feat: add ssh-parse-sign

src/cmd_sshparsesign.rs

@@ -0,0 +1,119 @@
+use std::io::{Cursor, Read};
+use std::str::FromStr;
+
+use clap::{App, Arg, ArgMatches, SubCommand};
+use pem::Pem;
+use rust_util::util_clap::{Command, CommandError};
+use rust_util::XResult;
+
+use crate::util;
+
+trait CursorReader {
+    fn read_bytes(&mut self, len: usize) -> XResult<Vec<u8>>;
+    fn read_u32(&mut self) -> XResult<u32>;
+    fn read_string(&mut self) -> XResult<Vec<u8>>;
+}
+
+impl CursorReader for Cursor<Vec<u8>> {
+    fn read_bytes(&mut self, len: usize) -> XResult<Vec<u8>> {
+        let mut buff = vec![0_u8; len];
+        Cursor::read_exact(self, &mut buff)?;
+        Ok(buff)
+    }
+
+    fn read_u32(&mut self) -> XResult<u32> {
+        let mut num = [0_u8; 4];
+        num.copy_from_slice(&self.read_bytes(4)?);
+        Ok(u32::from_be_bytes(num))
+    }
+
+    fn read_string(&mut self) -> XResult<Vec<u8>> {
+        let len = self.read_u32()?;
+        if len == 0 {
+            return Ok(Vec::new());
+        }
+        self.read_bytes(len as usize)
+    }
+}
+
+pub struct CommandImpl;
+
+// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.sshsig
+impl Command for CommandImpl {
+    fn name(&self) -> &str { "ssh-parse-sign" }
+
+    fn subcommand<'a>(&self) -> App<'a, 'a> {
+        SubCommand::with_name(self.name()).about("SSH parse sign subcommand")
+            .arg(Arg::with_name("in").long("in").required(true).takes_value(true).help("In file, - for stdin"))
+    }
+
+    fn run(&self, _arg_matches: &ArgMatches, sub_arg_matches: &ArgMatches) -> CommandError {
+        let file_in = sub_arg_matches.value_of("in").unwrap();
+        let bytes_in = util::read_file_or_stdin(file_in)?;
+        let pem_in = opt_result!(String::from_utf8(bytes_in), "Parse SSH sign failed: {}");
+
+        let pem = opt_result!( Pem::from_str(&pem_in), "Parse SSH sign pem failed: {}");
+        debugging!("PEM: {:?}", pem);
+
+        if pem.tag() != "SSH SIGNATURE" {
+            return simple_error!("Not SSH signature file.");
+        }
+
+        let ssh_signature = pem.contents().to_vec();
+        let mut cursor = Cursor::new(ssh_signature);
+
+        let magic_preamble = String::from_utf8(cursor.read_bytes(6)?)?;
+        if magic_preamble != "SSHSIG" {
+            return simple_error!("Bad SSH signature file: magic");
+        }
+        let ssh_signature_version = cursor.read_u32()?;
+        if ssh_signature_version != 1 {
+            return simple_error!("Bad SSH signature file: version");
+        }
+        let public_key = cursor.read_string()?;
+        debugging!("Public key: {}", hex::encode(&public_key));
+        let namespace = String::from_utf8(cursor.read_string()?)?;
+        debugging!("Namespace: {}", namespace);
+        let reserved = cursor.read_string()?;
+        debugging!("Reserved: {}", hex::encode(&reserved));
+        let hash_algorithm = String::from_utf8(cursor.read_string()?)?;
+        debugging!("Hash algorithm: {}", hash_algorithm);
+        let signature = cursor.read_string()?;
+        debugging!("Signature: {}", hex::encode(&signature));
+
+        let mut public_key_cursor = Cursor::new(public_key);
+        let public_key_algorithm = String::from_utf8(public_key_cursor.read_string()?)?;
+        debugging!("Public key algorithm: {}", public_key_algorithm);
+        let public_key_algorithm2 = String::from_utf8(public_key_cursor.read_string()?)?;
+        debugging!("Public key algorithm(2): {}", public_key_algorithm2);
+        let public_key_value = public_key_cursor.read_string()?;
+        debugging!("Public key value: {}", hex::encode(&public_key_value));
+
+        let mut signature_cursor = Cursor::new(signature);
+        let signature_algorithm = String::from_utf8(signature_cursor.read_string()?)?;
+        debugging!("Signature algorithm: {}", signature_algorithm);
+        let signature_value = signature_cursor.read_string()?;
+        debugging!("Signature value: {}", hex::encode(&signature_value));
+
+        println!("Public Key:\n> {}", public_key_algorithm);
+        println!("  > {}", public_key_algorithm2);
+        println!("  > {}", hex::encode(public_key_value));
+        println!("Namespace: {}", namespace);
+        println!("Reserved: {}", hex::encode(&reserved));
+        println!("Hash Algorithm: {}", &hash_algorithm);
+        println!("Signature:\n> {}", signature_algorithm);
+        if signature_algorithm.starts_with("ecdsa-") {
+            let mut signature_value_cursor = Cursor::new(signature_value);
+            let signature_value_x = signature_value_cursor.read_string()?;
+            let signature_value_y = signature_value_cursor.read_string()?;
+            println!("  > {}", hex::encode(signature_value_x));
+            println!("  > {}", hex::encode(signature_value_y));
+        } else if signature_algorithm.starts_with("rsa-") {
+            println!("  > {}", hex::encode(signature_value));
+        } else {
+            failure!("Unknown signature algorithm: {}", signature_algorithm);
+        }
+
+        Ok(None)
+    }
+}

src/main.rs

@@ -40,6 +40,7 @@ mod cmd_hmac_sha1;
 mod cmd_chall;
 mod cmd_challconfig;
 mod cmd_sshagent;
+mod cmd_sshparsesign;
 mod cmd_pgpageaddress;
 mod cmd_signjwt;
 mod cmd_signfile;
@@ -99,6 +100,7 @@ fn inner_main() -> CommandError {
         Box::new(cmd_u2fregister::CommandImpl),
         Box::new(cmd_u2fsign::CommandImpl),
         Box::new(cmd_sshagent::CommandImpl),
+        Box::new(cmd_sshparsesign::CommandImpl),
         Box::new(cmd_pgpageaddress::CommandImpl),
         Box::new(cmd_signjwt::CommandImpl),
         Box::new(cmd_signfile::CommandImpl),

src/util.rs

@@ -1,3 +1,4 @@
+use std::fs;
 use std::io::Read;
 
 use base64::{DecodeError, Engine};
@@ -32,3 +33,11 @@ pub fn read_stdin() -> XResult<Vec<u8>> {
     opt_result!(stdin.read_to_end(&mut buffer), "Read stdin failed: {}");
     Ok(buffer)
 }
+
+pub fn read_file_or_stdin(file: &str) -> XResult<Vec<u8>> {
+    if file == "-" {
+        read_stdin()
+    } else {
+        Ok(opt_result!(fs::read(file), "Read file: {} failed: {}", file))
+    }
+}