1 files changed, 245 insertions, 0 deletions
diff --git a/aero-user/src/login/mod.rs b/aero-user/src/login/mod.rs
new file mode 100644
index 0000000..5e54b4a
--- /dev/null
+++ b/aero-user/src/login/mod.rs
@@ -0,0 +1,245 @@
+pub mod demo_provider;
+pub mod ldap_provider;
+pub mod static_provider;
+
+use std::sync::Arc;
+
+use anyhow::{anyhow, bail, Context, Result};
+use async_trait::async_trait;
+use base64::Engine;
+use rand::prelude::*;
+
+use crate::cryptoblob::*;
+use crate::storage::*;
+
+/// The trait LoginProvider defines the interface for a login provider that allows
+/// to retrieve storage and cryptographic credentials for access to a user account
+/// from their username and password.
+#[async_trait]
+pub trait LoginProvider {
+    /// The login method takes an account's password as an input to decypher
+    /// decryption keys and obtain full access to the user's account.
+    async fn login(&self, username: &str, password: &str) -> Result<Credentials>;
+    /// The public_login method takes an account's email address and returns
+    /// public credentials for adding mails to the user's inbox.
+    async fn public_login(&self, email: &str) -> Result<PublicCredentials>;
+}
+
+/// ArcLoginProvider is simply an alias on a structure that is used
+/// in many places in the code
+pub type ArcLoginProvider = Arc<dyn LoginProvider + Send + Sync>;
+
+/// The struct Credentials represent all of the necessary information to interact
+/// with a user account's data after they are logged in.
+#[derive(Clone, Debug)]
+pub struct Credentials {
+    /// The storage credentials are used to authenticate access to the underlying storage (S3, K2V)
+    pub storage: Builder,
+    /// The cryptographic keys are used to encrypt and decrypt data stored in S3 and K2V
+    pub keys: CryptoKeys,
+}
+
+#[derive(Clone, Debug)]
+pub struct PublicCredentials {
+    /// The storage credentials are used to authenticate access to the underlying storage (S3, K2V)
+    pub storage: Builder,
+    pub public_key: PublicKey,
+}
+
+use serde::{Deserialize, Serialize};
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct CryptoRoot(pub String);
+
+impl CryptoRoot {
+    pub fn create_pass(password: &str, k: &CryptoKeys) -> Result<Self> {
+        let bytes = k.password_seal(password)?;
+        let b64 = base64::engine::general_purpose::STANDARD_NO_PAD.encode(bytes);
+        let cr = format!("aero:cryptoroot:pass:{}", b64);
+        Ok(Self(cr))
+    }
+
+    pub fn create_cleartext(k: &CryptoKeys) -> Self {
+        let bytes = k.serialize();
+        let b64 = base64::engine::general_purpose::STANDARD_NO_PAD.encode(bytes);
+        let cr = format!("aero:cryptoroot:cleartext:{}", b64);
+        Self(cr)
+    }
+
+    pub fn create_incoming(pk: &PublicKey) -> Self {
+        let bytes: &[u8] = &pk[..];
+        let b64 = base64::engine::general_purpose::STANDARD_NO_PAD.encode(bytes);
+        let cr = format!("aero:cryptoroot:incoming:{}", b64);
+        Self(cr)
+    }
+
+    pub fn public_key(&self) -> Result<PublicKey> {
+        match self.0.splitn(4, ':').collect::<Vec<&str>>()[..] {
+            ["aero", "cryptoroot", "pass", b64blob] => {
+                let blob = base64::engine::general_purpose::STANDARD_NO_PAD.decode(b64blob)?;
+                if blob.len() < 32 {
+                    bail!(
+                        "Decoded data is {} bytes long, expect at least 32 bytes",
+                        blob.len()
+                    );
+                }
+                PublicKey::from_slice(&blob[..32]).context("must be a valid public key")
+            }
+            ["aero", "cryptoroot", "cleartext", b64blob] => {
+                let blob = base64::engine::general_purpose::STANDARD_NO_PAD.decode(b64blob)?;
+                Ok(CryptoKeys::deserialize(&blob)?.public)
+            }
+            ["aero", "cryptoroot", "incoming", b64blob] => {
+                let blob = base64::engine::general_purpose::STANDARD_NO_PAD.decode(b64blob)?;
+                if blob.len() < 32 {
+                    bail!(
+                        "Decoded data is {} bytes long, expect at least 32 bytes",
+                        blob.len()
+                    );
+                }
+                PublicKey::from_slice(&blob[..32]).context("must be a valid public key")
+            }
+            ["aero", "cryptoroot", "keyring", _] => {
+                bail!("keyring is not yet implemented!")
+            }
+            _ => bail!(format!(
+                "passed string '{}' is not a valid cryptoroot",
+                self.0
+            )),
+        }
+    }
+    pub fn crypto_keys(&self, password: &str) -> Result<CryptoKeys> {
+        match self.0.splitn(4, ':').collect::<Vec<&str>>()[..] {
+            ["aero", "cryptoroot", "pass", b64blob] => {
+                let blob = base64::engine::general_purpose::STANDARD_NO_PAD.decode(b64blob)?;
+                CryptoKeys::password_open(password, &blob)
+            }
+            ["aero", "cryptoroot", "cleartext", b64blob] => {
+                let blob = base64::engine::general_purpose::STANDARD_NO_PAD.decode(b64blob)?;
+                CryptoKeys::deserialize(&blob)
+            }
+            ["aero", "cryptoroot", "incoming", _] => {
+                bail!("incoming cryptoroot does not contain a crypto key!")
+            }
+            ["aero", "cryptoroot", "keyring", _] => {
+                bail!("keyring is not yet implemented!")
+            }
+            _ => bail!(format!(
+                "passed string '{}' is not a valid cryptoroot",
+                self.0
+            )),
+        }
+    }
+}
+
+/// The struct CryptoKeys contains the cryptographic keys used to encrypt and decrypt
+/// data in a user's mailbox.
+#[derive(Clone, Debug)]
+pub struct CryptoKeys {
+    /// Master key for symmetric encryption of mailbox data
+    pub master: Key,
+    /// Public/private keypair for encryption of incomming emails (secret part)
+    pub secret: SecretKey,
+    /// Public/private keypair for encryption of incomming emails (public part)
+    pub public: PublicKey,
+}
+
+// ----
+
+impl CryptoKeys {
+    /// Initialize a new cryptography root
+    pub fn init() -> Self {
+        let (public, secret) = gen_keypair();
+        let master = gen_key();
+        CryptoKeys {
+            master,
+            secret,
+            public,
+        }
+    }
+
+    // Clear text serialize/deserialize
+    /// Serialize the root as bytes without encryption
+    fn serialize(&self) -> [u8; 64] {
+        let mut res = [0u8; 64];
+        res[..32].copy_from_slice(self.master.as_ref());
+        res[32..].copy_from_slice(self.secret.as_ref());
+        res
+    }
+
+    /// Deserialize a clear text crypto root without encryption
+    fn deserialize(bytes: &[u8]) -> Result<Self> {
+        if bytes.len() != 64 {
+            bail!("Invalid length: {}, expected 64", bytes.len());
+        }
+        let master = Key::from_slice(&bytes[..32]).unwrap();
+        let secret = SecretKey::from_slice(&bytes[32..]).unwrap();
+        let public = secret.public_key();
+        Ok(Self {
+            master,
+            secret,
+            public,
+        })
+    }
+
+    // Password sealed keys serialize/deserialize
+    pub fn password_open(password: &str, blob: &[u8]) -> Result<Self> {
+        let _pubkey = &blob[0..32];
+        let kdf_salt = &blob[32..64];
+        let password_openned = try_open_encrypted_keys(kdf_salt, password, &blob[64..])?;
+
+        let keys = Self::deserialize(&password_openned)?;
+        Ok(keys)
+    }
+
+    pub fn password_seal(&self, password: &str) -> Result<Vec<u8>> {
+        let mut kdf_salt = [0u8; 32];
+        thread_rng().fill(&mut kdf_salt);
+
+        // Calculate key for password secret box
+        let password_key = derive_password_key(&kdf_salt, password)?;
+
+        // Seal a secret box that contains our crypto keys
+        let password_sealed = seal(&self.serialize(), &password_key)?;
+
+        // Create blob
+        let password_blob = [&self.public[..], &kdf_salt[..], &password_sealed].concat();
+
+        Ok(password_blob)
+    }
+}
+
+fn derive_password_key(kdf_salt: &[u8], password: &str) -> Result<Key> {
+    Ok(Key::from_slice(&argon2_kdf(kdf_salt, password.as_bytes(), 32)?).unwrap())
+}
+
+fn try_open_encrypted_keys(
+    kdf_salt: &[u8],
+    password: &str,
+    encrypted_keys: &[u8],
+) -> Result<Vec<u8>> {
+    let password_key = derive_password_key(kdf_salt, password)?;
+    open(encrypted_keys, &password_key)
+}
+
+// ---- UTIL ----
+
+pub fn argon2_kdf(salt: &[u8], password: &[u8], output_len: usize) -> Result<Vec<u8>> {
+    use argon2::{password_hash, Algorithm, Argon2, ParamsBuilder, PasswordHasher, Version};
+
+    let params = ParamsBuilder::new()
+        .output_len(output_len)
+        .build()
+        .map_err(|e| anyhow!("Invalid argon2 params: {}", e))?;
+    let argon2 = Argon2::new(Algorithm::default(), Version::default(), params);
+
+    let b64_salt = base64::engine::general_purpose::STANDARD_NO_PAD.encode(salt);
+    let valid_salt = password_hash::Salt::from_b64(&b64_salt)
+        .map_err(|e| anyhow!("Invalid salt, error {}", e))?;
+    let hash = argon2
+        .hash_password(password, valid_salt)
+        .map_err(|e| anyhow!("Unable to hash: {}", e))?;
+
+    let hash = hash.hash.ok_or(anyhow!("Missing output"))?;
+    assert!(hash.len() == output_len);
+    Ok(hash.as_bytes().to_vec())
+}