secret-lib 1.0.0

#![cfg_attr(docs_rs, feature(doc_cfg, doc_auto_cfg))]
#![doc = include_str!("../README.md")]

#[cfg(feature = "derive")]
pub(crate) mod derive;
mod error;

#[cfg(feature = "keyring")]
pub use keyring;
#[cfg(feature = "keyring")]
use keyring::KeyringEntry;
#[cfg(feature = "command")]
pub use process;
#[cfg(feature = "command")]
use process::Command;
use tracing::debug;

#[doc(inline)]
pub use crate::error::{Error, Result};

#[cfg(any(
    all(feature = "tokio", feature = "async-std"),
    not(any(feature = "tokio", feature = "async-std"))
))]
compile_error!("Either feature `tokio` or `async-std` must be enabled for this crate.");

#[cfg(any(
    all(feature = "rustls", feature = "openssl"),
    not(any(feature = "rustls", feature = "openssl"))
))]
compile_error!("Either feature `rustls` or `openssl` must be enabled for this crate.");

/// The secret.
///
/// A secret can be retrieved either from a raw string, from a shell
/// command or from a keyring entry.
#[derive(Clone, Debug, Default, Eq, PartialEq)]
#[cfg_attr(
    feature = "derive",
    derive(serde::Serialize, serde::Deserialize),
    serde(rename_all = "kebab-case", from = "derive::Secret")
)]
pub enum Secret {
    /// The secret is empty.
    #[default]
    Empty,

    /// The secret is contained in a raw string.
    ///
    /// This variant is not safe to use and therefore not
    /// recommended. Yet it works well for testing purpose.
    Raw(String),

    /// The secret is exposed by the given shell command.
    ///
    /// This variant takes the secret from the first line returned by
    /// the given shell command.
    ///
    /// See [process-lib](https://crates.io/crates/process-lib).
    #[cfg(feature = "command")]
    #[cfg_attr(feature = "derive", serde(alias = "cmd"))]
    Command(Command),

    /// The secret is contained in the user's global keyring at the
    /// given entry.
    ///
    /// See [keyring-lib](https://crates.io/crates/keyring-lib).
    #[cfg(feature = "keyring")]
    Keyring(KeyringEntry),
}

impl Secret {
    /// Creates a new empty secret.
    pub fn new() -> Self {
        Default::default()
    }

    /// Creates a new secret from the given raw string.
    pub fn new_raw(raw: impl ToString) -> Self {
        Self::Raw(raw.to_string())
    }

    /// Creates a new secret from the given shell command.
    #[cfg(feature = "command")]
    pub fn new_command(cmd: impl ToString) -> Self {
        Self::Command(Command::new(cmd))
    }

    /// Creates a new secret from the given keyring entry.
    #[cfg(feature = "keyring")]
    pub fn new_keyring_entry(entry: KeyringEntry) -> Self {
        Self::Keyring(entry)
    }

    /// Tries to create a new secret from the given entry.
    #[cfg(feature = "keyring")]
    pub fn try_new_keyring_entry(
        entry: impl TryInto<KeyringEntry, Error = keyring::Error>,
    ) -> Result<Self> {
        let entry = entry.try_into()?;
        Ok(Self::new_keyring_entry(entry))
    }

    /// Returns `true` if the secret is empty.
    pub fn is_empty(&self) -> bool {
        *self == Self::Empty
    }

    /// Gets the secret value.
    ///
    /// The command-based secret execute its shell command and returns
    /// the output, and the keyring-based secret retrieves the value
    /// from the global keyring using its inner key.
    pub async fn get(&self) -> Result<String> {
        match self {
            Self::Empty => {
                return Err(Error::GetEmptySecretError);
            }
            Self::Raw(secret) => {
                return Ok(secret.clone());
            }
            #[cfg(feature = "command")]
            Self::Command(cmd) => {
                let full_secret = cmd
                    .run()
                    .await
                    .map_err(Error::GetSecretFromCommand)?
                    .to_string_lossy();

                let first_line_secret = full_secret
                    .lines()
                    .take(1)
                    .next()
                    .ok_or(Error::GetSecretFromCommandEmptyOutputError)?
                    .to_owned();

                Ok(first_line_secret)
            }
            #[cfg(feature = "keyring")]
            Self::Keyring(entry) => {
                let secret = entry.get_secret().await?;
                Ok(secret)
            }
        }
    }

    /// Finds the secret value.
    ///
    /// Like [`Secret::get`], but returns [`None`] if the secret value
    /// is not found or empty.
    pub async fn find(&self) -> Result<Option<String>> {
        match self {
            Self::Empty => {
                return Ok(None);
            }
            Self::Raw(secret) => {
                return Ok(Some(secret.clone()));
            }
            #[cfg(feature = "command")]
            Self::Command(cmd) => {
                let full_secret = cmd
                    .run()
                    .await
                    .map_err(Error::GetSecretFromCommand)?
                    .to_string_lossy();

                let first_line_secret = full_secret.lines().take(1).next().map(ToOwned::to_owned);

                Ok(first_line_secret)
            }
            #[cfg(feature = "keyring")]
            Self::Keyring(entry) => {
                let secret = entry.find_secret().await?;
                Ok(secret)
            }
        }
    }

    /// Updates the secret value.
    ///
    /// This is only applicable for raw secrets and keyring-based
    /// secrets. A secret value cannot be changed for command-base
    /// secrets, since the value is the output of the command.
    pub async fn set(&mut self, secret: impl ToString) -> Result<String> {
        match self {
            Self::Raw(prev) => {
                *prev = secret.to_string();
            }
            #[cfg(feature = "command")]
            Self::Command(_) => {
                debug!("cannot change value of command-based secret");
            }
            #[cfg(feature = "keyring")]
            Self::Keyring(entry) => entry.set_secret(secret.to_string()).await?,
            Self::Empty => {
                debug!("cannot change value of empty secret");
            }
        }

        Ok(secret.to_string())
    }

    /// Updates the secret value of the keyring-based secret only.
    ///
    /// This function as no effect on other secret variants.
    #[cfg(feature = "keyring")]
    pub async fn set_if_keyring(&self, secret: impl ToString) -> Result<String> {
        if let Self::Keyring(entry) = self {
            let secret = secret.to_string();
            entry.set_secret(&secret).await?;
            return Ok(secret);
        }

        Ok(secret.to_string())
    }

    /// Deletes the secret value and make the current secret empty.
    pub async fn delete(&mut self) -> Result<()> {
        #[cfg(feature = "keyring")]
        if let Self::Keyring(entry) = self {
            entry.delete_secret().await?;
        }

        *self = Self::Empty;

        Ok(())
    }

    /// Deletes the secret value of keyring-based secrets only.
    ///
    /// This function has no effect on other variants.
    #[cfg(feature = "keyring")]
    pub async fn delete_if_keyring(&self) -> Result<()> {
        if let Self::Keyring(entry) = self {
            entry.delete_secret().await?;
        }

        Ok(())
    }

    /// Replaces empty secret variant with the given one.
    ///
    /// This function has no effect on other variants.
    pub fn replace_if_empty(&mut self, new: Self) {
        if self.is_empty() {
            *self = new
        }
    }

    /// Replaces empty secret variant with a keyring one.
    ///
    /// This function has no effect on other variants.
    #[cfg(feature = "keyring")]
    pub fn replace_with_keyring_if_empty(&mut self, entry: impl ToString) -> Result<()> {
        if self.is_empty() {
            *self = Self::try_new_keyring_entry(entry.to_string())?;
        }

        Ok(())
    }
}