/*

 * Copyright 1995-2025 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 <string.h>

#include "internal/cryptlib.h"

#include "crypto/ctype.h"

#include "internal/numbers.h"

#include <openssl/bio.h>

#include <openssl/configuration.h>

int BIO_printf(BIO *bio, const char *format, ...)

{

    va_list args;

    int ret;

    va_start(args, format);

    ret = BIO_vprintf(bio, format, args);

    va_end(args);

    return ret;

}

#if defined(_WIN32)

/*

 * _MSC_VER described here:

 * https://learn.microsoft.com/en-us/cpp/overview/compiler-versions?view=msvc-170

 *

 * Beginning with the UCRT in Visual Studio 2015 and Windows 10, snprintf is no

 * longer identical to _snprintf. The snprintf behavior is now C99 standard

 * conformant. The difference is that if you run out of buffer, snprintf

 * null-terminates the end of the buffer and returns the number of characters

 * that would have been required whereas _snprintf doesn't null-terminate the

 * buffer and returns -1. Also, snprintf() includes one more character in the

 * output because it doesn't null-terminate the buffer.

 * [ https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/snprintf-snprintf-snprintf-l-snwprintf-snwprintf-l?view=msvc-170#remarks

 *

 * for older MSVC (older than 2015) we can use _vscprintf() and _vsnprintf()

 * as suggested here:

 * https://stackoverflow.com/questions/2915672/snprintf-and-visual-studio-2010

 *

 */

static int msvc_bio_vprintf(BIO *bio, const char *format, va_list args)

{

    char buf[512];

    char *abuf;

    int ret, sz;

    sz = _vsnprintf_s(buf, sizeof(buf), _TRUNCATE, format, args);

    if (sz == -1) {

        sz = _vscprintf(format, args) + 1;

        abuf = (char *)OPENSSL_malloc(sz);

        if (abuf == NULL) {

            ret = -1;

        } else {

            sz = _vsnprintf(abuf, sz, format, args);

            ret = BIO_write(bio, abuf, sz);

            OPENSSL_free(abuf);

        }

    } else {

        ret = BIO_write(bio, buf, sz);

    }

    return ret;

}

/*

 * This function is for unit test on windows only when built with Visual Studio

 */

int ossl_BIO_snprintf_msvc(char *buf, size_t n, const char *format, ...)

{

    va_list args;

    int ret;

    va_start(args, format);

    ret = _vsnprintf_s(buf, n, _TRUNCATE, format, args);

    va_end(args);

    return ret;

}

#endif

int BIO_vprintf(BIO *bio, const char *format, va_list args)

{

    va_list cp_args;

#if !defined(_MSC_VER) || _MSC_VER > 1900

    int sz;

#endif

    int ret = -1;

    va_copy(cp_args, args);

#if defined(_MSC_VER) && _MSC_VER < 1900

    ret = msvc_bio_vprintf(bio, format, cp_args);

#else

    char buf[512];

    char *abuf;

    /*

     * some compilers modify va_list, hence each call to v*printf()

     * should operate with its own instance of va_list. The first

     * call to vsnprintf() here uses args we got in function argument.

     * The second call is going to use cp_args we made earlier.

     */

    sz = vsnprintf(buf, sizeof(buf), format, args);

    if (sz >= 0) {

        if ((size_t)sz > sizeof(buf)) {

            sz += 1;

            abuf = (char *)OPENSSL_malloc(sz);

            if (abuf == NULL) {

                ret = -1;

            } else {

                sz = vsnprintf(abuf, sz, format, cp_args);

                ret = BIO_write(bio, abuf, sz);

                OPENSSL_free(abuf);

            }

        } else {

            /* vsnprintf returns length not including nul-terminator */

            ret = BIO_write(bio, buf, sz);

        }

    }

#endif

    va_end(cp_args);

    return ret;

}

/*

 * For historical reasons BIO_snprintf and friends return a failure for string

 * truncation (-1) instead of the POSIX requirement of a success with the

 * number of characters that would have been written. Upon seeing -1 on

 * return, the caller must treat output buf as unsafe (as a buf with missing

 * nul terminator).

 */

int BIO_snprintf(char *buf, size_t n, const char *format, ...)

{

    va_list args;

    int ret;

    va_start(args, format);

#if defined(_MSC_VER) && _MSC_VER < 1900

    ret = _vsnprintf_s(buf, n, _TRUNCATE, format, args);

#else

    ret = vsnprintf(buf, n, format, args);

    if ((size_t)ret >= n)

        ret = -1;

#endif

    va_end(args);

    return ret;

}

int BIO_vsnprintf(char *buf, size_t n, const char *format, va_list args)

{

    int ret;

#if defined(_MSC_VER) && _MSC_VER < 1900

    ret = _vsnprintf_s(buf, n, _TRUNCATE, format, args);

#else

    ret = vsnprintf(buf, n, format, args);

    if ((size_t)ret >= n)

        ret = -1;

#endif

    return ret;

}