C version re-added and made a release for it

Might be more noob friendly than a python script.

LICENSE-ctrtool

@@ -0,0 +1,22 @@
+MIT License
+
+Copyright (c) 2012 neimod
+Copyright (c) 2014 3DSGuy
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -0,0 +1,18 @@
+SOURCES   = source source/polarssl
+
+CFILES   := $(foreach dir, $(SOURCES), $(wildcard $(dir)/*.c))
+CPPFILES := $(foreach dir, $(SOURCES), $(wildcard $(dir)/*.cpp))
+
+OBJS      = $(CFILES:.c=.o) $(CPPFILES:.cpp=.o)
+
+LIBS      = -static-libstdc++ -static
+CXXFLAGS  = -Isource
+CFLAGS    = -std=c11 -Wall -Wextra -Os -posix -Isource -D_GNU_SOURCE
+OUTPUT    = mkey
+CC        = gcc
+
+main: $(OBJS)
+	g++ -o $(OUTPUT) $(LIBS) $(OBJS)
+
+clean:
+	rm -f $(OUTPUT) $(OUTPUT).exe $(OBJS)

README.md

@@ -5,6 +5,7 @@ Compatible with: 1.0-11.16 US,EU,JP,KR,TW,CN</br>
 - Attempt to unlock your parental controls from your 3DS's System Settings until it gives you an "Inquiry Number" (chose "I forgot" twice).
 - Next, read the rem comments in the "mkey.bat" script in a text editor for the remaining instructions, then run the same .bat script. 
 - Your masterkey should be generated, which you can use to unlock your 3DS in System Settings.
+Note: A windows exe is also provided in the release tab. You simply launch it and follow directions.
 
 mkey
 ====

source/ctr.c

@@ -0,0 +1,155 @@
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "ctr.h"
+
+void ctr_set_iv( ctr_aes_context* ctx,
+                  u8 iv[16] )
+{
+    memcpy(ctx->iv, iv, 16);
+}
+
+void ctr_add_counter( ctr_aes_context* ctx,
+                      u32 carry )
+{
+    u32 counter[4];
+    u32 sum;
+    int i;
+
+    for(i=0; i<4; i++)
+        counter[i] = (ctx->ctr[i*4+0]<<24) | (ctx->ctr[i*4+1]<<16) | (ctx->ctr[i*4+2]<<8) | (ctx->ctr[i*4+3]<<0);
+
+    for(i=3; i>=0; i--)
+    {
+        sum = counter[i] + carry;
+
+        if (sum < counter[i])
+            carry = 1;
+        else
+            carry = 0;
+
+        counter[i] = sum;
+    }
+
+    for(i=0; i<4; i++)
+    {
+        ctx->ctr[i*4+0] = counter[i]>>24;
+        ctx->ctr[i*4+1] = counter[i]>>16;
+        ctx->ctr[i*4+2] = counter[i]>>8;
+        ctx->ctr[i*4+3] = counter[i]>>0;
+    }
+}
+
+void ctr_set_counter( ctr_aes_context* ctx,
+                      u8 ctr[16] )
+{
+    memcpy(ctx->ctr, ctr, 16);
+}
+
+
+void ctr_init_counter( ctr_aes_context* ctx,
+                       u8 key[16],
+                       u8 ctr[16] )
+{
+    aes_setkey_enc(&ctx->aes, key, 128);
+    ctr_set_counter(ctx, ctr);
+}
+
+
+void ctr_crypt_counter_block( ctr_aes_context* ctx,
+                              u8 input[16],
+                              u8 output[16] )
+{
+    int i;
+    u8 stream[16];
+
+
+    aes_crypt_ecb(&ctx->aes, AES_ENCRYPT, ctx->ctr, stream);
+
+
+    if (input)
+    {
+        for(i=0; i<16; i++)
+        {
+            output[i] = stream[i] ^ input[i];
+        }
+    }
+    else
+    {
+        for(i=0; i<16; i++)
+            output[i] = stream[i];
+    }
+
+    ctr_add_counter(ctx, 1);
+}
+
+
+void ctr_crypt_counter( ctr_aes_context* ctx,
+                        u8* input,
+                        u8* output,
+                        u32 size )
+{
+    u8 stream[16];
+    u32 i;
+
+    while(size >= 16)
+    {
+        ctr_crypt_counter_block(ctx, input, output);
+
+        if (input)
+            input += 16;
+        if (output)
+            output += 16;
+
+        size -= 16;
+    }
+
+    if (size)
+    {
+        memset(stream, 0, 16);
+        ctr_crypt_counter_block(ctx, stream, stream);
+
+        if (input)
+        {
+            for(i=0; i<size; i++)
+                output[i] = input[i] ^ stream[i];
+        }
+        else
+        {
+            memcpy(output, stream, size);
+        }
+    }
+}
+
+void ctr_init_cbc_encrypt( ctr_aes_context* ctx,
+                           u8 key[16],
+                           u8 iv[16] )
+{
+    aes_setkey_enc(&ctx->aes, key, 128);
+    ctr_set_iv(ctx, iv);
+}
+
+void ctr_init_cbc_decrypt( ctr_aes_context* ctx,
+                           u8 key[16],
+                           u8 iv[16] )
+{
+    aes_setkey_dec(&ctx->aes, key, 128);
+    ctr_set_iv(ctx, iv);
+}
+
+void ctr_encrypt_cbc( ctr_aes_context* ctx,
+                      u8* input,
+                      u8* output,
+                      u32 size )
+{
+    aes_crypt_cbc(&ctx->aes, AES_ENCRYPT, size, ctx->iv, input, output);
+}
+
+void ctr_decrypt_cbc( ctr_aes_context* ctx,
+                      u8* input,
+                      u8* output,
+                      u32 size )
+{
+    aes_crypt_cbc(&ctx->aes, AES_DECRYPT, size, ctx->iv, input, output);
+}

source/ctr.h

@@ -0,0 +1,59 @@
+#ifndef _CTR_H
+#define _CTR_H
+
+#include "utils.h"
+
+#include "polarssl/aes.h"
+
+typedef struct
+{
+    u8 ctr[16];
+    u8 iv[16];
+    aes_context aes;
+} ctr_aes_context;
+
+void        ctr_set_iv( ctr_aes_context* ctx,
+                         u8 iv[16] );
+
+void        ctr_add_counter( ctr_aes_context* ctx,
+                             u32 carry );
+
+void        ctr_set_counter( ctr_aes_context* ctx,
+                         u8 ctr[16] );
+
+
+void        ctr_init_counter( ctr_aes_context* ctx,
+                          u8 key[16],
+                          u8 ctr[16] );
+
+
+void        ctr_crypt_counter_block( ctr_aes_context* ctx,
+                                     u8 input[16],
+                                     u8 output[16] );
+
+
+void        ctr_crypt_counter( ctr_aes_context* ctx,
+                               u8* input,
+                               u8* output,
+                               u32 size );
+
+
+void        ctr_init_cbc_encrypt( ctr_aes_context* ctx,
+                               u8 key[16],
+                               u8 iv[16] );
+
+void        ctr_init_cbc_decrypt( ctr_aes_context* ctx,
+                               u8 key[16],
+                               u8 iv[16] );
+
+void        ctr_encrypt_cbc( ctr_aes_context* ctx,
+                              u8* input,
+                              u8* output,
+                              u32 size );
+
+void        ctr_decrypt_cbc( ctr_aes_context* ctx,
+                              u8* input,
+                              u8* output,
+                              u32 size );
+
+#endif