/* $OpenBSD: encode.c,v 1.28 2020/03/04 11:53:21 inoguchi Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <openssl/evp.h>
static unsigned char conv_ascii2bin(unsigned char a);
#define conv_bin2ascii(a) (data_bin2ascii[(a)&0x3f])
/* 64 char lines
* pad input with 0
* left over chars are set to =
* 1 byte => xx==
* 2 bytes => xxx=
* 3 bytes => xxxx
*/
#define BIN_PER_LINE (64/4*3)
#define CHUNKS_PER_LINE (64/4)
#define CHAR_PER_LINE (64+1)
static const unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
abcdefghijklmnopqrstuvwxyz0123456789+/";
/* 0xF0 is a EOLN
* 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing).
* 0xF2 is EOF
* 0xE0 is ignore at start of line.
* 0xFF is error
*/
#define B64_EOLN 0xF0
#define B64_CR 0xF1
#define B64_EOF 0xF2
#define B64_WS 0xE0
#define B64_ERROR 0xFF
#define B64_NOT_BASE64(a) (((a)|0x13) == 0xF3)
#define B64_BASE64(a) !B64_NOT_BASE64(a)
static const unsigned char data_ascii2bin[128] = {
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
};
static unsigned char
conv_ascii2bin(unsigned char a)
{
if (a & 0x80)
return B64_ERROR;
return data_ascii2bin[a];
}
EVP_ENCODE_CTX *
EVP_ENCODE_CTX_new(void)
{
return calloc(1, sizeof(EVP_ENCODE_CTX));
}
void
EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx)
{
free(ctx);
}
void
EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
{
ctx->length = 48;
ctx->num = 0;
ctx->line_num = 0;
}
int
EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
const unsigned char *in, int inl)
{
int i, j;
size_t total = 0;
*outl = 0;
if (inl <= 0)
return 0;
OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
if (ctx->length - ctx->num > inl) {
memcpy(&(ctx->enc_data[ctx->num]), in, inl);
ctx->num += inl;
return 1;
}
if (ctx->num != 0) {
i = ctx->length - ctx->num;
memcpy(&(ctx->enc_data[ctx->num]), in, i);
in += i;
inl -= i;
j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
ctx->num = 0;
out += j;
*(out++) = '\n';
*out = '\0';
total = j + 1;
}
while (inl >= ctx->length && total <= INT_MAX) {
j = EVP_EncodeBlock(out, in, ctx->length);
in += ctx->length;
inl -= ctx->length;
out += j;
*(out++) = '\n';
*out = '\0';
total += j + 1;
}
if (total > INT_MAX) {
/* Too much output data! */
*outl = 0;
return 0;
}
if (inl != 0)
memcpy(&(ctx->enc_data[0]), in, inl);
ctx->num = inl;
*outl = total;
return 1;
}
void
EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
{
unsigned int ret = 0;
if (ctx->num != 0) {
ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
out[ret++] = '\n';
out[ret] = '\0';
ctx->num = 0;
}
*outl = ret;
}
int
EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
{
int i, ret = 0;
unsigned long l;
for (i = dlen; i > 0; i -= 3) {
if (i >= 3) {
l = (((unsigned long)f[0]) << 16L) |
(((unsigned long)f[1]) << 8L) | f[2];
*(t++) = conv_bin2ascii(l >> 18L);
*(t++) = conv_bin2ascii(l >> 12L);
*(t++) = conv_bin2ascii(l >> 6L);
*(t++) = conv_bin2ascii(l );
} else {
l = ((unsigned long)f[0]) << 16L;
if (i == 2)
l |= ((unsigned long)f[1] << 8L);
*(t++) = conv_bin2ascii(l >> 18L);
*(t++) = conv_bin2ascii(l >> 12L);
*(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
*(t++) = '=';
}
ret += 4;
f += 3;
}
*t = '\0';
return (ret);
}
void
EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
{
ctx->num = 0;
ctx->length = 0;
ctx->line_num = 0;
ctx->expect_nl = 0;
}
int
EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
const unsigned char *in, int inl)
{
int seof = 0, eof = 0, rv = -1, ret = 0, i, v, tmp, n, decoded_len;
unsigned char *d;
n = ctx->num;
d = ctx->enc_data;
if (n > 0 && d[n - 1] == '=') {
eof++;
if (n > 1 && d[n - 2] == '=')
eof++;
}
/* Legacy behaviour: an empty input chunk signals end of input. */
if (inl == 0) {
rv = 0;
goto end;
}
for (i = 0; i < inl; i++) {
tmp = *(in++);
v = conv_ascii2bin(tmp);
if (v == B64_ERROR) {
rv = -1;
goto end;
}
if (tmp == '=') {
eof++;
} else if (eof > 0 && B64_BASE64(v)) {
/* More data after padding. */
rv = -1;
goto end;
}
if (eof > 2) {
rv = -1;
goto end;
}
if (v == B64_EOF) {
seof = 1;
goto tail;
}
/* Only save valid base64 characters. */
if (B64_BASE64(v)) {
if (n >= 64) {
/*
* We increment n once per loop, and empty the
* buffer as soon as we reach 64 characters, so
* this can only happen if someone's manually
* messed with the ctx. Refuse to write any
* more data.
*/
rv = -1;
goto end;
}
OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
d[n++] = tmp;
}
if (n == 64) {
decoded_len = EVP_DecodeBlock(out, d, n);
n = 0;
if (decoded_len < 0 || eof > decoded_len) {
rv = -1;
goto end;
}
ret += decoded_len - eof;
out += decoded_len - eof;
}
}
/*
* Legacy behaviour: if the current line is a full base64-block (i.e.,
* has 0 mod 4 base64 characters), it is processed immediately. We keep
* this behaviour as applications may not be calling EVP_DecodeFinal
* properly.
*/
tail:
if (n > 0) {
if ((n & 3) == 0) {
decoded_len = EVP_DecodeBlock(out, d, n);
n = 0;
if (decoded_len < 0 || eof > decoded_len) {
rv = -1;
goto end;
}
ret += (decoded_len - eof);
} else if (seof) {
/* EOF in the middle of a base64 block. */
rv = -1;
goto end;
}
}
rv = seof || (n == 0 && eof) ? 0 : 1;
end:
/* Legacy behaviour. This should probably rather be zeroed on error. */
*outl = ret;
ctx->num = n;
return (rv);
}
int
EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
{
int i, ret = 0, a, b, c, d;
unsigned long l;
/* trim white space from the start of the line. */
while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
f++;
n--;
}
/* strip off stuff at the end of the line
* ascii2bin values B64_WS, B64_EOLN, B64_EOLN and B64_EOF */
while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1]))))
n--;
if (n % 4 != 0)
return (-1);
for (i = 0; i < n; i += 4) {
a = conv_ascii2bin(*(f++));
b = conv_ascii2bin(*(f++));
c = conv_ascii2bin(*(f++));
d = conv_ascii2bin(*(f++));
if ((a & 0x80) || (b & 0x80) ||
(c & 0x80) || (d & 0x80))
return (-1);
l = ((((unsigned long)a) << 18L) |
(((unsigned long)b) << 12L) |
(((unsigned long)c) << 6L) |
(((unsigned long)d)));
*(t++) = (unsigned char)(l >> 16L) & 0xff;
*(t++) = (unsigned char)(l >> 8L) & 0xff;
*(t++) = (unsigned char)(l) & 0xff;
ret += 3;
}
return (ret);
}
int
EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
{
int i;
*outl = 0;
if (ctx->num != 0) {
i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num);
if (i < 0)
return (-1);
ctx->num = 0;
*outl = i;
return (1);
} else
return (1);
}