Verify measure, host data, and report data function

README.md

@@ -306,7 +306,7 @@ snpguest verify <SUBCOMMAND>
 
     **Usage**
     ```bash
-    snpguest verify attestation $CERTS_DIR $ATT_REPORT_PATH [-t, --tcb] [-s, --signature]
+    snpguest verify attestation $CERTS_DIR $ATT_REPORT_PATH [-t, --tcb] [-s, --signature] [-m, --measurement] [-d, --host-data] [-r, --report-data]
     ```
     **Arguments**
 
@@ -318,6 +318,9 @@ snpguest verify <SUBCOMMAND>
 
     - `-t, --tcb`: Verify the Reported TCB section of the report only.
     - `-s, --signature`: Verify the signature of the report only.
+    - `-m, --measurement`: Verify the measurement from the attestation report.
+    - `-d, --host-data`: Verify the host-data from the attestation report.
+    - `-r, --report-data`: Verify the report-data from the attestation report. 
 
     **Example**
     ```bash
@@ -327,6 +330,12 @@ snpguest verify <SUBCOMMAND>
     snpguest verify attestation ./certs attestation-report.bin --tcb
     # Verify Attestation Signature only
     snpguest verify attestation ./certs attestation-report.bin --signature
+    # Verify Attestation Measurement only
+    snpguest verify attestation --measurement 0xf28aac58964258d8ae0b2e88a706fc7afd0bb524f6a291ac3eedeccb73f89d7cfcf2e4fb6045e7d5201e41d1726afa02 /home/amd/certs /home/amd/report.bin
+    # Verify Attestation host-data only
+    snpguest verify attestation --host-data 0x7e4a3f9c1b82a056d39f0d44e5c8a7b1f02394de6b58ac0d7e3c11af0042bd59 /home/amd/certs /home/amd/report.bin
+    # Verify Attestation report-data only
+    snpguest verify attestation --report-data 0x5482c1ffe29145d47cf678f7681e3b64a89909d6cf8ec0104cfacb0b0418f005f564ad14f5c1381c99b74903a780ea340e887c9b445e9c760bf0b74115b26d45 /home/amd/certs /home/amd/report.bin 
     ```
 
 ### Global Options

docs/snpguest.1.adoc

@@ -120,12 +120,25 @@ COMMANDS
     An error will be raised if the attestation verification fails at any point.
     The user can use the [-t, --tcb] flag to only validate the tcb contents of the report.
     The user can use the [-s, --signature] flag to only validate the report signature.
+    The user can use the [-m, --measurement] flag to verify that the measurement in the attestation 
+    report matches the expected measurement value (prefix with 0x for hex, without prefix it assumes 
+    decimal values).
+    The user can use the [-d, --host-data] flag to verify that the host-data in the attestation 
+    report matches the expected host-data value (prefix with 0x for hex, without prefix it assumes 
+    decimal values).
+    The user can use the [-r, --report-data] flag to verify that the report-data in the attestation 
+    report matches the expected report-data value (prefix with 0x for hex, without prefix it assumes 
+    decimal values).
+    If the optional flags are not passed, just the signature will be verified.
 
     options:
     -h, --help show a help message
     -p, --processor_model Specify the processor model to use for verification
     -t, --tcb verify the tcb section of the report only
     -s, --signature verify the signature of the report only
+    -m, --measurement provide an expected measurement to verify the measurement field in the attestation report
+    -d, --host-data provide the expected host-data to verify the host-data field in the attestation report
+    -r, --report-data provide the expected report-data to verify the report-data in the attestation report
 
 *snpguest key*::
     usage: snpguest key $KEY_PATH $ROOT_KEY_SELECT [-g, --guest_field_select] [-s, --guest_svn] [-t, --tcb_version] [-v, --vmpl]

src/verify.rs

@@ -16,6 +16,8 @@ use openssl::{ecdsa::EcdsaSig, sha::Sha384};
 use sev::certs::snp::Chain;
 use sev::parser::ByteParser;
 
+use hex::FromHex;
+
 #[derive(Subcommand)]
 pub enum VerifyCmd {
     /// Verify the certificate chain.
@@ -201,6 +203,18 @@ mod attestation {
         /// Run the Signature Verification Exclusively.
         #[arg(short, long, conflicts_with = "tcb")]
         pub signature: bool,
+
+        /// Optional measurement string (hex, 48 bytes / 96 chars)
+        #[arg(short, long, value_name = "measurement")]
+        pub measurement: Option<String>,
+
+        /// Optional host_data string (hex, 32 bytes / 64 chars)
+        #[arg(short = 'd', long, value_name = "host_data")]
+        pub host_data: Option<String>,
+
+        /// Optional report_data string (hex, 64 bytes / 128 chars)
+        #[arg(short, long, value_name = "report_data")]
+        pub report_data: Option<String>,
     }
 
     fn verify_attestation_signature(
@@ -418,7 +432,7 @@ mod attestation {
                 .context("Could not open attestation report")?
         };
 
-        let proc_model = if let Some(proc_model) = args.processor_model {
+        let proc_model = if let Some(proc_model) = args.processor_model.clone() {
             proc_model
         } else {
             let att_report = report::read_report(args.att_report_path.clone())
@@ -447,6 +461,89 @@ mod attestation {
             verify_attestation_signature(vek, att_report, quiet)?;
         }
 
+        // Verify optional fields if provided
+        if args.measurement.is_some() || args.host_data.is_some() || args.report_data.is_some() {
+            verify_report_fields(&args, &att_report, quiet)?;
+        }
+
+        Ok(())
+    }
+
+    fn decode_hex_or_decimal(input: &str) -> Result<Vec<u8>> {
+        // Look for "0x" at beginning. If it exists, treat as a hex.
+        if let Some(hex_str) = input.strip_prefix("0x") {
+            Ok(Vec::from_hex(hex_str)?)
+        } else {
+            Ok(input.as_bytes().to_vec())
+        }
+    }
+
+    fn verify_field(
+        field_name: &str,
+        expected: &[u8],
+        provided: &str,
+        expected_len: usize,
+        quiet: bool,
+    ) -> Result<()> {
+        let actual = decode_hex_or_decimal(provided)?;
+
+        if actual.len() != expected_len {
+            return Err(anyhow::anyhow!(
+                "Expected {} characters for {}, got {}",
+                expected_len,
+                field_name,
+                actual.len()
+            ));
+        }
+
+        if expected != actual.as_slice() {
+            return Err(anyhow::anyhow!(
+                "{} did not match:\n expected {}\n got {}",
+                field_name,
+                hex::encode(expected),
+                hex::encode(actual)
+            ));
+        }
+        if !quiet {
+            println!("{} verified successfully.", field_name);
+        }
+
+        Ok(())
+    }
+
+    fn verify_report_fields(
+        args: &Args,
+        att_report: &AttestationReport,
+        quiet: bool,
+    ) -> Result<()> {
+        if let Some(measure) = &args.measurement {
+            verify_field(
+                "Measurement",
+                att_report.measurement.as_slice(),
+                measure,
+                48,
+                quiet,
+            )?;
+        }
+        if let Some(host) = &args.host_data {
+            verify_field(
+                "Host Data",
+                att_report.host_data.as_slice(),
+                host,
+                32,
+                quiet,
+            )?;
+        }
+        if let Some(report) = &args.report_data {
+            verify_field(
+                "Report Data",
+                att_report.report_data.as_slice(),
+                report,
+                64,
+                quiet,
+            )?;
+        }
+
         Ok(())
     }