ref: 8bc69a872883224675a55db51ac8f60ab5ed9e5a
dir: /third_party/boringssl/src/decrepit/bio/base64_bio.c/
/* 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 <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <openssl/base64.h>
#include <openssl/bio.h>
#include <openssl/buffer.h>
#include <openssl/evp.h>
#include <openssl/mem.h>
#include "../../crypto/internal.h"
#define B64_BLOCK_SIZE 1024
#define B64_BLOCK_SIZE2 768
#define B64_NONE 0
#define B64_ENCODE 1
#define B64_DECODE 2
#define EVP_ENCODE_LENGTH(l) (((l+2)/3*4)+(l/48+1)*2+80)
typedef struct b64_struct {
int buf_len;
int buf_off;
int tmp_len; // used to find the start when decoding
int tmp_nl; // If true, scan until '\n'
int encode;
int start; // have we started decoding yet?
int cont; // <= 0 when finished
EVP_ENCODE_CTX base64;
char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
char tmp[B64_BLOCK_SIZE];
} BIO_B64_CTX;
static int b64_new(BIO *bio) {
BIO_B64_CTX *ctx;
ctx = OPENSSL_malloc(sizeof(*ctx));
if (ctx == NULL) {
return 0;
}
OPENSSL_memset(ctx, 0, sizeof(*ctx));
ctx->cont = 1;
ctx->start = 1;
bio->init = 1;
bio->ptr = (char *)ctx;
return 1;
}
static int b64_free(BIO *bio) {
if (bio == NULL) {
return 0;
}
OPENSSL_free(bio->ptr);
bio->ptr = NULL;
bio->init = 0;
bio->flags = 0;
return 1;
}
static int b64_read(BIO *b, char *out, int outl) {
int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;
BIO_B64_CTX *ctx;
uint8_t *p, *q;
if (out == NULL) {
return 0;
}
ctx = (BIO_B64_CTX *) b->ptr;
if (ctx == NULL || b->next_bio == NULL) {
return 0;
}
BIO_clear_retry_flags(b);
if (ctx->encode != B64_DECODE) {
ctx->encode = B64_DECODE;
ctx->buf_len = 0;
ctx->buf_off = 0;
ctx->tmp_len = 0;
EVP_DecodeInit(&ctx->base64);
}
// First check if there are bytes decoded/encoded
if (ctx->buf_len > 0) {
assert(ctx->buf_len >= ctx->buf_off);
i = ctx->buf_len - ctx->buf_off;
if (i > outl) {
i = outl;
}
assert(ctx->buf_off + i < (int)sizeof(ctx->buf));
OPENSSL_memcpy(out, &ctx->buf[ctx->buf_off], i);
ret = i;
out += i;
outl -= i;
ctx->buf_off += i;
if (ctx->buf_len == ctx->buf_off) {
ctx->buf_len = 0;
ctx->buf_off = 0;
}
}
// At this point, we have room of outl bytes and an empty buffer, so we
// should read in some more.
ret_code = 0;
while (outl > 0) {
if (ctx->cont <= 0) {
break;
}
i = BIO_read(b->next_bio, &(ctx->tmp[ctx->tmp_len]),
B64_BLOCK_SIZE - ctx->tmp_len);
if (i <= 0) {
ret_code = i;
// Should we continue next time we are called?
if (!BIO_should_retry(b->next_bio)) {
ctx->cont = i;
// If buffer empty break
if (ctx->tmp_len == 0) {
break;
} else {
// Fall through and process what we have
i = 0;
}
} else {
// else we retry and add more data to buffer
break;
}
}
i += ctx->tmp_len;
ctx->tmp_len = i;
// We need to scan, a line at a time until we have a valid line if we are
// starting.
if (ctx->start && (BIO_test_flags(b, BIO_FLAGS_BASE64_NO_NL))) {
// ctx->start = 1;
ctx->tmp_len = 0;
} else if (ctx->start) {
q = p = (uint8_t *)ctx->tmp;
num = 0;
for (j = 0; j < i; j++) {
if (*(q++) != '\n') {
continue;
}
// due to a previous very long line, we need to keep on scanning for a
// '\n' before we even start looking for base64 encoded stuff.
if (ctx->tmp_nl) {
p = q;
ctx->tmp_nl = 0;
continue;
}
k = EVP_DecodeUpdate(&(ctx->base64), (uint8_t *)ctx->buf, &num, p,
q - p);
if (k <= 0 && num == 0 && ctx->start) {
EVP_DecodeInit(&ctx->base64);
} else {
if (p != (uint8_t *)&(ctx->tmp[0])) {
i -= (p - (uint8_t *)&(ctx->tmp[0]));
for (x = 0; x < i; x++) {
ctx->tmp[x] = p[x];
}
}
EVP_DecodeInit(&ctx->base64);
ctx->start = 0;
break;
}
p = q;
}
// we fell off the end without starting
if (j == i && num == 0) {
// Is this is one long chunk?, if so, keep on reading until a new
// line.
if (p == (uint8_t *)&(ctx->tmp[0])) {
// Check buffer full
if (i == B64_BLOCK_SIZE) {
ctx->tmp_nl = 1;
ctx->tmp_len = 0;
}
} else if (p != q) { // finished on a '\n'
n = q - p;
for (ii = 0; ii < n; ii++) {
ctx->tmp[ii] = p[ii];
}
ctx->tmp_len = n;
}
// else finished on a '\n'
continue;
} else {
ctx->tmp_len = 0;
}
} else if (i < B64_BLOCK_SIZE && ctx->cont > 0) {
// If buffer isn't full and we can retry then restart to read in more
// data.
continue;
}
if (BIO_test_flags(b, BIO_FLAGS_BASE64_NO_NL)) {
int z, jj;
jj = i & ~3; // process per 4
z = EVP_DecodeBlock((uint8_t *)ctx->buf, (uint8_t *)ctx->tmp, jj);
if (jj > 2) {
if (ctx->tmp[jj - 1] == '=') {
z--;
if (ctx->tmp[jj - 2] == '=') {
z--;
}
}
}
// z is now number of output bytes and jj is the number consumed.
if (jj != i) {
OPENSSL_memmove(ctx->tmp, &ctx->tmp[jj], i - jj);
ctx->tmp_len = i - jj;
}
ctx->buf_len = 0;
if (z > 0) {
ctx->buf_len = z;
}
i = z;
} else {
i = EVP_DecodeUpdate(&(ctx->base64), (uint8_t *)ctx->buf,
&ctx->buf_len, (uint8_t *)ctx->tmp, i);
ctx->tmp_len = 0;
}
ctx->buf_off = 0;
if (i < 0) {
ret_code = 0;
ctx->buf_len = 0;
break;
}
if (ctx->buf_len <= outl) {
i = ctx->buf_len;
} else {
i = outl;
}
OPENSSL_memcpy(out, ctx->buf, i);
ret += i;
ctx->buf_off = i;
if (ctx->buf_off == ctx->buf_len) {
ctx->buf_len = 0;
ctx->buf_off = 0;
}
outl -= i;
out += i;
}
BIO_copy_next_retry(b);
return ret == 0 ? ret_code : ret;
}
static int b64_write(BIO *b, const char *in, int inl) {
int ret = 0, n, i;
BIO_B64_CTX *ctx;
ctx = (BIO_B64_CTX *)b->ptr;
BIO_clear_retry_flags(b);
if (ctx->encode != B64_ENCODE) {
ctx->encode = B64_ENCODE;
ctx->buf_len = 0;
ctx->buf_off = 0;
ctx->tmp_len = 0;
EVP_EncodeInit(&(ctx->base64));
}
assert(ctx->buf_off < (int)sizeof(ctx->buf));
assert(ctx->buf_len <= (int)sizeof(ctx->buf));
assert(ctx->buf_len >= ctx->buf_off);
n = ctx->buf_len - ctx->buf_off;
while (n > 0) {
i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
if (i <= 0) {
BIO_copy_next_retry(b);
return i;
}
assert(i <= n);
ctx->buf_off += i;
assert(ctx->buf_off <= (int)sizeof(ctx->buf));
assert(ctx->buf_len >= ctx->buf_off);
n -= i;
}
// at this point all pending data has been written.
ctx->buf_off = 0;
ctx->buf_len = 0;
if (in == NULL || inl <= 0) {
return 0;
}
while (inl > 0) {
n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;
if (BIO_test_flags(b, BIO_FLAGS_BASE64_NO_NL)) {
if (ctx->tmp_len > 0) {
assert(ctx->tmp_len <= 3);
n = 3 - ctx->tmp_len;
// There's a theoretical possibility of this.
if (n > inl) {
n = inl;
}
OPENSSL_memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);
ctx->tmp_len += n;
ret += n;
if (ctx->tmp_len < 3) {
break;
}
ctx->buf_len = EVP_EncodeBlock((uint8_t *)ctx->buf, (uint8_t *)ctx->tmp,
ctx->tmp_len);
assert(ctx->buf_len <= (int)sizeof(ctx->buf));
assert(ctx->buf_len >= ctx->buf_off);
// Since we're now done using the temporary buffer, the length should
// be zeroed.
ctx->tmp_len = 0;
} else {
if (n < 3) {
OPENSSL_memcpy(ctx->tmp, in, n);
ctx->tmp_len = n;
ret += n;
break;
}
n -= n % 3;
ctx->buf_len =
EVP_EncodeBlock((uint8_t *)ctx->buf, (const uint8_t *)in, n);
assert(ctx->buf_len <= (int)sizeof(ctx->buf));
assert(ctx->buf_len >= ctx->buf_off);
ret += n;
}
} else {
EVP_EncodeUpdate(&(ctx->base64), (uint8_t *)ctx->buf, &ctx->buf_len,
(uint8_t *)in, n);
assert(ctx->buf_len <= (int)sizeof(ctx->buf));
assert(ctx->buf_len >= ctx->buf_off);
ret += n;
}
inl -= n;
in += n;
ctx->buf_off = 0;
n = ctx->buf_len;
while (n > 0) {
i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
if (i <= 0) {
BIO_copy_next_retry(b);
return ret == 0 ? i : ret;
}
assert(i <= n);
n -= i;
ctx->buf_off += i;
assert(ctx->buf_off <= (int)sizeof(ctx->buf));
assert(ctx->buf_len >= ctx->buf_off);
}
ctx->buf_len = 0;
ctx->buf_off = 0;
}
return ret;
}
static long b64_ctrl(BIO *b, int cmd, long num, void *ptr) {
BIO_B64_CTX *ctx;
long ret = 1;
int i;
ctx = (BIO_B64_CTX *)b->ptr;
switch (cmd) {
case BIO_CTRL_RESET:
ctx->cont = 1;
ctx->start = 1;
ctx->encode = B64_NONE;
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
break;
case BIO_CTRL_EOF: // More to read
if (ctx->cont <= 0) {
ret = 1;
} else {
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
}
break;
case BIO_CTRL_WPENDING: // More to write in buffer
assert(ctx->buf_len >= ctx->buf_off);
ret = ctx->buf_len - ctx->buf_off;
if ((ret == 0) && (ctx->encode != B64_NONE) && (ctx->base64.data_used != 0)) {
ret = 1;
} else if (ret <= 0) {
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
}
break;
case BIO_CTRL_PENDING: // More to read in buffer
assert(ctx->buf_len >= ctx->buf_off);
ret = ctx->buf_len - ctx->buf_off;
if (ret <= 0) {
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
}
break;
case BIO_CTRL_FLUSH:
// do a final write
again:
while (ctx->buf_len != ctx->buf_off) {
i = b64_write(b, NULL, 0);
if (i < 0) {
return i;
}
}
if (BIO_test_flags(b, BIO_FLAGS_BASE64_NO_NL)) {
if (ctx->tmp_len != 0) {
ctx->buf_len = EVP_EncodeBlock((uint8_t *)ctx->buf,
(uint8_t *)ctx->tmp, ctx->tmp_len);
ctx->buf_off = 0;
ctx->tmp_len = 0;
goto again;
}
} else if (ctx->encode != B64_NONE && ctx->base64.data_used != 0) {
ctx->buf_off = 0;
EVP_EncodeFinal(&(ctx->base64), (uint8_t *)ctx->buf, &(ctx->buf_len));
// push out the bytes
goto again;
}
// Finally flush the underlying BIO
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
break;
case BIO_C_DO_STATE_MACHINE:
BIO_clear_retry_flags(b);
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
BIO_copy_next_retry(b);
break;
case BIO_CTRL_INFO:
case BIO_CTRL_GET:
case BIO_CTRL_SET:
default:
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
break;
}
return ret;
}
static long b64_callback_ctrl(BIO *b, int cmd, bio_info_cb fp) {
if (b->next_bio == NULL) {
return 0;
}
return BIO_callback_ctrl(b->next_bio, cmd, fp);
}
static const BIO_METHOD b64_method = {
BIO_TYPE_BASE64, "base64 encoding", b64_write, b64_read, NULL /* puts */,
NULL /* gets */, b64_ctrl, b64_new, b64_free, b64_callback_ctrl,
};
const BIO_METHOD *BIO_f_base64(void) { return &b64_method; }