/* * Copyright (C) 2026 Arthur SC Chan * * Copyright (C) secunet Security Networks AG * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. See . * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. */ #include #include #include /** * ECDSA256 private key (same as used in test_socket.c) */ static chunk_t ecdsa256 = chunk_from_chars( 0x30,0x77,0x02,0x01,0x01,0x04,0x20,0x2d,0x01,0x7e,0x5b,0x4a,0x7d,0x78,0xe9,0x23, 0xeb,0xb2,0xac,0x4c,0xf1,0x28,0x3b,0xfa,0x1d,0xa9,0x08,0x5c,0xd0,0x60,0x2a,0xa6, 0x54,0xd3,0x94,0xd4,0x05,0xa1,0x04,0xa0,0x0a,0x06,0x08,0x2a,0x86,0x48,0xce,0x3d, 0x03,0x01,0x07,0xa1,0x44,0x03,0x42,0x00,0x04,0x15,0x9c,0xbe,0xdb,0x54,0xa6,0xe7, 0x7f,0x76,0x05,0xa6,0x9d,0xf3,0x41,0x38,0x43,0x98,0xe9,0x0b,0x2b,0x8b,0x02,0xb4, 0x04,0x9b,0x61,0x84,0x65,0x63,0x3b,0x08,0xb2,0x4b,0x1e,0xd0,0x32,0x20,0xe9,0xfc, 0x62,0xa7,0xd0,0x71,0x9e,0xe9,0xf9,0x2d,0x91,0xb8,0xf2,0xa3,0x4d,0x8a,0x78,0xb2, 0x0b,0xfb,0x59,0x7c,0x40,0xbd,0xaf,0xa2,0x07 ); /** * TLS certificate for ECDSA256 key * pki --self --in ecdsa256.key --dn "C=CH, O=strongSwan, CN=tls-fuzz-ecdsa" --san server.test */ static chunk_t ecdsa256_crt = chunk_from_chars( 0x30,0x82,0x01,0x87,0x30,0x82,0x01,0x2C,0xA0,0x03,0x02,0x01,0x02,0x02,0x08,0x3D, 0x6D,0x48,0xA3,0x1F,0x8A,0x62,0x3E,0x30,0x0A,0x06,0x08,0x2A,0x86,0x48,0xCE,0x3D, 0x04,0x03,0x02,0x30,0x3B,0x31,0x0B,0x30,0x09,0x06,0x03,0x55,0x04,0x06,0x13,0x02, 0x43,0x48,0x31,0x13,0x30,0x11,0x06,0x03,0x55,0x04,0x0A,0x13,0x0A,0x73,0x74,0x72, 0x6F,0x6E,0x67,0x53,0x77,0x61,0x6E,0x31,0x17,0x30,0x15,0x06,0x03,0x55,0x04,0x03, 0x13,0x0E,0x74,0x6C,0x73,0x2D,0x66,0x75,0x7A,0x7A,0x2D,0x65,0x63,0x64,0x73,0x61, 0x30,0x1E,0x17,0x0D,0x32,0x36,0x30,0x35,0x32,0x39,0x30,0x38,0x33,0x38,0x33,0x36, 0x5A,0x17,0x0D,0x32,0x39,0x30,0x35,0x32,0x38,0x30,0x38,0x33,0x38,0x33,0x36,0x5A, 0x30,0x3B,0x31,0x0B,0x30,0x09,0x06,0x03,0x55,0x04,0x06,0x13,0x02,0x43,0x48,0x31, 0x13,0x30,0x11,0x06,0x03,0x55,0x04,0x0A,0x13,0x0A,0x73,0x74,0x72,0x6F,0x6E,0x67, 0x53,0x77,0x61,0x6E,0x31,0x17,0x30,0x15,0x06,0x03,0x55,0x04,0x03,0x13,0x0E,0x74, 0x6C,0x73,0x2D,0x66,0x75,0x7A,0x7A,0x2D,0x65,0x63,0x64,0x73,0x61,0x30,0x59,0x30, 0x13,0x06,0x07,0x2A,0x86,0x48,0xCE,0x3D,0x02,0x01,0x06,0x08,0x2A,0x86,0x48,0xCE, 0x3D,0x03,0x01,0x07,0x03,0x42,0x00,0x04,0x15,0x9C,0xBE,0xDB,0x54,0xA6,0xE7,0x7F, 0x76,0x05,0xA6,0x9D,0xF3,0x41,0x38,0x43,0x98,0xE9,0x0B,0x2B,0x8B,0x02,0xB4,0x04, 0x9B,0x61,0x84,0x65,0x63,0x3B,0x08,0xB2,0x4B,0x1E,0xD0,0x32,0x20,0xE9,0xFC,0x62, 0xA7,0xD0,0x71,0x9E,0xE9,0xF9,0x2D,0x91,0xB8,0xF2,0xA3,0x4D,0x8A,0x78,0xB2,0x0B, 0xFB,0x59,0x7C,0x40,0xBD,0xAF,0xA2,0x07,0xA3,0x1A,0x30,0x18,0x30,0x16,0x06,0x03, 0x55,0x1D,0x11,0x04,0x0F,0x30,0x0D,0x82,0x0B,0x73,0x65,0x72,0x76,0x65,0x72,0x2E, 0x74,0x65,0x73,0x74,0x30,0x0A,0x06,0x08,0x2A,0x86,0x48,0xCE,0x3D,0x04,0x03,0x02, 0x03,0x49,0x00,0x30,0x46,0x02,0x21,0x00,0xCB,0xD9,0x0D,0xC9,0x5C,0x68,0xF8,0x9D, 0x69,0x69,0xB3,0x73,0x33,0xE7,0x29,0x08,0x63,0x7D,0xDB,0x12,0x8E,0xB5,0x5F,0xBF, 0xEC,0xE7,0x81,0x95,0xC4,0x3F,0x7E,0xFA,0x02,0x21,0x00,0xB7,0x79,0xDA,0x0F,0xD1, 0x42,0x9C,0xC2,0xD1,0x32,0x03,0x2D,0xE5,0x55,0x22,0xD8,0x09,0xAC,0xA9,0x1B,0xA1, 0x0D,0x31,0xB8,0x24,0xEE,0xE3,0xE0,0xBF,0xBD,0x18,0xA5, ); /** * Credential set */ static mem_cred_t *creds; /** * Load the test certificate */ static void setup_cert() { private_key_t *key; certificate_t *cert; creds = mem_cred_create(); lib->credmgr->add_set(lib->credmgr, &creds->set); key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY, KEY_ANY, BUILD_BLOB, ecdsa256, BUILD_END); if (key) { creds->add_key(creds, key); } cert = lib->creds->create(lib->creds, CRED_CERTIFICATE, CERT_X509, BUILD_BLOB, ecdsa256_crt, BUILD_END); if (cert) { creds->add_cert(creds, TRUE, cert); } } /** * Minimal TLS application stub for fuzzing */ typedef struct { tls_application_t public; } fuzz_tls_application_t; static status_t app_process(tls_application_t *this, bio_reader_t *reader) { /* Consume application data without processing */ return NEED_MORE; } static status_t app_build(tls_application_t *this, bio_writer_t *writer) { /* No application data to send */ return INVALID_STATE; } static void app_destroy(tls_application_t *this) { free(this); } static tls_application_t *create_tls_application() { fuzz_tls_application_t *app; INIT(app, .public = { .process = app_process, .build = app_build, .destroy = app_destroy, }, ); return &app->public; } int LLVMFuzzerInitialize(int *argc, char ***argv) { dbg_default_set_level(-1); library_init(NULL, "fuzz_tls"); if (!lib->plugins->load(lib->plugins, PLUGINS)) { return 1; } setup_cert(); return 0; } int LLVMFuzzerTestOneInput(const uint8_t *buf, size_t len) { tls_t *tls; identification_t *server_id, *peer_id; tls_application_t *app; status_t status; char out[TLS_MAX_FRAGMENT_LEN + 2048]; size_t outlen, msglen; bool is_server; /* Need one role byte plus minimum TLS record header (5 bytes) */ if (len < 6) { return 0; } /* First byte selects role: input is then either a request (server) or * response (client) */ is_server = buf[0] & 1; buf++; len--; server_id = identification_create_from_string("server.test"); peer_id = identification_create_from_string("peer.test"); app = create_tls_application(); tls = tls_create(is_server, server_id, peer_id, TLS_PURPOSE_GENERIC, app, NULL, TLS_FLAG_ENCRYPTION_OPTIONAL); tls->set_version(tls, TLS_SUPPORTED_MIN, TLS_SUPPORTED_MAX); /* Client must emit ClientHello first so input is interpreted as the * server's reply */ if (!is_server) { do { outlen = sizeof(out); status = tls->build(tls, out, &outlen, &msglen); } while (status == NEED_MORE); } status = tls->process(tls, (void*)buf, len); /* Drive build() naturally based on process() status */ if (status == NEED_MORE) { do { outlen = sizeof(out); status = tls->build(tls, out, &outlen, &msglen); } while (status == NEED_MORE); } tls->destroy(tls); server_id->destroy(server_id); peer_id->destroy(peer_id); return 0; }