refactor(sql): recreate keypairs table

Removed unused `addr` and `created` field.
`is_default` boolean flag is moved into `config` row
pointing to the current default key.

Author: link2xt

src/config.rs

@@ -343,6 +343,10 @@ pub enum Config {
     /// until `chat_id.accept()` is called.
     #[strum(props(default = "0"))]
     VerifiedOneOnOneChats,
+
+    /// Row ID of the key in the `keypairs` table
+    /// used for signatures, encryption to self and included in `Autocrypt` header.
+    KeyId,
 }
 
 impl Config {
@@ -627,8 +631,6 @@ impl Context {
     ///
     /// This should only be used by test code and during configure.
     pub(crate) async fn set_primary_self_addr(&self, primary_new: &str) -> Result<()> {
-        let old_addr = self.get_config(Config::ConfiguredAddr).await?;
-
         // add old primary address (if exists) to secondary addresses
         let mut secondary_addrs = self.get_all_self_addrs().await?;
         // never store a primary address also as a secondary
@@ -642,17 +644,6 @@ impl Context {
         self.set_config(Config::ConfiguredAddr, Some(primary_new))
             .await?;
 
-        if let Some(old_addr) = old_addr {
-            let old_addr = EmailAddress::new(&old_addr)?;
-            let old_keypair = crate::key::load_keypair(self, &old_addr).await?;
-
-            if let Some(mut old_keypair) = old_keypair {
-                old_keypair.addr = EmailAddress::new(primary_new)?;
-                crate::key::store_self_keypair(self, &old_keypair, crate::key::KeyPairUse::Default)
-                    .await?;
-            }
-        }
-
         Ok(())
     }
 

src/context.rs

@@ -1318,6 +1318,7 @@ mod tests {
             "socks5_port",
             "socks5_user",
             "socks5_password",
+            "key_id",
         ];
         let t = TestContext::new().await;
         let info = t.get_info().await.unwrap();

src/imex.rs

@@ -670,7 +670,7 @@ async fn export_self_keys(context: &Context, dir: &Path) -> Result<()> {
     let keys = context
         .sql
         .query_map(
-            "SELECT id, public_key, private_key, is_default FROM keypairs;",
+            "SELECT id, public_key, private_key, id=(SELECT value FROM config WHERE keyname='key_id') FROM keypairs;",
             (),
             |row| {
                 let id = row.get(0)?;

src/key.rs

@@ -18,7 +18,7 @@ use crate::constants::KeyGenType;
 use crate::context::Context;
 use crate::log::LogExt;
 use crate::pgp::KeyPair;
-use crate::tools::{time, EmailAddress};
+use crate::tools::EmailAddress;
 
 /// Convenience trait for working with keys.
 ///
@@ -82,10 +82,9 @@ pub(crate) async fn load_self_public_key(context: &Context) -> Result<SignedPubl
     match context
         .sql
         .query_row_optional(
-            r#"SELECT public_key
-               FROM keypairs
-               WHERE addr=(SELECT value FROM config WHERE keyname="configured_addr")
-               AND is_default=1"#,
+            "SELECT public_key
+             FROM keypairs
+             WHERE id=(SELECT value FROM config WHERE keyname='key_id')",
             (),
             |row| {
                 let bytes: Vec<u8> = row.get(0)?;
@@ -106,10 +105,9 @@ pub(crate) async fn load_self_secret_key(context: &Context) -> Result<SignedSecr
     match context
         .sql
         .query_row_optional(
-            r#"SELECT private_key
-               FROM keypairs
-               WHERE addr=(SELECT value FROM config WHERE keyname="configured_addr")
-               AND is_default=1"#,
+            "SELECT private_key
+             FROM keypairs
+             WHERE id=(SELECT value FROM config WHERE keyname='key_id')",
             (),
             |row| {
                 let bytes: Vec<u8> = row.get(0)?;
@@ -132,8 +130,7 @@ pub(crate) async fn load_self_secret_keyring(context: &Context) -> Result<Vec<Si
         .query_map(
             r#"SELECT private_key
                FROM keypairs
-               WHERE addr=(SELECT value FROM config WHERE keyname="configured_addr")
-               ORDER BY is_default DESC"#,
+               ORDER BY id=(SELECT value FROM config WHERE keyname='key_id') DESC"#,
             (),
             |row| row.get::<_, Vec<u8>>(0),
             |keys| keys.collect::<Result<Vec<_>, _>>().map_err(Into::into),
@@ -233,13 +230,10 @@ pub(crate) async fn load_keypair(
     let res = context
         .sql
         .query_row_optional(
-            r#"
-        SELECT public_key, private_key
-          FROM keypairs
-         WHERE addr=?1
-           AND is_default=1;
-        "#,
-            (addr,),
+            "SELECT public_key, private_key
+             FROM keypairs
+             WHERE id=(SELECT value FROM config WHERE keyname='key_id')",
+            (),
             |row| {
                 let pub_bytes: Vec<u8> = row.get(0)?;
                 let sec_bytes: Vec<u8> = row.get(1)?;
@@ -288,42 +282,44 @@ pub async fn store_self_keypair(
     keypair: &KeyPair,
     default: KeyPairUse,
 ) -> Result<()> {
-    context
+    let mut config_cache_lock = context.sql.config_cache.write().await;
+    let new_key_id = context
         .sql
         .transaction(|transaction| {
             let public_key = DcKey::to_bytes(&keypair.public);
             let secret_key = DcKey::to_bytes(&keypair.secret);
-            transaction
-                .execute(
-                    "DELETE FROM keypairs WHERE public_key=? OR private_key=?;",
-                    (&public_key, &secret_key),
-                )
-                .context("failed to remove old use of key")?;
-            if default == KeyPairUse::Default {
-                transaction
-                    .execute("UPDATE keypairs SET is_default=0;", ())
-                    .context("failed to clear default")?;
-            }
+
             let is_default = match default {
-                KeyPairUse::Default => i32::from(true),
-                KeyPairUse::ReadOnly => i32::from(false),
+                KeyPairUse::Default => true,
+                KeyPairUse::ReadOnly => false,
             };
 
-            let addr = keypair.addr.to_string();
-            let t = time();
-
             transaction
                 .execute(
-                    "INSERT INTO keypairs (addr, is_default, public_key, private_key, created)
-                VALUES (?,?,?,?,?);",
-                    (addr, is_default, &public_key, &secret_key, t),
+                    "INSERT OR REPLACE INTO keypairs (public_key, private_key)
+                     VALUES (?,?)",
+                    (&public_key, &secret_key),
                 )
-                .context("failed to insert keypair")?;
-
-            Ok(())
+                .context("Failed to insert keypair")?;
+
+            if is_default {
+                let new_key_id = transaction.last_insert_rowid();
+                transaction.execute(
+                    "INSERT OR REPLACE INTO config (keyname, value) VALUES ('key_id', ?)",
+                    (new_key_id,),
+                )?;
+                Ok(Some(new_key_id))
+            } else {
+                Ok(None)
+            }
         })
         .await?;
 
+    if let Some(new_key_id) = new_key_id {
+        // Update config cache if transaction succeeded and changed current default key.
+        config_cache_lock.insert("key_id".to_string(), Some(new_key_id.to_string()));
+    }
+
     Ok(())
 }
 

src/sql/migrations.rs

@@ -804,6 +804,36 @@ CREATE INDEX msgs_status_updates_index2 ON msgs_status_updates (uid);
         .await?;
     }
 
+    if dbversion < 107 {
+        sql.execute_migration(
+            "CREATE TABLE new_keypairs (
+               id INTEGER PRIMARY KEY AUTOINCREMENT,
+               private_key UNIQUE NOT NULL,
+               public_key UNIQUE NOT NULL
+             );
+             INSERT OR IGNORE INTO new_keypairs SELECT id, private_key, public_key FROM keypairs;
+
+             INSERT OR IGNORE
+             INTO config (keyname, value)
+             VALUES
+             ('key_id', (SELECT id FROM new_keypairs
+                         WHERE private_key=
+                           (SELECT private_key FROM keypairs
+                            WHERE addr=(SELECT value FROM config WHERE keyname='configured_addr')
+                            AND is_default=1)));
+
+             -- We do not drop the old `keypairs` table for now,
+             -- but move it to `old_keypairs`. We can remove it later
+             -- in next migrations. This may be needed for recovery
+             -- in case something is wrong with the migration.
+             ALTER TABLE keypairs RENAME TO old_keypairs;
+             ALTER TABLE new_keypairs RENAME TO keypairs;
+             ",
+            107,
+        )
+        .await?;
+    }
+
     let new_version = sql
         .get_raw_config_int(VERSION_CFG)
         .await?