BIO_PAIR_DEBUG did nothing; remove it.
[openssl.git] / crypto / bio / bss_bio.c
index cff55bf..743a158 100644 (file)
-/* crypto/bio/bss_bio.c  -*- Mode: C; c-file-style: "eay" -*- */
-
-/* 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. */
-
-#ifndef BIO_PAIR_DEBUG
-# undef NDEBUG /* avoid conflicting definitions */
-# define NDEBUG
-#endif
+/* ====================================================================
+ * 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.
+ */
 
 #include <assert.h>
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/types.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, char *buf, int num);
+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, char *str);
+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 */
+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. */
+    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 = Malloc(sizeof *b);
-       if (b == NULL)
-               return 0;
+{
+    struct bio_bio_st *b;
 
-       b->peer = NULL;
-       b->size = 17*1024; /* enough for one TLS record (just a default) */
-       b->buf = NULL;
+    b = OPENSSL_malloc(sizeof(*b));
+    if (b == NULL)
+        return 0;
 
-       bio->ptr = b;
-       return 1;
-       }
+    b->peer = NULL;
+    /* enough for one TLS record (just a default) */
+    b->size = 17 * 1024;
+    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);
+{
+    struct bio_bio_st *b;
 
-       if (b->peer)
-               bio_destroy_pair(bio);
-       
-       if (b->buf != NULL)
-               {
-               Free(b->buf);
-               }
+    if (bio == NULL)
+        return 0;
+    b = bio->ptr;
 
-       Free(b);
+    assert(b != NULL);
 
-       return 1;
-       }
+    if (b->peer)
+        bio_destroy_pair(bio);
 
+    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
+{
+    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;
-       size_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;
-       size_t available;
-
-       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, 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
+/*
+ * WARNING: The non-copying interface is largely untested as of yet and may
+ * contain bugs.
+ */
+static ossl_ssize_t bio_nread0(BIO *bio, char **buf)
+{
+    struct bio_bio_st *b, *peer_b;
+    ossl_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 ossl_ssize_t bio_nread(BIO *bio, char **buf, size_t num_)
+{
+    struct bio_bio_st *b, *peer_b;
+    ossl_ssize_t num, available;
+
+    if (num_ > SSIZE_MAX)
+        num = SSIZE_MAX;
+    else
+        num = (ossl_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 size_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 size_t bio_nwrite(BIO *bio, char **buf, size_t num)
-       {
-       struct bio_bio_st *b;
-       size_t space;
-
-       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 ossl_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 ossl_ssize_t bio_nwrite(BIO *bio, char **buf, size_t num_)
+{
+    struct bio_bio_st *b;
+    ossl_ssize_t num, space;
+
+    if (num_ > SSIZE_MAX)
+        num = SSIZE_MAX;
+    else
+        num = (ossl_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) 
-                                       {
-                                       Free(b->buf);
-                                       b->buf = NULL;
-                                       }
-                               b->size = new_size;
-                               }
-                       ret = 1;
-                       }
-               break;
-
-       case BIO_C_GET_WRITE_BUF_SIZE:
-               num = (long) b->size;
-
-       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:
-               /* Effects 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_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, char *str)
-       {
-       return bio_write(bio, str, strlen(str));
-       }
-
+{
+    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) {
+                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 = 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 = 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;
-       }
+{
+    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;
-                       }
-               }
-       }
+{
+    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;
+                     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;
-        }
+    if (ret == 0) {
+        BIO_free(bio1);
+        bio1 = NULL;
+        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);
-       }
+{
+    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);
-       }
+{
+    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);
-       }
-
+{
+    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.)
+/*
+ * 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;
-       }
+{
+    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;
+{
+    int ret;
 
-       if (!bio->init)
-               {
-               BIOerr(BIO_F_BIO_NREAD, BIO_R_UNINITIALIZED);
-               return -2;
-               }
+    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;
-       }
+    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;
-       }
+{
+    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;
-       }
+{
+    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_write += ret;
+    return ret;
+}