1 files changed, 43 insertions, 0 deletions

diff --git a/core/crypto/crypto_core.cpp b/core/crypto/crypto_core.cpp
index 9f000c5aeb..3cf7b6c310 100644
--- a/core/crypto/crypto_core.cpp
+++ b/core/crypto/crypto_core.cpp
@@ -30,12 +30,55 @@
 
 #include "crypto_core.h"
 
+#include "core/os/os.h"
+
 #include <mbedtls/aes.h>
 #include <mbedtls/base64.h>
+#include <mbedtls/ctr_drbg.h>
+#include <mbedtls/entropy.h>
 #include <mbedtls/md5.h>
 #include <mbedtls/sha1.h>
 #include <mbedtls/sha256.h>
 
+// RandomGenerator
+CryptoCore::RandomGenerator::RandomGenerator() {
+	entropy = memalloc(sizeof(mbedtls_entropy_context));
+	mbedtls_entropy_init((mbedtls_entropy_context *)entropy);
+	mbedtls_entropy_add_source((mbedtls_entropy_context *)entropy, &CryptoCore::RandomGenerator::_entropy_poll, nullptr, 256, MBEDTLS_ENTROPY_SOURCE_STRONG);
+	ctx = memalloc(sizeof(mbedtls_ctr_drbg_context));
+	mbedtls_ctr_drbg_init((mbedtls_ctr_drbg_context *)ctx);
+}
+
+CryptoCore::RandomGenerator::~RandomGenerator() {
+	mbedtls_ctr_drbg_free((mbedtls_ctr_drbg_context *)ctx);
+	memfree(ctx);
+	mbedtls_entropy_free((mbedtls_entropy_context *)entropy);
+	memfree(entropy);
+}
+
+int CryptoCore::RandomGenerator::_entropy_poll(void *p_data, unsigned char *r_buffer, size_t p_len, size_t *r_len) {
+	*r_len = 0;
+	Error err = OS::get_singleton()->get_entropy(r_buffer, p_len);
+	ERR_FAIL_COND_V(err, MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
+	*r_len = p_len;
+	return 0;
+}
+
+Error CryptoCore::RandomGenerator::init() {
+	int ret = mbedtls_ctr_drbg_seed((mbedtls_ctr_drbg_context *)ctx, mbedtls_entropy_func, (mbedtls_entropy_context *)entropy, nullptr, 0);
+	if (ret) {
+		ERR_FAIL_COND_V_MSG(ret, FAILED, " failed\n  ! mbedtls_ctr_drbg_seed returned an error" + itos(ret));
+	}
+	return OK;
+}
+
+Error CryptoCore::RandomGenerator::get_random_bytes(uint8_t *r_buffer, size_t p_bytes) {
+	ERR_FAIL_COND_V(!ctx, ERR_UNCONFIGURED);
+	int ret = mbedtls_ctr_drbg_random((mbedtls_ctr_drbg_context *)ctx, r_buffer, p_bytes);
+	ERR_FAIL_COND_V_MSG(ret, FAILED, " failed\n  ! mbedtls_ctr_drbg_seed returned an error" + itos(ret));
+	return OK;
+}
+
 // MD5
 CryptoCore::MD5Context::MD5Context() {
 	ctx = memalloc(sizeof(mbedtls_md5_context));