Use repository Git remotes and SSH config

crates/storage/src/config.rs

@@ -13,7 +13,11 @@ use std::{
 
 use cap_std::{ambient_authority, fs::Dir};
 use cap_tempfile::TempFile;
+#[cfg(not(any(target_os = "ios", target_os = "watchos")))]
+use gix::bstr::ByteSlice as _;
 use serde::Deserialize;
+#[cfg(not(any(target_os = "ios", target_os = "watchos")))]
+use sha2::{Digest as _, Sha256};
 use url::Url;
 
 use crate::{
@@ -1694,7 +1698,14 @@ fn validate_config(
             });
         }
     };
-    let git_remotes = validate_remotes(raw.git.remotes, Some(base))?;
+    let configured_git_remotes = raw.git.remotes;
+    #[cfg(not(any(target_os = "ios", target_os = "watchos")))]
+    let git_remotes = match repository_git_remotes(&vault)? {
+        Some(remotes) => remotes,
+        None => validate_remotes(configured_git_remotes, Some(base))?,
+    };
+    #[cfg(any(target_os = "ios", target_os = "watchos"))]
+    let git_remotes = validate_remotes(configured_git_remotes, Some(base))?;
 
     Ok(Config {
         source,
@@ -1715,6 +1726,75 @@ fn validate_config(
     })
 }
 
+#[cfg(not(any(target_os = "ios", target_os = "watchos")))]
+fn repository_git_remotes(vault: &Path) -> Result<Option<Vec<GitRemote>>, ConfigError> {
+    let path = vault.join(".git/config");
+    if !path.is_file() {
+        return Ok(None);
+    }
+    let config =
+        gix_config::File::from_path_no_includes(path, gix_config::Source::Local).map_err(|_| {
+            ConfigError::InvalidField {
+                field: "git.repository_remotes",
+            }
+        })?;
+    let mut remotes = Vec::new();
+    if let Some(sections) = config.sections_by_name("remote") {
+        for section in sections {
+            let name = section
+                .header()
+                .subsection_name()
+                .and_then(|name| name.to_str().ok())
+                .ok_or(ConfigError::InvalidField {
+                    field: "git.repository_remotes",
+                })?;
+            let url = config
+                .raw_value_by("remote", Some(name.into()), "url")
+                .ok()
+                .and_then(|url| url.to_str().ok().map(str::to_owned))
+                .ok_or(ConfigError::InvalidRemoteUrl {
+                    name: name.to_owned(),
+                })?;
+            let endpoint =
+                RemoteEndpoint::parse(&url).map_err(|_| ConfigError::InvalidRemoteUrl {
+                    name: name.to_owned(),
+                })?;
+            let remote = match endpoint {
+                RemoteEndpoint::Https(ref endpoint) => GitRemote::https(
+                    name,
+                    &url,
+                    stable_identifier(
+                        "server",
+                        format!(
+                            "{}://{}:{}",
+                            endpoint.scheme(),
+                            endpoint.host_str().unwrap_or_default(),
+                            endpoint.port_or_known_default().unwrap_or(443)
+                        )
+                        .as_bytes(),
+                    ),
+                    stable_identifier("repository", url.as_bytes()),
+                )?,
+                RemoteEndpoint::Ssh(_) => GitRemote::ssh(name, &url)?,
+            };
+            remotes.push(remote);
+        }
+    }
+    Ok((!remotes.is_empty()).then_some(remotes))
+}
+
+#[cfg(not(any(target_os = "ios", target_os = "watchos")))]
+fn stable_identifier(prefix: &str, value: &[u8]) -> String {
+    const HEX: &[u8; 16] = b"0123456789abcdef";
+    let digest = Sha256::digest(value);
+    let suffix: String = digest[..8]
+        .iter()
+        .flat_map(|byte| [HEX[(byte >> 4) as usize], HEX[(byte & 0x0f) as usize]])
+        .map(char::from)
+        .collect();
+    format!("{prefix}-{suffix}")
+}
+
 fn resolve_required_path(
     base: &Path,
     value: Option<PathBuf>,

crates/storage/src/git.rs

@@ -892,13 +892,11 @@ pub fn confirm_ssh_host(remote: &GitRemote, host_key: &SshHostKey) -> Result<(),
         .endpoint()
         .as_ssh()
         .ok_or(GitError::SshAuthenticationNotConfigured)?;
-    if endpoint.host() != host_key.host() || endpoint.port() != host_key.port() {
+    let connection = crate::ssh::resolve_connection(endpoint, remote.ssh_authentication())?;
+    if connection.host != host_key.host() || connection.port != host_key.port() {
         return Err(GitError::SshProtocolFailed);
     }
-    let authentication = remote
-        .ssh_authentication()
-        .ok_or(GitError::SshAuthenticationNotConfigured)?;
-    crate::ssh::persist_confirmed_host(authentication.known_hosts_file(), host_key)
+    crate::ssh::persist_confirmed_host(&connection.known_hosts, host_key)
 }
 
 pub trait GitSmartHttpTransport {

crates/storage/src/ssh.rs

@@ -24,7 +24,10 @@ use russh::{
 use sha1::Sha1;
 
 use crate::{
-    config::{GitRemote, RemoteEndpoint, SshFingerprint, SshIdentitySource, SshRepositoryPath},
+    config::{
+        GitRemote, RemoteEndpoint, SshEndpoint, SshFingerprint, SshIdentitySource,
+        SshRemoteAuthentication, SshRepositoryPath,
+    },
     git::{GitError, GitOperationControl, GitProgressPhase, SshHostKey, SshPassphraseProvider},
 };
 
@@ -124,18 +127,16 @@ impl SshSession {
         let RemoteEndpoint::Ssh(endpoint) = remote.endpoint() else {
             return Err(GitError::ForbiddenRemoteUrl);
         };
-        let authentication = remote
-            .ssh_authentication()
-            .ok_or(GitError::SshAuthenticationNotConfigured)?;
+        let connection = resolve_connection(endpoint, remote.ssh_authentication())?;
         control.report(GitProgressPhase::Validating)?;
 
         let runtime = tokio::runtime::Builder::new_multi_thread()
             .enable_all()
             .build()
             .map_err(|_| GitError::SshProtocolFailed)?;
-        let host = endpoint.host().to_owned();
-        let port = endpoint.port();
-        let known_hosts = authentication.known_hosts_file().to_owned();
+        let host = connection.host.clone();
+        let port = connection.port;
+        let known_hosts = connection.known_hosts.clone();
         let verifier = HostVerifier {
             host: host.clone(),
             port,
@@ -159,8 +160,8 @@ impl SshSession {
         };
 
         control.report(GitProgressPhase::Authenticating)?;
-        let user = endpoint.user().unwrap_or("git");
-        let authenticated = match authentication.identity() {
+        let user = connection.user.as_deref().unwrap_or("git");
+        let authenticated = match &connection.identity {
             SshIdentitySource::KeyFile(path) => runtime.block_on(authenticate_key_file(
                 &mut handle,
                 user,
@@ -289,6 +290,150 @@ impl SshSession {
     }
 }
 
+pub(crate) struct SshConnection {
+    pub(crate) host: String,
+    pub(crate) port: u16,
+    user: Option<String>,
+    identity: SshIdentitySource,
+    pub(crate) known_hosts: PathBuf,
+}
+
+pub(crate) fn resolve_connection(
+    endpoint: &SshEndpoint,
+    authentication: Option<&SshRemoteAuthentication>,
+) -> Result<SshConnection, GitError> {
+    let home = home_directory().ok_or(GitError::SshAuthenticationNotConfigured)?;
+    let mut connection = SshConnection {
+        host: endpoint.host().to_owned(),
+        port: endpoint.port(),
+        user: endpoint.user().map(str::to_owned),
+        identity: authentication
+            .map(|authentication| authentication.identity().clone())
+            .unwrap_or_else(|| SshIdentitySource::KeyFile(home.join(".ssh/id_ed25519"))),
+        known_hosts: authentication
+            .map(|authentication| authentication.known_hosts_file().to_owned())
+            .unwrap_or_else(|| home.join(".ssh/known_hosts")),
+    };
+    apply_openssh_config(
+        &home.join(".ssh/config"),
+        endpoint.host(),
+        &home,
+        authentication.is_none(),
+        &mut connection,
+    )?;
+    Ok(connection)
+}
+
+fn home_directory() -> Option<PathBuf> {
+    #[cfg(target_os = "windows")]
+    let home = std::env::var_os("USERPROFILE");
+    #[cfg(not(target_os = "windows"))]
+    let home = std::env::var_os("HOME");
+    home.filter(|home| !home.is_empty()).map(PathBuf::from)
+}
+
+fn apply_openssh_config(
+    path: &Path,
+    alias: &str,
+    home: &Path,
+    use_identity: bool,
+    connection: &mut SshConnection,
+) -> Result<(), GitError> {
+    let Ok(contents) = fs::read_to_string(path) else {
+        return Ok(());
+    };
+    let mut active = true;
+    let mut hostname_set = false;
+    let mut user_set = connection.user.is_some();
+    let mut port_set = connection.port != 22;
+    let mut identity_set = !use_identity;
+    for line in contents.lines() {
+        let Some(words) = shlex::split(line.split('#').next().unwrap_or_default()) else {
+            return Err(GitError::SshAuthenticationNotConfigured);
+        };
+        let Some((keyword, values)) = words.split_first() else {
+            continue;
+        };
+        if keyword.eq_ignore_ascii_case("host") {
+            active = host_patterns_match(values, alias);
+        } else if active && keyword.eq_ignore_ascii_case("hostname") && !hostname_set {
+            if let Some(value) = values.first() {
+                connection.host = value.clone();
+                hostname_set = true;
+            }
+        } else if active && keyword.eq_ignore_ascii_case("user") && !user_set {
+            if let Some(value) = values.first() {
+                connection.user = Some(value.clone());
+                user_set = true;
+            }
+        } else if active && keyword.eq_ignore_ascii_case("port") && !port_set {
+            if let Some(value) = values.first() {
+                connection.port = value
+                    .parse()
+                    .ok()
+                    .filter(|port| *port != 0)
+                    .ok_or(GitError::SshAuthenticationNotConfigured)?;
+                port_set = true;
+            }
+        } else if active
+            && keyword.eq_ignore_ascii_case("identityfile")
+            && !identity_set
+            && let Some(value) = values.first()
+        {
+            let expanded = value
+                .replace("%h", &connection.host)
+                .replace("%p", &connection.port.to_string())
+                .replace("%r", connection.user.as_deref().unwrap_or("git"));
+            let identity = expanded
+                .strip_prefix("~/")
+                .map_or_else(|| PathBuf::from(&expanded), |path| home.join(path));
+            connection.identity = SshIdentitySource::KeyFile(identity);
+            identity_set = true;
+        }
+    }
+    Ok(())
+}
+
+fn host_patterns_match(patterns: &[String], host: &str) -> bool {
+    let mut matched = false;
+    for pattern in patterns {
+        let (negated, pattern) = pattern
+            .strip_prefix('!')
+            .map_or((false, pattern.as_str()), |pattern| (true, pattern));
+        if wildcard_match(pattern.as_bytes(), host.as_bytes()) {
+            if negated {
+                return false;
+            }
+            matched = true;
+        }
+    }
+    matched
+}
+
+fn wildcard_match(pattern: &[u8], value: &[u8]) -> bool {
+    let (mut pattern_index, mut value_index, mut star, mut retry) = (0, 0, None, 0);
+    while value_index < value.len() {
+        if pattern
+            .get(pattern_index)
+            .is_some_and(|byte| *byte == b'?' || byte.eq_ignore_ascii_case(&value[value_index]))
+        {
+            pattern_index += 1;
+            value_index += 1;
+        } else if pattern.get(pattern_index) == Some(&b'*') {
+            star = Some(pattern_index);
+            pattern_index += 1;
+            retry = value_index;
+        } else if let Some(star_index) = star {
+            pattern_index = star_index + 1;
+            retry += 1;
+            value_index = retry;
+        } else {
+            return false;
+        }
+    }
+    pattern[pattern_index..].iter().all(|byte| *byte == b'*')
+}
+
 fn client_config() -> client::Config {
     client::Config {
         inactivity_timeout: Some(CONNECTION_TIMEOUT),
@@ -1034,6 +1179,39 @@ mod tests {
         server,
     };
 
+    #[test]
+    fn openssh_host_alias_resolves_connection_and_identity() {
+        let temporary = tempfile::tempdir().expect("temporary directory");
+        let config = temporary.path().join("config");
+        fs::write(
+            &config,
+            "Host *\n  IdentityFile ~/.ssh/id_ed25519\nHost git.example\n  HostName internal.example\n  User git\n  Port 2222\n",
+        )
+        .expect("SSH config");
+        let mut connection = super::SshConnection {
+            host: "git.example".to_owned(),
+            port: 22,
+            user: None,
+            identity: crate::config::SshIdentitySource::KeyFile(temporary.path().join("unused")),
+            known_hosts: temporary.path().join("known_hosts"),
+        };
+        super::apply_openssh_config(
+            &config,
+            "git.example",
+            temporary.path(),
+            true,
+            &mut connection,
+        )
+        .expect("resolve SSH config");
+        assert_eq!(connection.host, "internal.example");
+        assert_eq!(connection.user.as_deref(), Some("git"));
+        assert_eq!(connection.port, 2222);
+        assert_eq!(
+            connection.identity.key_file(),
+            Some(temporary.path().join(".ssh/id_ed25519").as_path())
+        );
+    }
+
     use crate::{
         config::{GitRemote, RemoteEndpoint, SshFingerprint, SshRemoteAuthentication},
         git::{GitError, GitOperationControl, SshPassphraseProvider},

crates/storage/tests/config_contract.rs

@@ -102,6 +102,37 @@ fn explicit_relative_configuration_resolves_deterministically() -> TestResult {
     Ok(())
 }
 
+#[cfg(not(any(target_os = "ios", target_os = "watchos")))]
+#[test]
+fn desktop_configuration_uses_repository_remotes_without_duplicate_settings() -> TestResult {
+    let fixture = ConfigurationFixture::new()?;
+    let vault = fixture.temporary.path().join("cwd/vault");
+    fs::create_dir_all(vault.join(".git"))?;
+    fs::write(
+        vault.join(".git/config"),
+        "[remote \"origin\"]\n\turl = git@git.example:team/store.git\n\tfetch = +refs/heads/*:refs/remotes/origin/*\n",
+    )?;
+    fixture.write_explicit(
+        r#"
+vault = "../vault"
+default_key = "0123456789ABCDEF0123456789ABCDEF01234567"
+key_material = "keys"
+"#,
+    )?;
+
+    let config = fixture
+        .loader()
+        .load(Some(Path::new("config/config.toml")))?;
+    assert_eq!(config.git_remotes().len(), 1);
+    assert_eq!(config.git_remotes()[0].name().as_str(), "origin");
+    assert_eq!(
+        config.git_remotes()[0].url(),
+        "git@git.example:team/store.git"
+    );
+    assert!(config.git_remotes()[0].ssh_authentication().is_none());
+    Ok(())
+}
+
 #[test]
 fn git_commit_identity_defaults_validates_and_persists() -> TestResult {
     let fixture = ConfigurationFixture::new()?;