Reorganize crate structure and move documentation files

4 files changed, 0 insertions, 981 deletions

diff --git a/crates/utils/tcp_connection/src/error.rs b/crates/utils/tcp_connection/src/error.rs
deleted file mode 100644
index 32d06cc..0000000
--- a/crates/utils/tcp_connection/src/error.rs
+++ /dev/null
@@ -1,122 +0,0 @@
-use std::io;
-use thiserror::Error;
-
-#[derive(Error, Debug, Clone)]
-pub enum TcpTargetError {
-    #[error("Authentication failed: {0}")]
-    Authentication(String),
-
-    #[error("Reference sheet not allowed: {0}")]
-    ReferenceSheetNotAllowed(String),
-
-    #[error("Cryptographic error: {0}")]
-    Crypto(String),
-
-    #[error("File operation error: {0}")]
-    File(String),
-
-    #[error("I/O error: {0}")]
-    Io(String),
-
-    #[error("Invalid configuration: {0}")]
-    Config(String),
-
-    #[error("Locked: {0}")]
-    Locked(String),
-
-    #[error("Network error: {0}")]
-    Network(String),
-
-    #[error("No result: {0}")]
-    NoResult(String),
-
-    #[error("Not found: {0}")]
-    NotFound(String),
-
-    #[error("Not local machine: {0}")]
-    NotLocal(String),
-
-    #[error("Not remote machine: {0}")]
-    NotRemote(String),
-
-    #[error("Pool already exists: {0}")]
-    PoolAlreadyExists(String),
-
-    #[error("Protocol error: {0}")]
-    Protocol(String),
-
-    #[error("Serialization error: {0}")]
-    Serialization(String),
-
-    #[error("Timeout: {0}")]
-    Timeout(String),
-
-    #[error("Unsupported operation: {0}")]
-    Unsupported(String),
-}
-
-impl From<io::Error> for TcpTargetError {
-    fn from(error: io::Error) -> Self {
-        TcpTargetError::Io(error.to_string())
-    }
-}
-
-impl From<serde_json::Error> for TcpTargetError {
-    fn from(error: serde_json::Error) -> Self {
-        TcpTargetError::Serialization(error.to_string())
-    }
-}
-
-impl From<&str> for TcpTargetError {
-    fn from(value: &str) -> Self {
-        TcpTargetError::Protocol(value.to_string())
-    }
-}
-
-impl From<String> for TcpTargetError {
-    fn from(value: String) -> Self {
-        TcpTargetError::Protocol(value)
-    }
-}
-
-impl From<rsa::errors::Error> for TcpTargetError {
-    fn from(error: rsa::errors::Error) -> Self {
-        TcpTargetError::Crypto(error.to_string())
-    }
-}
-
-impl From<ed25519_dalek::SignatureError> for TcpTargetError {
-    fn from(error: ed25519_dalek::SignatureError) -> Self {
-        TcpTargetError::Crypto(error.to_string())
-    }
-}
-
-impl From<ring::error::Unspecified> for TcpTargetError {
-    fn from(error: ring::error::Unspecified) -> Self {
-        TcpTargetError::Crypto(error.to_string())
-    }
-}
-
-impl From<base64::DecodeError> for TcpTargetError {
-    fn from(error: base64::DecodeError) -> Self {
-        TcpTargetError::Serialization(error.to_string())
-    }
-}
-
-impl From<pem::PemError> for TcpTargetError {
-    fn from(error: pem::PemError) -> Self {
-        TcpTargetError::Crypto(error.to_string())
-    }
-}
-
-impl From<rmp_serde::encode::Error> for TcpTargetError {
-    fn from(error: rmp_serde::encode::Error) -> Self {
-        TcpTargetError::Serialization(error.to_string())
-    }
-}
-
-impl From<rmp_serde::decode::Error> for TcpTargetError {
-    fn from(error: rmp_serde::decode::Error) -> Self {
-        TcpTargetError::Serialization(error.to_string())
-    }
-}
diff --git a/crates/utils/tcp_connection/src/instance.rs b/crates/utils/tcp_connection/src/instance.rs
deleted file mode 100644
index 8e6886c..0000000
--- a/crates/utils/tcp_connection/src/instance.rs
+++ /dev/null
@@ -1,542 +0,0 @@
-use std::{path::Path, time::Duration};
-
-use serde::Serialize;
-use tokio::{
-    fs::{File, OpenOptions},
-    io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufReader, BufWriter},
-    net::TcpStream,
-};
-
-use ring::signature::{self};
-
-use crate::error::TcpTargetError;
-
-const DEFAULT_CHUNK_SIZE: usize = 4096;
-const DEFAULT_TIMEOUT_SECS: u64 = 10;
-
-const ECDSA_P256_SHA256_ASN1_SIGNING: &signature::EcdsaSigningAlgorithm =
-    &signature::ECDSA_P256_SHA256_ASN1_SIGNING;
-const ECDSA_P384_SHA384_ASN1_SIGNING: &signature::EcdsaSigningAlgorithm =
-    &signature::ECDSA_P384_SHA384_ASN1_SIGNING;
-
-#[derive(Debug, Clone)]
-pub struct ConnectionConfig {
-    pub chunk_size: usize,
-    pub timeout_secs: u64,
-    pub enable_crc_validation: bool,
-}
-
-impl Default for ConnectionConfig {
-    fn default() -> Self {
-        Self {
-            chunk_size: DEFAULT_CHUNK_SIZE,
-            timeout_secs: DEFAULT_TIMEOUT_SECS,
-            enable_crc_validation: false,
-        }
-    }
-}
-
-pub struct ConnectionInstance {
-    pub(crate) stream: TcpStream,
-    config: ConnectionConfig,
-}
-
-impl From<TcpStream> for ConnectionInstance {
-    fn from(stream: TcpStream) -> Self {
-        Self {
-            stream,
-            config: ConnectionConfig::default(),
-        }
-    }
-}
-
-impl ConnectionInstance {
-    /// Create a new ConnectionInstance with custom configuration
-    pub fn with_config(stream: TcpStream, config: ConnectionConfig) -> Self {
-        Self { stream, config }
-    }
-
-    /// Get a reference to the current configuration
-    pub fn config(&self) -> &ConnectionConfig {
-        &self.config
-    }
-
-    /// Get a mutable reference to the current configuration
-    pub fn config_mut(&mut self) -> &mut ConnectionConfig {
-        &mut self.config
-    }
-    /// Serialize data and write to the target machine
-    pub async fn write<Data>(&mut self, data: Data) -> Result<(), TcpTargetError>
-    where
-        Data: Default + Serialize,
-    {
-        let Ok(json_text) = serde_json::to_string(&data) else {
-            return Err(TcpTargetError::Serialization(
-                "Serialize failed.".to_string(),
-            ));
-        };
-        Self::write_text(self, json_text).await?;
-        Ok(())
-    }
-
-    /// Serialize data to MessagePack and write to the target machine
-    pub async fn write_msgpack<Data>(&mut self, data: Data) -> Result<(), TcpTargetError>
-    where
-        Data: Serialize,
-    {
-        let msgpack_data = rmp_serde::to_vec(&data)?;
-        let len = msgpack_data.len() as u32;
-
-        self.stream.write_all(&len.to_be_bytes()).await?;
-        self.stream.write_all(&msgpack_data).await?;
-        Ok(())
-    }
-
-    /// Read data from target machine and deserialize from MessagePack
-    pub async fn read_msgpack<Data>(&mut self) -> Result<Data, TcpTargetError>
-    where
-        Data: serde::de::DeserializeOwned,
-    {
-        let mut len_buf = [0u8; 4];
-        self.stream.read_exact(&mut len_buf).await?;
-        let len = u32::from_be_bytes(len_buf) as usize;
-
-        let mut buffer = vec![0; len];
-        self.stream.read_exact(&mut buffer).await?;
-
-        let data = rmp_serde::from_slice(&buffer)?;
-        Ok(data)
-    }
-
-    /// Read data from target machine and deserialize
-    pub async fn read<Data>(&mut self) -> Result<Data, TcpTargetError>
-    where
-        Data: Default + serde::de::DeserializeOwned,
-    {
-        let Ok(json_text) = Self::read_text(self).await else {
-            return Err(TcpTargetError::Io("Read failed.".to_string()));
-        };
-        let Ok(deser_obj) = serde_json::from_str::<Data>(&json_text) else {
-            return Err(TcpTargetError::Serialization(
-                "Deserialize failed.".to_string(),
-            ));
-        };
-        Ok(deser_obj)
-    }
-
-    /// Serialize data and write to the target machine
-    pub async fn write_large<Data>(&mut self, data: Data) -> Result<(), TcpTargetError>
-    where
-        Data: Default + Serialize,
-    {
-        let Ok(json_text) = serde_json::to_string(&data) else {
-            return Err(TcpTargetError::Serialization(
-                "Serialize failed.".to_string(),
-            ));
-        };
-        Self::write_large_text(self, json_text).await?;
-        Ok(())
-    }
-
-    /// Read data from target machine and deserialize
-    pub async fn read_large<Data>(
-        &mut self,
-        buffer_size: impl Into<u32>,
-    ) -> Result<Data, TcpTargetError>
-    where
-        Data: Default + serde::de::DeserializeOwned,
-    {
-        let Ok(json_text) = Self::read_large_text(self, buffer_size).await else {
-            return Err(TcpTargetError::Io("Read failed.".to_string()));
-        };
-        let Ok(deser_obj) = serde_json::from_str::<Data>(&json_text) else {
-            return Err(TcpTargetError::Serialization(
-                "Deserialize failed.".to_string(),
-            ));
-        };
-        Ok(deser_obj)
-    }
-
-    /// Write text to the target machine
-    pub async fn write_text(&mut self, text: impl Into<String>) -> Result<(), TcpTargetError> {
-        let text = text.into();
-        let bytes = text.as_bytes();
-        let len = bytes.len() as u32;
-
-        self.stream.write_all(&len.to_be_bytes()).await?;
-        match self.stream.write_all(bytes).await {
-            Ok(_) => Ok(()),
-            Err(err) => Err(TcpTargetError::Io(err.to_string())),
-        }
-    }
-
-    /// Read text from the target machine
-    pub async fn read_text(&mut self) -> Result<String, TcpTargetError> {
-        let mut len_buf = [0u8; 4];
-        self.stream.read_exact(&mut len_buf).await?;
-        let len = u32::from_be_bytes(len_buf) as usize;
-
-        let mut buffer = vec![0; len];
-        self.stream.read_exact(&mut buffer).await?;
-
-        match String::from_utf8(buffer) {
-            Ok(text) => Ok(text),
-            Err(err) => Err(TcpTargetError::Serialization(format!(
-                "Invalid UTF-8 sequence: {}",
-                err
-            ))),
-        }
-    }
-
-    /// Write large text to the target machine (chunked)
-    pub async fn write_large_text(
-        &mut self,
-        text: impl Into<String>,
-    ) -> Result<(), TcpTargetError> {
-        let text = text.into();
-        let bytes = text.as_bytes();
-        let mut offset = 0;
-
-        while offset < bytes.len() {
-            let chunk = &bytes[offset..];
-            let written = match self.stream.write(chunk).await {
-                Ok(n) => n,
-                Err(err) => return Err(TcpTargetError::Io(err.to_string())),
-            };
-            offset += written;
-        }
-
-        Ok(())
-    }
-
-    /// Read large text from the target machine (chunked)
-    pub async fn read_large_text(
-        &mut self,
-        chunk_size: impl Into<u32>,
-    ) -> Result<String, TcpTargetError> {
-        let chunk_size = chunk_size.into() as usize;
-        let mut buffer = Vec::new();
-        let mut chunk_buf = vec![0; chunk_size];
-
-        loop {
-            match self.stream.read(&mut chunk_buf).await {
-                Ok(0) => break, // EOF
-                Ok(n) => {
-                    buffer.extend_from_slice(&chunk_buf[..n]);
-                }
-                Err(err) => return Err(TcpTargetError::Io(err.to_string())),
-            }
-        }
-
-        Ok(String::from_utf8_lossy(&buffer).to_string())
-    }
-
-    /// Write large MessagePack data to the target machine (chunked)
-    pub async fn write_large_msgpack<Data>(
-        &mut self,
-        data: Data,
-        chunk_size: impl Into<u32>,
-    ) -> Result<(), TcpTargetError>
-    where
-        Data: Serialize,
-    {
-        let msgpack_data = rmp_serde::to_vec(&data)?;
-        let chunk_size = chunk_size.into() as usize;
-        let len = msgpack_data.len() as u32;
-
-        // Write total length first
-        self.stream.write_all(&len.to_be_bytes()).await?;
-
-        // Write data in chunks
-        let mut offset = 0;
-        while offset < msgpack_data.len() {
-            let end = std::cmp::min(offset + chunk_size, msgpack_data.len());
-            let chunk = &msgpack_data[offset..end];
-            match self.stream.write(chunk).await {
-                Ok(n) => offset += n,
-                Err(err) => return Err(TcpTargetError::Io(err.to_string())),
-            }
-        }
-
-        Ok(())
-    }
-
-    /// Read large MessagePack data from the target machine (chunked)
-    pub async fn read_large_msgpack<Data>(
-        &mut self,
-        chunk_size: impl Into<u32>,
-    ) -> Result<Data, TcpTargetError>
-    where
-        Data: serde::de::DeserializeOwned,
-    {
-        let chunk_size = chunk_size.into() as usize;
-
-        // Read total length first
-        let mut len_buf = [0u8; 4];
-        self.stream.read_exact(&mut len_buf).await?;
-        let total_len = u32::from_be_bytes(len_buf) as usize;
-
-        // Read data in chunks
-        let mut buffer = Vec::with_capacity(total_len);
-        let mut remaining = total_len;
-        let mut chunk_buf = vec![0; chunk_size];
-
-        while remaining > 0 {
-            let read_size = std::cmp::min(chunk_size, remaining);
-            let chunk = &mut chunk_buf[..read_size];
-
-            match self.stream.read_exact(chunk).await {
-                Ok(_) => {
-                    buffer.extend_from_slice(chunk);
-                    remaining -= read_size;
-                }
-                Err(err) => return Err(TcpTargetError::Io(err.to_string())),
-            }
-        }
-
-        let data = rmp_serde::from_slice(&buffer)?;
-        Ok(data)
-    }
-
-    /// Write file to target machine.
-    pub async fn write_file(&mut self, file_path: impl AsRef<Path>) -> Result<(), TcpTargetError> {
-        let path = file_path.as_ref();
-
-        // Validate file
-        if !path.exists() {
-            return Err(TcpTargetError::File(format!(
-                "File not found: {}",
-                path.display()
-            )));
-        }
-        if path.is_dir() {
-            return Err(TcpTargetError::File(format!(
-                "Path is directory: {}",
-                path.display()
-            )));
-        }
-
-        // Open file and get metadata
-        let mut file = File::open(path).await?;
-        let file_size = file.metadata().await?.len();
-
-        // Send file header (version + size + crc)
-        self.stream.write_all(&1u64.to_be_bytes()).await?;
-        self.stream.write_all(&file_size.to_be_bytes()).await?;
-
-        // Calculate and send CRC32 if enabled
-        let file_crc = if self.config.enable_crc_validation {
-            let crc32 = crc::Crc::<u32>::new(&crc::CRC_32_ISO_HDLC);
-            let mut crc_calculator = crc32.digest();
-
-            let mut temp_reader =
-                BufReader::with_capacity(self.config.chunk_size, File::open(path).await?);
-            let mut temp_buffer = vec![0u8; self.config.chunk_size];
-            let mut temp_bytes_read = 0;
-
-            while temp_bytes_read < file_size {
-                let bytes_to_read =
-                    (file_size - temp_bytes_read).min(self.config.chunk_size as u64) as usize;
-                temp_reader
-                    .read_exact(&mut temp_buffer[..bytes_to_read])
-                    .await?;
-                crc_calculator.update(&temp_buffer[..bytes_to_read]);
-                temp_bytes_read += bytes_to_read as u64;
-            }
-
-            crc_calculator.finalize()
-        } else {
-            0
-        };
-
-        self.stream.write_all(&file_crc.to_be_bytes()).await?;
-
-        // If file size is 0, skip content transfer
-        if file_size == 0 {
-            self.stream.flush().await?;
-
-            // Wait for receiver confirmation
-            let mut ack = [0u8; 1];
-            tokio::time::timeout(
-                Duration::from_secs(self.config.timeout_secs),
-                self.stream.read_exact(&mut ack),
-            )
-            .await
-            .map_err(|_| TcpTargetError::Timeout("Ack timeout".to_string()))??;
-
-            if ack[0] != 1 {
-                return Err(TcpTargetError::Protocol(
-                    "Receiver verification failed".to_string(),
-                ));
-            }
-
-            return Ok(());
-        }
-
-        // Transfer file content
-        let mut reader = BufReader::with_capacity(self.config.chunk_size, &mut file);
-        let mut bytes_sent = 0;
-
-        while bytes_sent < file_size {
-            let buffer = reader.fill_buf().await?;
-            if buffer.is_empty() {
-                break;
-            }
-
-            let chunk_size = buffer.len().min((file_size - bytes_sent) as usize);
-            self.stream.write_all(&buffer[..chunk_size]).await?;
-            reader.consume(chunk_size);
-
-            bytes_sent += chunk_size as u64;
-        }
-
-        // Verify transfer completion
-        if bytes_sent != file_size {
-            return Err(TcpTargetError::File(format!(
-                "Transfer incomplete: expected {} bytes, sent {} bytes",
-                file_size, bytes_sent
-            )));
-        }
-
-        self.stream.flush().await?;
-
-        // Wait for receiver confirmation
-        let mut ack = [0u8; 1];
-        tokio::time::timeout(
-            Duration::from_secs(self.config.timeout_secs),
-            self.stream.read_exact(&mut ack),
-        )
-        .await
-        .map_err(|_| TcpTargetError::Timeout("Ack timeout".to_string()))??;
-
-        if ack[0] != 1 {
-            return Err(TcpTargetError::Protocol(
-                "Receiver verification failed".to_string(),
-            ));
-        }
-
-        Ok(())
-    }
-
-    /// Read file from target machine
-    pub async fn read_file(&mut self, save_path: impl AsRef<Path>) -> Result<(), TcpTargetError> {
-        let path = save_path.as_ref();
-        // Create CRC instance at function scope to ensure proper lifetime
-        let crc_instance = crc::Crc::<u32>::new(&crc::CRC_32_ISO_HDLC);
-
-        // Make sure parent directory exists
-        if let Some(parent) = path.parent()
-            && !parent.exists()
-        {
-            tokio::fs::create_dir_all(parent).await?;
-        }
-
-        // Read file header (version + size + crc)
-        let mut version_buf = [0u8; 8];
-        self.stream.read_exact(&mut version_buf).await?;
-        let version = u64::from_be_bytes(version_buf);
-        if version != 1 {
-            return Err(TcpTargetError::Protocol(
-                "Unsupported transfer version".to_string(),
-            ));
-        }
-
-        let mut size_buf = [0u8; 8];
-        self.stream.read_exact(&mut size_buf).await?;
-        let file_size = u64::from_be_bytes(size_buf);
-
-        let mut expected_crc_buf = [0u8; 4];
-        self.stream.read_exact(&mut expected_crc_buf).await?;
-        let expected_crc = u32::from_be_bytes(expected_crc_buf);
-        if file_size == 0 {
-            // Create empty file and return early
-            let _file = OpenOptions::new()
-                .write(true)
-                .create(true)
-                .truncate(true)
-                .open(path)
-                .await?;
-            // Send confirmation
-            self.stream.write_all(&[1u8]).await?;
-            self.stream.flush().await?;
-            return Ok(());
-        }
-
-        // Prepare output file
-        let file = OpenOptions::new()
-            .write(true)
-            .create(true)
-            .truncate(true)
-            .open(path)
-            .await?;
-        let mut writer = BufWriter::with_capacity(self.config.chunk_size, file);
-
-        // Receive file content with CRC calculation if enabled
-        let mut bytes_received = 0;
-        let mut buffer = vec![0u8; self.config.chunk_size];
-        let mut crc_calculator = if self.config.enable_crc_validation {
-            Some(crc_instance.digest())
-        } else {
-            None
-        };
-
-        while bytes_received < file_size {
-            let bytes_to_read =
-                (file_size - bytes_received).min(self.config.chunk_size as u64) as usize;
-            let chunk = &mut buffer[..bytes_to_read];
-
-            self.stream.read_exact(chunk).await?;
-
-            writer.write_all(chunk).await?;
-
-            // Update CRC if validation is enabled
-            if let Some(ref mut crc) = crc_calculator {
-                crc.update(chunk);
-            }
-
-            bytes_received += bytes_to_read as u64;
-        }
-
-        // Verify transfer completion
-        if bytes_received != file_size {
-            return Err(TcpTargetError::File(format!(
-                "Transfer incomplete: expected {} bytes, received {} bytes",
-                file_size, bytes_received
-            )));
-        }
-
-        writer.flush().await?;
-
-        // Validate CRC if enabled
-        if self.config.enable_crc_validation
-            && let Some(crc_calculator) = crc_calculator
-        {
-            let actual_crc = crc_calculator.finalize();
-            if actual_crc != expected_crc && expected_crc != 0 {
-                return Err(TcpTargetError::File(format!(
-                    "CRC validation failed: expected {:08x}, got {:08x}",
-                    expected_crc, actual_crc
-                )));
-            }
-        }
-
-        // Final flush and sync
-        writer.flush().await?;
-        writer.into_inner().sync_all().await?;
-
-        // Verify completion
-        if bytes_received != file_size {
-            let _ = tokio::fs::remove_file(path).await;
-            return Err(TcpTargetError::File(format!(
-                "Transfer incomplete: expected {} bytes, received {} bytes",
-                file_size, bytes_received
-            )));
-        }
-
-        // Send confirmation
-        self.stream.write_all(&[1u8]).await?;
-        self.stream.flush().await?;
-
-        Ok(())
-    }
-}
diff --git a/crates/utils/tcp_connection/src/instance_challenge.rs b/crates/utils/tcp_connection/src/instance_challenge.rs
deleted file mode 100644
index 3a7f6a3..0000000
--- a/crates/utils/tcp_connection/src/instance_challenge.rs
+++ /dev/null
@@ -1,311 +0,0 @@
-use std::path::Path;
-
-use rand::TryRngCore;
-use rsa::{
-    RsaPrivateKey, RsaPublicKey,
-    pkcs1::{DecodeRsaPrivateKey, DecodeRsaPublicKey},
-    sha2,
-};
-use tokio::io::{AsyncReadExt, AsyncWriteExt};
-
-use ed25519_dalek::{Signature, Signer, SigningKey, Verifier, VerifyingKey};
-use ring::rand::SystemRandom;
-use ring::signature::{
-    self, ECDSA_P256_SHA256_ASN1, ECDSA_P384_SHA384_ASN1, EcdsaKeyPair, RSA_PKCS1_2048_8192_SHA256,
-    UnparsedPublicKey,
-};
-
-use crate::{error::TcpTargetError, instance::ConnectionInstance};
-
-const ECDSA_P256_SHA256_ASN1_SIGNING: &signature::EcdsaSigningAlgorithm =
-    &signature::ECDSA_P256_SHA256_ASN1_SIGNING;
-const ECDSA_P384_SHA384_ASN1_SIGNING: &signature::EcdsaSigningAlgorithm =
-    &signature::ECDSA_P384_SHA384_ASN1_SIGNING;
-
-impl ConnectionInstance {
-    /// Initiates a challenge to the target machine to verify connection security
-    ///
-    /// This method performs a cryptographic challenge-response authentication:
-    /// 1. Generates a random 32-byte challenge
-    /// 2. Sends the challenge to the target machine
-    /// 3. Receives a digital signature of the challenge
-    /// 4. Verifies the signature using the appropriate public key
-    ///
-    /// # Arguments
-    /// * `public_key_dir` - Directory containing public key files for verification
-    ///
-    /// # Returns
-    /// * `Ok((true, "KeyId"))` - Challenge verification successful
-    /// * `Ok((false, "KeyId"))` - Challenge verification failed
-    /// * `Err(TcpTargetError)` - Error during challenge process
-    pub async fn challenge(
-        &mut self,
-        public_key_dir: impl AsRef<Path>,
-    ) -> Result<(bool, String), TcpTargetError> {
-        // Generate random challenge
-        let mut challenge = [0u8; 32];
-        rand::rngs::OsRng
-            .try_fill_bytes(&mut challenge)
-            .map_err(|e| {
-                TcpTargetError::Crypto(format!("Failed to generate random challenge: {}", e))
-            })?;
-
-        // Send challenge to target
-        self.stream.write_all(&challenge).await?;
-        self.stream.flush().await?;
-
-        // Read signature from target
-        let mut signature = Vec::new();
-        let mut signature_len_buf = [0u8; 4];
-        self.stream.read_exact(&mut signature_len_buf).await?;
-
-        let signature_len = u32::from_be_bytes(signature_len_buf) as usize;
-        signature.resize(signature_len, 0);
-        self.stream.read_exact(&mut signature).await?;
-
-        // Read key identifier from target to identify which public key to use
-        let mut key_id_len_buf = [0u8; 4];
-        self.stream.read_exact(&mut key_id_len_buf).await?;
-        let key_id_len = u32::from_be_bytes(key_id_len_buf) as usize;
-
-        let mut key_id_buf = vec![0u8; key_id_len];
-        self.stream.read_exact(&mut key_id_buf).await?;
-        let key_id = String::from_utf8(key_id_buf)
-            .map_err(|e| TcpTargetError::Crypto(format!("Invalid key identifier: {}", e)))?;
-
-        // Load appropriate public key
-        let public_key_path = public_key_dir.as_ref().join(format!("{}.pem", key_id));
-        if !public_key_path.exists() {
-            return Ok((false, key_id));
-        }
-
-        let public_key_pem = tokio::fs::read_to_string(&public_key_path).await?;
-
-        // Try to verify with different key types
-        let verified = if let Ok(rsa_key) = RsaPublicKey::from_pkcs1_pem(&public_key_pem) {
-            let padding = rsa::pkcs1v15::Pkcs1v15Sign::new::<sha2::Sha256>();
-            rsa_key.verify(padding, &challenge, &signature).is_ok()
-        } else if let Ok(ed25519_key) =
-            VerifyingKey::from_bytes(&parse_ed25519_public_key(&public_key_pem))
-        {
-            if signature.len() == 64 {
-                let sig_bytes: [u8; 64] = signature.as_slice().try_into().map_err(|_| {
-                    TcpTargetError::Crypto("Invalid signature length for Ed25519".to_string())
-                })?;
-                let sig = Signature::from_bytes(&sig_bytes);
-                ed25519_key.verify(&challenge, &sig).is_ok()
-            } else {
-                false
-            }
-        } else if let Ok(dsa_key_info) = parse_dsa_public_key(&public_key_pem) {
-            verify_dsa_signature(&dsa_key_info, &challenge, &signature)
-        } else {
-            false
-        };
-
-        Ok((verified, key_id))
-    }
-
-    /// Accepts a challenge from the target machine to verify connection security
-    ///
-    /// This method performs a cryptographic challenge-response authentication:
-    /// 1. Receives a random 32-byte challenge from the target machine
-    /// 2. Signs the challenge using the appropriate private key
-    /// 3. Sends the digital signature back to the target machine
-    /// 4. Sends the key identifier for public key verification
-    ///
-    /// # Arguments
-    /// * `private_key_file` - Path to the private key file for signing
-    /// * `verify_public_key` - Key identifier for public key verification
-    ///
-    /// # Returns
-    /// * `Ok(true)` - Challenge response sent successfully
-    /// * `Ok(false)` - Private key format not supported
-    /// * `Err(TcpTargetError)` - Error during challenge response process
-    pub async fn accept_challenge(
-        &mut self,
-        private_key_file: impl AsRef<Path>,
-        verify_public_key: &str,
-    ) -> Result<bool, TcpTargetError> {
-        // Read challenge from initiator
-        let mut challenge = [0u8; 32];
-        self.stream.read_exact(&mut challenge).await?;
-
-        // Load private key
-        let private_key_pem = tokio::fs::read_to_string(&private_key_file)
-            .await
-            .map_err(|e| {
-                TcpTargetError::NotFound(format!(
-                    "Read private key \"{}\" failed: \"{}\"",
-                    private_key_file
-                        .as_ref()
-                        .display()
-                        .to_string()
-                        .split("/")
-                        .last()
-                        .unwrap_or("UNKNOWN"),
-                    e
-                ))
-            })?;
-
-        // Sign the challenge with supported key types
-        let signature = if let Ok(rsa_key) = RsaPrivateKey::from_pkcs1_pem(&private_key_pem) {
-            let padding = rsa::pkcs1v15::Pkcs1v15Sign::new::<sha2::Sha256>();
-            rsa_key.sign(padding, &challenge)?
-        } else if let Ok(ed25519_key) = parse_ed25519_private_key(&private_key_pem) {
-            ed25519_key.sign(&challenge).to_bytes().to_vec()
-        } else if let Ok(dsa_key_info) = parse_dsa_private_key(&private_key_pem) {
-            sign_with_dsa(&dsa_key_info, &challenge)?
-        } else {
-            return Ok(false);
-        };
-
-        // Send signature length and signature
-        let signature_len = signature.len() as u32;
-        self.stream.write_all(&signature_len.to_be_bytes()).await?;
-        self.stream.flush().await?;
-        self.stream.write_all(&signature).await?;
-        self.stream.flush().await?;
-
-        // Send key identifier for public key identification
-        let key_id_bytes = verify_public_key.as_bytes();
-        let key_id_len = key_id_bytes.len() as u32;
-        self.stream.write_all(&key_id_len.to_be_bytes()).await?;
-        self.stream.flush().await?;
-        self.stream.write_all(key_id_bytes).await?;
-        self.stream.flush().await?;
-
-        Ok(true)
-    }
-}
-
-/// Parse Ed25519 public key from PEM format
-fn parse_ed25519_public_key(pem: &str) -> [u8; 32] {
-    // Robust parsing for Ed25519 public key using pem crate
-    let mut key_bytes = [0u8; 32];
-
-    if let Ok(pem_data) = pem::parse(pem)
-        && pem_data.tag() == "PUBLIC KEY"
-        && pem_data.contents().len() >= 32
-    {
-        let contents = pem_data.contents();
-        key_bytes.copy_from_slice(&contents[contents.len() - 32..]);
-    }
-    key_bytes
-}
-
-/// Parse Ed25519 private key from PEM format
-fn parse_ed25519_private_key(pem: &str) -> Result<SigningKey, TcpTargetError> {
-    if let Ok(pem_data) = pem::parse(pem)
-        && pem_data.tag() == "PRIVATE KEY"
-        && pem_data.contents().len() >= 32
-    {
-        let contents = pem_data.contents();
-        let mut seed = [0u8; 32];
-        seed.copy_from_slice(&contents[contents.len() - 32..]);
-        return Ok(SigningKey::from_bytes(&seed));
-    }
-    Err(TcpTargetError::Crypto(
-        "Invalid Ed25519 private key format".to_string(),
-    ))
-}
-
-/// Parse DSA public key information from PEM
-fn parse_dsa_public_key(
-    pem: &str,
-) -> Result<(&'static dyn signature::VerificationAlgorithm, Vec<u8>), TcpTargetError> {
-    if let Ok(pem_data) = pem::parse(pem) {
-        let contents = pem_data.contents().to_vec();
-
-        // Try different DSA algorithms based on PEM tag
-        match pem_data.tag() {
-            "EC PUBLIC KEY" | "PUBLIC KEY" if pem.contains("ECDSA") || pem.contains("ecdsa") => {
-                if pem.contains("P-256") {
-                    return Ok((&ECDSA_P256_SHA256_ASN1, contents));
-                } else if pem.contains("P-384") {
-                    return Ok((&ECDSA_P384_SHA384_ASN1, contents));
-                }
-            }
-            "RSA PUBLIC KEY" | "PUBLIC KEY" => {
-                return Ok((&RSA_PKCS1_2048_8192_SHA256, contents));
-            }
-            _ => {}
-        }
-
-        // Default to RSA for unknown types
-        return Ok((&RSA_PKCS1_2048_8192_SHA256, contents));
-    }
-    Err(TcpTargetError::Crypto(
-        "Invalid DSA public key format".to_string(),
-    ))
-}
-
-/// Parse DSA private key information from PEM
-fn parse_dsa_private_key(
-    pem: &str,
-) -> Result<(&'static dyn signature::VerificationAlgorithm, Vec<u8>), TcpTargetError> {
-    // For DSA, private key verification uses the same algorithm as public key
-    parse_dsa_public_key(pem)
-}
-
-/// Verify DSA signature
-fn verify_dsa_signature(
-    algorithm_and_key: &(&'static dyn signature::VerificationAlgorithm, Vec<u8>),
-    message: &[u8],
-    signature: &[u8],
-) -> bool {
-    let (algorithm, key_bytes) = algorithm_and_key;
-    let public_key = UnparsedPublicKey::new(*algorithm, key_bytes);
-    public_key.verify(message, signature).is_ok()
-}
-
-/// Sign with DSA
-fn sign_with_dsa(
-    algorithm_and_key: &(&'static dyn signature::VerificationAlgorithm, Vec<u8>),
-    message: &[u8],
-) -> Result<Vec<u8>, TcpTargetError> {
-    let (algorithm, key_bytes) = algorithm_and_key;
-
-    // Handle different DSA/ECDSA algorithms by comparing algorithm identifiers
-    // Since we can't directly compare trait objects, we use pointer comparison
-    let algorithm_ptr = algorithm as *const _ as *const ();
-    let ecdsa_p256_ptr = &ECDSA_P256_SHA256_ASN1 as *const _ as *const ();
-    let ecdsa_p384_ptr = &ECDSA_P384_SHA384_ASN1 as *const _ as *const ();
-
-    if algorithm_ptr == ecdsa_p256_ptr {
-        let key_pair = EcdsaKeyPair::from_pkcs8(
-            ECDSA_P256_SHA256_ASN1_SIGNING,
-            key_bytes,
-            &SystemRandom::new(),
-        )
-        .map_err(|e| {
-            TcpTargetError::Crypto(format!("Failed to create ECDSA P-256 key pair: {}", e))
-        })?;
-
-        let signature = key_pair
-            .sign(&SystemRandom::new(), message)
-            .map_err(|e| TcpTargetError::Crypto(format!("ECDSA P-256 signing failed: {}", e)))?;
-
-        Ok(signature.as_ref().to_vec())
-    } else if algorithm_ptr == ecdsa_p384_ptr {
-        let key_pair = EcdsaKeyPair::from_pkcs8(
-            ECDSA_P384_SHA384_ASN1_SIGNING,
-            key_bytes,
-            &SystemRandom::new(),
-        )
-        .map_err(|e| {
-            TcpTargetError::Crypto(format!("Failed to create ECDSA P-384 key pair: {}", e))
-        })?;
-
-        let signature = key_pair
-            .sign(&SystemRandom::new(), message)
-            .map_err(|e| TcpTargetError::Crypto(format!("ECDSA P-384 signing failed: {}", e)))?;
-
-        Ok(signature.as_ref().to_vec())
-    } else {
-        // RSA or unsupported algorithm
-        Err(TcpTargetError::Unsupported(
-            "DSA/ECDSA signing not supported for this algorithm type".to_string(),
-        ))
-    }
-}
diff --git a/crates/utils/tcp_connection/src/lib.rs b/crates/utils/tcp_connection/src/lib.rs
deleted file mode 100644
index 6a2e599..0000000
--- a/crates/utils/tcp_connection/src/lib.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-#[allow(dead_code)]
-pub mod instance;
-
-pub mod instance_challenge;
-
-pub mod error;