/*
* Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <limits.h>
#include "internal/cryptlib.h"
#include <openssl/evp.h>
#include "crypto/evp.h"
#include "evp_local.h"
static unsigned char conv_ascii2bin(unsigned char a,
const unsigned char *table);
static int evp_encodeblock_int(EVP_ENCODE_CTX *ctx, unsigned char *t,
const unsigned char *f, int dlen);
static int evp_decodeblock_int(EVP_ENCODE_CTX *ctx, unsigned char *t,
const unsigned char *f, int n);
#ifndef CHARSET_EBCDIC
# define conv_bin2ascii(a, table) ((table)[(a)&0x3f])
#else
/*
* We assume that PEM encoded files are EBCDIC files (i.e., printable text
* files). Convert them here while decoding. When encoding, output is EBCDIC
* (text) format again. (No need for conversion in the conv_bin2ascii macro,
* as the underlying textstring data_bin2ascii[] is already EBCDIC)
*/
# define conv_bin2ascii(a, table) ((table)[(a)&0x3f])
#endif
/*-
* 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] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
/* SRP uses a different base64 alphabet */
static const unsigned char srpdata_bin2ascii[65] =
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./";
/*-
* 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 const unsigned char srpdata_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, 0xFF, 0xFF, 0xF2, 0x3E, 0x3F,
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
0xFF, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,
0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
0x21, 0x22, 0x23, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A,
0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32,
0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
0x3B, 0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
};
#ifndef CHARSET_EBCDIC
static unsigned char conv_ascii2bin(unsigned char a, const unsigned char *table)
{
if (a & 0x80)
return B64_ERROR;
return table[a];
}
#else
static unsigned char conv_ascii2bin(unsigned char a, const unsigned char *table)
{
a = os_toascii[a];
if (a & 0x80)
return B64_ERROR;
return table[a];
}
#endif
EVP_ENCODE_CTX *EVP_ENCODE_CTX_new(void)
{
return OPENSSL_zalloc(sizeof(EVP_ENCODE_CTX));
}
void EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx)
{
OPENSSL_free(ctx);
}
int EVP_ENCODE_CTX_copy(EVP_ENCODE_CTX *dctx, EVP_ENCODE_CTX *sctx)
{
memcpy(dctx, sctx, sizeof(EVP_ENCODE_CTX));
return 1;
}
int EVP_ENCODE_CTX_num(EVP_ENCODE_CTX *ctx)
{
return ctx->num;
}
void evp_encode_ctx_set_flags(EVP_ENCODE_CTX *ctx, unsigned int flags)
{
ctx->flags = flags;
}
void EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
{
ctx->length = 48;
ctx->num = 0;
ctx->line_num = 0;
ctx->flags = 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_int(ctx, out, ctx->enc_data, ctx->length);
ctx->num = 0;
out += j;
total = j;
if ((ctx->flags & EVP_ENCODE_CTX_NO_NEWLINES) == 0) {
*(out++) = '\n';
total++;
}
*out = '\0';
}
while (inl >= ctx->length && total <= INT_MAX) {
j = evp_encodeblock_int(ctx, out, in, ctx->length);
in += ctx->length;
inl -= ctx->length;
out += j;
total += j;
if ((ctx->flags & EVP_ENCODE_CTX_NO_NEWLINES) == 0) {
*(out++) = '\n';
total++;
}
*out = '\0';
}
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_int(ctx, out, ctx->enc_data, ctx->num);
if ((ctx->flags & EVP_ENCODE_CTX_NO_NEWLINES) == 0)
out[ret++] = '\n';
out[ret] = '\0';
ctx->num = 0;
}
*outl = ret;
}
static int evp_encodeblock_int(EVP_ENCODE_CTX *ctx, unsigned char *t,
const unsigned char *f, int dlen)
{
int i, ret = 0;
unsigned long l;
const unsigned char *table;
if (ctx != NULL && (ctx->flags & EVP_ENCODE_CTX_USE_SRP_ALPHABET) != 0)
table = srpdata_bin2ascii;
else
table = data_bin2ascii;
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, table);
*(t++) = conv_bin2ascii(l >> 12L, table);
*(t++) = conv_bin2ascii(l >> 6L, table);
*(t++) = conv_bin2ascii(l, table);
} else {
l = ((unsigned long)f[0]) << 16L;
if (i == 2)
l |= ((unsigned long)f[1] << 8L);
*(t++) = conv_bin2ascii(l >> 18L, table);
*(t++) = conv_bin2ascii(l >> 12L, table);
*(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L, table);
*(t++) = '=';
}
ret += 4;
f += 3;
}
*t = '\0';
return ret;
}
int EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
{
return evp_encodeblock_int(NULL, t, f, dlen);
}
void EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
{
/* Only ctx->num and ctx->flags are used during decoding. */
ctx->num = 0;
ctx->length = 0;
ctx->line_num = 0;
ctx->flags = 0;
}
/*-
* -1 for error
* 0 for last line
* 1 for full line
*
* Note: even though EVP_DecodeUpdate attempts to detect and report end of
* content, the context doesn't currently remember it and will accept more data
* in the next call. Therefore, the caller is responsible for checking and
* rejecting a 0 return value in the middle of content.
*
* Note: even though EVP_DecodeUpdate has historically tried to detect end of
* content based on line length, this has never worked properly. Therefore,
* we now return 0 when one of the following is true:
* - Padding or B64_EOF was detected and the last block is complete.
* - Input has zero-length.
* -1 is returned if:
* - Invalid characters are detected.
* - There is extra trailing padding, or data after padding.
* - B64_EOF is detected after an incomplete base64 block.
*/
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;
const unsigned char *table;
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;
}
if ((ctx->flags & EVP_ENCODE_CTX_USE_SRP_ALPHABET) != 0)
table = srpdata_ascii2bin;
else
table = data_ascii2bin;
for (i = 0; i < inl; i++) {
tmp = *(in++);
v = conv_ascii2bin(tmp, table);
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_int(ctx, 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_int(ctx, 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;
}
static int evp_decodeblock_int(EVP_ENCODE_CTX *ctx, unsigned char *t,
const unsigned char *f, int n)
{
int i, ret = 0, a, b, c, d;
unsigned long l;
const unsigned char *table;
if (ctx != NULL && (ctx->flags & EVP_ENCODE_CTX_USE_SRP_ALPHABET) != 0)
table = srpdata_ascii2bin;
else
table = data_ascii2bin;
/* trim white space from the start of the line. */
while ((conv_ascii2bin(*f, table) == 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], table))))
n--;
if (n % 4 != 0)
return -1;
for (i = 0; i < n; i += 4) {
a = conv_ascii2bin(*(f++), table);
b = conv_ascii2bin(*(f++), table);
c = conv_ascii2bin(*(f++), table);
d = conv_ascii2bin(*(f++), table);
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_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
{
return evp_decodeblock_int(NULL, t, f, n);
}
int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
{
int i;
*outl = 0;
if (ctx->num != 0) {
i = evp_decodeblock_int(ctx, out, ctx->enc_data, ctx->num);
if (i < 0)
return -1;
ctx->num = 0;
*outl = i;
return 1;
} else
return 1;
}