diff --git a/Makefile b/Makefile
index 25b983d..da37ddd 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@ CC := $(TOOL_PREFIX)-gcc
OBJDUMP := $(TOOL_PREFIX)-objdump
OBJCOPY := $(TOOL_PREFIX)-objcopy
-SRC := ch32fun.c main.c
+SRC := ch32fun.c main.c rsa.c rand.c
CFLAGS = -g \
-Os \
diff --git a/main.c b/main.c
index f7fded8..4128657 100644
--- a/main.c
+++ b/main.c
@@ -1,9 +1,10 @@
#include <ch32fun.h>
+#include <rand.h>
#include <rsa.h>
+#include <stdint.h>
+#include <stdio.h>
#define LED_PIN PD6
-#define FREQ 2
-#define BLINK_DELAY 1000 / FREQ
void exit_blink() {
for (int i = 0; i < 4; i++) {
@@ -12,28 +13,53 @@ void exit_blink() {
funDigitalWrite(LED_PIN, FUN_LOW);
Delay_Ms(50);
}
+}
- while (1){};
-
- funDigitalWrite(LED_PIN, FUN_HIGH);
+void enter_blink() {
+ for (int i = 0; i < 2; i++) {
+ funDigitalWrite(LED_PIN, FUN_HIGH);
+ Delay_Ms(200);
+ funDigitalWrite(LED_PIN, FUN_LOW);
+ Delay_Ms(200);
+ }
}
int main() {
SystemInit();
- // Enable GPIOs
- funGpioInitAll();
+ printf("Entering...");
+ funGpioInitAll();
funPinMode(LED_PIN, GPIO_Speed_10MHz | GPIO_CNF_OUT_PP);
- int i = 0;
- while (i < gcd(930, 10)) {
- i++;
- funDigitalWrite(LED_PIN, FUN_HIGH);
- Delay_Ms(BLINK_DELAY);
- funDigitalWrite(LED_PIN, FUN_LOW);
- Delay_Ms(BLINK_DELAY);
+ enter_blink();
+
+ uint64_t p = gen_prime(1 << 15, 1 << 16);
+ uint64_t q = gen_prime(1 << 15, 1 << 16);
+
+ while (p == q) p = gen_prime(1 << 15, 1 << 16);
+
+ uint64_t n = p * q;
+
+ // Make these work by patching printf
+ printf("P: %llu\n", p);
+ printf("Q: %llu\n", q);
+ printf("N: %llu\n", n);
+
+ for (int idx = 0; idx < 16; idx++) {
+ funDigitalWrite(LED_PIN, p >> idx & 1);
+ Delay_Ms(200);
+ }
+ for (int idx = 0; idx < 16; idx++) {
+ funDigitalWrite(LED_PIN, q >> idx & 1);
+ Delay_Ms(200);
+ }
+ for (int idx = 0; idx < 16; idx++) {
+ funDigitalWrite(LED_PIN, n >> idx & 1);
+ Delay_Ms(200);
}
+ // Exit and hang forever
exit_blink();
+ while (1);
}
diff --git a/rsa.c b/rsa.c
new file mode 100644
index 0000000..07e06bd
--- /dev/null
+++ b/rsa.c
@@ -0,0 +1,81 @@
+#include "rsa.h"
+#include "rand.h"
+#include <stdbool.h>
+#include <stdint.h>
+
+int gcd(int a, int b) {
+ while (b != 0) {
+ int temp = b;
+ b = a % b;
+ a = temp;
+ }
+
+ return a;
+}
+
+int totient(int n) {
+ int result = n;
+
+ // Check for prime factors
+ for (int p = 2; p * p <= n; p++) {
+ if (n % p == 0) {
+ // If p is a prime factor of n, remove all occurrences of p
+ while (n % p == 0) {
+ n /= p;
+ }
+ result -= result / p;
+ }
+ }
+
+ // If n is still greater than 1, then it's a prime factor itself
+ if (n > 1) {
+ result -= result / n;
+ }
+
+ return result;
+}
+
+uint64_t modexp(uint64_t a, uint64_t b, uint64_t m) {
+ uint64_t result = 1;
+ a = a % m; // In case a is greater than m
+
+ while (b > 0) {
+ // If b is odd, multiply a with result
+ if (b % 2 == 1)
+ result = (result * a) % m;
+
+ // b must be even now
+ b = b >> 1; // b = b // 2
+ a = (a * a) % m; // Change a to a^2
+ }
+
+ return result;
+}
+
+uint64_t gen_prime(uint64_t min, uint64_t max) {
+ uint64_t cand = 0;
+ while (!is_prime(cand)) cand = prand_range(min, max);
+
+ return cand;
+}
+
+bool is_prime(int n) {
+ if (n < 2)
+ return false;
+
+ for (int i = 2; i < n / 2 + 1; i++) {
+ if (n % i == 0)
+ return false;
+ }
+
+ return true;
+}
+
+int mod_inverse(int e, int phi) {
+ for (int d = 0; d < phi; d++) {
+ if ((d * e) % phi == 1)
+ return d;
+ }
+
+ return 0;
+}
diff --git a/rsa.h b/rsa.h
new file mode 100644
index 0000000..b84c43d
--- /dev/null
+++ b/rsa.h
@@ -0,0 +1,57 @@
+#pragma once
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * @brief Calculates greatest common divider of two integers using the euclidean
+ * algorithm
+ *
+ * @param a First number
+ * @param b Second number
+ * @return The greatest common divider
+ */
+int gcd(int a, int b);
+
+/**
+ * @brief Computes Euler's Totient function φ(n), which counts the number of
+ * integers from 1 to n that are coprime to n.
+ *
+ * @param n The input number.
+ * @return The number of integers from 1 to n that are coprime to n.
+ */
+int totient(int n);
+
+/**
+ * @brief Modular exponentiation (a^b) mod m
+ *
+ * @param a The base
+ * @param b The exponent
+ * @param m The modulus
+ */
+uint64_t modexp(uint64_t a, uint64_t b, uint64_t m);
+
+/**
+ * @brief Computes the modular inverse of e modulo phi.
+ *
+ * @param e The integer whose modular inverse is to be found.
+ * @param phi The modulus.
+ * @return The modular inverse of e modulo phi, or -1 if no inverse exists.
+ */
+int mod_inverse(int e, int phi);
+
+/**
+ * @brief Generates a random prime number within the given range.
+ *
+ * @param min The lower bound (inclusive).
+ * @param max The upper bound (inclusive).
+ * @return A prime number in the range [min, max].
+ */
+uint64_t gen_prime(uint64_t min, uint64_t max);
+
+/**
+ * @brief Checks if a number is prime.
+ *
+ * @param n The number to check.
+ * @return true if n is prime, false otherwise.
+ */
+bool is_prime(int n);