From 5cd20516567da82c60b5513c732e23db6918a4b6 Mon Sep 17 00:00:00 2001
From: ame <grantsquires@disroot.org>
Date: Fri, 3 Nov 2023 19:45:15 -0500
Subject: tons of checksums (i had fun:3)

---
 src/hash/crc.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 src/hash/crc.c

(limited to 'src/hash/crc.c')

diff --git a/src/hash/crc.c b/src/hash/crc.c
new file mode 100644
index 0000000..0588340
--- /dev/null
+++ b/src/hash/crc.c
@@ -0,0 +1,95 @@
+#include "../crypto.h"
+#include <stdio.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <inttypes.h>
+
+uint32_t i_crc32(uint8_t *data, size_t len){
+    uint32_t crc = 0xFFFFFFFF;
+
+    for(int i = 0; i < len; i++){
+        uint32_t extract = data[i];
+        for(int z = 0; z < 8; z++){
+            uint32_t b = (extract^crc)&1;
+            crc>>=1;
+            if(b) crc^=0xEDB88320;
+            extract>>=1;
+        }
+    }
+    return -(crc+1);
+}
+
+uint16_t i_crc16(uint8_t *aa, size_t len){
+    uint16_t crc = 0x0;
+    
+    for(int i = 0; i != len; i++){
+        uint8_t a = aa[i];
+        crc ^= a;
+        for (int z = 0; z < 8; z++){
+            if (crc & 1) crc = (crc >> 1) ^ 0xA001;
+            else crc = (crc >> 1);
+        }
+    }
+    return crc;
+}
+
+uint8_t i_crc8(uint8_t *aa, size_t len){
+    //crc8 maxim
+    uint8_t crc = 0x00;
+    
+    for(int i = 0; i != len; i++){
+        uint8_t a = aa[i];
+
+        for (int z = 0; z < 8; z++){
+            uint8_t b = (crc ^ a) & 1;
+            crc >>= 1;
+            if(b) crc ^= 0x8c;
+            a >>=1;
+        }
+    }
+    return crc;
+}
+
+int l_crc8(lua_State* L){
+  
+  size_t len = 0;
+  uint8_t* a = (uint8_t*)luaL_checklstring(L, 1, &len);
+  
+  char digest[8];
+
+  uint8_t u = i_crc8(a, len);
+  sprintf(digest,"%x",u);
+  lua_pushstring(L, digest);
+
+  return 1;
+}
+
+int l_crc16(lua_State* L){
+  
+  size_t len = 0;
+  uint8_t* a = (uint8_t*)luaL_checklstring(L, 1, &len);
+  
+  char digest[16];
+
+  uint16_t u = i_crc16(a, len);
+  sprintf(digest,"%x",u);
+  lua_pushstring(L, digest);
+
+  return 1;
+}
+
+int l_crc32(lua_State* L){
+  
+  size_t len = 0;
+  uint8_t* a = (uint8_t*)luaL_checklstring(L, 1, &len);
+  
+  char digest[32];
+
+  uint32_t u = i_crc32(a, len);
+  sprintf(digest,"%x",u);
+  lua_pushstring(L, digest);
+
+  return 1;
+}
-- 
cgit v1.2.3