source: rtems/c/src/libnetworking/rtems_webserver/websda.c @ 2e7f00fc

/*
 * websda.c -- Digest Access Authentication routines
 *
 * Copyright (c) GoAhead Software Inc., 1995-2000. All Rights Reserved.
 *
 * See the file "license.txt" for usage and redistribution license requirements
 *
 * $Id$
 */

/******************************** Description *********************************/

/*
 *      Routines for generating DAA data.       The module uses the
 *      "RSA Data Security, Inc. MD5 Message-Digest Algorithm" found in md5c.c
 */

/********************************* Includes ***********************************/

#ifndef CE
#include        <time.h>
#endif
#include        "websda.h"
#include        "md5.h"

/******************************** Local Data **********************************/

#define RANDOMKEY       T("onceuponatimeinparadise")
#define NONCE_SIZE      34
#define HASH_SIZE   16

/*********************************** Code *************************************/
/*
 *      websMD5binary returns the MD5 hash
 */

char *websMD5binary(unsigned char *buf, int length)
{
    const char          *hex = "0123456789abcdef";
    MD5_CONTEXT         md5ctx;
    unsigned char       hash[HASH_SIZE];
    char                        *r, *strReturn;
        char                    result[(HASH_SIZE * 2) + 1];
    int                         i;

/*
 *      Take the MD5 hash of the string argument.
 */
    MD5Init(&md5ctx);
    MD5Update(&md5ctx, buf, (unsigned int)length);
    MD5Final(hash, &md5ctx);

/*
 *      Prepare the resulting hash string
 */
    for (i = 0, r = result; i < 16; i++) {
                *r++ = hex[hash[i] >> 4];
                *r++ = hex[hash[i] & 0xF];
    }

/*
 *      Zero terminate the hash string
 */
    *r = '\0';

/*
 *      Allocate a new copy of the hash string
 */
        strReturn = balloc(B_L, sizeof(result));
        strcpy(strReturn, result);

    return strReturn;
}

/*****************************************************************************/
/*
 *      Convenience call to websMD5binary 
 *      (Performs char_t to char conversion and back)
 */

char_t *websMD5(char_t *string)
{
        char_t  *strReturn;

        a_assert(string && *string);

        if (string && *string) {
                char    *strTemp, *strHash;
                int             nLen;
/*
 *              Convert input char_t string to char string
 */
                nLen = gstrlen(string);
                strTemp = ballocUniToAsc(string, nLen + 1);
/*
 *              Execute the digest calculation
 */
                strHash = websMD5binary((unsigned char *)strTemp, nLen);
/*
 *              Convert the returned char string digest to a char_t string
 */
                nLen = strlen(strHash);
                strReturn = ballocAscToUni(strHash, nLen);
/*
 *              Free up the temporary allocated resources
 */
                bfree(B_L, strTemp);
                bfree(B_L, strHash);
        } else {
                strReturn = NULL;
        }

        return strReturn;
}

/******************************************************************************/
/*
 *      Get a Nonce value for passing along to the client.  This function 
 *      composes the string "RANDOMKEY:timestamp:myrealm" and 
 *      calculates the MD5 digest placing it in output. 
 */

char_t *websCalcNonce(webs_t wp)
{
        char_t          *nonce, *prenonce;
        struct tm       *newtime;
        time_t          longTime;

        a_assert(wp);
/*
 *      Get time as long integer.
 */
        time(&longTime);
/*
 *      Convert to local time.
 */
        newtime = localtime(&longTime);
/*
 *      Create prenonce string.
 */
        prenonce = NULL;
#ifdef DIGEST_ACCESS_SUPPORT
        fmtAlloc(&prenonce, 256, T("%s:%s:%s"), RANDOMKEY, gasctime(newtime),
                wp->realm); 
#else
        fmtAlloc(&prenonce, 256, T("%s:%s:%s"), RANDOMKEY, gasctime(newtime), 
                RANDOMKEY); 
#endif
        a_assert(prenonce);
/*
 *      Create the nonce
 */
    nonce = websMD5(prenonce);
/*
 *      Cleanup
 */
        bfreeSafe(B_L, prenonce);

        return nonce;
}

/******************************************************************************/
/*
 *      Get an Opaque value for passing along to the client
 */

char_t *websCalcOpaque(webs_t wp)
{
        char_t *opaque;
        a_assert(wp);
/*
 *      Temporary stub!
 */
    opaque = bstrdup(B_L, T("5ccc069c403ebaf9f0171e9517f40e41"));

        return opaque;
}

/******************************************************************************/
/*
 *      Get a Digest value using the MD5 algorithm
 */

char_t *websCalcDigest(webs_t wp)
{
#ifdef DIGEST_ACCESS_SUPPORT
        char_t  *digest, *a1, *a1prime, *a2, *a2prime, *preDigest, *method;

        a_assert(wp);
        digest = NULL;

/*
 *      Calculate first portion of digest H(A1)
 */
        a1 = NULL;
        fmtAlloc(&a1, 255, T("%s:%s:%s"), wp->userName, wp->realm, wp->password);
        a_assert(a1);
        a1prime = websMD5(a1);
        bfreeSafe(B_L, a1);
/*
 *      Calculate second portion of digest H(A2)
 */
        method = websGetVar(wp, T("REQUEST_METHOD"), NULL);
        a_assert(method);
        a2 = NULL;
        fmtAlloc(&a2, 255, T("%s:%s"), method, wp->uri);
        a_assert(a2);
        a2prime = websMD5(a2);
        bfreeSafe(B_L, a2);
/*
 *      Construct final digest KD(H(A1):nonce:H(A2))
 */
        a_assert(a1prime);
        a_assert(a2prime);
        a_assert(wp->nonce);

        preDigest = NULL;
        if (!wp->qop) {
                fmtAlloc(&preDigest, 255, T("%s:%s:%s"), a1prime, wp->nonce, a2prime);
        } else {
                fmtAlloc(&preDigest, 255, T("%s:%s:%s:%s:%s:%s"), 
                        a1prime, 
                        wp->nonce,
                        wp->nc,
                        wp->cnonce,
                        wp->qop,
                        a2prime);
        }

        a_assert(preDigest);
        digest = websMD5(preDigest);
/*
 *      Now clean up
 */
        bfreeSafe(B_L, a1prime);
        bfreeSafe(B_L, a2prime);
        bfreeSafe(B_L, preDigest);
        return digest;
#else
        return NULL;
#endif /* DIGEST_ACCESS_SUPPORT */
}

/******************************************************************************/