asuswrt-merlin.ng/release/src-rt-5.02L.07p2axhnd/router-sysdep.rt-ax86u/gen_util/base64encode.c

442 lines
12 KiB
C

/* ***** BEGIN LICENSE BLOCK *****
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* ***** END LICENSE BLOCK ***** */
/*
* This code is based on nssb64e.c from Mozilla.org, which allows
* the code to be licensed under MPL/GPL/or LGPL. We will license it
* under LGPL --mwang 8/22/07
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "genutil_base64.h"
struct PLBase64EncodeStateStr {
unsigned chunks;
unsigned saved;
unsigned char buf[3];
};
/*
* The following implementation of base64 encoding was based on code
* found in libmime (specifically, in mimeenc.c). It has been adapted to
* use PR types and naming as well as to provide other necessary semantics
* (like buffer-in/buffer-out in addition to "streaming" without undue
* performance hit of extra copying if you made the buffer versions
* use the output_fn). It also incorporates some aspects of the current
* NSPR base64 encoding code. As such, you may find similarities to
* both of those implementations. I tried to use names that reflected
* the original code when possible. For this reason you may find some
* inconsistencies -- libmime used lots of "in" and "out" whereas the
* NSPR version uses "src" and "dest"; sometimes I changed one to the other
* and sometimes I left them when I thought the subroutines were at least
* self-consistent.
*/
/*
* Opaque object used by the encoder to store state.
*/
typedef struct PLBase64EncoderStr {
/*
* The one or two bytes pending. (We need 3 to create a "token",
* and hold the leftovers here. in_buffer_count is *only* ever
* 0, 1, or 2.
*/
unsigned char in_buffer[2];
int in_buffer_count;
/*
* If the caller wants linebreaks added, line_length specifies
* where they come out. It must be a multiple of 4; if the caller
* provides one that isn't, we round it down to the nearest
* multiple of 4.
*
* The value of current_column counts how many characters have been
* added since the last linebreaks (or since the beginning, on the
* first line). It is also always a multiple of 4; it is unused when
* line_length is 0.
*/
UINT32 line_length;
UINT32 current_column;
/*
* Where the encoded output goes -- either temporarily (in the streaming
* case, staged here before it goes to the output function) or what will
* be the entire buffered result for users of the buffer version.
*/
char *output_buffer;
UINT32 output_buflen; /* the total length of allocated buffer */
UINT32 output_length; /* the length that is currently populated */
} PLBase64Encoder;
/*
* Table to convert a binary value to its corresponding ascii "code".
*/
static unsigned char base64_valuetocode[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
#define B64_PAD '='
#define B64_CR '\r'
#define B64_LF '\n'
static SINT32
pl_base64_encode_buffer(PLBase64Encoder *data, const unsigned char *in, UINT32 size)
{
const unsigned char *end;
char *out = data->output_buffer + data->output_length;
UINT32 i = data->in_buffer_count;
UINT32 n = 0;
SINT32 off;
UINT32 output_threshold;
/* If this input buffer is too small, wait until next time. */
if (size < (3 - i))
{
data->in_buffer[i++] = in[0];
if (size > 1)
{
data->in_buffer[i++] = in[1];
}
assert(i < 3);
data->in_buffer_count = i;
return B64RET_SUCCESS;
}
/* If there are bytes that were put back last time, take them now. */
if (i > 0)
{
n = data->in_buffer[0];
if (i > 1)
{
n = (n << 8) | data->in_buffer[1];
}
data->in_buffer_count = 0;
}
/* If our total is not a multiple of three, put one or two bytes back. */
off = (size + i) % 3;
if (off > 0)
{
size -= off;
data->in_buffer_count = off;
data->in_buffer[0] = in[size];
if (off > 1)
{
data->in_buffer[1] = in[size + 1];
}
}
// calculate end pointer after size adjustment. --mwang
end = in + size;
output_threshold = data->output_buflen - 3;
/*
* Populate the output buffer with base64 data, one line (or buffer)
* at a time.
*/
while (in < end)
{
SINT32 j, k;
while (i < 3)
{
n = (n << 8) | *in++;
i++;
}
i = 0;
if (data->line_length > 0)
{
if (data->current_column >= data->line_length)
{
data->current_column = 0;
*out++ = B64_CR;
*out++ = B64_LF;
data->output_length += 2;
}
data->current_column += 4; /* the bytes we are about to add */
}
for (j = 18; j >= 0; j -= 6)
{
k = (n >> j) & 0x3F;
*out++ = base64_valuetocode[k];
}
n = 0;
data->output_length += 4;
if (data->output_length >= output_threshold)
{
assert(data->output_length <= data->output_buflen);
/*
* Check that we are about to exit the loop. (Since we
* are over the threshold, there isn't enough room in the
* output buffer for another trip around.)
*/
assert(in == end);
if (in < end)
{
return B64RET_INTERNAL_ERROR;
}
}
}
return B64RET_SUCCESS;
}
static SINT32 pl_base64_encode_flush (PLBase64Encoder *data)
{
SINT32 i = data->in_buffer_count;
if (i == 0 && data->output_length == 0)
{
return B64RET_SUCCESS;
}
if (i > 0)
{
char *out = data->output_buffer + data->output_length;
UINT32 n;
SINT32 j, k;
n = ((UINT32) data->in_buffer[0]) << 16;
if (i > 1)
{
n |= ((UINT32) data->in_buffer[1] << 8);
}
data->in_buffer_count = 0;
if (data->line_length > 0)
{
if (data->current_column >= data->line_length)
{
data->current_column = 0;
*out++ = B64_CR;
*out++ = B64_LF;
data->output_length += 2;
}
}
/*
* This will fill in more than we really have data for, but the
* valid parts will end up in the correct position and the extras
* will be over-written with pad characters below.
*/
for (j = 18; j >= 0; j -= 6)
{
k = (n >> j) & 0x3F;
*out++ = base64_valuetocode[k];
}
data->output_length += 4;
/* Pad with equal-signs. */
if (i == 1)
{
out[-2] = B64_PAD;
out[-1] = B64_PAD;
}
else if (i == 2)
{
out[-1] = B64_PAD;
}
}
return B64RET_SUCCESS;
}
/*
* The maximum space needed to hold the output of the encoder given input
* data of length "size", and allowing for CRLF added at least every
* line_length bytes (we will add it at nearest lower multiple of 4).
* There is no trailing CRLF.
*/
static UINT32 PL_Base64MaxEncodedLength (UINT32 size, UINT32 line_length)
{
UINT32 tokens, tokens_per_line, full_lines, line_break_chars, remainder;
tokens = (size + 2) / 3;
if (line_length == 0)
{
return (tokens * 4 + 2); /* add 2 extra bytes for NULL terminator --mwang*/
}
if (line_length < 4) /* too small! */
line_length = 4;
tokens_per_line = line_length / 4;
full_lines = tokens / tokens_per_line;
remainder = (tokens - (full_lines * tokens_per_line)) * 4;
line_break_chars = full_lines * 2;
if (remainder == 0)
line_break_chars -= 2;
return (full_lines * tokens_per_line * 4) + line_break_chars + remainder + 1; /* add 1 extra byte for NULL terminator --mwang */
}
UINT32 genUtl_b64EncodedBufferLength(UINT32 srclen)
{
return PL_Base64MaxEncodedLength(srclen, 0);
}
/*
* A distinct internal creation function for the buffer version to use.
* (It does not want to specify an output_fn, and we want the normal
* Create function to require that.) All common initialization of the
* encoding context should be done *here*.
*
* Save "line_length", rounded down to nearest multiple of 4 (if not
* already even multiple).
*/
static PLBase64Encoder *
pl_base64_create_encoder (UINT32 line_length, char *output_buf, UINT32 output_buflen)
{
PLBase64Encoder *data;
UINT32 line_tokens;
data = calloc(1, sizeof(PLBase64Encoder));
if (data == NULL)
{
return NULL;
}
if (line_length > 0 && line_length < 4) /* too small! */
{
line_length = 4;
}
line_tokens = line_length / 4;
data->line_length = line_tokens * 4;
data->output_buflen = output_buflen;
data->output_buffer = output_buf;
return data;
}
/*
* When you're done encoding, call this to free the data. If "abort_p"
* is false, then calling this may cause the output_fn to be called
* one last time (as the last buffered data is flushed out).
*/
static void
PL_DestroyBase64Encoder(PLBase64Encoder *data)
{
/* don't free output_buffer. That is the user's buffer.
* just free the context buffer. */
free(data);
return;
}
SINT32 genUtl_b64EncodeMalloc(const unsigned char *src, UINT32 srclen,
char **b64StrBuf)
{
UINT32 b64StrBufLen;
SINT32 ret;
if (src == NULL || srclen < 1 || b64StrBuf == NULL)
{
return B64RET_INVALID_ARGUMENTS;
}
b64StrBufLen = genUtl_b64EncodedBufferLength(srclen);
*b64StrBuf = calloc(1, b64StrBufLen);
if (*b64StrBuf == NULL)
{
return B64RET_RESOURCE_EXCEEDED;
}
ret = genUtl_b64Encode(src, srclen, *b64StrBuf, b64StrBufLen);
if (ret != B64RET_SUCCESS)
{
free(*b64StrBuf);
*b64StrBuf = NULL;
}
return ret;
}
/*
* If linebreaks in the encoded output are desired, "line_length" specifies
* where to place them -- it will be rounded down to the nearest multiple of 4
* (if it is not already an even multiple of 4). If it is zero, no linebreaks
* will be added. (FYI, a linebreak is CRLF -- two characters.)
*/
SINT32 genUtl_b64Encode(const unsigned char *src, UINT32 srclen,
char *b64StrBuf, UINT32 b64StrBufLen)
{
UINT32 line_length=0; /* leave line_length at 0. Do not change it. miwang */
PLBase64Encoder *data = NULL;
SINT32 ret;
if (src == NULL || srclen < 1 || b64StrBuf == NULL)
{
return B64RET_INVALID_ARGUMENTS;
}
if (b64StrBufLen < genUtl_b64EncodedBufferLength(srclen))
{
return B64RET_INVALID_ARGUMENTS;
}
/* make sure end of buffer is null terminated. hold back 1 byte from the
* real encoder. -- mwang 10/20/18.
*/
memset(b64StrBuf, 0, b64StrBufLen);
if ((data = pl_base64_create_encoder(line_length, b64StrBuf, b64StrBufLen-1)) == NULL)
{
return B64RET_RESOURCE_EXCEEDED;
}
ret = pl_base64_encode_buffer(data, src, srclen);
/*
* We do not wait for Destroy to flush, because Destroy will also
* get rid of our encoder context, which we need to look at first!
*/
if (ret == B64RET_SUCCESS)
{
ret = pl_base64_encode_flush(data);
}
assert(data->output_length < data->output_buflen);
PL_DestroyBase64Encoder(data);
return ret;
}