward is affected.

The old code:

passed the original path argument to the signing function.

The new code:

passes options directly to signer.sign(), where options.path has already been overwritten with the proxyPath.

The _signRequest method already receives path as its 4th parameter. it just doesn't use it.

[bert-e]

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[bert-e]

Incorrect fix version

The Fix Version/s in issue VLTCLT-62 contains:

• None

Considering where you are trying to merge, I ignored possible hotfix versions and I expected to find:

• 8.5.4

Please check the Fix Version/s of VLTCLT-62, or the target
branch of this pull request.

[bert-e]

Waiting for approval

The following approvals are needed before I can proceed with the merge:

• the author

• 2 peers

[BourgoisMickael]

this should be required on top of the file