Initial project import

tools/v/vlib/veb/auth/auth.v

@@ -0,0 +1,93 @@
+// Copyright (c) 2019-2024 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module auth
+
+import rand
+import crypto.rand as crypto_rand
+import crypto.hmac
+import crypto.sha256
+
+const max_safe_unsigned_integer = u32(4_294_967_295)
+
+pub struct Auth[T] {
+	db T
+	// pub:
+	// salt string
+}
+
+pub struct Token {
+pub:
+	id      int @[primary; sql: serial]
+	user_id int
+	value   string
+	// ip      string
+}
+
+pub fn new[T](db T) Auth[T] {
+	set_rand_crypto_safe_seed()
+	sql db {
+		create table Token
+	} or { eprintln('veb.auth: failed to create table Token') }
+	return Auth[T]{
+		db: db
+		// salt: generate_salt()
+	}
+}
+
+// fn (mut app App) add_token(user_id int, ip string) !string {
+pub fn (mut app Auth[T]) add_token(user_id int) !string {
+	mut uuid := rand.uuid_v4()
+	token := Token{
+		user_id: user_id
+		value:   uuid
+		// ip: ip
+	}
+	sql app.db {
+		insert token into Token
+	}!
+	return uuid
+}
+
+pub fn (app &Auth[T]) find_token(value string) ?Token {
+	tokens := sql app.db {
+		select from Token where value == value limit 1
+	} or { []Token{} }
+	if tokens.len == 0 {
+		return none
+	}
+	return tokens.first()
+}
+
+pub fn (mut app Auth[T]) delete_tokens(user_id int) ! {
+	sql app.db {
+		delete from Token where user_id == user_id
+	}!
+}
+
+pub fn set_rand_crypto_safe_seed() {
+	first_seed := generate_crypto_safe_int_u32()
+	second_seed := generate_crypto_safe_int_u32()
+	rand.seed([first_seed, second_seed])
+}
+
+fn generate_crypto_safe_int_u32() u32 {
+	return u32(crypto_rand.int_u64(max_safe_unsigned_integer) or { 0 })
+}
+
+pub fn generate_salt() string {
+	return rand.i64().str()
+}
+
+pub fn hash_password_with_salt(plain_text_password string, salt string) string {
+	salted_password := '${plain_text_password}${salt}'
+	return sha256.sum(salted_password.bytes()).hex().str()
+}
+
+pub fn compare_password_with_hash(plain_text_password string, salt string, hashed string) bool {
+	digest := hash_password_with_salt(plain_text_password, salt)
+	// constant time comparison
+	// I know this is operating on the hex-encoded strings, but it's still constant time
+	// and better than not doing it at all
+	return hmac.equal(digest.bytes(), hashed.bytes())
+}