e2e: Wire in sqlite3 to hold e2e databases

We're going to need a:
  database of olm sessions
  a device trust database
  a database of megaolm sessions

Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>

2 files changed, 90 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 37644c9..f914496 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 #!/usr/bin/make -f
 
 CC=gcc
-LIBS=purple json-glib-1.0 glib-2.0
+LIBS=purple json-glib-1.0 glib-2.0 sqlite3
 
 PKG_CONFIG=pkg-config
 CFLAGS+=$(shell $(PKG_CONFIG) --cflags $(LIBS))
diff --git a/matrix-e2e.c b/matrix-e2e.c
index e7471fd..6d8918e 100644
--- a/matrix-e2e.c
+++ b/matrix-e2e.c
@@ -18,6 +18,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <sqlite3.h>
 #include "libmatrix.h"
 #include "matrix-api.h"
 #include "matrix-e2e.h"
@@ -36,6 +37,7 @@ struct _MatrixE2EData {
     gchar *device_id;
     gchar *curve25519_pubkey;
     gchar *ed25519_pubkey;
+    sqlite3 *db;
 };
 
 static void key_upload_callback(MatrixConnectionData *conn,
@@ -482,6 +484,86 @@ static void key_upload_callback(MatrixConnectionData *conn,
     matrix_e2e_handle_sync_key_counts(conn->pc, key_counts, !key_counts);
 }
 
+static void close_e2e_db(MatrixConnectionData *conn)
+{
+    sqlite3_close(conn->e2e->db);
+    conn->e2e->db = NULL;
+}
+
+/* 'check' and 'create' are SQL statements; call check, if it returns no result
+ * then run 'create'.
+ * typically for checking for the existence of a table and creating it if it didn't
+ * exist.
+ */
+static int ensure_table(MatrixConnectionData *conn, const char *check, const char *create)
+{
+    PurpleConnection *pc = conn->pc;
+    int ret;
+    sqlite3_stmt *dbstmt;
+    ret = sqlite3_prepare_v2(conn->e2e->db, check, -1, &dbstmt, NULL);
+    if (ret != SQLITE_OK || !dbstmt) {
+        purple_connection_error_reason(pc,
+            PURPLE_CONNECTION_ERROR_OTHER_ERROR,
+            "Failed to check e2e db table list (prep)");
+        return -1;
+    }
+    ret = sqlite3_step(dbstmt);
+    sqlite3_finalize(dbstmt);
+    purple_debug_info("matrixprpl", "%s:db table query %d\n", __func__, ret);
+    if (ret == SQLITE_ROW) {
+        /* Already exists */
+        return 0;
+    }
+    ret = sqlite3_prepare_v2(conn->e2e->db, create, -1, &dbstmt, NULL);
+    if (ret != SQLITE_OK || !dbstmt) {
+        purple_connection_error_reason(pc,
+            PURPLE_CONNECTION_ERROR_OTHER_ERROR,
+            "Failed to create e2e db table (prep)");
+        return -1;
+    }
+    ret = sqlite3_step(dbstmt);
+    sqlite3_finalize(dbstmt);
+    if (ret != SQLITE_DONE) {
+        purple_connection_error_reason(pc,
+            PURPLE_CONNECTION_ERROR_OTHER_ERROR,
+            "Failed to create e2e db table (step)");
+        return -1;
+    }
+
+    return 0;
+}
+static int open_e2e_db(MatrixConnectionData *conn)
+{
+    PurpleConnection *pc = conn->pc;
+    int ret;
+    const char *purple_username = 
+               purple_account_get_username(purple_connection_get_account(pc));
+    char *cfilename = g_strdup_printf("matrix-%s-%s.db", conn->user_id,
+                                       purple_username);
+    const char *escaped_filename = purple_escape_filename(cfilename);
+    g_free(cfilename);
+    char *full_path = g_strdup_printf("%s/%s", purple_user_dir(),
+                                               escaped_filename);
+    ret = sqlite3_open(full_path, &conn->e2e->db);
+    purple_debug_info("matrixprpl", "Opened e2e db at %s %d\n", full_path, ret);
+    g_free(full_path);
+    if (ret) {
+        purple_connection_error_reason(pc,
+            PURPLE_CONNECTION_ERROR_OTHER_ERROR,
+            "Failed to open e2e db");
+        return ret;
+    }
+
+    /* TODO: Add calls to ensure_table here */
+
+    if (ret) {
+        close_e2e_db(conn);
+        return ret;
+    }
+
+    return 0;
+}
+
 /*
  * Get a set of device keys for ourselves.  Either by retreiving it from our store
  * or by generating a new set.
@@ -539,6 +621,12 @@ int matrix_e2e_get_device_keys(MatrixConnectionData *conn, const gchar *device_i
         }
     }
 
+    /* Open the e2e db - an sqlite db held for the account */
+    ret = open_e2e_db(conn);
+    if (ret) {
+        goto out;
+    }
+
     /* Form a device keys object for an upload,
      * from https://matrix.org/speculator/spec/drafts%2Fe2e/client_server/unstable.html#post-matrix-client-unstable-keys-upload
      */
@@ -613,6 +701,7 @@ out:
 void matrix_e2e_cleanup_connection(MatrixConnectionData *conn)
 {
     if (conn->e2e) {
+        close_e2e_db(conn);
         g_free(conn->e2e->curve25519_pubkey);
         g_free(conn->e2e->oa);
         g_free(conn->e2e->device_id);