[pbs-devel] [RFC proxmox-backup 06/15] config: add token.shadow file

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

containing pairs of token ids and hashed secret values.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---

Notes:
    we could also do a simple
    
    tokenid:crypt(tokensecret)
    
    but then we'd need to be careful w.r.t. tokenid characters and quoting and whatnot..

 src/config.rs              |  1 +
 src/config/token_shadow.rs | 79 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100644 src/config/token_shadow.rs

diff --git a/src/config.rs b/src/config.rs
index c2ac6da1..a70740e1 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -23,6 +23,7 @@ pub mod network;
 pub mod remote;
 pub mod sync;
 pub mod user;
+pub mod token_shadow;
 
 /// Check configuration directory permissions
 ///
diff --git a/src/config/token_shadow.rs b/src/config/token_shadow.rs
new file mode 100644
index 00000000..afec6135
--- /dev/null
+++ b/src/config/token_shadow.rs
@@ -0,0 +1,79 @@
+use std::collections::HashMap;
+use std::time::Duration;
+
+use anyhow::{bail, format_err, Error};
+use serde::{Serialize, Deserialize};
+use serde_json::{from_value, Value};
+
+use proxmox::tools::fs::{open_file_locked, CreateOptions};
+
+use crate::api2::types::Userid;
+use crate::auth;
+
+const LOCK_FILE: &str = "/etc/proxmox-backup/token.shadow.lock";
+const CONF_FILE: &str = "/etc/proxmox-backup/token.shadow";
+const LOCK_TIMEOUT: Duration = Duration::from_secs(5);
+
+#[serde(rename_all="kebab-case")]
+#[derive(Serialize, Deserialize)]
+/// ApiToken id / secret pair
+pub struct ApiTokenSecret {
+    pub tokenid: Userid,
+    pub secret: String,
+}
+
+fn read_file() -> Result<HashMap<Userid, String>, Error> {
+    let json = proxmox::tools::fs::file_get_json(CONF_FILE, Some(Value::Null))?;
+
+    if json == Value::Null {
+        Ok(HashMap::new())
+    } else {
+        // swallow serde error which might contain sensitive data
+        from_value(json).map_err(|_err| format_err!("unable to parse '{}'", CONF_FILE))
+    }
+}
+
+fn write_file(data: HashMap<Userid, String>) -> Result<(), Error> {
+    let backup_user = crate::backup::backup_user()?;
+    let options = CreateOptions::new()
+        .perm(nix::sys::stat::Mode::from_bits_truncate(0o0640))
+        .owner(backup_user.uid)
+        .group(backup_user.gid);
+
+    let json = serde_json::to_vec(&data)?;
+    proxmox::tools::fs::replace_file(CONF_FILE, &json, options)
+}
+
+/// Verifies that an entry for given tokenid / API token secret exists
+pub fn verify_secret(tokenid: &Userid, secret: &str) -> Result<(), Error> {
+    let data = read_file()?;
+    match data.get(tokenid) {
+        Some(hashed_secret) => {
+            auth::verify_crypt_pw(secret, &hashed_secret)
+        },
+        None => bail!("invalid API token"),
+    }
+}
+
+/// Adds a new entry for the given tokenid / API token secret. The secret is stored as salted hash.
+pub fn set_secret(tokenid: &Userid, secret: &str) -> Result<(), Error> {
+    let _guard = open_file_locked(LOCK_FILE, LOCK_TIMEOUT, true)?;
+
+    let mut data = read_file()?;
+    let hashed_secret = auth::encrypt_pw(secret)?;
+    data.insert(tokenid.clone(), hashed_secret);
+    write_file(data)?;
+
+    Ok(())
+}
+
+/// Deletes the entry for the given tokenid.
+pub fn delete_secret(tokenid: &Userid) -> Result<(), Error> {
+    let _guard = open_file_locked(LOCK_FILE, LOCK_TIMEOUT, true)?;
+
+    let mut data = read_file()?;
+    data.remove(tokenid);
+    write_file(data)?;
+
+    Ok(())
+}
-- 
2.20.1