mbedTLS: Update to new LTS v3.6.0

Keep module compatibility with mbedtls 2.x (old LTS branch).

A patch has been added to allow compiling after removing all the `psa_*`
files from the library folder (will look into upstreaming it).

Note: mbedTLS 3.6 finally enabled TLSv1.3 by default, but it requires
some module changes, and to enable PSA crypto (new "standard" API
specification), so it might be best done in a separate commit/PR.

4 files changed, 60 insertions, 21 deletions

diff --git a/modules/mbedtls/SCsub b/modules/mbedtls/SCsub
index 04d26f9942..90ce98c751 100644
--- a/modules/mbedtls/SCsub
+++ b/modules/mbedtls/SCsub
@@ -12,24 +12,24 @@ thirdparty_obj = []
 if env["builtin_mbedtls"]:
     thirdparty_sources = [
         "aes.c",
+        "aesce.c",
         "aesni.c",
-        "arc4.c",
         "aria.c",
         "asn1parse.c",
         "asn1write.c",
         "base64.c",
         "bignum.c",
-        "blowfish.c",
+        "bignum_core.c",
+        "bignum_mod_raw.c",
         "camellia.c",
         "ccm.c",
-        "certs.c",
         "chacha20.c",
         "chachapoly.c",
         "cipher.c",
         "cipher_wrap.c",
         "cmac.c",
-        "ctr_drbg.c",
         "constant_time.c",
+        "ctr_drbg.c",
         "debug.c",
         "des.c",
         "dhm.c",
@@ -42,13 +42,10 @@ if env["builtin_mbedtls"]:
         "entropy_poll.c",
         "error.c",
         "gcm.c",
-        "havege.c",
         "hkdf.c",
         "hmac_drbg.c",
-        "md2.c",
-        "md4.c",
-        "md5.c",
         "md.c",
+        "md5.c",
         "memory_buffer_alloc.c",
         "mps_reader.c",
         "mps_trace.c",
@@ -58,30 +55,37 @@ if env["builtin_mbedtls"]:
         "padlock.c",
         "pem.c",
         "pk.c",
-        "pkcs11.c",
+        "pk_ecc.c",
+        "pk_wrap.c",
         "pkcs12.c",
         "pkcs5.c",
+        "pkcs7.c",
         "pkparse.c",
-        "pk_wrap.c",
         "pkwrite.c",
         "platform.c",
         "platform_util.c",
         "poly1305.c",
         "ripemd160.c",
         "rsa.c",
-        "rsa_internal.c",
+        "rsa_alt_helpers.c",
         "sha1.c",
+        "sha3.c",
         "sha256.c",
         "sha512.c",
         "ssl_cache.c",
         "ssl_ciphersuites.c",
-        "ssl_cli.c",
+        "ssl_client.c",
         "ssl_cookie.c",
+        "ssl_debug_helpers_generated.c",
         "ssl_msg.c",
-        "ssl_srv.c",
         "ssl_ticket.c",
         "ssl_tls.c",
+        "ssl_tls12_client.c",
+        "ssl_tls12_server.c",
+        "ssl_tls13_client.c",
+        "ssl_tls13_generic.c",
         "ssl_tls13_keys.c",
+        "ssl_tls13_server.c",
         "threading.c",
         "timing.c",
         "version.c",
@@ -91,9 +95,9 @@ if env["builtin_mbedtls"]:
         "x509_crl.c",
         "x509_crt.c",
         "x509_csr.c",
+        "x509write.c",
         "x509write_crt.c",
         "x509write_csr.c",
-        "xtea.c",
     ]
 
     thirdparty_dir = "#thirdparty/mbedtls/library/"
diff --git a/modules/mbedtls/crypto_mbedtls.cpp b/modules/mbedtls/crypto_mbedtls.cpp
index 859278d65e..e910627b32 100644
--- a/modules/mbedtls/crypto_mbedtls.cpp
+++ b/modules/mbedtls/crypto_mbedtls.cpp
@@ -69,7 +69,7 @@ Error CryptoKeyMbedTLS::load(const String &p_path, bool p_public_only) {
 	if (p_public_only) {
 		ret = mbedtls_pk_parse_public_key(&pkey, out.ptr(), out.size());
 	} else {
-		ret = mbedtls_pk_parse_key(&pkey, out.ptr(), out.size(), nullptr, 0);
+		ret = _parse_key(out.ptr(), out.size());
 	}
 	// We MUST zeroize the memory for safety!
 	mbedtls_platform_zeroize(out.ptrw(), out.size());
@@ -108,7 +108,7 @@ Error CryptoKeyMbedTLS::load_from_string(const String &p_string_key, bool p_publ
 	if (p_public_only) {
 		ret = mbedtls_pk_parse_public_key(&pkey, (unsigned char *)p_string_key.utf8().get_data(), p_string_key.utf8().size());
 	} else {
-		ret = mbedtls_pk_parse_key(&pkey, (unsigned char *)p_string_key.utf8().get_data(), p_string_key.utf8().size(), nullptr, 0);
+		ret = _parse_key((unsigned char *)p_string_key.utf8().get_data(), p_string_key.utf8().size());
 	}
 	ERR_FAIL_COND_V_MSG(ret, FAILED, "Error parsing key '" + itos(ret) + "'.");
 
@@ -134,6 +134,25 @@ String CryptoKeyMbedTLS::save_to_string(bool p_public_only) {
 	return s;
 }
 
+int CryptoKeyMbedTLS::_parse_key(const uint8_t *p_buf, int p_size) {
+#if MBEDTLS_VERSION_MAJOR >= 3
+	mbedtls_entropy_context rng_entropy;
+	mbedtls_ctr_drbg_context rng_drbg;
+
+	mbedtls_ctr_drbg_init(&rng_drbg);
+	mbedtls_entropy_init(&rng_entropy);
+	int ret = mbedtls_ctr_drbg_seed(&rng_drbg, mbedtls_entropy_func, &rng_entropy, nullptr, 0);
+	ERR_FAIL_COND_V_MSG(ret != 0, ret, vformat("mbedtls_ctr_drbg_seed returned -0x%x\n", (unsigned int)-ret));
+
+	ret = mbedtls_pk_parse_key(&pkey, p_buf, p_size, nullptr, 0, mbedtls_ctr_drbg_random, &rng_drbg);
+	mbedtls_ctr_drbg_free(&rng_drbg);
+	mbedtls_entropy_free(&rng_entropy);
+	return ret;
+#else
+	return mbedtls_pk_parse_key(&pkey, p_buf, p_size, nullptr, 0);
+#endif
+}
+
 X509Certificate *X509CertificateMbedTLS::create() {
 	return memnew(X509CertificateMbedTLS);
 }
@@ -393,12 +412,17 @@ Ref<X509Certificate> CryptoMbedTLS::generate_self_signed_certificate(Ref<CryptoK
 	mbedtls_x509write_crt_set_version(&crt, MBEDTLS_X509_CRT_VERSION_3);
 	mbedtls_x509write_crt_set_md_alg(&crt, MBEDTLS_MD_SHA256);
 
+	uint8_t rand_serial[20];
+	mbedtls_ctr_drbg_random(&ctr_drbg, rand_serial, sizeof(rand_serial));
+
+#if MBEDTLS_VERSION_MAJOR >= 3
+	mbedtls_x509write_crt_set_serial_raw(&crt, rand_serial, sizeof(rand_serial));
+#else
 	mbedtls_mpi serial;
 	mbedtls_mpi_init(&serial);
-	uint8_t rand_serial[20];
-	mbedtls_ctr_drbg_random(&ctr_drbg, rand_serial, 20);
-	ERR_FAIL_COND_V(mbedtls_mpi_read_binary(&serial, rand_serial, 20), nullptr);
+	ERR_FAIL_COND_V(mbedtls_mpi_read_binary(&serial, rand_serial, sizeof(rand_serial)), nullptr);
 	mbedtls_x509write_crt_set_serial(&crt, &serial);
+#endif
 
 	mbedtls_x509write_crt_set_validity(&crt, p_not_before.utf8().get_data(), p_not_after.utf8().get_data());
 	mbedtls_x509write_crt_set_basic_constraints(&crt, 1, -1);
@@ -407,7 +431,9 @@ Ref<X509Certificate> CryptoMbedTLS::generate_self_signed_certificate(Ref<CryptoK
 	unsigned char buf[4096];
 	memset(buf, 0, 4096);
 	int ret = mbedtls_x509write_crt_pem(&crt, buf, 4096, mbedtls_ctr_drbg_random, &ctr_drbg);
+#if MBEDTLS_VERSION_MAJOR < 3
 	mbedtls_mpi_free(&serial);
+#endif
 	mbedtls_x509write_crt_free(&crt);
 	ERR_FAIL_COND_V_MSG(ret != 0, nullptr, "Failed to generate certificate: " + itos(ret));
 	buf[4095] = '\0'; // Make sure strlen can't fail.
@@ -461,9 +487,17 @@ Vector<uint8_t> CryptoMbedTLS::sign(HashingContext::HashType p_hash_type, const
 	ERR_FAIL_COND_V_MSG(!key.is_valid(), Vector<uint8_t>(), "Invalid key provided.");
 	ERR_FAIL_COND_V_MSG(key->is_public_only(), Vector<uint8_t>(), "Invalid key provided. Cannot sign with public_only keys.");
 	size_t sig_size = 0;
+#if MBEDTLS_VERSION_MAJOR >= 3
+	unsigned char buf[MBEDTLS_PK_SIGNATURE_MAX_SIZE];
+#else
 	unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
+#endif
 	Vector<uint8_t> out;
-	int ret = mbedtls_pk_sign(&(key->pkey), type, p_hash.ptr(), size, buf, &sig_size, mbedtls_ctr_drbg_random, &ctr_drbg);
+	int ret = mbedtls_pk_sign(&(key->pkey), type, p_hash.ptr(), size, buf,
+#if MBEDTLS_VERSION_MAJOR >= 3
+			sizeof(buf),
+#endif
+			&sig_size, mbedtls_ctr_drbg_random, &ctr_drbg);
 	ERR_FAIL_COND_V_MSG(ret, out, "Error while signing: " + itos(ret));
 	out.resize(sig_size);
 	memcpy(out.ptrw(), buf, sig_size);
diff --git a/modules/mbedtls/crypto_mbedtls.h b/modules/mbedtls/crypto_mbedtls.h
index 60a413ed7c..52918cedf0 100644
--- a/modules/mbedtls/crypto_mbedtls.h
+++ b/modules/mbedtls/crypto_mbedtls.h
@@ -46,6 +46,8 @@ private:
 	int locks = 0;
 	bool public_only = true;
 
+	int _parse_key(const uint8_t *p_buf, int p_size);
+
 public:
 	static CryptoKey *create();
 	static void make_default() { CryptoKey::_create = create; }
diff --git a/modules/mbedtls/tls_context_mbedtls.h b/modules/mbedtls/tls_context_mbedtls.h
index 29323688fb..b8a9e80b9f 100644
--- a/modules/mbedtls/tls_context_mbedtls.h
+++ b/modules/mbedtls/tls_context_mbedtls.h
@@ -36,7 +36,6 @@
 #include "core/io/file_access.h"
 #include "core/object/ref_counted.h"
 
-#include <mbedtls/config.h>
 #include <mbedtls/ctr_drbg.h>
 #include <mbedtls/debug.h>
 #include <mbedtls/entropy.h>