openssl/crypto/bio/bss_mem.c
Matt Caswell a07dc8167b Fix instances of pointer addition with the NULL pointer
Addition using the NULL pointer (even when adding 0) is undefined
behaviour. Recent versions of ubsan are now complaining about this, so
we fix various instances.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/13513)
2020-11-30 10:37:14 +00:00

392 lines
9.1 KiB
C

/*
* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (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 mem_write(BIO *h, const char *buf, int num);
static int mem_read(BIO *h, char *buf, int size);
static int mem_puts(BIO *h, const char *str);
static int mem_gets(BIO *h, char *str, int size);
static long mem_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int mem_new(BIO *h);
static int secmem_new(BIO *h);
static int mem_free(BIO *data);
static int mem_buf_free(BIO *data);
static int mem_buf_sync(BIO *h);
static const BIO_METHOD mem_method = {
BIO_TYPE_MEM,
"memory buffer",
/* TODO: Convert to new style write function */
bwrite_conv,
mem_write,
/* TODO: Convert to new style read function */
bread_conv,
mem_read,
mem_puts,
mem_gets,
mem_ctrl,
mem_new,
mem_free,
NULL, /* mem_callback_ctrl */
};
static const BIO_METHOD secmem_method = {
BIO_TYPE_MEM,
"secure memory buffer",
/* TODO: Convert to new style write function */
bwrite_conv,
mem_write,
/* TODO: Convert to new style read function */
bread_conv,
mem_read,
mem_puts,
mem_gets,
mem_ctrl,
secmem_new,
mem_free,
NULL, /* mem_callback_ctrl */
};
/*
* BIO memory stores buffer and read pointer
* however the roles are different for read only BIOs.
* In that case the readp just stores the original state
* to be used for reset.
*/
typedef struct bio_buf_mem_st {
struct buf_mem_st *buf; /* allocated buffer */
struct buf_mem_st *readp; /* read pointer */
} BIO_BUF_MEM;
/*
* bio->num is used to hold the value to return on 'empty', if it is 0,
* should_retry is not set
*/
const BIO_METHOD *BIO_s_mem(void)
{
return &mem_method;
}
const BIO_METHOD *BIO_s_secmem(void)
{
return(&secmem_method);
}
BIO *BIO_new_mem_buf(const void *buf, int len)
{
BIO *ret;
BUF_MEM *b;
BIO_BUF_MEM *bb;
size_t sz;
if (buf == NULL) {
ERR_raise(ERR_LIB_BIO, BIO_R_NULL_PARAMETER);
return NULL;
}
sz = (len < 0) ? strlen(buf) : (size_t)len;
if ((ret = BIO_new(BIO_s_mem())) == NULL)
return NULL;
bb = (BIO_BUF_MEM *)ret->ptr;
b = bb->buf;
/* Cast away const and trust in the MEM_RDONLY flag. */
b->data = (void *)buf;
b->length = sz;
b->max = sz;
*bb->readp = *bb->buf;
ret->flags |= BIO_FLAGS_MEM_RDONLY;
/* Since this is static data retrying won't help */
ret->num = 0;
return ret;
}
static int mem_init(BIO *bi, unsigned long flags)
{
BIO_BUF_MEM *bb = OPENSSL_zalloc(sizeof(*bb));
if (bb == NULL)
return 0;
if ((bb->buf = BUF_MEM_new_ex(flags)) == NULL) {
OPENSSL_free(bb);
return 0;
}
if ((bb->readp = OPENSSL_zalloc(sizeof(*bb->readp))) == NULL) {
BUF_MEM_free(bb->buf);
OPENSSL_free(bb);
return 0;
}
*bb->readp = *bb->buf;
bi->shutdown = 1;
bi->init = 1;
bi->num = -1;
bi->ptr = (char *)bb;
return 1;
}
static int mem_new(BIO *bi)
{
return mem_init(bi, 0L);
}
static int secmem_new(BIO *bi)
{
return mem_init(bi, BUF_MEM_FLAG_SECURE);
}
static int mem_free(BIO *a)
{
BIO_BUF_MEM *bb;
if (a == NULL)
return 0;
bb = (BIO_BUF_MEM *)a->ptr;
if (!mem_buf_free(a))
return 0;
OPENSSL_free(bb->readp);
OPENSSL_free(bb);
return 1;
}
static int mem_buf_free(BIO *a)
{
if (a == NULL)
return 0;
if (a->shutdown && a->init && a->ptr != NULL) {
BIO_BUF_MEM *bb = (BIO_BUF_MEM *)a->ptr;
BUF_MEM *b = bb->buf;
if (a->flags & BIO_FLAGS_MEM_RDONLY)
b->data = NULL;
BUF_MEM_free(b);
}
return 1;
}
/*
* Reallocate memory buffer if read pointer differs
* NOT FOR RDONLY
*/
static int mem_buf_sync(BIO *b)
{
if (b != NULL && b->init != 0 && b->ptr != NULL) {
BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
if (bbm->readp->data != bbm->buf->data) {
memmove(bbm->buf->data, bbm->readp->data, bbm->readp->length);
bbm->buf->length = bbm->readp->length;
bbm->readp->data = bbm->buf->data;
}
}
return 0;
}
static int mem_read(BIO *b, char *out, int outl)
{
int ret = -1;
BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
BUF_MEM *bm = bbm->readp;
if (b->flags & BIO_FLAGS_MEM_RDONLY)
bm = bbm->buf;
BIO_clear_retry_flags(b);
ret = (outl >= 0 && (size_t)outl > bm->length) ? (int)bm->length : outl;
if ((out != NULL) && (ret > 0)) {
memcpy(out, bm->data, ret);
bm->length -= ret;
bm->max -= ret;
bm->data += ret;
} else if (bm->length == 0) {
ret = b->num;
if (ret != 0)
BIO_set_retry_read(b);
}
return ret;
}
static int mem_write(BIO *b, const char *in, int inl)
{
int ret = -1;
int blen;
BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
if (in == NULL) {
ERR_raise(ERR_LIB_BIO, BIO_R_NULL_PARAMETER);
goto end;
}
if (b->flags & BIO_FLAGS_MEM_RDONLY) {
ERR_raise(ERR_LIB_BIO, BIO_R_WRITE_TO_READ_ONLY_BIO);
goto end;
}
BIO_clear_retry_flags(b);
if (inl == 0)
return 0;
blen = bbm->readp->length;
mem_buf_sync(b);
if (BUF_MEM_grow_clean(bbm->buf, blen + inl) == 0)
goto end;
memcpy(bbm->buf->data + blen, in, inl);
*bbm->readp = *bbm->buf;
ret = inl;
end:
return ret;
}
static long mem_ctrl(BIO *b, int cmd, long num, void *ptr)
{
long ret = 1;
char **pptr;
BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
BUF_MEM *bm, *bo; /* bio_mem, bio_other */
long off, remain;
if (b->flags & BIO_FLAGS_MEM_RDONLY) {
bm = bbm->buf;
bo = bbm->readp;
} else {
bm = bbm->readp;
bo = bbm->buf;
}
off = bm->data - bo->data;
remain = bm->length;
switch (cmd) {
case BIO_CTRL_RESET:
bm = bbm->buf;
if (bm->data != NULL) {
if (!(b->flags & BIO_FLAGS_MEM_RDONLY)) {
if (!(b->flags & BIO_FLAGS_NONCLEAR_RST)) {
memset(bm->data, 0, bm->max);
bm->length = 0;
}
*bbm->readp = *bbm->buf;
} else {
/* For read only case just reset to the start again */
*bbm->buf = *bbm->readp;
}
}
break;
case BIO_C_FILE_SEEK:
if (num < 0 || num > off + remain)
return -1; /* Can't see outside of the current buffer */
bm->data = bo->data + num;
bm->length = bo->length - num;
bm->max = bo->max - num;
off = num;
/* FALLTHRU */
case BIO_C_FILE_TELL:
ret = off;
break;
case BIO_CTRL_EOF:
ret = (long)(bm->length == 0);
break;
case BIO_C_SET_BUF_MEM_EOF_RETURN:
b->num = (int)num;
break;
case BIO_CTRL_INFO:
ret = (long)bm->length;
if (ptr != NULL) {
pptr = (char **)ptr;
*pptr = (char *)(bm->data);
}
break;
case BIO_C_SET_BUF_MEM:
mem_buf_free(b);
b->shutdown = (int)num;
bbm->buf = ptr;
*bbm->readp = *bbm->buf;
break;
case BIO_C_GET_BUF_MEM_PTR:
if (ptr != NULL) {
if (!(b->flags & BIO_FLAGS_MEM_RDONLY))
mem_buf_sync(b);
bm = bbm->buf;
pptr = (char **)ptr;
*pptr = (char *)bm;
}
break;
case BIO_CTRL_GET_CLOSE:
ret = (long)b->shutdown;
break;
case BIO_CTRL_SET_CLOSE:
b->shutdown = (int)num;
break;
case BIO_CTRL_WPENDING:
ret = 0L;
break;
case BIO_CTRL_PENDING:
ret = (long)bm->length;
break;
case BIO_CTRL_DUP:
case BIO_CTRL_FLUSH:
ret = 1;
break;
case BIO_CTRL_PUSH:
case BIO_CTRL_POP:
default:
ret = 0;
break;
}
return ret;
}
static int mem_gets(BIO *bp, char *buf, int size)
{
int i, j;
int ret = -1;
char *p;
BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)bp->ptr;
BUF_MEM *bm = bbm->readp;
if (bp->flags & BIO_FLAGS_MEM_RDONLY)
bm = bbm->buf;
BIO_clear_retry_flags(bp);
j = bm->length;
if ((size - 1) < j)
j = size - 1;
if (j <= 0) {
*buf = '\0';
return 0;
}
p = bm->data;
for (i = 0; i < j; i++) {
if (p[i] == '\n') {
i++;
break;
}
}
/*
* i is now the max num of bytes to copy, either j or up to
* and including the first newline
*/
i = mem_read(bp, buf, i);
if (i > 0)
buf[i] = '\0';
ret = i;
return ret;
}
static int mem_puts(BIO *bp, const char *str)
{
int n, ret;
n = strlen(str);
ret = mem_write(bp, str, n);
/* memory semantics is that it will always work */
return ret;
}