Hashicorp Vault plugin for authenticating Trusted Execution Environments (TEE) like SGX enclaves
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fix(deps): update module golang.org/x/crypto to v0.17.0 [security] (#27)
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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| golang.org/x/crypto | `v0.16.0` -> `v0.17.0` |
[![age](https://developer.mend.io/api/mc/badges/age/go/golang.org%2fx%2fcrypto/v0.17.0?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![adoption](https://developer.mend.io/api/mc/badges/adoption/go/golang.org%2fx%2fcrypto/v0.17.0?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![passing](https://developer.mend.io/api/mc/badges/compatibility/go/golang.org%2fx%2fcrypto/v0.16.0/v0.17.0?slim=true)](https://docs.renovatebot.com/merge-confidence/)
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|

### GitHub Vulnerability Alerts

####
[CVE-2023-48795](https://togithub.com/warp-tech/russh/security/advisories/GHSA-45x7-px36-x8w8)

### Summary

Terrapin is a prefix truncation attack targeting the SSH protocol. More
precisely, Terrapin breaks the integrity of SSH's secure channel. By
carefully adjusting the sequence numbers during the handshake, an
attacker can remove an arbitrary amount of messages sent by the client
or server at the beginning of the secure channel without the client or
server noticing it.

### Mitigations

To mitigate this protocol vulnerability, OpenSSH suggested a so-called
"strict kex" which alters the SSH handshake to ensure a
Man-in-the-Middle attacker cannot introduce unauthenticated messages as
well as convey sequence number manipulation across handshakes.

**Warning: To take effect, both the client and server must support this
countermeasure.**

As a stop-gap measure, peers may also (temporarily) disable the affected
algorithms and use unaffected alternatives like AES-GCM instead until
patches are available.

### Details

The SSH specifications of ChaCha20-Poly1305
(chacha20-poly1305@​openssh.com) and Encrypt-then-MAC
(*-etm@openssh.com MACs) are vulnerable against an arbitrary prefix
truncation attack (a.k.a. Terrapin attack). This allows for an extension
negotiation downgrade by stripping the SSH_MSG_EXT_INFO sent after the
first message after SSH_MSG_NEWKEYS, downgrading security, and disabling
attack countermeasures in some versions of OpenSSH. When targeting
Encrypt-then-MAC, this attack requires the use of a CBC cipher to be
practically exploitable due to the internal workings of the cipher mode.
Additionally, this novel attack technique can be used to exploit
previously unexploitable implementation flaws in a Man-in-the-Middle
scenario.

The attack works by an attacker injecting an arbitrary number of
SSH_MSG_IGNORE messages during the initial key exchange and consequently
removing the same number of messages just after the initial key exchange
has concluded. This is possible due to missing authentication of the
excess SSH_MSG_IGNORE messages and the fact that the implicit sequence
numbers used within the SSH protocol are only checked after the initial
key exchange.

In the case of ChaCha20-Poly1305, the attack is guaranteed to work on
every connection as this cipher does not maintain an internal state
other than the message's sequence number. In the case of
Encrypt-Then-MAC, practical exploitation requires the use of a CBC
cipher; while theoretical integrity is broken for all ciphers when using
this mode, message processing will fail at the application layer for CTR
and stream ciphers.

For more details see
[https://terrapin-attack.com](https://terrapin-attack.com).

### Impact

This attack targets the specification of ChaCha20-Poly1305
(chacha20-poly1305@​openssh.com) and Encrypt-then-MAC
(*-etm@openssh.com), which are widely adopted by well-known SSH
implementations and can be considered de-facto standard. These
algorithms can be practically exploited; however, in the case of
Encrypt-Then-MAC, we additionally require the use of a CBC cipher. As a
consequence, this attack works against all well-behaving SSH
implementations supporting either of those algorithms and can be used to
downgrade (but not fully strip) connection security in case SSH
extension negotiation (RFC8308) is supported. The attack may also enable
attackers to exploit certain implementation flaws in a man-in-the-middle
(MitM) scenario.

---

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schedule defined).

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are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
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Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
2023-12-21 19:59:18 +01:00
.github chore(deps): update actions/setup-go action to v5 (#23) 2023-12-21 19:54:09 +01:00
ratee feat: initial commit 2023-10-26 14:15:52 +02:00
tee feat: initial commit 2023-10-26 14:15:52 +02:00
version feat: initial commit 2023-10-26 14:15:52 +02:00
.gitignore feat: initial commit 2023-10-26 14:15:52 +02:00
CONTRIBUTING.md feat: initial commit 2023-10-26 14:15:52 +02:00
Dockerfile feat: initial commit 2023-10-26 14:15:52 +02:00
flake.nix feat: initial commit 2023-10-26 14:15:52 +02:00
go.mod fix(deps): update module golang.org/x/crypto to v0.17.0 [security] (#27) 2023-12-21 19:59:18 +01:00
go.sum fix(deps): update module golang.org/x/crypto to v0.17.0 [security] (#27) 2023-12-21 19:59:18 +01:00
LICENSE feat: initial commit 2023-10-26 14:15:52 +02:00
main.go feat: initial commit 2023-10-26 14:15:52 +02:00
README.md feat: initial commit 2023-10-26 14:15:52 +02:00
renovate.json feat: initial commit 2023-10-26 14:15:52 +02:00
SECURITY.md feat: initial commit 2023-10-26 14:15:52 +02:00

vault-auth-tee

TEE remote attestation plugin for Hashicorp Vault

⚠️☢️☣️ WARNING: not yet for production use ☣️☢️⚠️

License

All of the code is licensed under the Mozilla Public License 2.0 unless otherwise specified. Most of the vault plugin code is based on the vault builtin/credential/cert plugin.

Build Setup

$ wget -qO - https://download.01.org/intel-sgx/sgx_repo/ubuntu/intel-sgx-deb.key | sudo apt-key add -
$ sudo bash -c 'echo "deb [arch=amd64] https://download.01.org/intel-sgx/sgx_repo/ubuntu focal main" > /etc/apt/sources.list.d/intel-sgx.list'
$ sudo apt update
$ sudo apt install -y --no-install-recommends \
    libsgx-headers \
    libsgx-enclave-common \
    libsgx-urts \
    libsgx-dcap-quote-verify \
    libsgx-dcap-quote-verify-dev

Configuration

Create or Update via the ${plugin}/tees/$name endpoint

{
    "name": "TEE_role_name",
    "token_policies": "policy1,policy2,...",
    "types": "sgx",
    "sgx_mrsigner": "298037d88782e022e019b3020745b78aa40ed95c77da4bf7f3253d3a44c4fd7e",
    "sgx_mrenclave": "18946b3547d3ca036f4df7b516857e28fd512d69fed3411dc660537912faabf8",
    "sgx_isv_prodid": 0,
    "sgx_min_isv_svn": 0,
    "sgx_allowed_tcb_levels": "Ok,ConfigNeeded,OutOfDate,OutOfDateConfigNeeded,SwHardeningNeeded,ConfigAndSwHardeningNeeded"
}
  • At least one of sgx_mrsigner or sgx_mrenclave must be set. If both are set, both are used for matching.
  • sgx_isv_prodid is optional and defaults to 0.
  • sgx_min_isv_svn is optional and defaults to 0.
  • sgx_allowed_tcb_levels is optional and defaults to Ok.

Authentication

  • Client TEE generates a self-signed TLS client certificate
  • Client TEE generates an attestation report, which includes the hash of the public key of the client certificate (in case of SGX, a sha256 sum of the public key)
  • Client TEE fetches all collateral material via e.g. Intel DCAP (tee_qv_get_collateral)
  • Client TEE sends POST request with a TLS connection using the client certificate to Vault via the ${plugin}/login endpoint with the name, attestation report and the attestation collateral material
  • An optional challenge can be included in the POST request, which is then included in the attestation report of the vault response
{
    "name": "The name of the TEE role to authenticate against.",
    "quote": "The quote Base64 encoded.",
    "collateral": "The collateral Json string encoded.",
    "challenge": "An optional challenge hex encoded."
}

The response contains the Vault token and, if a challenge was included, the vault attestation report, which must contain the challenge bytes in the report_data of the quote.

{
    "auth": {
        "client_token": "The Vault token.",
        "....": "...."
    },
    "data": {
        "quote": "The vault quote Base64 encoded.",
        "collateral": "The vault collateral Json string encoded."
    }
}

Collateral Json encoding

See sgx_ql_lib_common.h

{
    "major_version": uint16,
    "minor_version": uint16,
    "tee_type": uint32,
    "pck_crl_issuer_chain": []byte,
    "root_ca_crl": []byte,
    "pck_crl": []byte,
    "tcb_info_issuer_chain": []byte,
    "tcb_info": []byte,
    "qe_identity_issuer_chain": []byte,
    "qe_identity": []byte
}