openssl/crypto/bio/bf_buff.c

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2023-05-09 22:08:48 +00:00
/*
* Copyright 1995-2016 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 <errno.h>
#include "bio_local.h"
#include "internal/cryptlib.h"
static int buffer_write(BIO *h, const char *buf, int num);
static int buffer_read(BIO *h, char *buf, int size);
static int buffer_puts(BIO *h, const char *str);
static int buffer_gets(BIO *h, char *str, int size);
static long buffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int buffer_new(BIO *h);
static int buffer_free(BIO *data);
static long buffer_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
#define DEFAULT_BUFFER_SIZE 4096
static const BIO_METHOD methods_buffer = {
BIO_TYPE_BUFFER,
"buffer",
/* TODO: Convert to new style write function */
bwrite_conv,
buffer_write,
/* TODO: Convert to new style read function */
bread_conv,
buffer_read,
buffer_puts,
buffer_gets,
buffer_ctrl,
buffer_new,
buffer_free,
buffer_callback_ctrl,
};
const BIO_METHOD *BIO_f_buffer(void)
{
return &methods_buffer;
}
static int buffer_new(BIO *bi)
{
BIO_F_BUFFER_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
if (ctx == NULL)
return 0;
ctx->ibuf_size = DEFAULT_BUFFER_SIZE;
ctx->ibuf = OPENSSL_malloc(DEFAULT_BUFFER_SIZE);
if (ctx->ibuf == NULL) {
OPENSSL_free(ctx);
return 0;
}
ctx->obuf_size = DEFAULT_BUFFER_SIZE;
ctx->obuf = OPENSSL_malloc(DEFAULT_BUFFER_SIZE);
if (ctx->obuf == NULL) {
OPENSSL_free(ctx->ibuf);
OPENSSL_free(ctx);
return 0;
}
bi->init = 1;
bi->ptr = (char *)ctx;
bi->flags = 0;
return 1;
}
static int buffer_free(BIO *a)
{
BIO_F_BUFFER_CTX *b;
if (a == NULL)
return 0;
b = (BIO_F_BUFFER_CTX *)a->ptr;
OPENSSL_free(b->ibuf);
OPENSSL_free(b->obuf);
OPENSSL_free(a->ptr);
a->ptr = NULL;
a->init = 0;
a->flags = 0;
return 1;
}
static int buffer_read(BIO *b, char *out, int outl)
{
int i, num = 0;
BIO_F_BUFFER_CTX *ctx;
if (out == NULL)
return 0;
ctx = (BIO_F_BUFFER_CTX *)b->ptr;
if ((ctx == NULL) || (b->next_bio == NULL))
return 0;
num = 0;
BIO_clear_retry_flags(b);
start:
i = ctx->ibuf_len;
/* If there is stuff left over, grab it */
if (i != 0) {
if (i > outl)
i = outl;
memcpy(out, &(ctx->ibuf[ctx->ibuf_off]), i);
ctx->ibuf_off += i;
ctx->ibuf_len -= i;
num += i;
if (outl == i)
return num;
outl -= i;
out += i;
}
/*
* We may have done a partial read. try to do more. We have nothing in
* the buffer. If we get an error and have read some data, just return it
* and let them retry to get the error again. copy direct to parent
* address space
*/
if (outl > ctx->ibuf_size) {
for (;;) {
i = BIO_read(b->next_bio, out, outl);
if (i <= 0) {
BIO_copy_next_retry(b);
if (i < 0)
return ((num > 0) ? num : i);
if (i == 0)
return num;
}
num += i;
if (outl == i)
return num;
out += i;
outl -= i;
}
}
/* else */
/* we are going to be doing some buffering */
i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);
if (i <= 0) {
BIO_copy_next_retry(b);
if (i < 0)
return ((num > 0) ? num : i);
if (i == 0)
return num;
}
ctx->ibuf_off = 0;
ctx->ibuf_len = i;
/* Lets re-read using ourselves :-) */
goto start;
}
static int buffer_write(BIO *b, const char *in, int inl)
{
int i, num = 0;
BIO_F_BUFFER_CTX *ctx;
if ((in == NULL) || (inl <= 0))
return 0;
ctx = (BIO_F_BUFFER_CTX *)b->ptr;
if ((ctx == NULL) || (b->next_bio == NULL))
return 0;
BIO_clear_retry_flags(b);
start:
i = ctx->obuf_size - (ctx->obuf_len + ctx->obuf_off);
/* add to buffer and return */
if (i >= inl) {
memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, inl);
ctx->obuf_len += inl;
return (num + inl);
}
/* else */
/* stuff already in buffer, so add to it first, then flush */
if (ctx->obuf_len != 0) {
if (i > 0) { /* lets fill it up if we can */
memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, i);
in += i;
inl -= i;
num += i;
ctx->obuf_len += i;
}
/* we now have a full buffer needing flushing */
for (;;) {
i = BIO_write(b->next_bio, &(ctx->obuf[ctx->obuf_off]),
ctx->obuf_len);
if (i <= 0) {
BIO_copy_next_retry(b);
if (i < 0)
return ((num > 0) ? num : i);
if (i == 0)
return num;
}
ctx->obuf_off += i;
ctx->obuf_len -= i;
if (ctx->obuf_len == 0)
break;
}
}
/*
* we only get here if the buffer has been flushed and we still have
* stuff to write
*/
ctx->obuf_off = 0;
/* we now have inl bytes to write */
while (inl >= ctx->obuf_size) {
i = BIO_write(b->next_bio, in, inl);
if (i <= 0) {
BIO_copy_next_retry(b);
if (i < 0)
return ((num > 0) ? num : i);
if (i == 0)
return num;
}
num += i;
in += i;
inl -= i;
if (inl == 0)
return num;
}
/*
* copy the rest into the buffer since we have only a small amount left
*/
goto start;
}
static long buffer_ctrl(BIO *b, int cmd, long num, void *ptr)
{
BIO *dbio;
BIO_F_BUFFER_CTX *ctx;
long ret = 1;
char *p1, *p2;
int r, i, *ip;
int ibs, obs;
ctx = (BIO_F_BUFFER_CTX *)b->ptr;
switch (cmd) {
case BIO_CTRL_RESET:
ctx->ibuf_off = 0;
ctx->ibuf_len = 0;
ctx->obuf_off = 0;
ctx->obuf_len = 0;
if (b->next_bio == NULL)
return 0;
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
break;
case BIO_CTRL_EOF:
if (ctx->ibuf_len > 0)
return 0;
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
break;
case BIO_CTRL_INFO:
ret = (long)ctx->obuf_len;
break;
case BIO_C_GET_BUFF_NUM_LINES:
ret = 0;
p1 = ctx->ibuf;
for (i = 0; i < ctx->ibuf_len; i++) {
if (p1[ctx->ibuf_off + i] == '\n')
ret++;
}
break;
case BIO_CTRL_WPENDING:
ret = (long)ctx->obuf_len;
if (ret == 0) {
if (b->next_bio == NULL)
return 0;
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
}
break;
case BIO_CTRL_PENDING:
ret = (long)ctx->ibuf_len;
if (ret == 0) {
if (b->next_bio == NULL)
return 0;
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
}
break;
case BIO_C_SET_BUFF_READ_DATA:
if (num > ctx->ibuf_size) {
p1 = OPENSSL_malloc((int)num);
if (p1 == NULL)
goto malloc_error;
OPENSSL_free(ctx->ibuf);
ctx->ibuf = p1;
}
ctx->ibuf_off = 0;
ctx->ibuf_len = (int)num;
memcpy(ctx->ibuf, ptr, (int)num);
ret = 1;
break;
case BIO_C_SET_BUFF_SIZE:
if (ptr != NULL) {
ip = (int *)ptr;
if (*ip == 0) {
ibs = (int)num;
obs = ctx->obuf_size;
} else { /* if (*ip == 1) */
ibs = ctx->ibuf_size;
obs = (int)num;
}
} else {
ibs = (int)num;
obs = (int)num;
}
p1 = ctx->ibuf;
p2 = ctx->obuf;
if ((ibs > DEFAULT_BUFFER_SIZE) && (ibs != ctx->ibuf_size)) {
p1 = OPENSSL_malloc((int)num);
if (p1 == NULL)
goto malloc_error;
}
if ((obs > DEFAULT_BUFFER_SIZE) && (obs != ctx->obuf_size)) {
p2 = OPENSSL_malloc((int)num);
if (p2 == NULL) {
if (p1 != ctx->ibuf)
OPENSSL_free(p1);
goto malloc_error;
}
}
if (ctx->ibuf != p1) {
OPENSSL_free(ctx->ibuf);
ctx->ibuf = p1;
ctx->ibuf_off = 0;
ctx->ibuf_len = 0;
ctx->ibuf_size = ibs;
}
if (ctx->obuf != p2) {
OPENSSL_free(ctx->obuf);
ctx->obuf = p2;
ctx->obuf_off = 0;
ctx->obuf_len = 0;
ctx->obuf_size = obs;
}
break;
case BIO_C_DO_STATE_MACHINE:
if (b->next_bio == NULL)
return 0;
BIO_clear_retry_flags(b);
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
BIO_copy_next_retry(b);
break;
case BIO_CTRL_FLUSH:
if (b->next_bio == NULL)
return 0;
if (ctx->obuf_len <= 0) {
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
break;
}
for (;;) {
BIO_clear_retry_flags(b);
if (ctx->obuf_len > 0) {
r = BIO_write(b->next_bio,
&(ctx->obuf[ctx->obuf_off]), ctx->obuf_len);
BIO_copy_next_retry(b);
if (r <= 0)
return (long)r;
ctx->obuf_off += r;
ctx->obuf_len -= r;
} else {
ctx->obuf_len = 0;
ctx->obuf_off = 0;
break;
}
}
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
break;
case BIO_CTRL_DUP:
dbio = (BIO *)ptr;
if (!BIO_set_read_buffer_size(dbio, ctx->ibuf_size) ||
!BIO_set_write_buffer_size(dbio, ctx->obuf_size))
ret = 0;
break;
case BIO_CTRL_PEEK:
/* Ensure there's stuff in the input buffer */
{
char fake_buf[1];
(void)buffer_read(b, fake_buf, 0);
}
if (num > ctx->ibuf_len)
num = ctx->ibuf_len;
memcpy(ptr, &(ctx->ibuf[ctx->ibuf_off]), num);
ret = num;
break;
default:
if (b->next_bio == NULL)
return 0;
ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
break;
}
return ret;
malloc_error:
BIOerr(BIO_F_BUFFER_CTRL, ERR_R_MALLOC_FAILURE);
return 0;
}
static long buffer_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
{
long ret = 1;
if (b->next_bio == NULL)
return 0;
switch (cmd) {
default:
ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
break;
}
return ret;
}
static int buffer_gets(BIO *b, char *buf, int size)
{
BIO_F_BUFFER_CTX *ctx;
int num = 0, i, flag;
char *p;
ctx = (BIO_F_BUFFER_CTX *)b->ptr;
size--; /* reserve space for a '\0' */
BIO_clear_retry_flags(b);
for (;;) {
if (ctx->ibuf_len > 0) {
p = &(ctx->ibuf[ctx->ibuf_off]);
flag = 0;
for (i = 0; (i < ctx->ibuf_len) && (i < size); i++) {
*(buf++) = p[i];
if (p[i] == '\n') {
flag = 1;
i++;
break;
}
}
num += i;
size -= i;
ctx->ibuf_len -= i;
ctx->ibuf_off += i;
if (flag || size == 0) {
*buf = '\0';
return num;
}
} else { /* read another chunk */
i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);
if (i <= 0) {
BIO_copy_next_retry(b);
*buf = '\0';
if (i < 0)
return ((num > 0) ? num : i);
if (i == 0)
return num;
}
ctx->ibuf_len = i;
ctx->ibuf_off = 0;
}
}
}
static int buffer_puts(BIO *b, const char *str)
{
return buffer_write(b, str, strlen(str));
}