Skip to content

[FIX] support both single and multiple GCP nonces in attestation #74

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Scratch-net merged 2 commits into from
Apr 14, 2026
Merged

[FIX] support both single and multiple GCP nonces in attestation #74

Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
90e0d19
[FIX] support both single and multiple GCP nonces in attestation
Scratch-net Apr 14, 2026
05b3b9e
[FIX] support both single and multiple GCP nonces in attestation
Scratch-net Apr 14, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 15 additions & 4 deletions src/server/utils/gcp-attestation.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -27,7 +27,7 @@ interface JwtPayload {
exp: number
iat: number
aud: string
eat_nonce?: string // Contains "tee_k_public_key:0x..." or "tee_t_public_key:0x..."
eat_nonce?: string | string[] // Single nonce or array; first element is always the public key nonce
dbgstat?: string // Debug status: "enabled" or "disabled-since-boot"
// GCP Confidential Computing specific claims
google?: {
Expand Down Expand Up @@ -353,15 +353,26 @@ export async function validateGcpAttestationAndExtractKey(
}

// 5. Extract ETH address from eat_nonce
// GCP returns eat_nonce as a string (single nonce) or string array (multiple nonces).
// The public key nonce is always first; additional nonces (e.g. cert hash) may follow.
if(!payload.eat_nonce) {
errors.push('No eat_nonce field found in JWT payload')
return { isValid: false, errors }
}

const eatNonce = Array.isArray(payload.eat_nonce)
? payload.eat_nonce[0]
: payload.eat_nonce
Comment thread
Scratch-net marked this conversation as resolved.
Outdated

if(!eatNonce) {
errors.push('eat_nonce is empty')
return { isValid: false, errors }
}

// Format: "tee_k_public_key:0x..." or "tee_t_public_key:0x..."
const match = payload.eat_nonce.match(/^(tee_[kt])_public_key:0x([0-9a-fA-F]{40})$/)
const match = eatNonce.match(/^(tee_[kt])_public_key:0x([0-9a-fA-F]{40})$/)
if(!match) {
errors.push(`Invalid eat_nonce format: ${payload.eat_nonce}`)
errors.push(`Invalid eat_nonce format: ${eatNonce}`)
return { isValid: false, errors }
}

Expand All @@ -371,7 +382,7 @@ export async function validateGcpAttestationAndExtractKey(
const ethAddress = new Uint8Array(Buffer.from(hexAddress, 'hex'))

if(logger) {
logger.info(`Extracted address from eat_nonce: ${payload.eat_nonce}`)
logger.info(`Extracted address from eat_nonce: ${eatNonce}`)
}

// Extract image digest from JWT payload (GCP's equivalent to PCR0)
Expand Down
Loading