Adds support for inspecting a hex encoded public key (#7344)

* Adds support for inspecting a hex encoded public key

This adds support for inspecting hex encoded public keys to subkey. The
command looks like:

`subkey inspect --public 0xPUBLICHEX`

* Update client/cli/src/commands/utils.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

substrate/client/cli/src/commands/utils.rs

@@ -17,7 +17,7 @@
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
 //! subcommand utilities
-use std::{io::Read, path::PathBuf};
+use std::{io::Read, path::PathBuf, convert::TryFrom};
 use sp_core::{
 	Pair, hexdisplay::HexDisplay,
 	crypto::{Ss58Codec, Ss58AddressFormat},
@@ -50,13 +50,23 @@ pub fn read_uri(uri: Option<&String>) -> error::Result<String> {
 	Ok(uri)
 }
 
-/// print formatted pair from uri
+/// Try to parse given `uri` and print relevant information.
+///
+/// 1. Try to construct the `Pair` while using `uri` as input for [`sp_core::Pair::from_phrase`].
+///
+/// 2. Try to construct the `Pair` while using `uri` as input for [`sp_core::Pair::from_string_with_seed`].
+///
+/// 3. Try to construct the `Pair::Public` while using `uri` as input for
+///    [`sp_core::Pair::Public::from_string_with_version`].
 pub fn print_from_uri<Pair>(
 	uri: &str,
 	password: Option<SecretString>,
 	network_override: Option<Ss58AddressFormat>,
 	output: OutputType,
-) where Pair: sp_core::Pair, Pair::Public: Into<MultiSigner> {
+) where
+	Pair: sp_core::Pair,
+	Pair::Public: Into<MultiSigner>,
+{
 	let password = password.as_ref().map(|s| s.expose_secret().as_str());
 	if let Ok((pair, seed)) = Pair::from_phrase(uri, password.clone()) {
 		let public_key = pair.public();
@@ -130,28 +140,74 @@ pub fn print_from_uri<Pair>(
 					"accountId": format_account_id::<Pair>(public_key.clone()),
 					"ss58Address": public_key.to_ss58check_with_version(network_override),
 				});
+
 				println!("{}", serde_json::to_string_pretty(&json).expect("Json pretty print failed"));
 			},
 			OutputType::Text => {
 				println!(
 					"Public Key URI `{}` is account:\n  \
-					Network ID/version: {}\n  \
-					Public key (hex):   {}\n  \
-					Account ID:         {}\n  \
-					SS58 Address:       {}",
+					 Network ID/version: {}\n  \
+					 Public key (hex):   {}\n  \
+					 Account ID:         {}\n  \
+					 SS58 Address:       {}",
 					uri,
 					String::from(network_override),
 					format_public_key::<Pair>(public_key.clone()),
 					format_account_id::<Pair>(public_key.clone()),
 					public_key.to_ss58check_with_version(network_override),
 				);
-			},
+			}
 		}
 	} else {
 		println!("Invalid phrase/URI given");
 	}
 }
 
+/// Try to parse given `public` as hex encoded public key and print relevant information.
+pub fn print_from_public<Pair>(
+	public_str: &str,
+	network_override: Option<Ss58AddressFormat>,
+	output: OutputType,
+) -> Result<(), Error>
+where
+	Pair: sp_core::Pair,
+	Pair::Public: Into<MultiSigner>,
+{
+	let public = decode_hex(public_str)?;
+
+	let public_key = Pair::Public::try_from(&public)
+		.map_err(|_| "Failed to construct public key from given hex")?;
+
+	let network_override = network_override.unwrap_or_default();
+
+	match output {
+		OutputType::Json => {
+			let json = json!({
+				"networkId": String::from(network_override),
+				"publicKey": format_public_key::<Pair>(public_key.clone()),
+				"accountId": format_account_id::<Pair>(public_key.clone()),
+				"ss58Address": public_key.to_ss58check_with_version(network_override),
+			});
+
+			println!("{}", serde_json::to_string_pretty(&json).expect("Json pretty print failed"));
+		},
+		OutputType::Text => {
+			println!(
+				"Network ID/version: {}\n  \
+				 Public key (hex):   {}\n  \
+				 Account ID:         {}\n  \
+				 SS58 Address:       {}",
+				String::from(network_override),
+				format_public_key::<Pair>(public_key.clone()),
+				format_account_id::<Pair>(public_key.clone()),
+				public_key.to_ss58check_with_version(network_override),
+			);
+		}
+	}
+
+	Ok(())
+}
+
 /// generate a pair from suri
 pub fn pair_from_suri<P: Pair>(suri: &str, password: Option<SecretString>) -> Result<P, Error> {
 	let result = if let Some(pass) = password {