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-rw-r--r--src/cc20rng/cc20_prng.c124
-rw-r--r--src/cc20rng/cc20_prng.h21
-rw-r--r--src/cc20rng/main.c55
-rw-r--r--src/cc20rng/main.h4
-rw-r--r--src/cc20rng/stm32f4xx_it.h2
5 files changed, 104 insertions, 102 deletions
diff --git a/src/cc20rng/cc20_prng.c b/src/cc20rng/cc20_prng.c
index 50739bd..36c06a4 100644
--- a/src/cc20rng/cc20_prng.c
+++ b/src/cc20rng/cc20_prng.c
@@ -41,16 +41,16 @@
#define CHACHA20_CONSTANT3 0x6b206574
#ifdef CHACHA20_PRNG_DEBUG
-void _dump(struct cc20_state *cc, char *str);
+static void _dump(struct cc20_state *cc, char *str);
#endif
-inline uint32_t rotl32(uint32_t x, uint32_t n)
+static inline uint32_t rotl32(uint32_t x, uint32_t n)
{
return (x << n) | (x >> (32 - n));
}
-inline void _qr(struct cc20_state *cc, uint32_t a, uint32_t b, uint32_t c,
- uint32_t d)
+static inline void _qr(struct cc20_state *cc, uint32_t a, uint32_t b,
+ uint32_t c, uint32_t d)
{
cc->i[a] += cc->i[b];
cc->i[d] ^= cc->i[a];
@@ -69,44 +69,40 @@ inline void _qr(struct cc20_state *cc, uint32_t a, uint32_t b, uint32_t c,
cc->i[b] = rotl32(cc->i[b], 7);
}
-void chacha20_prng_reseed(struct cc20_state *cc, uint32_t *entropy)
+static void chacha20_setup(struct cc20_state *state,
+ const struct cc20_state *src)
{
- uint32_t i = 256 / 8 / 4;
- while (i--) {
- cc->i[i] = entropy[i];
- }
+ state->s.constant[0] = CHACHA20_CONSTANT0;
+ state->s.constant[1] = CHACHA20_CONSTANT1;
+ state->s.constant[2] = CHACHA20_CONSTANT2;
+ state->s.constant[3] = CHACHA20_CONSTANT3;
+
+ for (int i = 4; i < CHACHA20_BLOCK_SIZE_WORDS; i++)
+ state->i[i] = src->i[i];
}
-void chacha20_prng_block(struct cc20_state *cc, uint32_t block_counter,
- struct cc20_state *out)
+void chacha20_prng_block(struct cc20_state *cc, uint8_t *out)
{
uint32_t i;
+ struct cc20_state *ws = (struct cc20_state *)out;
- out->i[0] = CHACHA20_CONSTANT0;
- out->i[1] = CHACHA20_CONSTANT1;
- out->i[2] = CHACHA20_CONSTANT2;
- out->i[3] = CHACHA20_CONSTANT3;
-
- cc->i[12] = block_counter;
-
- for (i = 4; i < CHACHA20_NUM_WORDS; i++) {
- out->i[i] = cc->i[i];
- }
+ chacha20_setup(ws, cc);
for (i = 10; i; i--) {
- _qr(out, 0, 4, 8, 12);
- _qr(out, 1, 5, 9, 13);
- _qr(out, 2, 6, 10, 14);
- _qr(out, 3, 7, 11, 15);
- _qr(out, 0, 5, 10, 15);
- _qr(out, 1, 6, 11, 12);
- _qr(out, 2, 7, 8, 13);
- _qr(out, 3, 4, 9, 14);
+ _qr(ws, 0, 4, 8, 12);
+ _qr(ws, 1, 5, 9, 13);
+ _qr(ws, 2, 6, 10, 14);
+ _qr(ws, 3, 7, 11, 15);
+ _qr(ws, 0, 5, 10, 15);
+ _qr(ws, 1, 6, 11, 12);
+ _qr(ws, 2, 7, 8, 13);
+ _qr(ws, 3, 4, 9, 14);
}
- for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
- out->i[i] += cc->i[i];
- }
+ for (i = 0; i < CHACHA20_BLOCK_SIZE_WORDS; i++)
+ ws->i[i] += cc->i[i];
+
+ cc->s.counter--;
}
int chacha20_prng_self_test1()
@@ -115,16 +111,18 @@ int chacha20_prng_self_test1()
* https://tools.ietf.org/html/rfc7539#section-2.3.2
*/
struct cc20_state test = {
- {0x61707865, 0x3320646e, 0x79622d32, 0x6b206574,
- 0x03020100, 0x07060504, 0x0b0a0908, 0x0f0e0d0c,
- 0x13121110, 0x17161514, 0x1b1a1918, 0x1f1e1d1c,
- 0x00000001, 0x09000000, 0x4a000000, 0x00000000,
+ .i = {
+ 0x61707865, 0x3320646e, 0x79622d32, 0x6b206574,
+ 0x03020100, 0x07060504, 0x0b0a0908, 0x0f0e0d0c,
+ 0x13121110, 0x17161514, 0x1b1a1918, 0x1f1e1d1c,
+ 0x00000001, 0x09000000, 0x4a000000, 0x00000000,
}};
struct cc20_state expected = {
- {0xe4e7f110, 0x15593bd1, 0x1fdd0f50, 0xc47120a3,
- 0xc7f4d1c7, 0x0368c033, 0x9aaa2204, 0x4e6cd4c3,
- 0x466482d2, 0x09aa9f07, 0x05d7c214, 0xa2028bd9,
- 0xd19c12b5, 0xb94e16de, 0xe883d0cb, 0x4e3c50a2,
+ .i = {
+ 0xe4e7f110, 0x15593bd1, 0x1fdd0f50, 0xc47120a3,
+ 0xc7f4d1c7, 0x0368c033, 0x9aaa2204, 0x4e6cd4c3,
+ 0x466482d2, 0x09aa9f07, 0x05d7c214, 0xa2028bd9,
+ 0xd19c12b5, 0xb94e16de, 0xe883d0cb, 0x4e3c50a2,
}};
uint32_t i;
struct cc20_state out;
@@ -133,12 +131,13 @@ int chacha20_prng_self_test1()
_dump(&test, "Test vector from RFC7539, section 2.3.2. Input:");
#endif
- chacha20_prng_block(&test, 1, &out);
+ test.s.counter = 1; /* nop */
+ chacha20_prng_block(&test, (uint8_t *)&out);
#ifdef CHACHA20_PRNG_DEBUG
_dump(&out, "Test vector from RFC7539, section 2.3.2. Output:");
#endif
- for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
+ for (i = 0; i < CHACHA20_BLOCK_SIZE_WORDS; i++) {
if (out.i[i] != expected.i[i])
return 0;
}
@@ -152,22 +151,25 @@ int chacha20_prng_self_test2()
* https://tools.ietf.org/html/rfc7539#section-2.4.2
*/
struct cc20_state test = {
- {0x61707865, 0x3320646e, 0x79622d32, 0x6b206574,
- 0x03020100, 0x07060504, 0x0b0a0908, 0x0f0e0d0c,
- 0x13121110, 0x17161514, 0x1b1a1918, 0x1f1e1d1c,
- 0x00000001, 0x00000000, 0x4a000000, 0x00000000,
+ .i = {
+ 0x61707865, 0x3320646e, 0x79622d32, 0x6b206574,
+ 0x03020100, 0x07060504, 0x0b0a0908, 0x0f0e0d0c,
+ 0x13121110, 0x17161514, 0x1b1a1918, 0x1f1e1d1c,
+ 0x00000001, 0x00000000, 0x4a000000, 0x00000000,
}};
struct cc20_state expected1 = {
- {0xf3514f22, 0xe1d91b40, 0x6f27de2f, 0xed1d63b8,
- 0x821f138c, 0xe2062c3d, 0xecca4f7e, 0x78cff39e,
- 0xa30a3b8a, 0x920a6072, 0xcd7479b5, 0x34932bed,
- 0x40ba4c79, 0xcd343ec6, 0x4c2c21ea, 0xb7417df0,
+ .i = {
+ 0xf3514f22, 0xe1d91b40, 0x6f27de2f, 0xed1d63b8,
+ 0x821f138c, 0xe2062c3d, 0xecca4f7e, 0x78cff39e,
+ 0xa30a3b8a, 0x920a6072, 0xcd7479b5, 0x34932bed,
+ 0x40ba4c79, 0xcd343ec6, 0x4c2c21ea, 0xb7417df0,
}};
struct cc20_state expected2 = {
- {0x9f74a669, 0x410f633f, 0x28feca22, 0x7ec44dec,
- 0x6d34d426, 0x738cb970, 0x3ac5e9f3, 0x45590cc4,
- 0xda6e8b39, 0x892c831a, 0xcdea67c1, 0x2b7e1d90,
- 0x037463f3, 0xa11a2073, 0xe8bcfb88, 0xedc49139,
+ .i = {
+ 0x9f74a669, 0x410f633f, 0x28feca22, 0x7ec44dec,
+ 0x6d34d426, 0x738cb970, 0x3ac5e9f3, 0x45590cc4,
+ 0xda6e8b39, 0x892c831a, 0xcdea67c1, 0x2b7e1d90,
+ 0x037463f3, 0xa11a2073, 0xe8bcfb88, 0xedc49139,
}};
struct cc20_state out;
uint32_t i;
@@ -176,20 +178,22 @@ int chacha20_prng_self_test2()
_dump(&test, "Test vector from RFC7539, section 2.4.2. Input:");
#endif
- chacha20_prng_block(&test, 1, &out);
+ test.s.counter = 1; /* nop */
+ chacha20_prng_block(&test, (uint8_t *)&out);
#ifdef CHACHA20_PRNG_DEBUG
_dump(&out, "First block");
#endif
- for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
+ for (i = 0; i < CHACHA20_BLOCK_SIZE_WORDS; i++) {
if (out.i[i] != expected1.i[i])
return 0;
}
- chacha20_prng_block(&test, 2, &out);
+ test.s.counter = 2;
+ chacha20_prng_block(&test, (uint8_t *)&out);
#ifdef CHACHA20_PRNG_DEBUG
_dump(&out, "Second block");
#endif
- for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
+ for (i = 0; i < CHACHA20_BLOCK_SIZE_WORDS; i++) {
if (out.i[i] != expected2.i[i])
return 0;
}
@@ -213,8 +217,8 @@ void _dump(struct cc20_state *cc, char *str)
}
#endif
-/* Test vector from RFC, used as simple power-on self-test of ability to compute
- * a block correctly.
+/* Test vector from RFC7539, used as simple power-on self-test of
+ * ability to compute a block correctly.
*/
int chacha20_prng_self_test()
{
diff --git a/src/cc20rng/cc20_prng.h b/src/cc20rng/cc20_prng.h
index 7b597d0..08f78d7 100644
--- a/src/cc20rng/cc20_prng.h
+++ b/src/cc20rng/cc20_prng.h
@@ -3,17 +3,22 @@
#include <stdint.h>
-#define CHACHA20_MAX_BLOCK_COUNTER 0xffffffff
-#define CHACHA20_NUM_WORDS 16
-#define CHACHA20_BLOCK_SIZE (CHACHA20_NUM_WORDS * 4)
+#define CHACHA20_BLOCK_SIZE_WORDS 16
+#define CHACHA20_BLOCK_SIZE (CHACHA20_BLOCK_SIZE_WORDS * 4)
struct cc20_state {
- uint32_t i[CHACHA20_NUM_WORDS];
+ union {
+ struct {
+ uint32_t constant[4];
+ uint32_t key[8];
+ uint32_t counter;
+ uint32_t nonce[3];
+ } s;
+ uint32_t i[CHACHA20_BLOCK_SIZE_WORDS];
+ };
};
-extern void chacha20_prng_reseed(struct cc20_state *cc, uint32_t *entropy);
-extern void chacha20_prng_block(struct cc20_state *cc, uint32_t block_counter,
- struct cc20_state *out);
-extern int chacha20_prng_self_test();
+void chacha20_prng_block(struct cc20_state *cc, uint8_t *out);
+int chacha20_prng_self_test();
#endif /* __STM32_CHACHA20_H */
diff --git a/src/cc20rng/main.c b/src/cc20rng/main.c
index 88b5144..cc063f4 100644
--- a/src/cc20rng/main.c
+++ b/src/cc20rng/main.c
@@ -1,5 +1,6 @@
/*
* Copyright (c) 2014, 2015, 2016 NORDUnet A/S
+ * Copyright (c) 2019 Sunet
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
@@ -32,7 +33,6 @@
#include <string.h>
#include "cc20_prng.h"
-#include "main.h"
#include "stm_init.h"
#define UART_RANDOM_BYTES_PER_CHUNK 8
@@ -79,13 +79,14 @@ static inline volatile uint32_t *get_DMA_read_buf(void);
static inline uint32_t safe_get_counter(volatile uint32_t *dmabuf,
const uint32_t dmabuf_idx);
static void check_uart_rx(UART_HandleTypeDef *this);
-static void cc_reseed(struct cc20_state *cc);
+static uint32_t cc_reseed(struct cc20_state *cc);
void Error_Handler(void);
int main() {
- uint32_t i, timeout, block_counter = 0;
- struct cc20_state cc, out;
+ uint32_t i, timeout, block_counter;
+ struct cc20_state cc_state = {0};
+ uint8_t cc_result[CHACHA20_BLOCK_SIZE];
HAL_StatusTypeDef res;
/* Initialize buffers */
@@ -113,40 +114,32 @@ int main() {
HAL_Delay(125);
}
- /* Generate initial block of random data directly into buf */
- cc_reseed(&cc);
- block_counter = RESEED_BLOCKS;
- chacha20_prng_block(&cc, block_counter--, (struct cc20_state *)buf.rnd32);
+ /* Generate initial block of ChaCha20 output directly into buf. */
+ block_counter = cc_reseed(&cc_state);
+ chacha20_prng_block(&cc_state, buf.rnd);
+ block_counter--;
/* Main loop */
while (1) {
- if (!(block_counter % 1000)) {
+ if (!(block_counter % 1000))
HAL_GPIO_TogglePin(LED_PORT, LED_YELLOW);
- }
-
- if (!block_counter) {
- cc_reseed(&cc);
- block_counter = RESEED_BLOCKS;
- }
/* Send buf on UART (non blocking interrupt driven send). */
UartReady = RESET;
- res = HAL_UART_Transmit_IT(huart, &buf.rnd[0], CHACHA20_BLOCK_SIZE);
+ res = HAL_UART_Transmit_IT(huart, buf.rnd, CHACHA20_BLOCK_SIZE);
/* Generate next block while this block is being transmitted */
- chacha20_prng_block(&cc, block_counter--, &out);
- /* Copying using a loop is faster than memcpy on STM32 */
- for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
- buf.rnd32[i] = out.i[i];
- }
+ if (!block_counter)
+ block_counter = cc_reseed(&cc_state);
+ chacha20_prng_block(&cc_state, cc_result);
+ block_counter--;
+ /* Wait for transfer to complete. */
if (res == HAL_OK) {
timeout = 0xffff;
- while (UartReady != SET && timeout) {
+ while (UartReady != SET && timeout)
timeout--;
- }
}
-
if (UartReady != SET) {
/* Failed to send, turn on RED LED for one second */
HAL_GPIO_WritePin(LED_PORT, LED_RED, GPIO_PIN_SET);
@@ -154,6 +147,10 @@ int main() {
HAL_GPIO_WritePin(LED_PORT, LED_RED, GPIO_PIN_RESET);
}
+ /* Fill buffer with ChaCha20 output. */
+ for (i = 0; i < CHACHA20_BLOCK_SIZE; i++)
+ buf.rnd[i] = cc_result[i];
+
/* Check for UART change request */
check_uart_rx(&huart1);
check_uart_rx(&huart2);
@@ -163,16 +160,18 @@ int main() {
/**
* @brief Reseed chacha20 state with hardware generated entropy.
* @param cc: ChaCha20 state
- * @retval None
+ * @retval ChaCha20 block counter
*/
-static void cc_reseed(struct cc20_state *cc) {
+static uint32_t cc_reseed(struct cc20_state *cc) {
HAL_GPIO_WritePin(LED_PORT, LED_BLUE, GPIO_PIN_SET);
- get_entropy32(CHACHA20_BLOCK_SIZE / 4, 0);
+ get_entropy32(CHACHA20_BLOCK_SIZE_WORDS, 0);
restart_DMA();
- chacha20_prng_reseed(cc, (uint32_t *)&buf);
+ memcpy(cc, buf.rnd, CHACHA20_BLOCK_SIZE);
HAL_GPIO_WritePin(LED_PORT, LED_BLUE, GPIO_PIN_RESET);
+
+ return cc->s.counter;
}
/**
diff --git a/src/cc20rng/main.h b/src/cc20rng/main.h
deleted file mode 100644
index 902ecf4..0000000
--- a/src/cc20rng/main.h
+++ /dev/null
@@ -1,4 +0,0 @@
-#ifndef __MAIN_H
-#define __MAIN_H
-
-#endif /* __MAIN_H */
diff --git a/src/cc20rng/stm32f4xx_it.h b/src/cc20rng/stm32f4xx_it.h
index 04c5a36..6edba3c 100644
--- a/src/cc20rng/stm32f4xx_it.h
+++ b/src/cc20rng/stm32f4xx_it.h
@@ -44,8 +44,6 @@
#endif
/* Includes ------------------------------------------------------------------*/
-#include "main.h"
-
/* Exported types ------------------------------------------------------------*/
/* Exported constants --------------------------------------------------------*/
/* Exported macro ------------------------------------------------------------*/
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 18:07:47 +0000