Sesstion token generation + storage

4 files changed, 61 insertions, 5 deletions

diff --git a/backend/src/API/AuthenticationAPI.zig b/backend/src/API/AuthenticationAPI.zig
index af3a975..a792e33 100644
--- a/backend/src/API/AuthenticationAPI.zig
+++ b/backend/src/API/AuthenticationAPI.zig
@@ -4,6 +4,7 @@ const model = @import("../Models/User.zig");
 const db = @import("../Database/Connection.zig");
 const errDesc = @import("ErrorDescription.zig");
 const Handler = @import("../Handler.zig");
+const Tokens = @import("../Authentication/Tokens.zig");
 
 pub fn RegisterEndpoints(router: *httpz.Router(*Handler.Handler,*const fn (*Handler.Handler, *httpz.request.Request, *httpz.response.Response) anyerror!void)) void {
     router.post("/auth/register", register, .{});
@@ -39,7 +40,7 @@ fn login(_: *Handler.Handler, req: *httpz.Request, res: *httpz.Response) !void {
     const username = body.Username;
     const pwd = body.Password;
 
-    _ = db.Users.GetByCredentials(req.arena, username, pwd) catch |err| {
+    const user = db.Users.GetByCredentials(req.arena, username, pwd) catch |err| {
         if (err == db.ResultErrors.NotFound) {
             res.setStatus(.unauthorized);
             try res.json(errDesc.ErrorDescriptor {
@@ -50,5 +51,8 @@ fn login(_: *Handler.Handler, req: *httpz.Request, res: *httpz.Response) !void {
         return err;
     };
 
+    const token = try Tokens.GenerateNewSession(res.arena, user);
+    try res.json(.{ .Token = token } , .{});
+
     // TODO: add token here
 }
diff --git a/backend/src/Authentication/Tokens.zig b/backend/src/Authentication/Tokens.zig
new file mode 100644
index 0000000..6548ce7
--- /dev/null
+++ b/backend/src/Authentication/Tokens.zig
@@ -0,0 +1,42 @@
+const std = @import("std");
+const redis = @import("../Redis/Connection.zig");
+const userModel = @import("../Models/User.zig");
+
+const topicName = "cp2020_auth";
+const token_ttl: u16 = 43_200; // 12 hours
+
+var prng: std.Random.DefaultPrng= undefined;
+var rnd: std.Random = undefined;
+
+pub fn Init() !void {
+    // Random enough
+    var seed: u64 = undefined;
+    try std.posix.getrandom(std.mem.asBytes(&seed));
+    prng = std.Random.DefaultPrng.init(seed);
+    rnd = prng.random();
+}
+
+/// Generates a new token in the heap. Expects [64]u8 as an input 
+fn generateSessionToken(buf: []u8) []u8 {
+    for (0..64) |i| {
+        buf[i] = std.Random.intRangeAtMost(rnd, u8, 'A', 'z');
+    }
+    return buf;
+}
+
+pub fn GenerateNewSession(allocator: std.mem.Allocator, user: userModel.User) ![]u8 {
+    const token: []u8 = try allocator.alloc(u8, 64);
+    const newToken = generateSessionToken(token);
+
+    // Redis cache 
+    var string: std.io.Writer.Allocating = .init(allocator);
+    defer string.deinit();
+    try string.writer.print("{f}", .{std.json.fmt(user, .{})});
+    try redis.WriteToTopic(topicName, redis.Message {
+        .Key = token,
+        .Value = string.written(),
+        .SecondsToLive = token_ttl,
+    });
+
+    return newToken;
+}
diff --git a/backend/src/Redis/Connection.zig b/backend/src/Redis/Connection.zig
index 83adb2c..737d5cb 100644
--- a/backend/src/Redis/Connection.zig
+++ b/backend/src/Redis/Connection.zig
@@ -28,11 +28,15 @@ pub const Message = struct {
 };
 
 pub fn WriteToTopic(topic: []const u8, message: Message) !void {
-    _ = redis.redisCommand(connection, "SET %s:%s %s EX %d", 
-        topic.ptr,
-        message.Key.ptr,
-        message.Value.ptr,
+    const rep = redis.redisCommand(connection, "SET %b:%b %b EX %d", 
+        topic.ptr, topic.len,
+        message.Key.ptr, message.Key.len,
+        message.Value.ptr, message.Value.len,
         message.SecondsToLive); 
+
+    if (rep != null) {
+        redis.freeReplyObject(rep);
+    }
 }
 
 pub fn ReadFromTopic(topic: []const u8, Key: []const u8) ?[]const u8 {
@@ -42,6 +46,9 @@ pub fn ReadFromTopic(topic: []const u8, Key: []const u8) ?[]const u8 {
     if (raw == null) {
         return null;
     }
+    defer {
+        redis.freeReplyObject(raw);
+    }
     const resp: *redis.redisReply = @alignCast(@ptrCast(raw));
     if (resp.type != redis.REDIS_REPLY_STRING) {
         return null;
diff --git a/backend/src/main.zig b/backend/src/main.zig
index 6f9b21b..6fa8f56 100644
--- a/backend/src/main.zig
+++ b/backend/src/main.zig
@@ -3,11 +3,14 @@ const backend = @import("backend");
 const httpz = @import("httpz");
 const db = @import("Database/Connection.zig");
 const handler = @import("Handler.zig");
+const tokens = @import("Authentication/Tokens.zig");
 const redis = @import("Redis/Connection.zig");
 
 pub fn main() !void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     const allocator = gpa.allocator();
+
+    try tokens.Init();
    
     // PSQL connection
     try db.Connect(allocator);