view src/os/unix/ngx_user.c @ 5050:f9a29f401770 stable-1.2

Merge of r4983: crypt_r() error handling fixed. The crypt_r() function returns NULL on errors, check it explicitly instead of assuming errno will remain 0 if there are no errors (per POSIX, the setting of errno after a successful call to a function is unspecified unless the description of that function specifies that errno shall not be modified). Additionally, dropped unneeded ngx_set_errno(0) and fixed error handling of memory allocation after normal crypt(), which was inapropriate and resulted in null pointer dereference on allocation failures.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 11 Feb 2013 12:37:06 +0000
parents 778ef9c3fd2d
children fd6fd02f6a4d
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


/*
 * Solaris has thread-safe crypt()
 * Linux has crypt_r(); "struct crypt_data" is more than 128K
 * FreeBSD needs the mutex to protect crypt()
 *
 * TODO:
 *     ngx_crypt_init() to init mutex
 */


#if (NGX_CRYPT)

#if (NGX_HAVE_GNU_CRYPT_R)

ngx_int_t
ngx_libc_crypt(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted)
{
    char               *value;
    size_t              len;
    struct crypt_data   cd;

    cd.initialized = 0;
    /* work around the glibc bug */
    cd.current_salt[0] = ~salt[0];

    value = crypt_r((char *) key, (char *) salt, &cd);

    if (value) {
        len = ngx_strlen(value) + 1;

        *encrypted = ngx_pnalloc(pool, len);
        if (*encrypted == NULL) {
            return NGX_ERROR;
        }

        ngx_memcpy(*encrypted, value, len);
        return NGX_OK;
    }

    ngx_log_error(NGX_LOG_CRIT, pool->log, ngx_errno, "crypt_r() failed");

    return NGX_ERROR;
}

#else

ngx_int_t
ngx_libc_crypt(ngx_pool_t *pool, u_char *key, u_char *salt, u_char **encrypted)
{
    char       *value;
    size_t      len;
    ngx_err_t   err;

#if (NGX_THREADS && NGX_NONREENTRANT_CRYPT)

    /* crypt() is a time consuming function, so we only try to lock */

    if (ngx_mutex_trylock(ngx_crypt_mutex) != NGX_OK) {
        return NGX_AGAIN;
    }

#endif

    value = crypt((char *) key, (char *) salt);

    if (value) {
        len = ngx_strlen(value) + 1;

        *encrypted = ngx_pnalloc(pool, len);
        if (*encrypted == NULL) {
#if (NGX_THREADS && NGX_NONREENTRANT_CRYPT)
            ngx_mutex_unlock(ngx_crypt_mutex);
#endif
            return NGX_ERROR;
        }

        ngx_memcpy(*encrypted, value, len);
#if (NGX_THREADS && NGX_NONREENTRANT_CRYPT)
        ngx_mutex_unlock(ngx_crypt_mutex);
#endif
        return NGX_OK;
    }

    err = ngx_errno;

#if (NGX_THREADS && NGX_NONREENTRANT_CRYPT)
    ngx_mutex_unlock(ngx_crypt_mutex);
#endif

    ngx_log_error(NGX_LOG_CRIT, pool->log, err, "crypt() failed");

    return NGX_ERROR;
}

#endif

#endif /* NGX_CRYPT */