1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #include <openssl/bio.h>
58 
59 #include <assert.h>
60 #include <stdarg.h>
61 #include <stdio.h>
62 
63 #include <openssl/err.h>
64 #include <openssl/mem.h>
65 
BIO_printf(BIO * bio,const char * format,...)66 int BIO_printf(BIO *bio, const char *format, ...) {
67   va_list args;
68   char buf[256], *out, out_malloced = 0;
69   int out_len, ret;
70 
71   va_start(args, format);
72   out_len = vsnprintf(buf, sizeof(buf), format, args);
73   va_end(args);
74 
75 #if defined(OPENSSL_WINDOWS)
76   // On Windows, vsnprintf returns -1 rather than the requested length on
77   // truncation
78   if (out_len < 0) {
79     va_start(args, format);
80     out_len = _vscprintf(format, args);
81     va_end(args);
82     assert(out_len >= (int)sizeof(buf));
83   }
84 #endif
85 
86   if (out_len < 0) {
87     return -1;
88   }
89 
90   if ((size_t) out_len >= sizeof(buf)) {
91     const int requested_len = out_len;
92     // The output was truncated. Note that vsnprintf's return value
93     // does not include a trailing NUL, but the buffer must be sized
94     // for it.
95     out = OPENSSL_malloc(requested_len + 1);
96     out_malloced = 1;
97     if (out == NULL) {
98       OPENSSL_PUT_ERROR(BIO, ERR_R_MALLOC_FAILURE);
99       return -1;
100     }
101     va_start(args, format);
102     out_len = vsnprintf(out, requested_len + 1, format, args);
103     va_end(args);
104     assert(out_len == requested_len);
105   } else {
106     out = buf;
107   }
108 
109   ret = BIO_write(bio, out, out_len);
110   if (out_malloced) {
111     OPENSSL_free(out);
112   }
113 
114   return ret;
115 }
116