project skeleton

password.c

@@ -0,0 +1,43 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <crypt.h>
+
+void generate_salt(char *salt_buffer)
+{
+	const char *charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789./";
+	salt_buffer[0] = '$';
+	salt_buffer[1] = '6'; // SHA-512
+	salt_buffer[2] = '$';
+	
+	srand(time(NULL));
+	for (int i = 3; i < 19; i++) {
+		salt_buffer[i] = charset[rand() % 64];
+	}
+	salt_buffer[19] = '$';
+	salt_buffer[20] = '\0';
+}
+
+char* hash_password(const char *password)
+{
+	struct crypt_data data;
+	data.initialized = 0;
+	
+	char salt[21];
+	generate_salt(salt);
+	
+	char *hash = crypt_r(password, salt, &data);
+	return hash ? strdup(hash) : NULL;
+}
+
+int verify_password(const char *password, const char *stored_hash)
+{
+	struct crypt_data data;
+	data.initialized = 0;
+	
+	char *calculated = crypt_r(password, stored_hash, &data);
+	
+	return (calculated && strcmp(calculated, stored_hash) == 0);
+}