clap-migration: Moving from StructOpt to Clap

As StructOpt is deprecated and no longer
maintained, we need to switch to clap.

Signed-off-by: Larry Dewey <larry.dewey@amd.com>

Cargo.toml

@@ -19,7 +19,7 @@ default = []
 hyperv = ["tss-esapi"]
 
 [dependencies]
-structopt = "0.3"
+clap = { version = "^4.5", features = [ "derive" ] }
 env_logger = "0.10.0"
 anyhow = "1.0.69"
 sev = { version = "^3.1.1", default-features = false, features = ['openssl','snp']}

src/certs.rs

@@ -22,12 +22,13 @@ pub struct CertPaths {
     pub ask_path: PathBuf,
     pub vek_path: PathBuf,
 }
-#[derive(StructOpt, Clone, Copy)]
+
+#[derive(ValueEnum, Clone, Copy)]
 pub enum CertFormat {
-    #[structopt(about = "Certificates are encoded in PEM format.")]
+    /// Certificates are encoded in PEM format.
     Pem,
 
-    #[structopt(about = "Certificates are encoded in DER format.")]
+    /// Certificates are encoded in DER format.
     Der,
 }
 
@@ -164,14 +165,14 @@ pub fn write_cert(
     Ok(())
 }
 
-#[derive(StructOpt)]
+#[derive(Parser)]
 pub struct CertificatesArgs {
-    #[structopt(help = "Specify encoding to use for certificates. [PEM | DER]")]
+    /// Specify encoding to use for certificates.
+    #[arg(value_name = "encoding", required = true)]
     pub encoding: CertFormat,
 
-    #[structopt(
-        help = "Directory to store certificates in. Required if requesting an extended-report."
-    )]
+    /// Directory to store certificates in. Required if requesting an extended-report.
+    #[arg(value_name = "certs-dir", required = true)]
     pub certs_dir: PathBuf,
 }
 

src/display.rs

@@ -4,12 +4,12 @@
 use super::*;
 use std::path::PathBuf;
 
-#[derive(StructOpt)]
+#[derive(Subcommand)]
 pub enum DisplayCmd {
-    #[structopt(about = "Display an attestation report in console.")]
+    /// Display an attestation report in console.
     Report(report_display::Args),
 
-    #[structopt(about = "Display the derived key in console.")]
+    /// Display the derived key in console.
     Key(key_display::Args),
 }
 
@@ -22,9 +22,10 @@ pub fn cmd(cmd: DisplayCmd, quiet: bool) -> Result<()> {
 mod report_display {
     use super::*;
 
-    #[derive(StructOpt)]
+    #[derive(Parser)]
     pub struct Args {
-        #[structopt(help = "Path to attestation report to display.")]
+        /// Path to attestation report to display.
+        #[arg(value_name = "att-report-path", required = true)]
         pub att_report_path: PathBuf,
     }
 
@@ -44,9 +45,10 @@ mod report_display {
 mod key_display {
     use super::*;
 
-    #[derive(StructOpt)]
+    #[derive(Parser)]
     pub struct Args {
-        #[structopt(help = "Path of key to be displayed.")]
+        /// Path of key to be displayed.
+        #[arg(value_name = "key-path", required = true)]
         pub key_path: PathBuf,
     }
 

src/fetch.rs

@@ -13,16 +13,16 @@ use sev::firmware::host::CertType;
 
 use certs::{write_cert, CertFormat};
 
-#[derive(StructOpt)]
+#[derive(Subcommand)]
 pub enum FetchCmd {
-    #[structopt(about = "Fetch the certificate authority (ARK & ASK) from the KDS.")]
+    /// Fetch the certificate authority (ARK & ASK) from the KDS.
     CA(cert_authority::Args),
 
-    #[structopt(about = "Fetch the VCEK from the KDS.")]
+    /// Fetch the VCEK from the KDS.
     Vcek(vcek::Args),
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(ValueEnum, Debug, Clone, PartialEq, Eq)]
 pub enum Endorsement {
     Vcek,
     Vlek,
@@ -48,11 +48,18 @@ impl FromStr for Endorsement {
         }
     }
 }
-#[derive(Debug, Clone)]
+#[derive(ValueEnum, Debug, Clone)]
 pub enum ProcType {
+    /// 3rd Gen AMD EPYC Processor (Standard)
     Milan,
+
+    /// 4th Gen AMD EPYC Processor (Standard)
     Genoa,
+
+    /// 4th Gen AMD EPYC Processor (Performance)
     Bergamo,
+
+    /// 4th Gen AMD EPYC Processor (Edge)
     Siena,
 }
 
@@ -102,25 +109,22 @@ mod cert_authority {
     use openssl::x509::X509;
     use reqwest::StatusCode;
 
-    #[derive(StructOpt)]
+    #[derive(Parser)]
     pub struct Args {
-        #[structopt(help = "Specify encoding to use for certificates. [PEM | DER]")]
+        /// Specify encoding to use for certificates.
+        #[arg(value_name = "encoding", required = true)]
         pub encoding: CertFormat,
 
-        #[structopt(
-            help = "Specify the processor model for the certificate chain. [Milan | Genoa]"
-        )]
+        /// Specify the processor model for the certificate chain.
+        #[arg(value_name = "processor-model", required = true)]
         pub processor_model: ProcType,
 
-        #[structopt(help = "Directory to store the certificates in.")]
+        /// Directory to store the certificates in.
+        #[arg(value_name = "certs-dir", required = true)]
         pub certs_dir: PathBuf,
 
-        #[structopt(
-            long,
-            short,
-            default_value = "vcek",
-            help = "Specify to pull the VLEK certificate chain instead of VCEK."
-        )]
+        ///  Specify to pull the VLEK certificate chain instead of VCEK.
+        #[arg(short, long, default_value_t = Endorsement::Vcek)]
         pub endorser: Endorsement,
     }
 
@@ -194,20 +198,22 @@ mod vcek {
 
     use super::*;
 
-    #[derive(StructOpt)]
+    #[derive(Parser)]
     pub struct Args {
-        #[structopt(help = "Specify encoding to use for certificates. [PEM | DER]")]
+        /// Specify encoding to use for certificates.
+        #[arg(value_name = "encoding", required = true)]
         pub encoding: CertFormat,
 
-        #[structopt(
-            help = "Specify the processor model for the certificate chain. [Milan | Genoa]"
-        )]
+        /// Specify the processor model for the certificate chain.
+        #[arg(value_name = "processor-model", required = true)]
         pub processor_model: ProcType,
 
-        #[structopt(help = "Directory to store the certificates in.")]
+        /// Directory to store the certificates in.
+        #[arg(value_name = "certs-dir", required = true)]
         pub certs_dir: PathBuf,
 
-        #[structopt(help = "Path to attestation report to use to request VCEK.")]
+        /// Path to attestation report to use to request VCEK.
+        #[arg(value_name = "att-report-path", required = true)]
         pub att_report_path: PathBuf,
     }
 

src/key.rs

@@ -6,43 +6,31 @@ use sev::firmware::guest::{DerivedKey, Firmware, GuestFieldSelect};
 use std::io::Read;
 use std::{fs, path::PathBuf};
 
-#[derive(StructOpt)]
+#[derive(Parser)]
 pub struct KeyArgs {
-    #[structopt(help = "This is the path where the derived key will be saved")]
+    /// This is the path where the derived key will be saved.
+    #[arg(short, long, value_name = "FILE", required = true)]
     pub key_path: PathBuf,
 
-    #[structopt(
-        help = "This is the root key from which to derive the key. Input either VCEK or VMRK."
-    )]
+    /// This is the root key from which to derive the key. Input either VCEK or VMRK.
+    #[arg(short, long, value_name = "ROOT_KEY", required = true)]
     pub root_key_select: String,
 
-    #[structopt(
-        long = "vmpl",
-        short,
-        help = "Specify VMPL level the Guest is running on. Defaults to 1."
-    )]
+    /// Specify an integer VMPL level between 0 and 3 that the Guest is running on.
+    #[arg(short, long, value_name = "INTEGER", default_value = "Some(1)")]
     pub vmpl: Option<u32>,
 
-    #[structopt(
-        long = "guest_field_select",
-        short = "g",
-        help = "Specify which Guest Field Select bits to enable. It is a 6 digit binary string. For each bit, 0 denotes off and 1 denotes on.
-        The least significant (rightmost) bit is Guest Policy followed by Image ID, Family ID, Measurement, SVN, TCB Version which is the most significant (leftmost) bit. "
-    )]
+    /// Specify which Guest Field Select bits to enable. It is a 6 digit binary string. For each bit, 0 denotes off and 1 denotes on.
+    /// The least significant (rightmost) bit is Guest Policy followed by Image ID, Family ID, Measurement, SVN, TCB Version which is the most significant (leftmost) bit.
+    #[arg(short, long = "guest_file_select")]
     pub gfs: Option<String>,
 
-    #[structopt(
-        long = "guest_svn",
-        short = "s",
-        help = "Specify the guest SVN to mix into the key. Must not exceed the guest SVN provided at launch in the ID block."
-    )]
+    /// Specify the guest SVN to mix into the key. Must not exceed the guest SVN provided at launch in the ID block.
+    #[arg(short = 's', long = "guest_svn")]
     pub gsvn: Option<u32>,
 
-    #[structopt(
-        long = "tcb_version",
-        short,
-        help = "Specify the TCB version to mix into the derived key. Must not exceed CommittedTcb"
-    )]
+    /// Specify the TCB version to mix into the derived key. Must not exceed CommittedTcb.
+    #[arg(short, long = "tcb_version")]
     pub tcbv: Option<u64>,
 }
 

src/main.rs

@@ -20,50 +20,53 @@ use report::ReportArgs;
 use verify::VerifyCmd;
 
 use anyhow::{Context, Result};
-use structopt::StructOpt;
+use clap::{arg, Parser, Subcommand, ValueEnum};
 
-const VERSION: &str = env!("CARGO_PKG_VERSION");
-const AUTHORS: &str = env!("CARGO_PKG_AUTHORS");
-
-#[derive(StructOpt)]
+#[derive(Parser)]
+#[command(version, about, long_about = None)]
 struct SnpGuest {
-    #[structopt(subcommand)]
+    #[command(subcommand)]
     pub cmd: SnpGuestCmd,
 
-    #[structopt(short, long, help = "Don't print anything to the console")]
+    /// Don't print anything to the console
+    #[arg(short, long, default_value_t = false)]
     pub quiet: bool,
 }
 
 #[allow(clippy::large_enum_variant)]
-#[derive(StructOpt)]
-#[structopt(author = AUTHORS, version = VERSION, about = "Utilities for managing the SNP Guest environment")]
+/// Utilities for managing the SNP Guest environment
+#[derive(Subcommand)]
 enum SnpGuestCmd {
-    #[structopt(about = "Report command to request an attestation report.")]
+    /// Report command to request an attestation report.
     Report(ReportArgs),
 
-    #[structopt(about = "Certificates command to request cached certificates from the AMD PSP")]
+    /// Certificates command to request cached certificates from the AMD PSP.
     Certificates(CertificatesArgs),
 
-    #[structopt(about = "Fetch command to request certificates.")]
+    /// Fetch command to request certificates.
+    #[command(subcommand)]
     Fetch(FetchCmd),
 
-    #[structopt(about = "Verify command to verify certificates and attestation report.")]
+    /// Verify command to verify certificates and attestation report.
+    #[command(subcommand)]
     Verify(VerifyCmd),
 
-    #[structopt(about = "Display command to display files in human readable form.")]
+    /// Display command to display files in human readable form.
+    #[command(subcommand)]
     Display(DisplayCmd),
 
-    #[structopt(about = "Key command to generate derived key.")]
+    /// Key command to generate derived key.
     Key(KeyArgs),
 
-    #[structopt(about = "Probe system for SEV-SNP support")]
+    /// Probe system for SEV-SNP support.
+    #[command(subcommand)]
     Ok,
 }
 
 fn main() -> Result<()> {
     env_logger::init();
 
-    let snpguest = SnpGuest::from_args();
+    let snpguest = SnpGuest::parse();
 
     #[cfg(feature = "hyperv")]
     let hv = hyperv::present();

src/report.rs

@@ -30,35 +30,31 @@ pub fn create_random_request() -> [u8; 64] {
     data
 }
 
-#[derive(StructOpt)]
+/// Report command to request an attestation report.
+#[derive(Parser)]
 pub struct ReportArgs {
-    #[structopt(help = "File to write the attestation report to.")]
+    /// File to write the attestation report to.
+    #[arg(value_name = "att-report-path", required = true)]
     pub att_report_path: PathBuf,
 
-    #[structopt(
-        long = "random",
-        short,
-        help = "Use random data for attestation report request. Writes data to ./random-request-file.txt by default, use --request to specify where to write data."
-    )]
+    /// Use random data for attestation report request. Writes data
+    /// to ./random-request-file.txt by default, use --request to specify
+    /// where to write data.
+    #[arg(short, long, default_value_t = false, conflicts_with = "platform")]
     pub random: bool,
 
-    #[structopt(
-        long = "vmpl",
-        short,
-        help = "Specify VMPL level the Guest is running on. Defaults to 1."
-    )]
+    /// Specify an integer VMPL level between 0 and 3 that the Guest is running on.
+    #[arg(short, long, default_value = "1", value_name = "INTEGER")]
     pub vmpl: Option<u32>,
 
-    #[structopt(
-        help = "Provide file with data for attestation-report request. If provided with random flag, then the random data will be written in the provided path."
-    )]
+    /// Provide file with data for attestation-report request. If provided
+    /// with random flag, then the random data will be written in the
+    /// provided path.
+    #[arg(value_name = "request-file", required = true)]
     pub request_file: PathBuf,
 
-    #[structopt(
-        long,
-        short,
-        help = "Expect that the 64-byte report data will already be provided by the platform provider."
-    )]
+    /// Expect that the 64-byte report data will already be provided by the platform provider.
+    #[arg(short, long, conflicts_with = "random")]
     pub platform: bool,
 }