diff --git a/Makefile b/Makefile index ccd6d27..bdf06c6 100644 --- a/Makefile +++ b/Makefile @@ -1,4 +1,5 @@ -REV := master +# 'master' or hash +REV := 8ba9981e5 BASE := https://raw.githubusercontent.com/cnlohr/ch32v003fun/$(REV) CURL_FLAGS := -O -\# --fail --location --tlsv1.3 --proto =https --max-time 300 diff --git a/assert.h b/assert.h new file mode 100644 index 0000000..e56b318 --- /dev/null +++ b/assert.h @@ -0,0 +1,25 @@ +#pragma once + +#include +#include + +#define ASSERT(expr) \ + do { \ + if (!(expr)) { \ + printf("ASSERTION FAILED: %s at %s:%d\n", #expr, __FILE__, \ + __LINE__); \ + while (1); \ + } \ + } while (0) + +#define ASSERT_EQ(expr, expected) \ + do { \ + uint64_t result = (expr); \ + if (result != (expected)) { \ + printf("ASSERTION FAILED: %s at %s:%d\n", #expr, __FILE__, \ + __LINE__); \ + printf("Expected: %lu, Got: %lu\n", (unsigned long)(expected), \ + (unsigned long)result); \ + while (1); \ + } \ + } while (0) diff --git a/funconfig.h b/funconfig.h index 998cf76..561ab22 100644 --- a/funconfig.h +++ b/funconfig.h @@ -1,7 +1,18 @@ +#include + #ifndef _FUNCONFIG_H #define _FUNCONFIG_H -#define CH32V003 1 +#define CH32V003 1 + +#define NULL ((void *)0) + +typedef int8_t i8; +typedef uint8_t u8; +typedef int16_t i16; +typedef uint32_t u32; +typedef int32_t i32; +typedef int64_t i64; +typedef uint64_t u64; #endif - diff --git a/main.c b/main.c index 29770df..28a423d 100644 --- a/main.c +++ b/main.c @@ -1,10 +1,14 @@ +#include "assert.h" #include #include #include #include #include +#include #define LED_PIN PD6 +#define RANDOM +#define W 16 void exit_blink() { for (int i = 0; i < 4; i++) { @@ -24,6 +28,30 @@ void enter_blink() { } } +void test_mulmod() { + ASSERT_EQ(mulmod(3, 2, 4), 2); + ASSERT_EQ((3 * 2) % 4, 2); + + ASSERT_EQ(mulmod(31, 3, 8), 5); + ASSERT_EQ(mulmod((u64)1 << 63, 2, 1000000007ULL), 582344008); +} + +void test_modexp() { + ASSERT_EQ(modexp(3, 2, 4), 1); + ASSERT_EQ((3 ^ 2) % 4, 1); + + ASSERT_EQ(modexp(31, 3, 8), 7); + ASSERT_EQ(modexp((u64)1 << 63, 2, 1000000007ULL), 319908071); +} + +void debug_string(char *str) { + printf("Got string: %s\n", str); + for (int i = 0; i < strlen(str); i++) { + printf("decoded[%d] = '%c' (ASCII: %d)\n", i, str[i], + str[i]); // Print decoded chars and ASCII values + } +} + int main() { SystemInit(); sprand(0); @@ -33,54 +61,59 @@ int main() { enter_blink(); -#ifdef RANDOM - uint64_t p = gen_prime(1 << 15, 1 << 16); - uint64_t q = p; + test_mulmod(); + test_modexp(); - while (p == q) p = gen_prime(1 << 15, 1 << 16); -#else - uint64_t p = 56857; - uint64_t q = 47963; -#endif + const u64 p = gen_prime(1 << (W - 1), 1 << W); + printf("P: %u\n", (u32)p); - uint64_t n = p * q; - uint64_t phi_n = (p - 1) * (q - 1); + u64 qprev = p; + while (p == qprev) qprev = gen_prime(1 << (W - 1), 1 << W); - // 'e' is public. E for encrypt. - uint64_t e = 0; - while (gcd(e, phi_n) != 1) e = prand_range(3, phi_n - 1); + const u64 q = qprev; + printf("Q: %u\n", (u32)q); - // 'd' is our private key. D as in decrypt - uint64_t d = mod_inverse(e, phi_n); + ASSERT(gcd(p - 1, PUBEXP) == 1); + ASSERT(gcd(q - 1, PUBEXP) == 1); + + u64 n = p * q; + printf("N: %u\n", (u32)n); + + u64 phi_n = (p - 1) * (q - 1); + printf("Phi_N: %u\n", (u32)phi_n); + + u64 d = mod_inverse(PUBEXP, phi_n); + printf("D: %u\n", (u32)d); if (d == 0 || d == 1) { printf("Modular inverse not found..."); - while (1); } + ASSERT_EQ(mulmod(PUBEXP, d, phi_n), 1); + char msg[] = "Hello"; - uint64_t coded[sizeof(msg)] = {0}; + u64 coded[sizeof(msg)] = {0}; char decoded[sizeof(msg)] = {0}; // Encode the message - for (int i = 0; i < sizeof(msg); i++) { - coded[i] = (uint64_t)modexp((uint64_t)msg[i], e, n); + for (int i = 0; i < strlen(msg); i++) { + coded[i] = modexp((u64)msg[i], PUBEXP, n); } // Decode the message - for (int i = 0; i < sizeof(msg); i++) { - decoded[i] = (char)modexp(coded[i], d, n); + for (int i = 0; i < strlen(msg); i++) { + u64 dec = modexp(coded[i], d, n); + decoded[i] = dec & 0xFF; } { - printf("P: %u\n", (uint32_t)p); - printf("Q: %u\n", (uint32_t)q); - printf("N: %u\n", (uint32_t)n); - printf("Phi_N: %u\n", (uint32_t)phi_n); - printf("Pubkey (e): %u\n", (uint32_t)e); - printf("Privkey (d): %u\n", (uint32_t)d); - printf("Message: %s\n", msg); printf("Decoded: %s\n", decoded); + + for (int i = 0; i < strlen(msg); i++) { + printf("coded[%d] = 0x%016lx\n", i, (unsigned long)coded[i]); + } + + debug_string(decoded); } // Exit and hang forever diff --git a/rsa.c b/rsa.c index b547c93..89a3069 100644 --- a/rsa.c +++ b/rsa.c @@ -1,15 +1,11 @@ #include "rsa.h" +#include "funconfig.h" #include "rand.h" #include -#include -#define NULL ((void *)0) +u64 gcd(u64 a, u64 b) { return extended_euclid(a, b, NULL, NULL); } -uint64_t gcd(uint64_t a, uint64_t b) { - return extended_euclid(a, b, NULL, NULL); -} - -int extended_euclid(int a, int b, int *x, int *y) { +u64 extended_euclid(u64 a, u64 b, u64 *x, u64 *y) { if (b == 0) { if (x) *x = 1; @@ -18,8 +14,8 @@ int extended_euclid(int a, int b, int *x, int *y) { return a; } - int x1, y1; - int gcd = extended_euclid(b, a % b, &x1, &y1); + u64 x1, y1; + u64 gcd = extended_euclid(b, a % b, &x1, &y1); if (x) *x = y1; @@ -29,7 +25,7 @@ int extended_euclid(int a, int b, int *x, int *y) { return gcd; } -int totient(int n) { +u64 totient(u64 n) { int result = n; // Check for prime factors @@ -51,23 +47,24 @@ int totient(int n) { return result; } -uint64_t mulmod(uint64_t a, uint64_t b, uint64_t m) { - uint64_t result = 0; +u64 mulmod(u64 a, u64 b, u64 m) { + u64 result = 0; a %= m; + // Perform the multiplication bit by bit (binary multiplication) while (b > 0) { if (b & 1) { - result = (result + a) % m; // Avoid overflow + result = (result + a) % m; } - a = (a * 2) % m; // Double a, keep within mod - b >>= 1; + a = (a * 2) % m; // Double a, keep it within the modulus + b >>= 1; // Right shift b (divide by 2) } return result; } -uint64_t modexp(uint64_t a, uint64_t b, uint64_t m) { - uint64_t result = 1; +u64 modexp(u64 a, u64 b, u64 m) { + u64 result = 1; a %= m; while (b > 0) { @@ -81,14 +78,14 @@ uint64_t modexp(uint64_t a, uint64_t b, uint64_t m) { return result; } -uint64_t gen_prime(uint64_t min, uint64_t max) { - uint64_t cand = 0; +u64 gen_prime(u64 min, u64 max) { + u64 cand = 0; while (!miller_rabin(cand, 10)) cand = prand_range(min, max); return cand; } -bool is_prime(int n) { +bool is_prime(u64 n) { if (n < 2) return false; @@ -100,26 +97,26 @@ bool is_prime(int n) { return true; } -bool miller_rabin(uint64_t n, uint64_t k) { +bool miller_rabin(u64 n, u64 k) { if (n < 2) return false; - uint64_t d = n - 1; - uint64_t s = 0; + u64 d = n - 1; + u64 s = 0; while (d % 2 == 0) { d /= 2; s++; } - for (uint64_t i = 0; i < k; i++) { - uint64_t a = prand_range(2, n - 2); - uint64_t x = modexp(a, d, n); + for (u64 i = 0; i < k; i++) { + u64 a = prand_range(2, n - 2); + u64 x = modexp(a, d, n); if (x == 1 || x == n - 1) continue; - for (uint64_t r = 1; r < s; r++) { + for (u64 r = 1; r < s; r++) { x = modexp(x, 2, n); if (x == n - 1) break; @@ -132,17 +129,18 @@ bool miller_rabin(uint64_t n, uint64_t k) { return true; // Likely prime } -uint64_t mod_inverse(uint64_t a, uint64_t m) { - uint64_t m0 = m; - uint64_t y = 0, x = 1; +u64 mod_inverse(u64 a, u64 m) { + u64 m0 = m; + u64 y = 0, x = 1; + // Modular inverse does not exist when m is 1 if (m == 1) return 0; while (a > 1) { // q is quotient - uint64_t q = a / m; - uint64_t t = m; + u64 q = a / m; + u64 t = m; // m is remainder now m = a % m; diff --git a/rsa.h b/rsa.h index 53bc78d..910ae1a 100644 --- a/rsa.h +++ b/rsa.h @@ -1,7 +1,11 @@ #pragma once +#include "funconfig.h" #include #include +// Common public exponent, in Fermat prime form +#define PUBEXP ((1 << 16) | 0x1) + /** * @brief Calculates greatest common divider of two integers using the euclidean * algorithm @@ -10,7 +14,7 @@ * @param b Second number * @return The greatest common divider */ -uint64_t gcd(uint64_t a, uint64_t b); +u64 gcd(u64 a, u64 b); /** * @brief Computes Euler's Totient function φ(n), which counts the number of @@ -19,7 +23,7 @@ uint64_t gcd(uint64_t a, uint64_t b); * @param n The input number. * @return The number of integers from 1 to n that are coprime to n. */ -int totient(int n); +u64 totient(u64 n); /** * @brief Computes (a * b) % m safely without overflow. @@ -32,7 +36,7 @@ int totient(int n); * @param m The modulus. * @return (a * b) % m computed safely. */ -uint64_t mulmod(uint64_t a, uint64_t b, uint64_t m); +u64 mulmod(u64 a, u64 b, u64 m); /** * @brief Modular exponentiation (a^b) mod m @@ -41,7 +45,7 @@ uint64_t mulmod(uint64_t a, uint64_t b, uint64_t m); * @param b The exponent * @param m The modulus */ -uint64_t modexp(uint64_t a, uint64_t b, uint64_t m); +u64 modexp(u64 a, u64 b, u64 m); /** * @brief Computes the modular inverse of a modulo m. @@ -50,7 +54,7 @@ uint64_t modexp(uint64_t a, uint64_t b, uint64_t m); * @param m The modulus. * @return The modular inverse of a modulo m, or -1 if no inverse exists. */ -uint64_t mod_inverse(uint64_t a, uint64_t m); +u64 mod_inverse(u64 a, u64 m); /** * @brief Generates a random prime number within the given range. @@ -59,7 +63,7 @@ uint64_t mod_inverse(uint64_t a, uint64_t m); * @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); +u64 gen_prime(u64 min, u64 max); /** * @brief Checks if a number is prime. @@ -67,7 +71,7 @@ uint64_t gen_prime(uint64_t min, uint64_t max); * @param n The number to check. * @return true if n is prime, false otherwise. */ -bool is_prime(int n); +bool is_prime(u64 n); /** * @brief Performs the Miller-Rabin primality test to check if a number is @@ -77,7 +81,7 @@ bool is_prime(int n); * @param k The number of rounds of testing to perform. * @return true if n is probably prime, false if n is composite. */ -bool miller_rabin(uint64_t n, uint64_t k); +bool miller_rabin(u64 n, u64 k); /** * @brief Computes the greatest common divisor (GCD) of two integers a and b @@ -92,4 +96,4 @@ bool miller_rabin(uint64_t n, uint64_t k); * + by = gcd(a, b). * @return The greatest common divisor (gcd) of a and b. */ -int extended_euclid(int a, int b, int *x, int *y); +u64 extended_euclid(u64 a, u64 b, u64 *x, u64 *y);