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-rw-r--r--src/cc20rng/.clang-format4
-rw-r--r--src/cc20rng/Makefile4
-rw-r--r--src/cc20rng/cc20_prng.c87
-rw-r--r--src/cc20rng/cc20_prng.h9
-rw-r--r--src/cc20rng/main.c118
5 files changed, 111 insertions, 111 deletions
diff --git a/src/cc20rng/.clang-format b/src/cc20rng/.clang-format
new file mode 100644
index 0000000..8367454
--- /dev/null
+++ b/src/cc20rng/.clang-format
@@ -0,0 +1,4 @@
+IndentWidth: 4
+BreakBeforeBraces: Custom
+BraceWrapping:
+ AfterFunction: true
diff --git a/src/cc20rng/Makefile b/src/cc20rng/Makefile
index 2873505..6c274be 100644
--- a/src/cc20rng/Makefile
+++ b/src/cc20rng/Makefile
@@ -29,6 +29,10 @@ $(PROJ_NAME).elf: $(SRCS)
$(OBJDUMP) -St $(PROJ_NAME).elf >$(PROJ_NAME).lst
$(SIZE) $(PROJ_NAME).elf
+c-format:
+ clang-format-4.0 -i cc20_prng.[ch]
+ clang-format-4.0 -style="{IndentWidth: 2}" -i main.c
+
clean:
find ./ -name '*~' | xargs rm -f
rm -f *.o
diff --git a/src/cc20rng/cc20_prng.c b/src/cc20rng/cc20_prng.c
index 3d52fc6..50739bd 100644
--- a/src/cc20rng/cc20_prng.c
+++ b/src/cc20rng/cc20_prng.c
@@ -44,12 +44,13 @@
void _dump(struct cc20_state *cc, char *str);
#endif
-inline uint32_t rotl32 (uint32_t x, uint32_t n)
+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)
+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];
@@ -72,11 +73,12 @@ void chacha20_prng_reseed(struct cc20_state *cc, uint32_t *entropy)
{
uint32_t i = 256 / 8 / 4;
while (i--) {
- cc->i[i] = entropy[i];
+ cc->i[i] = entropy[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, uint32_t block_counter,
+ struct cc20_state *out)
{
uint32_t i;
@@ -88,22 +90,22 @@ void chacha20_prng_block(struct cc20_state *cc, uint32_t block_counter, struct c
cc->i[12] = block_counter;
for (i = 4; i < CHACHA20_NUM_WORDS; i++) {
- out->i[i] = cc->i[i];
+ out->i[i] = cc->i[i];
}
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(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);
}
for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
- out->i[i] += cc->i[i];
+ out->i[i] += cc->i[i];
}
}
@@ -119,11 +121,11 @@ int chacha20_prng_self_test1()
0x00000001, 0x09000000, 0x4a000000, 0x00000000,
}};
struct cc20_state expected = {
- {0xe4e7f110, 0x15593bd1, 0x1fdd0f50, 0xc47120a3,
- 0xc7f4d1c7, 0x0368c033, 0x9aaa2204, 0x4e6cd4c3,
- 0x466482d2, 0x09aa9f07, 0x05d7c214, 0xa2028bd9,
- 0xd19c12b5, 0xb94e16de, 0xe883d0cb, 0x4e3c50a2,
- }};
+ {0xe4e7f110, 0x15593bd1, 0x1fdd0f50, 0xc47120a3,
+ 0xc7f4d1c7, 0x0368c033, 0x9aaa2204, 0x4e6cd4c3,
+ 0x466482d2, 0x09aa9f07, 0x05d7c214, 0xa2028bd9,
+ 0xd19c12b5, 0xb94e16de, 0xe883d0cb, 0x4e3c50a2,
+ }};
uint32_t i;
struct cc20_state out;
@@ -137,7 +139,8 @@ int chacha20_prng_self_test1()
#endif
for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
- if (out.i[i] != expected.i[i]) return 0;
+ if (out.i[i] != expected.i[i])
+ return 0;
}
return 1;
@@ -149,23 +152,23 @@ 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,
- }};
+ {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,
- }};
+ {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,
- }};
+ {0x9f74a669, 0x410f633f, 0x28feca22, 0x7ec44dec,
+ 0x6d34d426, 0x738cb970, 0x3ac5e9f3, 0x45590cc4,
+ 0xda6e8b39, 0x892c831a, 0xcdea67c1, 0x2b7e1d90,
+ 0x037463f3, 0xa11a2073, 0xe8bcfb88, 0xedc49139,
+ }};
struct cc20_state out;
uint32_t i;
@@ -178,7 +181,8 @@ int chacha20_prng_self_test2()
_dump(&out, "First block");
#endif
for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
- if (out.i[i] != expected1.i[i]) return 0;
+ if (out.i[i] != expected1.i[i])
+ return 0;
}
chacha20_prng_block(&test, 2, &out);
@@ -186,7 +190,8 @@ int chacha20_prng_self_test2()
_dump(&out, "Second block");
#endif
for (i = 0; i < CHACHA20_NUM_WORDS; i++) {
- if (out.i[i] != expected2.i[i]) return 0;
+ if (out.i[i] != expected2.i[i])
+ return 0;
}
return 1;
@@ -201,8 +206,8 @@ void _dump(struct cc20_state *cc, char *str)
printf("%s\n", str);
for (i = 0; i < 4; i++) {
- printf("%02i %08x %08x %08x %08x\n", i * 4, cc->i[i * 4 + 0],
- cc->i[i * 4 + 1], cc->i[i * 4 + 2], cc->i[i * 4 + 3]);
+ printf("%02i %08x %08x %08x %08x\n", i * 4, cc->i[i * 4 + 0],
+ cc->i[i * 4 + 1], cc->i[i * 4 + 2], cc->i[i * 4 + 3]);
}
printf("\n");
}
@@ -213,7 +218,5 @@ void _dump(struct cc20_state *cc, char *str)
*/
int chacha20_prng_self_test()
{
- return \
- chacha20_prng_self_test1() && \
- chacha20_prng_self_test2();
+ return chacha20_prng_self_test1() && chacha20_prng_self_test2();
}
diff --git a/src/cc20rng/cc20_prng.h b/src/cc20rng/cc20_prng.h
index 6940f53..7b597d0 100644
--- a/src/cc20rng/cc20_prng.h
+++ b/src/cc20rng/cc20_prng.h
@@ -3,16 +3,17 @@
#include <stdint.h>
-#define CHACHA20_MAX_BLOCK_COUNTER 0xffffffff
-#define CHACHA20_NUM_WORDS 16
-#define CHACHA20_BLOCK_SIZE (CHACHA20_NUM_WORDS * 4)
+#define CHACHA20_MAX_BLOCK_COUNTER 0xffffffff
+#define CHACHA20_NUM_WORDS 16
+#define CHACHA20_BLOCK_SIZE (CHACHA20_NUM_WORDS * 4)
struct cc20_state {
uint32_t i[CHACHA20_NUM_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 void chacha20_prng_block(struct cc20_state *cc, uint32_t block_counter,
+ struct cc20_state *out);
extern int chacha20_prng_self_test();
#endif /* __STM32_CHACHA20_H */
diff --git a/src/cc20rng/main.c b/src/cc20rng/main.c
index e478409..88b5144 100644
--- a/src/cc20rng/main.c
+++ b/src/cc20rng/main.c
@@ -31,12 +31,12 @@
*/
#include <string.h>
+#include "cc20_prng.h"
#include "main.h"
#include "stm_init.h"
-#include "cc20_prng.h"
-#define UART_RANDOM_BYTES_PER_CHUNK 8
-#define RESEED_BLOCKS CHACHA20_MAX_BLOCK_COUNTER
+#define UART_RANDOM_BYTES_PER_CHUNK 8
+#define RESEED_BLOCKS CHACHA20_MAX_BLOCK_COUNTER
extern DMA_HandleTypeDef hdma_tim;
@@ -44,19 +44,22 @@ static UART_HandleTypeDef *huart;
static __IO ITStatus UartReady = RESET;
static union {
- uint8_t rnd[257]; /* 256 bytes + 1 for use in the POST */
+ uint8_t rnd[257]; /* 256 bytes + 1 for use in the POST */
uint32_t rnd32[64];
} buf;
-/* First DMA value (DMA_counters[0]) is unreliable, leftover in DMA FIFO perhaps? */
-#define FIRST_DMA_IDX_USED 3
+/* First DMA value (DMA_counters[0]) is unreliable, leftover in DMA FIFO
+ * perhaps? */
+#define FIRST_DMA_IDX_USED 3
/*
* Number of counters used to produce 8 bits of entropy is:
- * 8 * 4 - four flanks are used to produce two (hopefully) uncorrelated bits (a and b)
+ * 8 * 4 - four flanks are used to produce two (hopefully) uncorrelated bits
+ * (a and b)
* * 2 - von Neumann will on average discard 1/2 of the bits 'a' and 'b'
*/
-#define DMA_COUNTERS_NUM ((UART_RANDOM_BYTES_PER_CHUNK * 8 * 4 * 2) + FIRST_DMA_IDX_USED + 1)
+#define DMA_COUNTERS_NUM \
+ ((UART_RANDOM_BYTES_PER_CHUNK * 8 * 4 * 2) + FIRST_DMA_IDX_USED + 1)
struct DMA_params {
volatile uint32_t buf0[DMA_COUNTERS_NUM];
volatile uint32_t buf1[DMA_COUNTERS_NUM];
@@ -64,28 +67,23 @@ struct DMA_params {
};
static struct DMA_params DMA = {
- {},
- {},
- 0,
+ {}, {}, 0,
};
-
/* The main work horse functions */
static void get_entropy32(uint32_t num_bytes, uint32_t buf_idx);
/* Various support functions */
static inline uint32_t get_one_bit(void) __attribute__((__always_inline__));
static volatile uint32_t *restart_DMA(void);
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 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);
void Error_Handler(void);
-
-int
-main()
-{
+int main() {
uint32_t i, timeout, block_counter = 0;
struct cc20_state cc, out;
HAL_StatusTypeDef res;
@@ -97,10 +95,10 @@ main()
DMA.buf1[i] = 0xffff0100 + i;
}
- stm_init((uint32_t *) &DMA.buf0, DMA_COUNTERS_NUM);
+ stm_init((uint32_t *)&DMA.buf0, DMA_COUNTERS_NUM);
- if (! chacha20_prng_self_test()) {
- Error_Handler();
+ if (!chacha20_prng_self_test()) {
+ Error_Handler();
}
/* Ensure there is actual Timer IC counters in both DMA buffers. */
@@ -110,29 +108,25 @@ main()
huart = &huart1;
/* Toggle GREEN LED to show we've initialized */
- {
- for (i = 0; i < 10; i++) {
- HAL_GPIO_TogglePin(LED_PORT, LED_GREEN);
- HAL_Delay(125);
- }
+ for (i = 0; i < 10; i++) {
+ HAL_GPIO_TogglePin(LED_PORT, LED_GREEN);
+ 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);
+ chacha20_prng_block(&cc, block_counter--, (struct cc20_state *)buf.rnd32);
- /*
- * Main loop
- */
+ /* 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;
+ if (!block_counter) {
+ cc_reseed(&cc);
+ block_counter = RESEED_BLOCKS;
}
/* Send buf on UART (non blocking interrupt driven send). */
@@ -143,12 +137,14 @@ main()
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];
+ buf.rnd32[i] = out.i[i];
}
if (res == HAL_OK) {
timeout = 0xffff;
- while (UartReady != SET && timeout) { timeout--; }
+ while (UartReady != SET && timeout) {
+ timeout--;
+ }
}
if (UartReady != SET) {
@@ -164,22 +160,19 @@ main()
}
}
-
/**
* @brief Reseed chacha20 state with hardware generated entropy.
* @param cc: ChaCha20 state
* @retval None
*/
-static void
-cc_reseed(struct cc20_state *cc)
-{
- HAL_GPIO_WritePin(LED_PORT, LED_BLUE, GPIO_PIN_SET);
+static void cc_reseed(struct cc20_state *cc) {
+ HAL_GPIO_WritePin(LED_PORT, LED_BLUE, GPIO_PIN_SET);
- get_entropy32(CHACHA20_BLOCK_SIZE / 4, 0);
- restart_DMA();
- chacha20_prng_reseed(cc, (uint32_t *) &buf);
+ get_entropy32(CHACHA20_BLOCK_SIZE / 4, 0);
+ restart_DMA();
+ chacha20_prng_reseed(cc, (uint32_t *)&buf);
- HAL_GPIO_WritePin(LED_PORT, LED_BLUE, GPIO_PIN_RESET);
+ HAL_GPIO_WritePin(LED_PORT, LED_BLUE, GPIO_PIN_RESET);
}
/**
@@ -188,16 +181,14 @@ cc_reseed(struct cc20_state *cc)
* @param start: Start index value into buf.rnd32.
* @retval None
*/
-static inline void get_entropy32(uint32_t count, const uint32_t start)
-{
+static inline void get_entropy32(uint32_t count, const uint32_t start) {
uint32_t i, bits, buf_idx;
buf_idx = start;
do {
bits = 0;
- /* Get 32 bits of entropy.
- */
+ /* Get 32 bits of entropy. */
for (i = 32; i; i--) {
bits <<= 1;
bits += get_one_bit();
@@ -213,8 +204,7 @@ static inline void get_entropy32(uint32_t count, const uint32_t start)
* @param None
* @retval One bit, in the LSB of an uint32_t since this is a 32 bit MCU.
*/
-static inline uint32_t get_one_bit()
-{
+static inline uint32_t get_one_bit() {
register uint32_t a, b, temp;
/* Start at end of buffer so restart_DMA() is called. */
static uint32_t dmabuf_idx = DMA_COUNTERS_NUM - 1;
@@ -264,8 +254,7 @@ static inline uint32_t get_one_bit()
* @param None
* @retval Pointer to buffer currently being read from.
*/
-static inline volatile uint32_t *get_DMA_read_buf(void)
-{
+static inline volatile uint32_t *get_DMA_read_buf(void) {
return DMA.write_buf ? DMA.buf0 : DMA.buf1;
}
@@ -274,8 +263,7 @@ static inline volatile uint32_t *get_DMA_read_buf(void)
* @param None
* @retval Pointer to buffer currently being written to.
*/
-static inline volatile uint32_t *get_DMA_write_buf(void)
-{
+static inline volatile uint32_t *get_DMA_write_buf(void) {
return DMA.write_buf ? DMA.buf1 : DMA.buf0;
}
@@ -284,16 +272,17 @@ static inline volatile uint32_t *get_DMA_write_buf(void)
* @param None
* @retval Pointer to buffer full of Timer IC values ready to be consumed.
*/
-static volatile uint32_t *restart_DMA(void)
-{
+static volatile uint32_t *restart_DMA(void) {
/* Wait for transfer complete flag to become SET. Trying to change the
* M0AR register while the DMA is running is a no-no.
*/
- while(__HAL_DMA_GET_FLAG(&hdma_tim, __HAL_DMA_GET_TC_FLAG_INDEX(&hdma_tim)) == RESET) { ; }
+ while (__HAL_DMA_GET_FLAG(&hdma_tim,
+ __HAL_DMA_GET_TC_FLAG_INDEX(&hdma_tim)) == RESET)
+ ;
/* Switch buffer being written to */
DMA.write_buf ^= 1;
- hdma_tim.Instance->M0AR = (uint32_t) get_DMA_write_buf();
+ hdma_tim.Instance->M0AR = (uint32_t)get_DMA_write_buf();
/* Start at 0 to help manual inspection */
TIM2->CNT = 0;
@@ -311,7 +300,8 @@ static volatile uint32_t *restart_DMA(void)
* @param dmabuf_idx: Word index into `dmabuf'.
* @retval One Timer IC counter value.
*/
-static inline uint32_t safe_get_counter(volatile uint32_t *dmabuf, const uint32_t dmabuf_idx) {
+static inline uint32_t safe_get_counter(volatile uint32_t *dmabuf,
+ const uint32_t dmabuf_idx) {
register uint32_t a;
/* Prevent re-use of values. DMA stored values are <= 0xffff. */
do {
@@ -322,8 +312,7 @@ static inline uint32_t safe_get_counter(volatile uint32_t *dmabuf, const uint32_
}
/* UART transmit complete callback */
-void HAL_UART_TxCpltCallback(UART_HandleTypeDef *UH)
-{
+void HAL_UART_TxCpltCallback(UART_HandleTypeDef *UH) {
if ((UH->Instance == USART1 && huart->Instance == USART1) ||
(UH->Instance == USART2 && huart->Instance == USART2)) {
/* Signal UART transmit complete to the code in the main loop. */
@@ -350,10 +339,9 @@ static void check_uart_rx(UART_HandleTypeDef *this) {
* @param None
* @retval None
*/
-
-void Error_Handler(void)
-{
+void Error_Handler(void) {
/* Turn on RED LED and then loop indefinitely */
HAL_GPIO_WritePin(LED_PORT, LED_RED, GPIO_PIN_SET);
- while(1) { ; }
+ while (1)
+ ;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-21 21:09:19 +0000