Implement an "info" command that prints capabilities/metadata for a card (the output format is currently not very nice, it would benefit from working on https://gitlab.com/hkos/openpgp-card/-/issues/9).

tools/README.md

@@ -91,8 +91,7 @@ is plugged in):
 $ opgpcard status --card ABCD:01234567
 ```
 
-Add `-v` for more verbose card status (including the list of supported
+Add `-v` for more verbose card status (this prints public key data for each key slot):
-algorithms, if the card returns an algorithm list):
 
 ```
 $ opgpcard status -c ABCD:01234567 -v
@@ -122,23 +121,6 @@ Signature counter: 3
 Signature pin only valid once: true
 Password validation retry count:
   user pw: 3, reset: 3, admin pw: 3
-
-Supported algorithms:
-SIG: RSA 2048 [e 32]
-SIG: RSA 4096 [e 32]
-SIG: Secp256k1 (ECDSA)
-SIG: Ed25519 (EdDSA)
-SIG: Ed448 (EdDSA)
-DEC: RSA 2048 [e 32]
-DEC: RSA 4096 [e 32]
-DEC: Secp256k1 (ECDSA)
-DEC: Cv25519 (ECDH)
-DEC: X448 (ECDH)
-AUT: RSA 2048 [e 32]
-AUT: RSA 4096 [e 32]
-AUT: Secp256k1 (ECDSA)
-AUT: Ed25519 (EdDSA)
-AUT: Ed448 (EdDSA)
 ```
 
 ### Get OpenPGP public key
@@ -214,6 +196,55 @@ In the example output above, this string is the ssh public key:
 
 `ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAII2dcYBqMCamidT5MpE3Cl3MIKcYMBekGXbK2aaN6JaH opgpcard:ABCD:01234567`
 
+### Show OpenPGP card metadata
+
+Print information about the capabilities of a card, including the list of supported algorithms (if the card returns
+that list).
+
+Most of the output is probably not of interest to regular users.
+
+```
+$ opgpcard info
+OpenPGP card FF06:00002001 (card version 2.0)
+
+CardCapabilities {
+    command_chaining: true,
+    extended_lc_le: false,
+    extended_length_information: false,
+}
+
+ExtendedCapabilities {
+    secure_messaging: true,
+    get_challenge: true,
+    key_import: true,
+    pw_status_change: true,
+    private_use_dos: true,
+    algo_attrs_changeable: false,
+    aes: false,
+    kdf_do: false,
+    sm_algo: 0,
+    max_len_challenge: 255,
+    max_len_cardholder_cert: 1216,
+    max_cmd_len: Some(
+        255,
+    ),
+    max_resp_len: Some(
+        255,
+    ),
+    max_len_special_do: None,
+    pin_block_2_format_support: None,
+    mse_command_support: None,
+}
+
+Firmware Version: 1.0.18
+```
+
+Or to query a specific card:
+
+```
+$ opgpcard info --card ABCD:01234567
+```
+
 ### Admin commands
 
 All `admin` commands need the admin PIN. It can be provided as a file, with `-P <admin-pin-file>`,

tools/src/bin/opgpcard/cli.rs

@@ -27,6 +27,10 @@ pub enum Command {
         #[clap(name = "verbose", short = 'v', long = "verbose")]
         verbose: bool,
     },
+    Info {
+        #[clap(name = "card ident", short = 'c', long = "card")]
+        ident: Option<String>,
+    },
     Ssh {
         #[clap(name = "card ident", short = 'c', long = "card")]
         ident: Option<String>,

tools/src/bin/opgpcard/main.rs

@@ -39,6 +39,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         cli::Command::Status { ident, verbose } => {
             print_status(ident, verbose)?;
         }
+        cli::Command::Info { ident } => {
+            print_info(ident)?;
+        }
         cli::Command::Ssh { ident } => {
             print_ssh(ident)?;
         }
@@ -310,22 +313,48 @@ fn print_status(ident: Option<String>, verbose: bool) -> Result<()> {
         pws.err_count_pw3(),
     );
 
-    // FIXME: add General key info; login data; KDF setting
+    // FIXME: print "Login Data", "Key Information"
+
+    Ok(())
+}
+
+/// print metadata information about a card
+fn print_info(ident: Option<String>) -> Result<()> {
+    let mut card = pick_card_for_reading(ident)?;
+
+    let mut pgp = OpenPgp::new(&mut *card);
+    let mut open = Open::new(pgp.transaction()?)?;
+
+    print!("OpenPGP card {}", open.application_identifier()?.ident());
+
+    let ai = open.application_identifier()?;
+    let version = ai.version().to_be_bytes();
+    println!(" (card version {}.{})\n", version[0], version[1]);
+
+    if let Some(cc) = open.historical_bytes()?.card_capabilities() {
+        println!("{:#?}\n", cc);
+    }
+
+    if let Some(eli) = open.extended_length_information()? {
+        println!("{:#?}\n", eli);
+    }
+
+    let ec = open.extended_capabilities()?;
+    println!("{:#?}\n", ec);
 
-    if verbose {
     // Algorithm information (list of supported algorithms)
     if let Ok(Some(ai)) = open.algorithm_information() {
-            println!();
         println!("Supported algorithms:");
         println!("{}", ai);
     }
 
+    // FIXME: print KDF info
+
     // YubiKey specific (?) firmware version
     if let Ok(ver) = open.firmware_version() {
         let ver = ver.iter().map(u8::to_string).collect::<Vec<_>>().join(".");
 
-            println!("Firmware Version: {}", ver);
+        println!("Firmware Version: {}\n", ver);
-        }
     }
 
     Ok(())