Use ssh2 config IdentityFile as fallback for key based authentication

CHANGELOG.md

@@ -35,6 +35,7 @@ Released on ??
 - **Changed keybindings for BACKTAB**: backtab will now change the explorer tab
   - To active the LOG PANEL, use `P`
 - **Yes/No dialogs** are now answerable by pressing `Y` or `N` on your keyboard ([Issue 121](https://github.com/veeso/termscp/issues/121))
+- **Use ssh2 config IdentityFile** as fallback for key based authentication
 - **Bugfix**
   - Fixed [Issue 122](https://github.com/veeso/termscp/issues/122)
   - Fixed version comparison when going above 0.9
@@ -44,6 +45,8 @@ Released on ??
   - Bump `keyring` to `1.2.0`
   - Bump `open` to `3.0.2`
   - Changed `regex` to `lazy-regex 2.3.0`
+  - Bump `remotefs-ssh` to `0.1.2`
+  - Bump `ssh2-config` to `0.1.3`
   - Bump `tuirealm` to `1.8.0`
   - Bump `tui-realm-stdlib` to `1.1.7`
   - Added `version-compare 0.1.0`

Cargo.lock

@@ -1719,6 +1719,12 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "498a099351efa4becc6a19c72aa9270598e8fd274ca47052e37455241c88b696"
 
+[[package]]
+name = "path-slash"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e91099d4268b0e11973f036e885d652fb0b21fedcf69738c627f94db6a44f42"
+
 [[package]]
 name = "pathdiff"
 version = "0.2.1"
@@ -1938,7 +1944,7 @@ checksum = "9939849e0b3895b07f258458d0fa5cd4632c78ffc517e66e1f758ddf23990542"
 dependencies = [
  "chrono",
  "log",
- "path-slash",
+ "path-slash 0.1.5",
  "remotefs",
  "rust-s3",
  "thiserror",
@@ -1952,7 +1958,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "359fd989a6ad50fa6defae771e453695412cbfdb5476f49e42d1bb1d51b5c096"
 dependencies = [
  "log",
- "path-slash",
+ "path-slash 0.1.5",
  "remotefs",
  "suppaftp",
  "users",
@@ -1960,14 +1966,14 @@ dependencies = [
 
 [[package]]
 name = "remotefs-ssh"
-version = "0.1.1"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea2ac5a7f475c1b63ffd2aaab57ca4e37e6a6ed23461046d4fb1554835e6088a"
+checksum = "190106b53b839cf094172d2f1bc14e8d2846a69de06b239f11c2fc353080e9e0"
 dependencies = [
  "chrono",
  "lazy_static",
  "log",
- "path-slash",
+ "path-slash 0.2.1",
  "regex",
  "remotefs",
  "ssh2",
@@ -2511,6 +2517,7 @@ dependencies = [
  "serde",
  "serial_test",
  "simplelog",
+ "ssh2-config",
  "tempfile",
  "thiserror",
  "toml",

Cargo.toml

@@ -51,11 +51,12 @@ rand = "0.8.5"
 remotefs = "^0.2.0"
 remotefs-aws-s3 = "^0.2.0"
 remotefs-ftp = { version = "^0.1.0", features = [ "secure" ] }
-remotefs-ssh = { version = "^0.1.1", features = [ "ssh2-vendored" ] }
+remotefs-ssh = { version = "^0.1.2", features = [ "ssh2-vendored" ] }
 rpassword = "6.0.1"
 self_update = { version = "0.30.0", features = [ "archive-tar", "archive-zip", "compression-flate2", "compression-zip-deflate" ] }
 serde = { version = "^1.0.0", features = [ "derive" ] }
 simplelog = "0.12.0"
+ssh2-config = "^0.1.3"
 tempfile = "3.2.0"
 thiserror = "^1.0.0"
 toml = "0.5.0"

src/system/sshkey_storage.rs

@@ -5,12 +5,16 @@
 // Locals
 use super::config_client::ConfigClient;
 // Ext
-use remotefs_ssh::SshKeyStorage as SshKeyStorageT;
+use remotefs_ssh::SshKeyStorage as SshKeyStorageTrait;
+use ssh2_config::SshConfig;
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
 
 pub struct SshKeyStorage {
-    hosts: HashMap<String, PathBuf>, // Association between {user}@{host} and RSA key path
+    /// Association between {user}@{host} and RSA key path
+    hosts: HashMap<String, PathBuf>,
+    /// Ssh2 configuration
+    ssh_config: Option<SshConfig>,
 }
 
 impl SshKeyStorage {
@@ -19,6 +23,7 @@ impl SshKeyStorage {
     pub fn empty() -> Self {
         SshKeyStorage {
             hosts: HashMap::new(),
+            ssh_config: None,
         }
     }
 
@@ -34,21 +39,67 @@ impl SshKeyStorage {
         let key: String = Self::make_mapkey(host, username);
         self.hosts.insert(key, p);
     }
-}
 
-impl SshKeyStorageT for SshKeyStorage {
-    fn resolve(&self, host: &str, username: &str) -> Option<&Path> {
+    /// Parse ssh2 config
+    fn parse_ssh2_config(path: &str) -> Result<SshConfig, String> {
+        use std::fs::File;
+        use std::io::BufReader;
+
+        let mut reader = File::open(path)
+            .map_err(|e| format!("failed to open {}: {}", path, e))
+            .map(BufReader::new)?;
+        SshConfig::default()
+            .parse(&mut reader)
+            .map_err(|e| format!("Failed to parse ssh2 config: {}", e))
+    }
+
+    /// Resolve host via termscp ssh keys storage
+    fn resolve_host_in_termscp_storage(&self, host: &str, username: &str) -> Option<&Path> {
         let key: String = Self::make_mapkey(host, username);
         self.hosts.get(&key).map(|x| x.as_path())
     }
+
+    /// Resolve host via ssh2 configuration
+    fn resolve_host_in_ssh2_configuration(&self, host: &str) -> Option<PathBuf> {
+        if let Some(config) = self.ssh_config.as_ref() {
+            let params = config.query(host);
+            params
+                .identity_file
+                .as_ref()
+                .and_then(|x| x.get(0).cloned())
+        } else {
+            debug!("ssh2 config is not available; no key has been found");
+            None
+        }
+    }
+}
+
+impl SshKeyStorageTrait for SshKeyStorage {
+    fn resolve(&self, host: &str, username: &str) -> Option<PathBuf> {
+        // search in termscp keys
+        if let Some(path) = self.resolve_host_in_termscp_storage(host, username) {
+            return Some(path.to_path_buf());
+        }
+        debug!(
+            "couldn't find any ssh key associated to {} at {}. Trying with ssh2 config",
+            username, host
+        );
+        // otherwise search in configuration
+        self.resolve_host_in_ssh2_configuration(host)
+    }
 }
 
 impl From<&ConfigClient> for SshKeyStorage {
     fn from(cfg_client: &ConfigClient) -> Self {
+        // read ssh2 config
+        let ssh_config = cfg_client.get_ssh_config().and_then(|x| {
+            debug!("reading ssh config at {}", x);
+            Self::parse_ssh2_config(x).ok()
+        });
         let mut hosts: HashMap<String, PathBuf> =
             HashMap::with_capacity(cfg_client.iter_ssh_keys().count());
         debug!("Setting up SSH key storage");
-        // Iterate over keys
+        // Iterate over keys in storage
         for key in cfg_client.iter_ssh_keys() {
             match cfg_client.get_ssh_key(key) {
                 Ok(host) => match host {
@@ -66,7 +117,7 @@ impl From<&ConfigClient> for SshKeyStorage {
             info!("Got SSH key for {}", key);
         }
         // Return storage
-        SshKeyStorage { hosts }
+        SshKeyStorage { hosts, ssh_config }
     }
 }
 
@@ -75,6 +126,7 @@ mod tests {
 
     use super::*;
     use crate::system::config_client::ConfigClient;
+    use crate::utils::test_helpers;
 
     use pretty_assertions::assert_eq;
     use std::path::Path;
@@ -103,6 +155,35 @@ mod tests {
         assert!(storage.resolve("deskichup", "veeso").is_none());
     }
 
+    #[test]
+    fn sould_resolve_key_from_ssh2_config() {
+        let rsa_key = test_helpers::create_sample_file_with_content("ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDErJhQxEI0+VvhlXVUyh+vMCm7aXfCA/g633AG8ezD/5EylwchtAr2JCoBWnxn4zV8nI9dMqOgm0jO4IsXpKOjQojv+0VOH7I+cDlBg0tk4hFlvyyS6YviDAfDDln3jYUM+5QNDfQLaZlH2WvcJ3mkDxLVlI9MBX1BAeSmChLxwAvxALp2ncImNQLzDO9eHcig3dtMrEKkzXQowRW5Y7eUzg2+vvVq4H2DOjWwUndvB5sJkhEfTUVE7ID8ZdGJo60kUb/02dZYj+IbkAnMCsqktk0cg/4XFX82hEfRYFeb1arkysFisPU1DOb6QielL/axeTebVplaouYcXY0pFdJt root@8c50fd4c345a");
+        let ssh_config_file = test_helpers::create_sample_file_with_content(format!(
+            r#"
+Host test
+        HostName 127.0.0.1
+        Port 2222
+        User test
+        IdentityFile {}
+        StrictHostKeyChecking no
+        UserKnownHostsFile /dev/null
+"#,
+            rsa_key.path().display()
+        ));
+        // make storage
+        let tmp_dir: tempfile::TempDir = tempfile::TempDir::new().ok().unwrap();
+        let (cfg_path, key_path): (PathBuf, PathBuf) = get_paths(tmp_dir.path());
+        let mut client: ConfigClient = ConfigClient::new(cfg_path.as_path(), key_path.as_path())
+            .ok()
+            .unwrap();
+        client.set_ssh_config(Some(ssh_config_file.path().to_string_lossy().to_string()));
+        let storage: SshKeyStorage = SshKeyStorage::from(&client);
+        assert_eq!(
+            storage.resolve("test", "pi").unwrap().as_path(),
+            rsa_key.path()
+        );
+    }
+
     #[test]
     fn test_system_sshkey_storage_empty() {
         let storage: SshKeyStorage = SshKeyStorage::empty();

src/utils/test_helpers.rs

@@ -21,14 +21,15 @@ pub fn create_sample_file_entry() -> (File, NamedTempFile) {
     )
 }
 
+/// Create sample file with default lorem ipsum content
 pub fn create_sample_file() -> NamedTempFile {
-    // Write
+    create_sample_file_with_content("Lorem ipsum dolor sit amet, consectetur adipiscing elit.Mauris ultricies consequat eros,nec scelerisque magna imperdiet metus.")
+}
+
+/// Create sample file with provided content
+pub fn create_sample_file_with_content(content: impl std::fmt::Display) -> NamedTempFile {
     let mut tmpfile: tempfile::NamedTempFile = tempfile::NamedTempFile::new().unwrap();
-    writeln!(
-        tmpfile,
-        "Lorem ipsum dolor sit amet, consectetur adipiscing elit.Mauris ultricies consequat eros,nec scelerisque magna imperdiet metus."
-    )
-    .unwrap();
+    writeln!(tmpfile, "{}", content).unwrap();
     tmpfile
 }