---
layout: docs
page_title: Validate recorded session integrity
description: >-
  View the components of the Boundary Session Recording (BSR) file. Verify the integrity of the contents of a BSR cryptographically to ensure security compliance.
---

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> [!IMPORTANT]  
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# Validate the integrity of session recordings

<EnterpriseAlert product="boundary">This feature requires <a href="https://www.hashicorp.com/products/boundary">HCP Boundary or Boundary Enterprise</a></EnterpriseAlert>

BSR directories are validated based on the contents in the directory.
Boundary cryptographically verifies each individual Boundary Session Recording (BSR) file.
The keys used for verifying all Boundary Session Recording files are written to storage and wrapped by the KMS you configured.
Each session recording has its own individual key.
Boundary generates the following keys when a session recording is authorized:

-  The BSR key is a plaintext AES-GCM key.
It is not uploaded to the external object store.

- The private and public key pair is a ed25519 key pair.
The key pair is not uploaded to the external object store.

The following files are stored in the BSR file structure to ensure the integrity of a session recording:

- `bsrKey.pub` is the public ed25519 key.
- `wrappedBsrKey` is the BSR key wrapped by the external KMS AES-GCM key that you configure.
- `wrappedPrivKey` is the private ed25519 key wrapped by the external KMS AES-GCM key that you configure.
- `pubKeySelfSignature.sign` is a self-signature of the plaintext public ed25519 key created with its private key.
- `pubKeyBsrSignature.sign` is a signature of the plaintext public ed25519 key created with the BSR key.
- `SHA256SUM.sig` is a signature of the plaintext `SHA256SUM` file created with the private key.

Encrypting the BSR key with an external KMS means that Boundary is not responsible for the longevity of the keys.
The Boundary admin can always use that external KMS to unwrap the `wrappedBsrKey` and `wrappedPrivKey`.
A BSR’s key is encrypted using the `go-kms-wrapping` package, and therefore the encrypted BlobInfo includes the metadata required to identify the key-version used during encryption.
So if the wrapper is reinitialized properly, you can unwrap the keys even if the key has been rotated.

Each BSR directory contains a SHA256SUM and SHA256SUM.sig file that you can use to cryptographically verify the BSR directory's contents.
The SHA256SUM file contains rows of file names paired with a checksum for the file contents.
The SHA256SUM.sig is a copy of the SHA256SUM file, signed with the BSR's private key.
Refer to the following example of a SHA256SUM file:

   ```
   dc8ce2c42553ce510197c99efe21d89d6229feb4b49170511f49965f2e3cf1a3  wrappedBsrKey
   a5a91b1b52fb53c4bab661b2e5846bb2a836f050e3d745e436078871914a0bc2  wrappedPrivKey
   1ca281852ec0d447b94708f28a51b562d47b84affdba25e13a97b0fbd9126424  pubKeyBsrSignature.sign
   7b5e18e5930bb4cce12a3f203328d9065cae29f26aba3963bb5faece2cf97231  pubKeySelfSignature.sign
   dc7c6b1316624c7c486a22bab157f947df92b9f2ce4a72469b1f335399a043d5  bsrKey.pub
   4d3966c458f4e5d67f9ac70b804540b927c718965267c3f36526bf0b18c40ad9  session-meta.json
   6fec2173d331828677fb5e77fc19168daad3c5f0e82517a82e5701e6c2bdcbe1  session-recording.meta
   ad76483e7cf3e65391a3a1d0b86a3ad436333ee225bea042b13900abc188b226  session-recording-summary.json
   ```

Follow these steps to validate a session recording:

1. Unwrap `wrappedBsrKey` using the external KMS you configured to retrieve the BSR key.
2. Unwrap `wrappedPrivKey` using the external KMS you configured to retrieve the private key.
3. Use the BSR key or the private key to verify the `bsrKey.pub` key using `go-kms-wrapping` HmacSha256(...).
4. When the key is verified, use the `bsrKey.pub` key to verify the BSR SHA256SUM.sig file using `go-kms-wrapping` ed25519.Sign(...).
5. After verifying the SHA256SUM.sig file, use the `sha256` commandline tool to verify BSR checksums using `sha256sum -c SHA256SUM`.
6. Examine the *.meta files in the directory. For session-recording.meta, every connection logged in the meta file should
correspond to a connection folder in the directory. For a connection-recording.meta, every channel logged in the meta file should
correspond to a channel folder in the directory.
