1 files changed, 440 insertions, 0 deletions
diff --git a/crates/turtle/src/atuin_client/encryption.rs b/crates/turtle/src/atuin_client/encryption.rs
new file mode 100644
index 00000000..20a0cd90
--- /dev/null
+++ b/crates/turtle/src/atuin_client/encryption.rs
@@ -0,0 +1,440 @@
+// The general idea is that we NEVER send cleartext history to the server
+// This way the odds of anything private ending up where it should not are
+// very low
+// The server authenticates via the usual username and password. This has
+// nothing to do with the encryption, and is purely authentication! The client
+// generates its own secret key, and encrypts all shell history with libsodium's
+// secretbox. The data is then sent to the server, where it is stored. All
+// clients must share the secret in order to be able to sync, as it is needed
+// to decrypt
+
+use std::{io::prelude::*, path::PathBuf};
+
+use base64::prelude::{BASE64_STANDARD, Engine};
+pub use crypto_secretbox::Key;
+use crypto_secretbox::{
+    AeadCore, AeadInPlace, KeyInit, XSalsa20Poly1305,
+    aead::{Nonce, OsRng},
+};
+use eyre::{Context, Result, bail, ensure, eyre};
+use fs_err as fs;
+use rmp::{Marker, decode::Bytes};
+use serde::{Deserialize, Serialize};
+use time::{OffsetDateTime, format_description::well_known::Rfc3339, macros::format_description};
+
+use crate::atuin_client::{history::History, settings::Settings};
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct EncryptedHistory {
+    pub ciphertext: Vec<u8>,
+    pub nonce: Nonce<XSalsa20Poly1305>,
+}
+
+pub fn generate_encoded_key() -> Result<(Key, String)> {
+    let key = XSalsa20Poly1305::generate_key(&mut OsRng);
+    let encoded = encode_key(&key)?;
+
+    Ok((key, encoded))
+}
+
+pub fn new_key(settings: &Settings) -> Result<Key> {
+    let path = settings.key_path.as_str();
+    let path = PathBuf::from(path);
+
+    if path.exists() {
+        bail!("key already exists! cannot overwrite");
+    }
+
+    let (key, encoded) = generate_encoded_key()?;
+
+    let mut file = fs::File::create(path)?;
+    file.write_all(encoded.as_bytes())?;
+
+    Ok(key)
+}
+
+// Loads the secret key, will create + save if it doesn't exist
+pub fn load_key(settings: &Settings) -> Result<Key> {
+    let path = settings.key_path.as_str();
+
+    let key = if PathBuf::from(path).exists() {
+        let key = fs_err::read_to_string(path)?;
+        decode_key(key)?
+    } else {
+        new_key(settings)?
+    };
+
+    Ok(key)
+}
+
+pub fn encode_key(key: &Key) -> Result<String> {
+    let mut buf = vec![];
+    rmp::encode::write_array_len(&mut buf, key.len() as u32)
+        .wrap_err("could not encode key to message pack")?;
+    for b in key {
+        rmp::encode::write_uint(&mut buf, *b as u64)
+            .wrap_err("could not encode key to message pack")?;
+    }
+    let buf = BASE64_STANDARD.encode(buf);
+
+    Ok(buf)
+}
+
+pub fn decode_key(key: String) -> Result<Key> {
+    use rmp::decode;
+
+    let buf = BASE64_STANDARD
+        .decode(key.trim_end())
+        .wrap_err("encryption key is not a valid base64 encoding")?;
+
+    // old code wrote the key as a fixed length array of 32 bytes
+    // new code writes the key with a length prefix
+    match <[u8; 32]>::try_from(&*buf) {
+        Ok(key) => Ok(key.into()),
+        Err(_) => {
+            let mut bytes = rmp::decode::Bytes::new(&buf);
+
+            match Marker::from_u8(buf[0]) {
+                Marker::Bin8 => {
+                    let len = decode::read_bin_len(&mut bytes).map_err(|err| eyre!("{err:?}"))?;
+                    ensure!(len == 32, "encryption key is not the correct size");
+                    let key = <[u8; 32]>::try_from(bytes.remaining_slice())
+                        .context("could not decode encryption key")?;
+                    Ok(key.into())
+                }
+                Marker::Array16 => {
+                    let len = decode::read_array_len(&mut bytes).map_err(|err| eyre!("{err:?}"))?;
+                    ensure!(len == 32, "encryption key is not the correct size");
+
+                    let mut key = Key::default();
+                    for i in &mut key {
+                        *i = rmp::decode::read_int(&mut bytes).map_err(|err| eyre!("{err:?}"))?;
+                    }
+                    Ok(key)
+                }
+                _ => bail!("could not decode encryption key"),
+            }
+        }
+    }
+}
+
+pub fn encrypt(history: &History, key: &Key) -> Result<EncryptedHistory> {
+    // serialize with msgpack
+    let mut buf = encode(history)?;
+
+    let nonce = XSalsa20Poly1305::generate_nonce(&mut OsRng);
+    XSalsa20Poly1305::new(key)
+        .encrypt_in_place(&nonce, &[], &mut buf)
+        .map_err(|_| eyre!("could not encrypt"))?;
+
+    Ok(EncryptedHistory {
+        ciphertext: buf,
+        nonce,
+    })
+}
+
+pub fn decrypt(mut encrypted_history: EncryptedHistory, key: &Key) -> Result<History> {
+    XSalsa20Poly1305::new(key)
+        .decrypt_in_place(
+            &encrypted_history.nonce,
+            &[],
+            &mut encrypted_history.ciphertext,
+        )
+        .map_err(|_| eyre!("could not decrypt history"))?;
+    let plaintext = encrypted_history.ciphertext;
+
+    let history = decode(&plaintext)?;
+
+    Ok(history)
+}
+
+fn format_rfc3339(ts: OffsetDateTime) -> Result<String> {
+    // horrible hack. chrono AutoSI limits to 0, 3, 6, or 9 decimal places for nanoseconds.
+    // time does not have this functionality.
+    static PARTIAL_RFC3339_0: &[time::format_description::FormatItem<'static>] =
+        format_description!("[year]-[month]-[day]T[hour]:[minute]:[second]Z");
+    static PARTIAL_RFC3339_3: &[time::format_description::FormatItem<'static>] =
+        format_description!("[year]-[month]-[day]T[hour]:[minute]:[second].[subsecond digits:3]Z");
+    static PARTIAL_RFC3339_6: &[time::format_description::FormatItem<'static>] =
+        format_description!("[year]-[month]-[day]T[hour]:[minute]:[second].[subsecond digits:6]Z");
+    static PARTIAL_RFC3339_9: &[time::format_description::FormatItem<'static>] =
+        format_description!("[year]-[month]-[day]T[hour]:[minute]:[second].[subsecond digits:9]Z");
+
+    let fmt = match ts.nanosecond() {
+        0 => PARTIAL_RFC3339_0,
+        ns if ns % 1_000_000 == 0 => PARTIAL_RFC3339_3,
+        ns if ns % 1_000 == 0 => PARTIAL_RFC3339_6,
+        _ => PARTIAL_RFC3339_9,
+    };
+
+    Ok(ts.format(fmt)?)
+}
+
+fn encode(h: &History) -> Result<Vec<u8>> {
+    use rmp::encode;
+
+    let mut output = vec![];
+    // INFO: ensure this is updated when adding new fields
+    encode::write_array_len(&mut output, 9)?;
+
+    encode::write_str(&mut output, &h.id.0)?;
+    encode::write_str(&mut output, &(format_rfc3339(h.timestamp)?))?;
+    encode::write_sint(&mut output, h.duration)?;
+    encode::write_sint(&mut output, h.exit)?;
+    encode::write_str(&mut output, &h.command)?;
+    encode::write_str(&mut output, &h.cwd)?;
+    encode::write_str(&mut output, &h.session)?;
+    encode::write_str(&mut output, &h.hostname)?;
+    match h.deleted_at {
+        Some(d) => encode::write_str(&mut output, &format_rfc3339(d)?)?,
+        None => encode::write_nil(&mut output)?,
+    }
+
+    Ok(output)
+}
+
+fn decode(bytes: &[u8]) -> Result<History> {
+    use rmp::decode::{self, DecodeStringError};
+
+    let mut bytes = Bytes::new(bytes);
+
+    let nfields = decode::read_array_len(&mut bytes).map_err(error_report)?;
+    if nfields < 8 {
+        bail!("malformed decrypted history")
+    }
+    if nfields > 9 {
+        bail!("cannot decrypt history from a newer version of atuin");
+    }
+
+    let bytes = bytes.remaining_slice();
+    let (id, bytes) = decode::read_str_from_slice(bytes).map_err(error_report)?;
+    let (timestamp, bytes) = decode::read_str_from_slice(bytes).map_err(error_report)?;
+
+    let mut bytes = Bytes::new(bytes);
+    let duration = decode::read_int(&mut bytes).map_err(error_report)?;
+    let exit = decode::read_int(&mut bytes).map_err(error_report)?;
+
+    let bytes = bytes.remaining_slice();
+    let (command, bytes) = decode::read_str_from_slice(bytes).map_err(error_report)?;
+    let (cwd, bytes) = decode::read_str_from_slice(bytes).map_err(error_report)?;
+    let (session, bytes) = decode::read_str_from_slice(bytes).map_err(error_report)?;
+    let (hostname, bytes) = decode::read_str_from_slice(bytes).map_err(error_report)?;
+
+    // if we have more fields, try and get the deleted_at
+    let mut deleted_at = None;
+    let mut bytes = bytes;
+    if nfields > 8 {
+        bytes = match decode::read_str_from_slice(bytes) {
+            Ok((d, b)) => {
+                deleted_at = Some(d);
+                b
+            }
+            // we accept null here
+            Err(DecodeStringError::TypeMismatch(Marker::Null)) => {
+                // consume the null marker
+                let mut c = Bytes::new(bytes);
+                decode::read_nil(&mut c).map_err(error_report)?;
+                c.remaining_slice()
+            }
+            Err(err) => return Err(error_report(err)),
+        };
+    }
+
+    if !bytes.is_empty() {
+        bail!("trailing bytes in encoded history. malformed")
+    }
+
+    Ok(History {
+        id: id.to_owned().into(),
+        timestamp: OffsetDateTime::parse(timestamp, &Rfc3339)?,
+        duration,
+        exit,
+        command: command.to_owned(),
+        cwd: cwd.to_owned(),
+        session: session.to_owned(),
+        hostname: hostname.to_owned(),
+        author: History::author_from_hostname(hostname),
+        intent: None,
+        deleted_at: deleted_at
+            .map(|t| OffsetDateTime::parse(t, &Rfc3339))
+            .transpose()?,
+    })
+}
+
+fn error_report<E: std::fmt::Debug>(err: E) -> eyre::Report {
+    eyre!("{err:?}")
+}
+
+#[cfg(test)]
+mod test {
+    use crypto_secretbox::{KeyInit, XSalsa20Poly1305, aead::OsRng};
+    use pretty_assertions::assert_eq;
+    use time::{OffsetDateTime, macros::datetime};
+
+    use crate::history::History;
+
+    use super::{decode, decrypt, encode, encrypt};
+
+    #[test]
+    fn test_encrypt_decrypt() {
+        let key1 = XSalsa20Poly1305::generate_key(&mut OsRng);
+        let key2 = XSalsa20Poly1305::generate_key(&mut OsRng);
+
+        let history = History::from_db()
+            .id("1".into())
+            .timestamp(OffsetDateTime::now_utc())
+            .command("ls".into())
+            .cwd("/home/ellie".into())
+            .exit(0)
+            .duration(1)
+            .session("beep boop".into())
+            .hostname("booop".into())
+            .author("booop".into())
+            .intent(None)
+            .deleted_at(None)
+            .build()
+            .into();
+
+        let e1 = encrypt(&history, &key1).unwrap();
+        let e2 = encrypt(&history, &key2).unwrap();
+
+        assert_ne!(e1.ciphertext, e2.ciphertext);
+        assert_ne!(e1.nonce, e2.nonce);
+
+        // test decryption works
+        // this should pass
+        match decrypt(e1, &key1) {
+            Err(e) => panic!("failed to decrypt, got {e}"),
+            Ok(h) => assert_eq!(h, history),
+        };
+
+        // this should err
+        let _ = decrypt(e2, &key1).expect_err("expected an error decrypting with invalid key");
+    }
+
+    #[test]
+    fn test_decode() {
+        let bytes = [
+            0x99, 0xD9, 32, 54, 54, 100, 49, 54, 99, 98, 101, 101, 55, 99, 100, 52, 55, 53, 51, 56,
+            101, 53, 99, 53, 98, 56, 98, 52, 52, 101, 57, 48, 48, 54, 101, 187, 50, 48, 50, 51, 45,
+            48, 53, 45, 50, 56, 84, 49, 56, 58, 51, 53, 58, 52, 48, 46, 54, 51, 51, 56, 55, 50, 90,
+            206, 2, 238, 210, 240, 0, 170, 103, 105, 116, 32, 115, 116, 97, 116, 117, 115, 217, 42,
+            47, 85, 115, 101, 114, 115, 47, 99, 111, 110, 114, 97, 100, 46, 108, 117, 100, 103, 97,
+            116, 101, 47, 68, 111, 99, 117, 109, 101, 110, 116, 115, 47, 99, 111, 100, 101, 47, 97,
+            116, 117, 105, 110, 217, 32, 98, 57, 55, 100, 57, 97, 51, 48, 54, 102, 50, 55, 52, 52,
+            55, 51, 97, 50, 48, 51, 100, 50, 101, 98, 97, 52, 49, 102, 57, 52, 53, 55, 187, 102,
+            118, 102, 103, 57, 51, 54, 99, 48, 107, 112, 102, 58, 99, 111, 110, 114, 97, 100, 46,
+            108, 117, 100, 103, 97, 116, 101, 192,
+        ];
+        let history = History {
+            id: "66d16cbee7cd47538e5c5b8b44e9006e".to_owned().into(),
+            timestamp: datetime!(2023-05-28 18:35:40.633872 +00:00),
+            duration: 49206000,
+            exit: 0,
+            command: "git status".to_owned(),
+            cwd: "/Users/conrad.ludgate/Documents/code/atuin".to_owned(),
+            session: "b97d9a306f274473a203d2eba41f9457".to_owned(),
+            hostname: "fvfg936c0kpf:conrad.ludgate".to_owned(),
+            author: "conrad.ludgate".to_owned(),
+            intent: None,
+            deleted_at: None,
+        };
+
+        let h = decode(&bytes).unwrap();
+        assert_eq!(history, h);
+
+        let b = encode(&h).unwrap();
+        assert_eq!(&bytes, &*b);
+    }
+
+    #[test]
+    fn test_decode_deleted() {
+        let history = History {
+            id: "66d16cbee7cd47538e5c5b8b44e9006e".to_owned().into(),
+            timestamp: datetime!(2023-05-28 18:35:40.633872 +00:00),
+            duration: 49206000,
+            exit: 0,
+            command: "git status".to_owned(),
+            cwd: "/Users/conrad.ludgate/Documents/code/atuin".to_owned(),
+            session: "b97d9a306f274473a203d2eba41f9457".to_owned(),
+            hostname: "fvfg936c0kpf:conrad.ludgate".to_owned(),
+            author: "conrad.ludgate".to_owned(),
+            intent: None,
+            deleted_at: Some(datetime!(2023-05-28 18:35:40.633872 +00:00)),
+        };
+
+        let b = encode(&history).unwrap();
+        let h = decode(&b).unwrap();
+        assert_eq!(history, h);
+    }
+
+    #[test]
+    fn test_decode_old() {
+        let bytes = [
+            0x98, 0xD9, 32, 54, 54, 100, 49, 54, 99, 98, 101, 101, 55, 99, 100, 52, 55, 53, 51, 56,
+            101, 53, 99, 53, 98, 56, 98, 52, 52, 101, 57, 48, 48, 54, 101, 187, 50, 48, 50, 51, 45,
+            48, 53, 45, 50, 56, 84, 49, 56, 58, 51, 53, 58, 52, 48, 46, 54, 51, 51, 56, 55, 50, 90,
+            206, 2, 238, 210, 240, 0, 170, 103, 105, 116, 32, 115, 116, 97, 116, 117, 115, 217, 42,
+            47, 85, 115, 101, 114, 115, 47, 99, 111, 110, 114, 97, 100, 46, 108, 117, 100, 103, 97,
+            116, 101, 47, 68, 111, 99, 117, 109, 101, 110, 116, 115, 47, 99, 111, 100, 101, 47, 97,
+            116, 117, 105, 110, 217, 32, 98, 57, 55, 100, 57, 97, 51, 48, 54, 102, 50, 55, 52, 52,
+            55, 51, 97, 50, 48, 51, 100, 50, 101, 98, 97, 52, 49, 102, 57, 52, 53, 55, 187, 102,
+            118, 102, 103, 57, 51, 54, 99, 48, 107, 112, 102, 58, 99, 111, 110, 114, 97, 100, 46,
+            108, 117, 100, 103, 97, 116, 101,
+        ];
+        let history = History {
+            id: "66d16cbee7cd47538e5c5b8b44e9006e".to_owned().into(),
+            timestamp: datetime!(2023-05-28 18:35:40.633872 +00:00),
+            duration: 49206000,
+            exit: 0,
+            command: "git status".to_owned(),
+            cwd: "/Users/conrad.ludgate/Documents/code/atuin".to_owned(),
+            session: "b97d9a306f274473a203d2eba41f9457".to_owned(),
+            hostname: "fvfg936c0kpf:conrad.ludgate".to_owned(),
+            author: "conrad.ludgate".to_owned(),
+            intent: None,
+            deleted_at: None,
+        };
+
+        let h = decode(&bytes).unwrap();
+        assert_eq!(history, h);
+    }
+
+    #[test]
+    fn key_encodings() {
+        use super::{Key, decode_key, encode_key};
+
+        // a history of our key encodings.
+        // v11.0.0 xCAbWypb0msJ2Kq+8j4GVEWUlDX7deKnrTRSIopuqXxc5Q==
+        // v12.0.0 xCAbWypb0msJ2Kq+8j4GVEWUlDX7deKnrTRSIopuqXxc5Q==
+        // v13.0.0 xCAbWypb0msJ2Kq+8j4GVEWUlDX7deKnrTRSIopuqXxc5Q==
+        // v13.0.1 xCAbWypb0msJ2Kq+8j4GVEWUlDX7deKnrTRSIopuqXxc5Q==
+        // v14.0.0 xCAbWypb0msJ2Kq+8j4GVEWUlDX7deKnrTRSIopuqXxc5Q==
+        // v14.0.1 xCAbWypb0msJ2Kq+8j4GVEWUlDX7deKnrTRSIopuqXxc5Q==
+        // c7d89c1 3AAgG1sqW8zSawnM2MyqzL7M8j4GVEXMlMyUNcz7dczizKfMrTRSIsyKbsypfFzM5Q== (https://github.com/ellie/atuin/pull/805)
+        // b53ca35 3AAgG1sqW8zSawnM2MyqzL7M8j4GVEXMlMyUNcz7dczizKfMrTRSIsyKbsypfFzM5Q== (https://github.com/ellie/atuin/pull/974)
+        // v15.0.0 3AAgG1sqW8zSawnM2MyqzL7M8j4GVEXMlMyUNcz7dczizKfMrTRSIsyKbsypfFzM5Q==
+        // b8b57c8 xCAbWypb0msJ2Kq+8j4GVEWUlDX7deKnrTRSIopuqXxc5Q==                     (https://github.com/ellie/atuin/pull/1057)
+        // 8c94d79 3AAgG1sqW8zSawnM2MyqzL7M8j4GVEXMlMyUNcz7dczizKfMrTRSIsyKbsypfFzM5Q== (https://github.com/ellie/atuin/pull/1089)
+
+        let key = Key::from([
+            27, 91, 42, 91, 210, 107, 9, 216, 170, 190, 242, 62, 6, 84, 69, 148, 148, 53, 251, 117,
+            226, 167, 173, 52, 82, 34, 138, 110, 169, 124, 92, 229,
+        ]);
+
+        assert_eq!(
+            encode_key(&key).unwrap(),
+            "3AAgG1sqW8zSawnM2MyqzL7M8j4GVEXMlMyUNcz7dczizKfMrTRSIsyKbsypfFzM5Q=="
+        );
+
+        // key encodings we have to support
+        let valid_encodings = [
+            "xCAbWypb0msJ2Kq+8j4GVEWUlDX7deKnrTRSIopuqXxc5Q==",
+            "3AAgG1sqW8zSawnM2MyqzL7M8j4GVEXMlMyUNcz7dczizKfMrTRSIsyKbsypfFzM5Q==",
+        ];
+
+        for k in valid_encodings {
+            assert_eq!(decode_key(k.to_owned()).expect(k), key);
+        }
+    }
+}