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mirror of https://github.com/SoftEtherVPN/SoftEtherVPN.git synced 2025-12-16 07:01:32 +03:00

Refactor Base64 functions, encode/decode using OpenSSL's EVP interface

Our own implementation works fine, however we should use OpenSSL's one since we already link to the library.

Base64Decode() and Base64Encode() return the required buffer size when "dst" is NULL.

This allows to efficiently allocate a buffer, without wasting memory or risking an overflow.

Base64FromBin() and Base64ToBin() perform all steps, returning a heap-allocated buffer with the data in it.
This commit is contained in:
Davide Beatrici
2021-07-02 09:24:41 +02:00
parent 03d67fd5b1
commit 233e28f38c
14 changed files with 224 additions and 369 deletions

View File

@ -7,6 +7,7 @@
#include "Memory.h"
#include "Encoding.h"
#include "Encrypt.h"
#include "FileIO.h"
#include "Internat.h"
@ -3407,232 +3408,62 @@ UINT64 Swap64(UINT64 value)
return r;
}
// Base64 encode
UINT Encode64(char *dst, char *src)
void *Base64ToBin(UINT *out_size, const void *src, const UINT size)
{
// Validate arguments
if (dst == NULL || src == NULL)
if (src == NULL || size == 0)
{
return 0;
return NULL;
}
return B64_Encode(dst, src, StrLen(src));
UINT bin_size = Base64Decode(NULL, src, size);
if (bin_size == 0)
{
return NULL;
}
void *bin = Malloc(bin_size);
bin_size = Base64Decode(bin, src, size);
if (bin_size == 0)
{
Free(bin);
return NULL;
}
if (out_size != NULL)
{
*out_size = bin_size;
}
return bin;
}
// Base64 decoding
UINT Decode64(char *dst, char *src)
void *Base64FromBin(UINT *out_size, const void *src, const UINT size)
{
// Validate arguments
if (dst == NULL || src == NULL)
if (src == NULL || size == 0)
{
return 0;
return NULL;
}
return B64_Decode(dst, src, StrLen(src));
}
UINT base64_size = Base64Encode(NULL, src, size);
if (base64_size == 0)
{
return NULL;
}
// Base64 encode
int B64_Encode(char *set, char *source, int len)
{
BYTE *src;
int i,j;
src = (BYTE *)source;
j = 0;
i = 0;
if (!len)
void *base64 = Malloc(base64_size);
base64_size = Base64Encode(base64, src, size);
if (base64_size == 0)
{
return 0;
Free(base64);
return NULL;
}
while (true)
{
if (i >= len)
{
return j;
}
if (set)
{
set[j] = B64_CodeToChar((src[i]) >> 2);
}
if (i + 1 >= len)
{
if (set)
{
set[j + 1] = B64_CodeToChar((src[i] & 0x03) << 4);
set[j + 2] = '=';
set[j + 3] = '=';
}
return j + 4;
}
if (set)
{
set[j + 1] = B64_CodeToChar(((src[i] & 0x03) << 4) + ((src[i + 1] >> 4)));
}
if (i + 2 >= len)
{
if (set)
{
set[j + 2] = B64_CodeToChar((src[i + 1] & 0x0f) << 2);
set[j + 3] = '=';
}
return j + 4;
}
if (set)
{
set[j + 2] = B64_CodeToChar(((src[i + 1] & 0x0f) << 2) + ((src[i + 2] >> 6)));
set[j + 3] = B64_CodeToChar(src[i + 2] & 0x3f);
}
i += 3;
j += 4;
}
}
// Base64 decode
int B64_Decode(char *set, char *source, int len)
{
int i,j;
char a1,a2,a3,a4;
char *src;
int f1,f2,f3,f4;
src = source;
i = 0;
j = 0;
while (true)
if (out_size != NULL)
{
f1 = f2 = f3 = f4 = 0;
if (i >= len)
{
break;
}
f1 = 1;
a1 = B64_CharToCode(src[i]);
if (a1 == -1)
{
f1 = 0;
}
if (i >= len + 1)
{
a2 = 0;
}
else
{
a2 = B64_CharToCode(src[i + 1]);
f2 = 1;
if (a2 == -1)
{
f2 = 0;
}
}
if (i >= len + 2)
{
a3 = 0;
}
else
{
a3 = B64_CharToCode(src[i + 2]);
f3 = 1;
if (a3 == -1)
{
f3 = 0;
}
}
if (i >= len + 3)
{
a4 = 0;
}
else
{
a4 = B64_CharToCode(src[i + 3]);
f4 = 1;
if (a4 == -1)
{
f4 = 0;
}
}
if (f1 && f2)
{
if (set)
{
set[j] = (a1 << 2) + (a2 >> 4);
}
j++;
}
if (f2 && f3)
{
if (set)
{
set[j] = (a2 << 4) + (a3 >> 2);
}
j++;
}
if (f3 && f4)
{
if (set)
{
set[j] = (a3 << 6) + a4;
}
j++;
}
i += 4;
*out_size = base64_size;
}
return j;
}
// Base64 : Convert a code to a character
char B64_CodeToChar(BYTE c)
{
BYTE r;
r = '=';
if (c <= 0x19)
{
r = c + 'A';
}
if (c >= 0x1a && c <= 0x33)
{
r = c - 0x1a + 'a';
}
if (c >= 0x34 && c <= 0x3d)
{
r = c - 0x34 + '0';
}
if (c == 0x3e)
{
r = '+';
}
if (c == 0x3f)
{
r = '/';
}
return r;
}
// Base64 : Convert a character to a code
char B64_CharToCode(char c)
{
if (c >= 'A' && c <= 'Z')
{
return c - 'A';
}
if (c >= 'a' && c <= 'z')
{
return c - 'a' + 0x1a;
}
if (c >= '0' && c <= '9')
{
return c - '0' + 0x34;
}
if (c == '+')
{
return 0x3e;
}
if (c == '/')
{
return 0x3f;
}
if (c == '=')
{
return -1;
}
return 0;
return base64;
}
// Malloc