azure

Documentation

Overview

Azure attestation

Constellation supports multiple attestation technologies on Azure.

• SEV - Secure Nested Paging (SEV-SNP)

  TPM attestation verified using an SEV-SNP attestation statement.

• TDX - Trust Domain Extensions

  TPM attestation verified using a TDX attestation statement.

• Trusted Launch

  Basic TPM attestation.

Index

• func GetAttestationKey(tpm io.ReadWriter) (*tpmclient.Key, error)
• type HCLAkValidator
  • func (a *HCLAkValidator) Validate(runtimeDataRaw []byte, reportData []byte, rsaParameters *tpm2.RSAParams) error

Functions

func GetAttestationKey

func GetAttestationKey(tpm io.ReadWriter) (*tpmclient.Key, error)

GetAttestationKey reads the attestation key put into the TPM during early boot.

Types

type HCLAkValidator

type HCLAkValidator struct{}

HCLAkValidator validates an attestation key issued by the Host Compatibility Layer (HCL). The HCL is written by Azure, and sits between the Hypervisor and CVM OS. The HCL runs in the protected context of the CVM.

func (*HCLAkValidator) Validate

func (a *HCLAkValidator) Validate(runtimeDataRaw []byte, reportData []byte, rsaParameters *tpm2.RSAParams) error

Validate validates that the attestation key from the TPM is trustworthy. The steps are: 1. runtime data read from the TPM has the same sha256 digest as reported in `report_data` of the SNP report or `TdQuoteBody.ReportData` of the TDX report. 2. modulus reported in runtime data matches modulus from key at idx 0x81000003. 3. exponent reported in runtime data matches exponent from key at idx 0x81000003. The function is currently tested manually on a Azure Ubuntu CVM.