bss_bio.c
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上传日期:2020-08-09
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- /* crypto/bio/bss_bio.c -*- Mode: C; c-file-style: "eay" -*- */
- /* ====================================================================
- * Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved.
- *
- * 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 above 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 acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
- *
- * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
- * endorse or promote products derived from this software without
- * prior written permission. For written permission, please contact
- * openssl-core@openssl.org.
- *
- * 5. Products derived from this software may not be called "OpenSSL"
- * nor may "OpenSSL" appear in their names without prior written
- * permission of the OpenSSL Project.
- *
- * 6. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
- *
- * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
- * EXPRESSED 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 OpenSSL PROJECT OR
- * ITS 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.
- * ====================================================================
- *
- * This product includes cryptographic software written by Eric Young
- * (eay@cryptsoft.com). This product includes software written by Tim
- * Hudson (tjh@cryptsoft.com).
- *
- */
- /* Special method for a BIO where the other endpoint is also a BIO
- * of this kind, handled by the same thread (i.e. the "peer" is actually
- * ourselves, wearing a different hat).
- * Such "BIO pairs" are mainly for using the SSL library with I/O interfaces
- * for which no specific BIO method is available.
- * See ssl/ssltest.c for some hints on how this can be used. */
- /* BIO_DEBUG implies BIO_PAIR_DEBUG */
- #ifdef BIO_DEBUG
- # ifndef BIO_PAIR_DEBUG
- # define BIO_PAIR_DEBUG
- # endif
- #endif
- /* disable assert() unless BIO_PAIR_DEBUG has been defined */
- #ifndef BIO_PAIR_DEBUG
- # ifndef NDEBUG
- # define NDEBUG
- # endif
- #endif
- #include <assert.h>
- #include <limits.h>
- #include <stdlib.h>
- #include <string.h>
- #include <openssl/bio.h>
- #include <openssl/err.h>
- #include <openssl/crypto.h>
- #include "e_os.h"
- /* VxWorks defines SSIZE_MAX with an empty value causing compile errors */
- #if defined(OPENSSL_SYS_VXWORKS)
- # undef SSIZE_MAX
- #endif
- #ifndef SSIZE_MAX
- # define SSIZE_MAX INT_MAX
- #endif
- static int bio_new(BIO *bio);
- static int bio_free(BIO *bio);
- static int bio_read(BIO *bio, char *buf, int size);
- static int bio_write(BIO *bio, const char *buf, int num);
- static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr);
- static int bio_puts(BIO *bio, const char *str);
- static int bio_make_pair(BIO *bio1, BIO *bio2);
- static void bio_destroy_pair(BIO *bio);
- static BIO_METHOD methods_biop =
- {
- BIO_TYPE_BIO,
- "BIO pair",
- bio_write,
- bio_read,
- bio_puts,
- NULL /* no bio_gets */,
- bio_ctrl,
- bio_new,
- bio_free,
- NULL /* no bio_callback_ctrl */
- };
- BIO_METHOD *BIO_s_bio(void)
- {
- return &methods_biop;
- }
- struct bio_bio_st
- {
- BIO *peer; /* NULL if buf == NULL.
- * If peer != NULL, then peer->ptr is also a bio_bio_st,
- * and its "peer" member points back to us.
- * peer != NULL iff init != 0 in the BIO. */
-
- /* This is for what we write (i.e. reading uses peer's struct): */
- int closed; /* valid iff peer != NULL */
- size_t len; /* valid iff buf != NULL; 0 if peer == NULL */
- size_t offset; /* valid iff buf != NULL; 0 if len == 0 */
- size_t size;
- char *buf; /* "size" elements (if != NULL) */
- size_t request; /* valid iff peer != NULL; 0 if len != 0,
- * otherwise set by peer to number of bytes
- * it (unsuccessfully) tried to read,
- * never more than buffer space (size-len) warrants. */
- };
- static int bio_new(BIO *bio)
- {
- struct bio_bio_st *b;
-
- b = OPENSSL_malloc(sizeof *b);
- if (b == NULL)
- return 0;
- b->peer = NULL;
- b->size = 17*1024; /* enough for one TLS record (just a default) */
- b->buf = NULL;
- bio->ptr = b;
- return 1;
- }
- static int bio_free(BIO *bio)
- {
- struct bio_bio_st *b;
- if (bio == NULL)
- return 0;
- b = bio->ptr;
- assert(b != NULL);
- if (b->peer)
- bio_destroy_pair(bio);
-
- if (b->buf != NULL)
- {
- OPENSSL_free(b->buf);
- }
- OPENSSL_free(b);
- return 1;
- }
- static int bio_read(BIO *bio, char *buf, int size_)
- {
- size_t size = size_;
- size_t rest;
- struct bio_bio_st *b, *peer_b;
- BIO_clear_retry_flags(bio);
- if (!bio->init)
- return 0;
- b = bio->ptr;
- assert(b != NULL);
- assert(b->peer != NULL);
- peer_b = b->peer->ptr;
- assert(peer_b != NULL);
- assert(peer_b->buf != NULL);
- peer_b->request = 0; /* will be set in "retry_read" situation */
- if (buf == NULL || size == 0)
- return 0;
- if (peer_b->len == 0)
- {
- if (peer_b->closed)
- return 0; /* writer has closed, and no data is left */
- else
- {
- BIO_set_retry_read(bio); /* buffer is empty */
- if (size <= peer_b->size)
- peer_b->request = size;
- else
- /* don't ask for more than the peer can
- * deliver in one write */
- peer_b->request = peer_b->size;
- return -1;
- }
- }
- /* we can read */
- if (peer_b->len < size)
- size = peer_b->len;
- /* now read "size" bytes */
-
- rest = size;
-
- assert(rest > 0);
- do /* one or two iterations */
- {
- size_t chunk;
-
- assert(rest <= peer_b->len);
- if (peer_b->offset + rest <= peer_b->size)
- chunk = rest;
- else
- /* wrap around ring buffer */
- chunk = peer_b->size - peer_b->offset;
- assert(peer_b->offset + chunk <= peer_b->size);
-
- memcpy(buf, peer_b->buf + peer_b->offset, chunk);
-
- peer_b->len -= chunk;
- if (peer_b->len)
- {
- peer_b->offset += chunk;
- assert(peer_b->offset <= peer_b->size);
- if (peer_b->offset == peer_b->size)
- peer_b->offset = 0;
- buf += chunk;
- }
- else
- {
- /* buffer now empty, no need to advance "buf" */
- assert(chunk == rest);
- peer_b->offset = 0;
- }
- rest -= chunk;
- }
- while (rest);
-
- return size;
- }
- /* non-copying interface: provide pointer to available data in buffer
- * bio_nread0: return number of available bytes
- * bio_nread: also advance index
- * (example usage: bio_nread0(), read from buffer, bio_nread()
- * or just bio_nread(), read from buffer)
- */
- /* WARNING: The non-copying interface is largely untested as of yet
- * and may contain bugs. */
- static ssize_t bio_nread0(BIO *bio, char **buf)
- {
- struct bio_bio_st *b, *peer_b;
- ssize_t num;
-
- BIO_clear_retry_flags(bio);
- if (!bio->init)
- return 0;
-
- b = bio->ptr;
- assert(b != NULL);
- assert(b->peer != NULL);
- peer_b = b->peer->ptr;
- assert(peer_b != NULL);
- assert(peer_b->buf != NULL);
-
- peer_b->request = 0;
-
- if (peer_b->len == 0)
- {
- char dummy;
-
- /* avoid code duplication -- nothing available for reading */
- return bio_read(bio, &dummy, 1); /* returns 0 or -1 */
- }
- num = peer_b->len;
- if (peer_b->size < peer_b->offset + num)
- /* no ring buffer wrap-around for non-copying interface */
- num = peer_b->size - peer_b->offset;
- assert(num > 0);
- if (buf != NULL)
- *buf = peer_b->buf + peer_b->offset;
- return num;
- }
- static ssize_t bio_nread(BIO *bio, char **buf, size_t num_)
- {
- struct bio_bio_st *b, *peer_b;
- ssize_t num, available;
- if (num_ > SSIZE_MAX)
- num = SSIZE_MAX;
- else
- num = (ssize_t)num_;
- available = bio_nread0(bio, buf);
- if (num > available)
- num = available;
- if (num <= 0)
- return num;
- b = bio->ptr;
- peer_b = b->peer->ptr;
- peer_b->len -= num;
- if (peer_b->len)
- {
- peer_b->offset += num;
- assert(peer_b->offset <= peer_b->size);
- if (peer_b->offset == peer_b->size)
- peer_b->offset = 0;
- }
- else
- peer_b->offset = 0;
- return num;
- }
- static int bio_write(BIO *bio, const char *buf, int num_)
- {
- size_t num = num_;
- size_t rest;
- struct bio_bio_st *b;
- BIO_clear_retry_flags(bio);
- if (!bio->init || buf == NULL || num == 0)
- return 0;
- b = bio->ptr;
- assert(b != NULL);
- assert(b->peer != NULL);
- assert(b->buf != NULL);
- b->request = 0;
- if (b->closed)
- {
- /* we already closed */
- BIOerr(BIO_F_BIO_WRITE, BIO_R_BROKEN_PIPE);
- return -1;
- }
- assert(b->len <= b->size);
- if (b->len == b->size)
- {
- BIO_set_retry_write(bio); /* buffer is full */
- return -1;
- }
- /* we can write */
- if (num > b->size - b->len)
- num = b->size - b->len;
-
- /* now write "num" bytes */
- rest = num;
-
- assert(rest > 0);
- do /* one or two iterations */
- {
- size_t write_offset;
- size_t chunk;
- assert(b->len + rest <= b->size);
- write_offset = b->offset + b->len;
- if (write_offset >= b->size)
- write_offset -= b->size;
- /* b->buf[write_offset] is the first byte we can write to. */
- if (write_offset + rest <= b->size)
- chunk = rest;
- else
- /* wrap around ring buffer */
- chunk = b->size - write_offset;
-
- memcpy(b->buf + write_offset, buf, chunk);
-
- b->len += chunk;
- assert(b->len <= b->size);
-
- rest -= chunk;
- buf += chunk;
- }
- while (rest);
- return num;
- }
- /* non-copying interface: provide pointer to region to write to
- * bio_nwrite0: check how much space is available
- * bio_nwrite: also increase length
- * (example usage: bio_nwrite0(), write to buffer, bio_nwrite()
- * or just bio_nwrite(), write to buffer)
- */
- static ssize_t bio_nwrite0(BIO *bio, char **buf)
- {
- struct bio_bio_st *b;
- size_t num;
- size_t write_offset;
- BIO_clear_retry_flags(bio);
- if (!bio->init)
- return 0;
- b = bio->ptr;
- assert(b != NULL);
- assert(b->peer != NULL);
- assert(b->buf != NULL);
- b->request = 0;
- if (b->closed)
- {
- BIOerr(BIO_F_BIO_NWRITE0, BIO_R_BROKEN_PIPE);
- return -1;
- }
- assert(b->len <= b->size);
- if (b->len == b->size)
- {
- BIO_set_retry_write(bio);
- return -1;
- }
- num = b->size - b->len;
- write_offset = b->offset + b->len;
- if (write_offset >= b->size)
- write_offset -= b->size;
- if (write_offset + num > b->size)
- /* no ring buffer wrap-around for non-copying interface
- * (to fulfil the promise by BIO_ctrl_get_write_guarantee,
- * BIO_nwrite may have to be called twice) */
- num = b->size - write_offset;
- if (buf != NULL)
- *buf = b->buf + write_offset;
- assert(write_offset + num <= b->size);
- return num;
- }
- static ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_)
- {
- struct bio_bio_st *b;
- ssize_t num, space;
- if (num_ > SSIZE_MAX)
- num = SSIZE_MAX;
- else
- num = (ssize_t)num_;
- space = bio_nwrite0(bio, buf);
- if (num > space)
- num = space;
- if (num <= 0)
- return num;
- b = bio->ptr;
- assert(b != NULL);
- b->len += num;
- assert(b->len <= b->size);
- return num;
- }
- static long bio_ctrl(BIO *bio, int cmd, long num, void *ptr)
- {
- long ret;
- struct bio_bio_st *b = bio->ptr;
-
- assert(b != NULL);
- switch (cmd)
- {
- /* specific CTRL codes */
- case BIO_C_SET_WRITE_BUF_SIZE:
- if (b->peer)
- {
- BIOerr(BIO_F_BIO_CTRL, BIO_R_IN_USE);
- ret = 0;
- }
- else if (num == 0)
- {
- BIOerr(BIO_F_BIO_CTRL, BIO_R_INVALID_ARGUMENT);
- ret = 0;
- }
- else
- {
- size_t new_size = num;
- if (b->size != new_size)
- {
- if (b->buf)
- {
- OPENSSL_free(b->buf);
- b->buf = NULL;
- }
- b->size = new_size;
- }
- ret = 1;
- }
- break;
- case BIO_C_GET_WRITE_BUF_SIZE:
- ret = (long) b->size;
- break;
- case BIO_C_MAKE_BIO_PAIR:
- {
- BIO *other_bio = ptr;
-
- if (bio_make_pair(bio, other_bio))
- ret = 1;
- else
- ret = 0;
- }
- break;
-
- case BIO_C_DESTROY_BIO_PAIR:
- /* Affects both BIOs in the pair -- call just once!
- * Or let BIO_free(bio1); BIO_free(bio2); do the job. */
- bio_destroy_pair(bio);
- ret = 1;
- break;
- case BIO_C_GET_WRITE_GUARANTEE:
- /* How many bytes can the caller feed to the next write
- * without having to keep any? */
- if (b->peer == NULL || b->closed)
- ret = 0;
- else
- ret = (long) b->size - b->len;
- break;
- case BIO_C_GET_READ_REQUEST:
- /* If the peer unsuccessfully tried to read, how many bytes
- * were requested? (As with BIO_CTRL_PENDING, that number
- * can usually be treated as boolean.) */
- ret = (long) b->request;
- break;
- case BIO_C_RESET_READ_REQUEST:
- /* Reset request. (Can be useful after read attempts
- * at the other side that are meant to be non-blocking,
- * e.g. when probing SSL_read to see if any data is
- * available.) */
- b->request = 0;
- ret = 1;
- break;
- case BIO_C_SHUTDOWN_WR:
- /* similar to shutdown(..., SHUT_WR) */
- b->closed = 1;
- ret = 1;
- break;
- case BIO_C_NREAD0:
- /* prepare for non-copying read */
- ret = (long) bio_nread0(bio, ptr);
- break;
-
- case BIO_C_NREAD:
- /* non-copying read */
- ret = (long) bio_nread(bio, ptr, (size_t) num);
- break;
-
- case BIO_C_NWRITE0:
- /* prepare for non-copying write */
- ret = (long) bio_nwrite0(bio, ptr);
- break;
- case BIO_C_NWRITE:
- /* non-copying write */
- ret = (long) bio_nwrite(bio, ptr, (size_t) num);
- break;
-
- /* standard CTRL codes follow */
- case BIO_CTRL_RESET:
- if (b->buf != NULL)
- {
- b->len = 0;
- b->offset = 0;
- }
- ret = 0;
- break;
- case BIO_CTRL_GET_CLOSE:
- ret = bio->shutdown;
- break;
- case BIO_CTRL_SET_CLOSE:
- bio->shutdown = (int) num;
- ret = 1;
- break;
- case BIO_CTRL_PENDING:
- if (b->peer != NULL)
- {
- struct bio_bio_st *peer_b = b->peer->ptr;
-
- ret = (long) peer_b->len;
- }
- else
- ret = 0;
- break;
- case BIO_CTRL_WPENDING:
- if (b->buf != NULL)
- ret = (long) b->len;
- else
- ret = 0;
- break;
- case BIO_CTRL_DUP:
- /* See BIO_dup_chain for circumstances we have to expect. */
- {
- BIO *other_bio = ptr;
- struct bio_bio_st *other_b;
-
- assert(other_bio != NULL);
- other_b = other_bio->ptr;
- assert(other_b != NULL);
-
- assert(other_b->buf == NULL); /* other_bio is always fresh */
- other_b->size = b->size;
- }
- ret = 1;
- break;
- case BIO_CTRL_FLUSH:
- ret = 1;
- break;
- case BIO_CTRL_EOF:
- {
- BIO *other_bio = ptr;
-
- if (other_bio)
- {
- struct bio_bio_st *other_b = other_bio->ptr;
-
- assert(other_b != NULL);
- ret = other_b->len == 0 && other_b->closed;
- }
- else
- ret = 1;
- }
- break;
- default:
- ret = 0;
- }
- return ret;
- }
- static int bio_puts(BIO *bio, const char *str)
- {
- return bio_write(bio, str, strlen(str));
- }
- static int bio_make_pair(BIO *bio1, BIO *bio2)
- {
- struct bio_bio_st *b1, *b2;
- assert(bio1 != NULL);
- assert(bio2 != NULL);
- b1 = bio1->ptr;
- b2 = bio2->ptr;
-
- if (b1->peer != NULL || b2->peer != NULL)
- {
- BIOerr(BIO_F_BIO_MAKE_PAIR, BIO_R_IN_USE);
- return 0;
- }
-
- if (b1->buf == NULL)
- {
- b1->buf = OPENSSL_malloc(b1->size);
- if (b1->buf == NULL)
- {
- BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
- return 0;
- }
- b1->len = 0;
- b1->offset = 0;
- }
-
- if (b2->buf == NULL)
- {
- b2->buf = OPENSSL_malloc(b2->size);
- if (b2->buf == NULL)
- {
- BIOerr(BIO_F_BIO_MAKE_PAIR, ERR_R_MALLOC_FAILURE);
- return 0;
- }
- b2->len = 0;
- b2->offset = 0;
- }
-
- b1->peer = bio2;
- b1->closed = 0;
- b1->request = 0;
- b2->peer = bio1;
- b2->closed = 0;
- b2->request = 0;
- bio1->init = 1;
- bio2->init = 1;
- return 1;
- }
- static void bio_destroy_pair(BIO *bio)
- {
- struct bio_bio_st *b = bio->ptr;
- if (b != NULL)
- {
- BIO *peer_bio = b->peer;
- if (peer_bio != NULL)
- {
- struct bio_bio_st *peer_b = peer_bio->ptr;
- assert(peer_b != NULL);
- assert(peer_b->peer == bio);
- peer_b->peer = NULL;
- peer_bio->init = 0;
- assert(peer_b->buf != NULL);
- peer_b->len = 0;
- peer_b->offset = 0;
-
- b->peer = NULL;
- bio->init = 0;
- assert(b->buf != NULL);
- b->len = 0;
- b->offset = 0;
- }
- }
- }
-
- /* Exported convenience functions */
- int BIO_new_bio_pair(BIO **bio1_p, size_t writebuf1,
- BIO **bio2_p, size_t writebuf2)
- {
- BIO *bio1 = NULL, *bio2 = NULL;
- long r;
- int ret = 0;
- bio1 = BIO_new(BIO_s_bio());
- if (bio1 == NULL)
- goto err;
- bio2 = BIO_new(BIO_s_bio());
- if (bio2 == NULL)
- goto err;
- if (writebuf1)
- {
- r = BIO_set_write_buf_size(bio1, writebuf1);
- if (!r)
- goto err;
- }
- if (writebuf2)
- {
- r = BIO_set_write_buf_size(bio2, writebuf2);
- if (!r)
- goto err;
- }
- r = BIO_make_bio_pair(bio1, bio2);
- if (!r)
- goto err;
- ret = 1;
- err:
- if (ret == 0)
- {
- if (bio1)
- {
- BIO_free(bio1);
- bio1 = NULL;
- }
- if (bio2)
- {
- BIO_free(bio2);
- bio2 = NULL;
- }
- }
- *bio1_p = bio1;
- *bio2_p = bio2;
- return ret;
- }
- size_t BIO_ctrl_get_write_guarantee(BIO *bio)
- {
- return BIO_ctrl(bio, BIO_C_GET_WRITE_GUARANTEE, 0, NULL);
- }
- size_t BIO_ctrl_get_read_request(BIO *bio)
- {
- return BIO_ctrl(bio, BIO_C_GET_READ_REQUEST, 0, NULL);
- }
- int BIO_ctrl_reset_read_request(BIO *bio)
- {
- return (BIO_ctrl(bio, BIO_C_RESET_READ_REQUEST, 0, NULL) != 0);
- }
- /* BIO_nread0/nread/nwrite0/nwrite are available only for BIO pairs for now
- * (conceivably some other BIOs could allow non-copying reads and writes too.)
- */
- int BIO_nread0(BIO *bio, char **buf)
- {
- long ret;
- if (!bio->init)
- {
- BIOerr(BIO_F_BIO_NREAD0, BIO_R_UNINITIALIZED);
- return -2;
- }
- ret = BIO_ctrl(bio, BIO_C_NREAD0, 0, buf);
- if (ret > INT_MAX)
- return INT_MAX;
- else
- return (int) ret;
- }
- int BIO_nread(BIO *bio, char **buf, int num)
- {
- int ret;
- if (!bio->init)
- {
- BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED);
- return -2;
- }
- ret = (int) BIO_ctrl(bio, BIO_C_NREAD, num, buf);
- if (ret > 0)
- bio->num_read += ret;
- return ret;
- }
- int BIO_nwrite0(BIO *bio, char **buf)
- {
- long ret;
- if (!bio->init)
- {
- BIOerr(BIO_F_BIO_NWRITE0, BIO_R_UNINITIALIZED);
- return -2;
- }
- ret = BIO_ctrl(bio, BIO_C_NWRITE0, 0, buf);
- if (ret > INT_MAX)
- return INT_MAX;
- else
- return (int) ret;
- }
- int BIO_nwrite(BIO *bio, char **buf, int num)
- {
- int ret;
- if (!bio->init)
- {
- BIOerr(BIO_F_BIO_NWRITE, BIO_R_UNINITIALIZED);
- return -2;
- }
- ret = BIO_ctrl(bio, BIO_C_NWRITE, num, buf);
- if (ret > 0)
- bio->num_read += ret;
- return ret;
- }