view src/os/win32/ngx_errno.c @ 7094:c7d4017c8876

Secure link: fixed stack buffer overflow. When secure link checksum has length of 23 or 24 bytes, decoded base64 value could occupy 17 or 18 bytes which is more than 16 bytes previously allocated for it on stack. The buffer overflow does not have any security implications since only one local variable was corrupted and this variable was not used in this case. The fix is to increase buffer size up to 18 bytes. Useless buffer size initialization is removed as well.
author Roman Arutyunyan <arut@nginx.com>
date Tue, 22 Aug 2017 21:22:59 +0300
parents f1a0de6eb505
children 746567d633ac
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


u_char *
ngx_strerror(ngx_err_t err, u_char *errstr, size_t size)
{
    u_int          len;
    static u_long  lang = MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US);

    if (size == 0) {
        return errstr;
    }

    len = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM,
                        NULL, err, lang, (char *) errstr, size, NULL);

    if (len == 0 && lang && GetLastError() == ERROR_RESOURCE_LANG_NOT_FOUND) {

        /*
         * Try to use English messages first and fallback to a language,
         * based on locale: non-English Windows have no English messages
         * at all.  This way allows to use English messages at least on
         * Windows with MUI.
         */

        lang = 0;

        len = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM,
                            NULL, err, lang, (char *) errstr, size, NULL);
    }

    if (len == 0) {
        return ngx_snprintf(errstr, size,
                            "FormatMessage() error:(%d)", GetLastError());
    }

    /* remove ".\r\n\0" */
    while (errstr[len] == '\0' || errstr[len] == CR
           || errstr[len] == LF || errstr[len] == '.')
    {
        --len;
    }

    return &errstr[++len];
}


ngx_int_t
ngx_strerror_init(void)
{
    return NGX_OK;
}