sq: Derive packet subcommand.

  - This is part of the effort of moving to clap3's derive API and
    profit from the added type safety.

2 files changed, 225 insertions, 172 deletions

diff --git a/sq/src/sq-usage.rs b/sq/src/sq-usage.rs
index 96e63f09..9515aac6 100644
--- a/sq/src/sq-usage.rs
+++ b/sq/src/sq-usage.rs
@@ -1396,7 +1396,6 @@
 //! ## Subcommand packet
 //!
 //! ```text
-//!
 //! Low-level packet manipulation
 //!
 //! An OpenPGP data stream consists of packets.  These tools allow working
diff --git a/sq/src/sq_cli.rs b/sq/src/sq_cli.rs
index b1e81529..e867d243 100644
--- a/sq/src/sq_cli.rs
+++ b/sq/src/sq_cli.rs
@@ -962,176 +962,6 @@ $ sq certify --time 20130721T0550+0200 neal.pgp ada.pgp ada
                          .required(true)
                          .index(3)
                          .help("Certifies USERID for CERTIFICATE."))
-        )
-
-        .subcommand(Command::new("packet")
-                    .display_order(610)
-                    .about("Low-level packet manipulation")
-                    .long_about(
-"
-Low-level packet manipulation
-
-An OpenPGP data stream consists of packets.  These tools allow working
-with packet streams.  They are mostly of interest to developers, but
-\"sq packet dump\" may be helpful to a wider audience both to provide
-valuable information in bug reports to OpenPGP-related software, and
-as a learning tool.
-")
-                    .subcommand_required(true)
-                    .arg_required_else_help(true)
-                    .subcommand(Command::new("dump")
-                                .display_order(100)
-                                .about("Lists packets")
-                                .long_about(
-"
-Lists packets
-
-Creates a human-readable description of the packet sequence.
-Additionally, it can print cryptographic artifacts, and print the raw
-octet stream similar to hexdump(1), annotating specifically which
-bytes are parsed into OpenPGP values.
-
-To inspect encrypted messages, either supply the session key, or see
-\"sq decrypt --dump\" or \"sq packet decrypt\".
-")
-                                .after_help(
-"EXAMPLES:
-
-# Prints the packets of a certificate
-$ sq packet dump juliet.pgp
-
-# Prints cryptographic artifacts of a certificate
-$ sq packet dump --mpis juliet.pgp
-
-# Prints a hexdump of a certificate
-$ sq packet dump --hex juliet.pgp
-
-# Prints the packets of an encrypted message
-$ sq packet dump --session-key AAAABBBBCCCC... ciphertext.pgp
-")
-                                .arg(Arg::new("input")
-                                     .value_name("FILE")
-                                     .help("Reads from FILE or stdin if omitted"))
-                                .arg(Arg::new("output")
-                                     .short('o').long("output").value_name("FILE")
-                                     .help("Writes to FILE or stdout if omitted"))
-                                .arg(Arg::new("session-key")
-                                     .long("session-key").value_name("SESSION-KEY")
-                                     .help("Decrypts an encrypted message using \
-                                            SESSION-KEY"))
-                                .arg(Arg::new("mpis")
-                                     .long("mpis")
-                                     .help("Prints cryptographic artifacts"))
-                                .arg(Arg::new("hex")
-                                     .short('x').long("hex")
-                                     .help("Prints a hexdump"))
-                    )
-                    .subcommand(Command::new("decrypt")
-                                .display_order(200)
-                                .about("Unwraps an encryption container")
-                                .long_about(
-"
-Unwraps an encryption container
-
-Decrypts a message, dumping the content of the encryption container
-without further processing.  The result is a valid OpenPGP message
-that can, among other things, be inspected using \"sq packet dump\".
-")
-                                .after_help(
-"EXAMPLES:
-
-# Unwraps the encryption revealing the signed message
-$ sq packet decrypt --recipient-key juliet.pgp ciphertext.pgp
-")
-                                .arg(Arg::new("input")
-                                     .value_name("FILE")
-                                     .help("Reads from FILE or stdin if omitted"))
-                                .arg(Arg::new("output")
-                                     .short('o').long("output").value_name("FILE")
-                                     .help("Writes to FILE or stdout if omitted"))
-                                .arg(Arg::new("binary")
-                                     .short('B').long("binary")
-                                     .help("Emits binary data"))
-                                .arg(Arg::new("secret-key-file")
-                                     .long("recipient-key").value_name("KEY")
-                                     .multiple_occurrences(true)
-                                     .help("Decrypts the message with KEY"))
-                                .arg(Arg::new("private-key-store")
-                                     .long("private-key-store").value_name("KEY_STORE")
-                                     .help("Provides parameters for private key store"))
-                                .arg(Arg::new("dump-session-key")
-                                     .long("dump-session-key")
-                                     .help("Prints the session key to stderr"))
-                    )
-                    .subcommand(Command::new("split")
-                                .display_order(300)
-                                .about("Splits a message into packets")
-                                .long_about(
-"
-Splits a message into packets
-
-Splitting a packet sequence into individual packets, then recombining
-them freely with \"sq packet join\" is a great way to experiment with
-OpenPGP data.
-
-The converse operation is \"sq packet join\".
-")
-                                .after_help(
-"EXAMPLES:
-
-# Split a certificate into individual packets
-$ sq packet split juliet.pgp
-")
-                                .arg(Arg::new("input")
-                                     .value_name("FILE")
-                                     .help("Reads from FILE or stdin if omitted"))
-                                .arg(Arg::new("prefix")
-                                     .short('p').long("prefix").value_name("PREFIX")
-                                     .help("Writes to files with PREFIX \
-                                            [defaults: FILE a dash, \
-                                            or \"output\" if read from stdin)"))
-                    )
-                    .subcommand(Command::new("join")
-                                .display_order(310)
-                                .about("Joins packets split across \
-                                        files")
-                                .long_about(
-"
-Joins packets split across files
-
-Splitting a packet sequence into individual packets, then recombining
-them freely with \"sq packet join\" is a great way to experiment with
-OpenPGP data.
-
-The converse operation is \"sq packet split\".
-")
-                        .after_help(
-"EXAMPLES:
-
-# Split a certificate into individual packets
-$ sq packet split juliet.pgp
-
-# Then join only a subset of these packets
-$ sq packet join juliet.pgp-[0-3]*
-")
-                                .arg(Arg::new("input")
-                                     .value_name("FILE")
-                                     .multiple_occurrences(true)
-                                     .help("Reads from FILE or stdin if omitted"))
-                                .arg(Arg::new("output")
-                                     .short('o').long("output").value_name("FILE")
-                                     .help("Writes to FILE or stdout if omitted"))
-                                .arg(Arg::new("kind")
-                                     .long("label").value_name("LABEL")
-                                     .possible_values(&["auto", "message",
-                                                        "cert", "key", "sig",
-                                                        "file"])
-                                     .default_value("auto")
-                                     .conflicts_with("binary")
-                                     .help("Selects the kind of armor header"))
-                                .arg(Arg::new("binary")
-                                     .short('B').long("binary")
-                                     .help("Emits binary data")))
         );
 
     let app = if ! feature_autocrypt {
@@ -1147,7 +977,8 @@ $ sq packet join juliet.pgp-[0-3]*
     .subcommand(VerifyCommand::command())
     .subcommand(WkdCommand::command())
     .subcommand(KeyserverCommand::command())
-    .subcommand(RevokeCommand::command());
+    .subcommand(RevokeCommand::command())
+    .subcommand(PacketCommand::command());
 
     app
 }
@@ -1462,6 +1293,229 @@ pub struct SignCommand {
 
 #[derive(Parser, Debug)]
 #[clap(
+    name = "packet",
+    display_order = 610,
+    about = "Low-level packet manipulation",
+    long_about =
+"Low-level packet manipulation
+
+An OpenPGP data stream consists of packets.  These tools allow working
+with packet streams.  They are mostly of interest to developers, but
+\"sq packet dump\" may be helpful to a wider audience both to provide
+valuable information in bug reports to OpenPGP-related software, and
+as a learning tool.
+",
+    subcommand_required = true,
+    arg_required_else_help = true,
+    )]
+pub struct PacketCommand {
+    #[clap(subcommand)]
+    pub subcommand: PacketSubcommands,
+}
+
+#[derive(Debug, Subcommand)]
+pub enum PacketSubcommands {
+    Dump(PacketDumpCommand),
+    Decrypt(PacketDecryptCommand),
+    Split(PacketSplitCommand),
+    Join(PacketJoinCommand),
+}
+
+#[derive(Debug, Args)]
+#[clap(
+    display_order = 100,
+    about = "Lists packets",
+    long_about =
+"
+Lists packets
+
+Creates a human-readable description of the packet sequence.
+Additionally, it can print cryptographic artifacts, and print the raw
+octet stream similar to hexdump(1), annotating specifically which
+bytes are parsed into OpenPGP values.
+
+To inspect encrypted messages, either supply the session key, or see
+\"sq decrypt --dump\" or \"sq packet decrypt\".
+",
+    after_help =
+"EXAMPLES:
+
+# Prints the packets of a certificate
+$ sq packet dump juliet.pgp
+
+# Prints cryptographic artifacts of a certificate
+$ sq packet dump --mpis juliet.pgp
+
+# Prints a hexdump of a certificate
+$ sq packet dump --hex juliet.pgp
+
+# Prints the packets of an encrypted message
+$ sq packet dump --session-key AAAABBBBCCCC... ciphertext.pgp
+",
+)]
+pub struct PacketDumpCommand {
+    #[clap(flatten)]
+    pub io: IoArgs,
+    #[clap(
+        long = "session-key",
+        value_name = "SESSION-KEY",
+        help = "Decrypts an encrypted message using SESSION-KEY",
+    )]
+    pub session_key: Option<String>,
+    #[clap(
+        long = "mpis",
+        help = "Prints cryptographic artifacts",
+    )]
+    pub mpis: bool,
+    #[clap(
+        short = 'x',
+        long = "hex",
+        help = "Prints a hexdump",
+    )]
+    pub hex: bool,
+}
+
+#[derive(Debug, Args)]
+#[clap(
+    display_order = 200,
+    about = "Unwraps an encryption container",
+    long_about = "
+Unwraps an encryption container
+
+Decrypts a message, dumping the content of the encryption container
+without further processing.  The result is a valid OpenPGP message
+that can, among other things, be inspected using \"sq packet dump\".
+",
+    after_help =
+"EXAMPLES:
+
+# Unwraps the encryption revealing the signed message
+$ sq packet decrypt --recipient-key juliet.pgp ciphertext.pgp
+",
+)]
+pub struct PacketDecryptCommand {
+    #[clap(flatten)]
+    pub io: IoArgs,
+    #[clap(
+        short = 'B',
+        long,
+        help = "Emits binary data",
+    )]
+    pub binary: bool,
+    #[clap(
+        long = "recipient-key",
+        value_name = "KEY",
+        help = "Decrypts the message with KEY",
+    )]
+    pub secret_key_file: Vec<String>,
+    #[clap(
+        long = "private-key-store",
+        value_name = "KEY_STORE",
+        help = "Provides parameters for private key store",
+    )]
+    pub private_key_store: Option<String>,
+    #[clap(
+            long = "dump-session-key",
+            help = "Prints the session key to stderr",
+    )]
+    pub dump_session_key: bool,
+}
+
+#[derive(Debug, Args)]
+#[clap(
+    display_order = 300,
+    about = "Splits a message into packets",
+    long_about = "
+Splits a message into packets
+
+Splitting a packet sequence into individual packets, then recombining
+them freely with \"sq packet join\" is a great way to experiment with
+OpenPGP data.
+
+The converse operation is \"sq packet join\".
+",
+    after_help =
+"EXAMPLES:
+
+# Split a certificate into individual packets
+$ sq packet split juliet.pgp
+",
+)]
+pub struct PacketSplitCommand {
+    #[clap(value_name = "FILE", help = "Reads from FILE or stdin if omitted")]
+    pub input: Option<String>,
+    #[clap(
+        short = 'p',
+        long = "prefix",
+        value_name = "PREFIX",
+        help = "Writes to files with PREFIX \
+            [defaults: FILE a dash, or \"output\" if read from stdin)",
+    )]
+    pub prefix: Option<String>,
+}
+
+#[derive(Debug, Args)]
+#[clap(
+    display_order = 310,
+    about = "Joins packets split across files",
+    long_about = "
+Joins packets split across files
+
+Splitting a packet sequence into individual packets, then recombining
+them freely with \"sq packet join\" is a great way to experiment with
+OpenPGP data.
+
+The converse operation is \"sq packet split\".
+",
+    after_help =
+"EXAMPLES:
+
+# Split a certificate into individual packets
+$ sq packet split juliet.pgp
+
+# Then join only a subset of these packets
+$ sq packet join juliet.pgp-[0-3]*
+",
+)]
+pub struct PacketJoinCommand {
+    #[clap(value_name = "FILE", help = "Reads from FILE or stdin if omitted")]
+    pub input: Vec<String>,
+    #[clap(
+        short,
+        long,
+        value_name = "FILE",
+        help = "Writes to FILE or stdout if omitted"
+    )]
+    pub output: Option<String>,
+    #[clap(
+        long = "label",
+        value_name = "LABEL",
+        default_value_t = PacketKind::Auto,
+        conflicts_with = "binary",
+        help = "Selects the kind of armor header",
+        arg_enum,
+    )]
+    pub kind: PacketKind,
+    #[clap(
+        short = 'B',
+        long,
+        help = "Emits binary data",
+    )]
+    pub binary: bool,
+}
+// TODO: reuse CliArmorKind, requires changes in sq.rs
+#[derive(ArgEnum, Clone, Debug)]
+pub enum PacketKind {
+    Auto,
+    Message,
+    Cert,
+    Key,
+    Sig,
+    File
+}
+
+#[derive(Parser, Debug)]
+#[clap(
     name = "revoke",
     display_order = 700,
     about = "Generates revocation certificates",