add encrypting for save files

add libhydrogen for encrypting and decrypting #9
2026-04-03 14:59:37 +02:00
parent abb6556fd4
commit c277ab10d9
68 changed files with 5737 additions and 74 deletions
@@ -0,0 +1,63 @@
+
+// Use hardware RNG peripheral
+// Working with HAL, LL Driver (untested)
+#if defined(STM32F4) || defined(STM32L4)
+
+#    if defined(STM32F4)
+#        include "stm32f4xx.h"
+#    elif defined(STM32L4)
+#        include "stm32l4xx_hal_rng.h"
+
+static RNG_HandleTypeDef RngHandle;
+#    endif
+
+static int
+hydro_random_init(void)
+{
+    const char       ctx[hydro_hash_CONTEXTBYTES] = { 'h', 'y', 'd', 'r', 'o', 'P', 'R', 'G' };
+    hydro_hash_state st;
+    uint16_t         ebits = 0;
+
+    __IO uint32_t tmpreg;
+
+#    if defined(STM32F4)
+    // Enable RNG clock source
+    SET_BIT(RCC->AHB2ENR, RCC_AHB2ENR_RNGEN);
+
+    // Delay after an RCC peripheral clock enabling
+    tmpreg = READ_BIT(RCC->AHB2ENR, RCC_AHB2ENR_RNGEN);
+    UNUSED(tmpreg);
+
+    // RNG Peripheral enable
+    SET_BIT(RNG->CR, RNG_CR_RNGEN);
+#    elif defined(STM32L4)
+    RngHandle.Instance = RNG;
+    HAL_RNG_Init(&RngHandle);
+#    endif
+
+    hydro_hash_init(&st, ctx, NULL);
+
+    while (ebits < 256) {
+        uint32_t r = 0;
+#    if defined(STM32F4)
+        while (!(READ_BIT(RNG->SR, RNG_SR_DRDY))) {
+        }
+
+        r = RNG->DR;
+#    elif defined(STM32L4)
+        if (HAL_RNG_GenerateRandomNumber(&RngHandle, &r) != HAL_OK) {
+            continue;
+        }
+#    endif
+        hydro_hash_update(&st, (const uint32_t *) &r, sizeof r);
+        ebits += 32;
+    }
+
+    hydro_hash_final(&st, hydro_random_context.state, sizeof hydro_random_context.state);
+    hydro_random_context.counter = ~LOAD64_LE(hydro_random_context.state);
+
+    return 0;
+}
+#else
+#    error SMT32 implementation missing!
+#endif