1 files changed, 37 insertions, 12 deletions

diff --git a/src/sshkeys.rs b/src/sshkeys.rs
index 1425cb3..349cabe 100644
--- a/src/sshkeys.rs
+++ b/src/sshkeys.rs
@@ -3,7 +3,7 @@
 use std::fs::{read, File, Permissions};
 use std::io::Write;
 use std::os::unix::fs::PermissionsExt;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::process::Command;
 use tempfile::tempdir;
 
@@ -18,9 +18,29 @@ pub enum KeyError {
     #[error("ssh-keygen failed to certify a key: {0}")]
     CertError(String),
 
-    /// I/O error.
-    #[error(transparent)]
-    IoError(#[from] std::io::Error),
+    /// Error creating a temporary directory.
+    #[error("Couldn't create temporary directory")]
+    TempDir(#[source] std::io::Error),
+
+    /// Error running ssh-keygen.
+    #[error("Couldn't run ssh-keygen")]
+    Run(#[source] std::io::Error),
+
+    /// Error reading a file.
+    #[error("Couldn't read file {0}")]
+    Read(PathBuf, #[source] std::io::Error),
+
+    /// Error writing a file.
+    #[error("Couldn't write file {0}")]
+    Write(PathBuf, #[source] std::io::Error),
+
+    /// Error creating a file.
+    #[error("Couldn't create file {0}")]
+    Create(PathBuf, #[source] std::io::Error),
+
+    /// Error setting file permissions.
+    #[error("Couldn't set permissions for file {0}")]
+    SetPerm(PathBuf, #[source] std::io::Error),
 
     /// Error parsing a string as UTF8.
     #[error(transparent)]
@@ -90,7 +110,7 @@ impl KeyPair {
 
     /// Generate a new key pair of the desired kind.
     pub fn generate(kind: KeyKind) -> Result<Self, KeyError> {
-        let dirname = tempdir()?;
+        let dirname = tempdir().map_err(|err| KeyError::TempDir(err))?;
         let private_key = dirname.path().join("key");
         let output = Command::new("ssh-keygen")
             .arg("-f")
@@ -101,7 +121,8 @@ impl KeyPair {
             .arg(format!("{}", kind.bits()))
             .arg("-N")
             .arg("")
-            .output()?;
+            .output()
+            .map_err(|err| KeyError::Run(err))?;
 
         if !output.status.success() {
             let stderr = String::from_utf8_lossy(&output.stderr).into_owned();
@@ -128,7 +149,7 @@ impl KeyPair {
 }
 
 fn read_string(filename: &Path) -> Result<String, KeyError> {
-    let bytes = read(filename)?;
+    let bytes = read(filename).map_err(|err| KeyError::Read(filename.to_path_buf(), err))?;
     Ok(String::from_utf8(bytes)?)
 }
 
@@ -157,7 +178,7 @@ impl CaKey {
     ///
     /// Return as a string.
     pub fn certify_host(&self, host_key: &KeyPair, hostname: &str) -> Result<String, KeyError> {
-        let dirname = tempdir()?;
+        let dirname = tempdir().map_err(|err| KeyError::TempDir(err))?;
         let ca_key = dirname.path().join("ca");
         let host_key_pub = dirname.path().join("host.pub");
         let cert = dirname.path().join("host-cert.pub");
@@ -174,7 +195,8 @@ impl CaKey {
             .arg("-I")
             .arg(format!("host key for {}", hostname))
             .arg(&host_key_pub)
-            .output()?;
+            .output()
+            .map_err(|err| KeyError::Run(err))?;
 
         if !output.status.success() {
             let stderr = String::from_utf8_lossy(&output.stderr).into_owned();
@@ -186,10 +208,13 @@ impl CaKey {
 }
 
 fn write_string(filename: &Path, s: &str) -> Result<(), KeyError> {
-    let mut file = File::create(filename)?;
+    let mut file =
+        File::create(filename).map_err(|err| KeyError::Create(filename.to_path_buf(), err))?;
     let ro_user = Permissions::from_mode(0o600);
-    file.set_permissions(ro_user)?;
-    file.write_all(s.as_bytes())?;
+    file.set_permissions(ro_user)
+        .map_err(|err| KeyError::SetPerm(filename.to_path_buf(), err))?;
+    file.write_all(s.as_bytes())
+        .map_err(|err| KeyError::Write(filename.to_path_buf(), err))?;
     Ok(())
 }