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Policy enum

The Policy enum determines which verifier to use and its configuration. Policies can be serialized/deserialized with serde, making them easy to load from JSON configuration files.

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Definition

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "type")]
pub enum Policy {
    #[serde(rename = "dstack_tdx")]
    DstackTdx(DstackTdxPolicy),
}

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Methods

impl Policy {
    /// Convert this policy into its corresponding verifier.
    pub fn into_verifier(self) -> Result<Verifier, AtlsVerificationError>
}

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Usage examples

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Default policy

use atlas_rs::Policy;

let policy = Policy::default();

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Development policy

use atlas_rs::{Policy, DstackTdxPolicy};

let policy = Policy::DstackTdx(DstackTdxPolicy::dev());

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From JSON

use atlas_rs::Policy;

let json = r#"{
    "type": "dstack_tdx",
    "allowed_tcb_status": ["UpToDate", "SWHardeningNeeded"]
}"#;
let policy: Policy = serde_json::from_str(json).unwrap();

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DstackTdxPolicy

Policy configuration for dstack TDX verification.

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Definition

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DstackTdxPolicy {
    pub expected_bootchain: Option<ExpectedBootchain>,
    pub app_compose: Option<serde_json::Value>,
    pub os_image_hash: Option<String>,
    pub allowed_tcb_status: Vec<String>,
    pub grace_period: Option<u64>,
    pub pccs_url: Option<String>,
    pub cache_collateral: bool,
    pub disable_runtime_verification: bool,
}

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Fields

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expected_bootchain
Option<ExpectedBootchain>
Expected bootchain measurements (MRTD, RTMR0-2). Required unless disable_runtime_verification is true.
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app_compose
Option<serde_json::Value>
Expected app compose configuration. Required unless disable_runtime_verification is true.
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os_image_hash
Option<String>
Expected OS image hash (SHA256, lowercase hex). Required unless disable_runtime_verification is true.
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allowed_tcb_status
Vec<String>
default:"[\"UpToDate\"]"
Allowed TCB status values. Valid values: UpToDate, OutOfDate, ConfigurationNeeded, TDRelaunchAdvised, SWHardeningNeeded, Revoked.
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grace_period
Option<u64>
Grace period in seconds for OutOfDate platforms. If set, requires allowed_tcb_status to include OutOfDate. Platform is allowed only if tcb_date + grace_period >= current_time.
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pccs_url
Option<String>
PCCS URL for collateral fetching.
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cache_collateral
bool
default:false
Cache collateral to avoid repeated fetches.
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disable_runtime_verification
bool
default:false
Disable runtime verification (NOT RECOMMENDED for production). When false, all runtime fields (expected_bootchain, app_compose, os_image_hash) must be provided. Set to true only for development/testing.

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Methods

impl DstackTdxPolicy {
    /// Relaxed policy for development.
    pub fn dev() -> Self
    
    /// Validate the policy configuration.
    pub fn validate(&self) -> Result<(), AtlsVerificationError>
}

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Usage examples

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Default production policy

use atlas_rs::DstackTdxPolicy;
use atlas_rs::tdx::ExpectedBootchain;

let policy = DstackTdxPolicy {
    expected_bootchain: Some(ExpectedBootchain {
        mrtd: "abc123...".to_string(),
        rtmr0: "def456...".to_string(),
        rtmr1: "ghi789...".to_string(),
        rtmr2: "jkl012...".to_string(),
    }),
    app_compose: Some(serde_json::json!({
        "runner": "docker-compose",
        "docker_compose_file": "..."
    })),
    os_image_hash: Some("86b181...".to_string()),
    allowed_tcb_status: vec!["UpToDate".to_string()],
    ..Default::default()
};

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Development policy

use atlas_rs::DstackTdxPolicy;

// Accepts UpToDate, SWHardeningNeeded, and OutOfDate
// Disables runtime verification
let policy = DstackTdxPolicy::dev();

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With grace period

use atlas_rs::DstackTdxPolicy;

let policy = DstackTdxPolicy {
    allowed_tcb_status: vec!["UpToDate".to_string(), "OutOfDate".to_string()],
    grace_period: Some(3600), // 1 hour grace period
    disable_runtime_verification: true,
    ..Default::default()
};

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From JSON

use atlas_rs::DstackTdxPolicy;

let json = r#"{
    "expected_bootchain": {
        "mrtd": "abc123...",
        "rtmr0": "def456...",
        "rtmr1": "ghi789...",
        "rtmr2": "jkl012..."
    },
    "allowed_tcb_status": ["UpToDate", "SWHardeningNeeded"],
    "pccs_url": "https://pccs.example.com/tdx/v4"
}"#;
let policy: DstackTdxPolicy = serde_json::from_str(json).unwrap();

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ExpectedBootchain

Expected bootchain measurements for verification. These measurements represent the known-good values for TDX bootchain components.

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Definition

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ExpectedBootchain {
    pub mrtd: String,
    pub rtmr0: String,
    pub rtmr1: String,
    pub rtmr2: String,
}

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Fields

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mrtd
String
required
MRTD - Initial TD memory contents (TDVF/firmware). Hash of the initial TD memory layout, including the firmware/TDVF that runs before the OS kernel. Must be lowercase hex string.
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rtmr0
String
required
RTMR0 - Virtual hardware environment. Measures the virtual hardware configuration and TD configuration. Must be lowercase hex string.
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rtmr1
String
required
RTMR1 - Linux kernel. Measures the Linux kernel loaded into the TD. Must be lowercase hex string.
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rtmr2
String
required
RTMR2 - Kernel cmdline + initramfs. Measures the kernel command line parameters and initial ramdisk. Must be lowercase hex string.

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Usage example

use atlas_rs::tdx::ExpectedBootchain;

let bootchain = ExpectedBootchain {
    mrtd: "abc123...".to_string(),
    rtmr0: "def456...".to_string(),
    rtmr1: "ghi789...".to_string(),
    rtmr2: "jkl012...".to_string(),
};

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TCB status values

The following TCB status values are recognized: 
pub const TCB_STATUS_LIST: &[&str] = &[
    "UpToDate",
    "OutOfDate",
    "ConfigurationNeeded",
    "TDRelaunchAdvised",
    "SWHardeningNeeded",
    "Revoked",
];

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Status descriptions

  • UpToDate: Platform TCB is up to date
  • OutOfDate: Platform TCB is out of date and should be updated
  • ConfigurationNeeded: Platform configuration needs to be updated
  • TDRelaunchAdvised: TD should be relaunched to apply updates
  • SWHardeningNeeded: Additional software hardening is needed
  • Revoked: Platform TCB has been revoked

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Production recommendations

For production environments:
  • Use ["UpToDate"] for strictest security
  • Consider ["UpToDate", "SWHardeningNeeded"] if you understand the security implications
  • Use grace_period with OutOfDate to allow time for platform updates
  • Never allow Revoked status

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Validation rules

The DstackTdxPolicy::validate() method checks:
  1. All allowed_tcb_status values are in TCB_STATUS_LIST
  2. os_image_hash is a valid lowercase hex string (if provided)
  3. All expected_bootchain fields are valid lowercase hex strings (if provided)
  4. grace_period requires allowed_tcb_status to include OutOfDate
  5. If disable_runtime_verification is false, expected_bootchain, app_compose, and os_image_hash must be provided (enforced at verifier build time)

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See also

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