Merge pull request #136 from scitokens/sqlite3_err_handling

Improve error handling around the sqlite3 library

src/scitokens_cache.cpp

@@ -95,38 +95,53 @@ std::string get_cache_file() {
     return keycache_file;
 }
 
-void remove_issuer_entry(sqlite3 *db, const std::string &issuer,
-                         bool new_transaction) {
-
-    if (new_transaction)
-        sqlite3_exec(db, "BEGIN", 0, 0, 0);
+// Remove a given issuer from the database.  Starts a new transaction
+// if `new_transaction` is true.
+// If a failure occurs, then this function returns nonzero and closes
+// the database handle.
+int remove_issuer_entry(sqlite3 *db, const std::string &issuer,
+                        bool new_transaction) {
+
+    int rc;
+    if (new_transaction) {
+        if ((rc = sqlite3_exec(db, "BEGIN", 0, 0, 0)) != SQLITE_OK) {
+            sqlite3_close(db);
+            return -1;
+        }
+    }
 
     sqlite3_stmt *stmt;
-    int rc = sqlite3_prepare_v2(db, "DELETE FROM keycache WHERE issuer = ?", -1,
-                                &stmt, NULL);
+    rc = sqlite3_prepare_v2(db, "DELETE FROM keycache WHERE issuer = ?", -1,
+                            &stmt, NULL);
     if (rc != SQLITE_OK) {
         sqlite3_close(db);
-        return;
+        return -1;
     }
 
     if (sqlite3_bind_text(stmt, 1, issuer.c_str(), issuer.size(),
                           SQLITE_STATIC) != SQLITE_OK) {
         sqlite3_finalize(stmt);
         sqlite3_close(db);
-        return;
+        return -1;
     }
 
     rc = sqlite3_step(stmt);
     if (rc != SQLITE_DONE) {
         sqlite3_finalize(stmt);
         sqlite3_close(db);
-        return;
+        return -1;
     }
 
     sqlite3_finalize(stmt);
 
-    if (new_transaction)
-        sqlite3_exec(db, "COMMIT", 0, 0, 0);
+    if (new_transaction) {
+        if ((rc = sqlite3_exec(db, "COMMIT", 0, 0, 0)) != SQLITE_OK) {
+            sqlite3_close(db);
+            return -1;
+        }
+    }
+
+    return 0;
 }
 
 } // namespace
@@ -170,27 +185,35 @@ bool scitokens::Validator::get_public_keys_from_db(const std::string issuer,
         picojson::value json_obj;
         auto err = picojson::parse(json_obj, metadata);
         if (!err.empty() || !json_obj.is<picojson::object>()) {
-            remove_issuer_entry(db, issuer, true);
+            if (remove_issuer_entry(db, issuer, true) != 0) {
+                return false;
+            }
             sqlite3_close(db);
             return false;
         }
         auto top_obj = json_obj.get<picojson::object>();
         auto iter = top_obj.find("jwks");
         if (iter == top_obj.end() || !iter->second.is<picojson::object>()) {
-            remove_issuer_entry(db, issuer, true);
+            if (remove_issuer_entry(db, issuer, true) != 0) {
+                return false;
+            }
             sqlite3_close(db);
             return false;
         }
         auto keys_local = iter->second;
         iter = top_obj.find("expires");
         if (iter == top_obj.end() || !iter->second.is<int64_t>()) {
-            remove_issuer_entry(db, issuer, true);
+            if (remove_issuer_entry(db, issuer, true) != 0) {
+                return false;
+            }
             sqlite3_close(db);
             return false;
         }
         auto expiry = iter->second.get<int64_t>();
         if (now > expiry) {
-            remove_issuer_entry(db, issuer, true);
+            if (remove_issuer_entry(db, issuer, true) != 0) {
+                return false;
+            }
             sqlite3_close(db);
             return false;
         }
@@ -238,9 +261,14 @@ bool scitokens::Validator::store_public_keys(const std::string &issuer,
         return false;
     }
 
-    sqlite3_exec(db, "BEGIN", 0, 0, 0);
+    if ((rc = sqlite3_exec(db, "BEGIN", 0, 0, 0)) != SQLITE_OK) {
+        sqlite3_close(db);
+        return false;
+    }
 
-    remove_issuer_entry(db, issuer, false);
+    if (remove_issuer_entry(db, issuer, false) != 0) {
+        return false;
+    }
 
     sqlite3_stmt *stmt;
     rc = sqlite3_prepare_v2(db, "INSERT INTO keycache VALUES (?, ?)", -1, &stmt,
@@ -270,10 +298,13 @@ bool scitokens::Validator::store_public_keys(const std::string &issuer,
         sqlite3_close(db);
         return false;
     }
+    sqlite3_finalize(stmt);
 
-    sqlite3_exec(db, "COMMIT", 0, 0, 0);
+    if (sqlite3_exec(db, "COMMIT", 0, 0, 0) != SQLITE_OK) {
+        sqlite3_close(db);
+        return false;
+    }
 
-    sqlite3_finalize(stmt);
     sqlite3_close(db);
     return true;
 }