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POST
/
tdx_quote
TDX Quote
curl --request POST \
  --url https://api.example.com/tdx_quote
{
  "success": true,
  "quote": {},
  "tcb_info": {},
  "timestamp": "<string>",
  "quote_type": "<string>",
  "error": "<string>"
}

​
Get TDX Quote

Generate an Intel TDX attestation quote with custom report data. This endpoint implements TLS channel binding using EKM (Exported Keying Material) as defined in RFC 5705.

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Endpoint

POST /tdx_quote

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Authentication

Requires X-TLS-EKM-Channel-Binding header with HMAC-signed EKM value.
The EKM header format is {ekm_hex}:{hmac_hex} where:
  • ekm_hex: 64-character hex string (32 bytes) of the TLS Exported Keying Material
  • hmac_hex: 64-character HMAC-SHA256 signature of the EKM value
The HMAC is computed as: HMAC-SHA256(ekm_hex, EKM_SHARED_SECRET)

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Request Parameters

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nonce_hex
string
required
64-character hexadecimal string (32 bytes). Provides freshness to the attestation quote. Must be a valid hex string.

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Request Body

{
  "nonce_hex": "a1b2c3d4e5f6789012345678901234567890abcdef1234567890abcdef123456"
}

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Response

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success
boolean
required
Whether the quote generation succeeded
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quote
GetQuoteResponse
required
TDX quote object from dstack_sdk containing the raw attestation data
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tcb_info
TcbInfoV05x
required
Trusted Computing Base (TCB) information for quote verification
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timestamp
string
required
Unix timestamp (in seconds) when the quote was generated
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quote_type
string
required
Type of quote generated (always “tdx” for Intel TDX)
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error
string
Error message if quote generation failed

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Error Responses

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400 Bad Request

  • Missing or invalid nonce_hex (must be exactly 64 hex characters)
  • Missing EKM header

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403 Forbidden

  • Invalid EKM header HMAC signature

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500 Internal Server Error

  • Dstack client not initialized
  • Failed to obtain TDX quote or TCB info
  • EKM_SHARED_SECRET not configured

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Report Data Computation

The report_data field in the TDX quote is computed as: 
report_data = SHA512(nonce_hex + ekm_hex)
This binds the attestation to both:
  1. The specific nonce (freshness)
  2. The TLS session via EKM (channel binding)
Clients must verify that the same nonce and EKM were used when validating the quote.

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Example

curl -X POST https://your-attestation-service.com/tdx_quote \
  -H "Content-Type: application/json" \
  -H "X-TLS-EKM-Channel-Binding: a1b2c3d4e5f6789012345678901234567890abcdef1234567890abcdef123456:8f3a2b1c4d5e6f7890123456789abcdef01234567890abcdef1234567890abcd" \
  -d '{
    "nonce_hex": "deadbeef0123456789abcdef0123456789abcdef0123456789abcdef01234567"
  }'

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Success Response

{
  "success": true,
  "quote": {
    // GetQuoteResponse object from dstack_sdk
    // Contains raw TDX quote bytes and metadata
  },
  "tcb_info": {
    // TcbInfoV05x object with TCB level information
    // Used for verifying the quote
  },
  "timestamp": "1709654400",
  "quote_type": "tdx"
}

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Security Considerations

EKM Channel Binding: The EKM header must be forwarded by a TLS-terminating proxy (e.g., Nginx) running inside the same TEE as the attestation service. The proxy and service must share the EKM_SHARED_SECRET to prevent header forgery.
Development Mode: In non-TEE environments, the service falls back to using the EKM_SHARED_SECRET environment variable. The secret must be at least 32 characters long.

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Implementation Details

The service uses the dstack_sdk to interact with Intel TDX hardware. The quote generation happens asynchronously, with both the quote and TCB info fetched concurrently for optimal performance. Source: cvm/attestation-service/attestation_service.py:182-263