From 6202eb83795142abeea9fe38ee5111672b866946 Mon Sep 17 00:00:00 2001
From: ame <grantsquires@disroot.org>
Date: Thu, 2 Nov 2023 01:03:57 -0500
Subject: base64 & uuencode

---
 b.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 b.c

(limited to 'b.c')

diff --git a/b.c b/b.c
new file mode 100644
index 0000000..1f08f1f
--- /dev/null
+++ b/b.c
@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+int char_index(int c){
+    if(c <= 25) return 65 + c;
+    if(c <= 51) return 71 + c;
+    if(c <= 61) return (c - 52)+48;
+    if(c == 62) return 43;
+    if(c == 63) return 47;
+    return 61;
+}
+
+int ichar_index(int c){
+    if(65 <= c && c <= 90) return c - 65;
+    if(97 <= c && c <= 122) return c - 97 + 26;
+    if(48 <= c && c <= 57) return c - 48 + 52;
+    if(c == 47) return 63;
+    return 0;
+}
+
+int de_base64(char* in, char* out){
+    int len = 0;
+    for(int i = 0; in[i]!='\0'; i++) len++;
+    
+    //char out[len];
+    for(int i = 0; i < len; i+=4){
+        uint8_t u1 = i>len?0:in[i];
+        uint8_t u2 = i+1>len?0:in[i+1];
+        uint8_t u3 = i+2>len?0:in[i+2];
+        uint8_t u4 = i+3>len?0:in[i+3];
+        
+        u1 = ichar_index(u1);
+        u2 = ichar_index(u2);
+        u3 = ichar_index(u3);
+        u4 = ichar_index(u4);
+        
+        uint8_t left = u1 << 2 | u2 >> 4;
+        uint8_t middle = u2 << 4 | u3 >> 2;
+        uint8_t right = u3 << 6 | u4;
+        
+        if(u4==0) sprintf(out,"%s%c%c",out,left,middle);
+        else if(u3==0) sprintf(out,"%s%c",out,left);
+        else sprintf(out,"%s%c%c%c",out,left,middle,right);
+        
+    }
+    return 0;
+}
+int en_base64(char* in, char* out){
+    int len = 0;
+    for(int i = 0; in[i]!='\0'; i++) len++;
+
+    //char out[(len+1)*3];
+    for(int i = 0; i < len; i+=3){
+        uint8_t f = i>len?0:in[i];
+        uint8_t s = i+1>len?0:in[i+1];
+        uint8_t t = i+2>len?0:in[i+2];
+        
+        uint8_t i1 = f>>2;
+        uint8_t i2 = (uint8_t)(f<<6)>>2 | (s>>4);
+        uint8_t i3 = (uint8_t)(s<<4)>>2 | (t>>6);
+        uint8_t i4 = t & 0x3f;
+        
+        if(t==0)i4 = 64;
+        if(s==0)i3 = 64;
+        sprintf(out,"%s%c%c%c%c",out,char_index(i1),char_index(i2),
+                char_index(i3),char_index(i4));
+    }
+    return 0;
+}
+
+int main(){
+    char* uwu = "Many hands make light work.AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+    char uwue[20*8000];
+    char uwud[20*8000];
+    
+    en_base64(uwu, uwue);
+    de_base64(uwue, uwud);
+    
+    printf("%s\n%s\n%s",uwu,uwue,uwud);
+}
+
+
-- 
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