apr_md5.c

Apache V2.0.15 Alpha For Linuxhttpd-2_0_15-alpha.tar.Z

    return APR_SUCCESS;
}

/* MD5 basic transformation. Transforms state based on block. */
static void MD5Transform(UINT4 state[4], const unsigned char block[64])
{
    UINT4 a = state[0], b = state[1], c = state[2], d = state[3],
          x[MD5_DIGESTSIZE];

    Decode(x, block, 64);

    /* Round 1 */
    FF(a, b, c, d, x[0], S11, 0xd76aa478);	/* 1 */
    FF(d, a, b, c, x[1], S12, 0xe8c7b756);	/* 2 */
    FF(c, d, a, b, x[2], S13, 0x242070db);	/* 3 */
    FF(b, c, d, a, x[3], S14, 0xc1bdceee);	/* 4 */
    FF(a, b, c, d, x[4], S11, 0xf57c0faf);	/* 5 */
    FF(d, a, b, c, x[5], S12, 0x4787c62a);	/* 6 */
    FF(c, d, a, b, x[6], S13, 0xa8304613);	/* 7 */
    FF(b, c, d, a, x[7], S14, 0xfd469501);	/* 8 */
    FF(a, b, c, d, x[8], S11, 0x698098d8);	/* 9 */
    FF(d, a, b, c, x[9], S12, 0x8b44f7af);	/* 10 */
    FF(c, d, a, b, x[10], S13, 0xffff5bb1);	/* 11 */
    FF(b, c, d, a, x[11], S14, 0x895cd7be);	/* 12 */
    FF(a, b, c, d, x[12], S11, 0x6b901122);	/* 13 */
    FF(d, a, b, c, x[13], S12, 0xfd987193);	/* 14 */
    FF(c, d, a, b, x[14], S13, 0xa679438e);	/* 15 */
    FF(b, c, d, a, x[15], S14, 0x49b40821);	/* 16 */

    /* Round 2 */
    GG(a, b, c, d, x[1], S21, 0xf61e2562);	/* 17 */
    GG(d, a, b, c, x[6], S22, 0xc040b340);	/* 18 */
    GG(c, d, a, b, x[11], S23, 0x265e5a51);	/* 19 */
    GG(b, c, d, a, x[0], S24, 0xe9b6c7aa);	/* 20 */
    GG(a, b, c, d, x[5], S21, 0xd62f105d);	/* 21 */
    GG(d, a, b, c, x[10], S22, 0x2441453);	/* 22 */
    GG(c, d, a, b, x[15], S23, 0xd8a1e681);	/* 23 */
    GG(b, c, d, a, x[4], S24, 0xe7d3fbc8);	/* 24 */
    GG(a, b, c, d, x[9], S21, 0x21e1cde6);	/* 25 */
    GG(d, a, b, c, x[14], S22, 0xc33707d6);	/* 26 */
    GG(c, d, a, b, x[3], S23, 0xf4d50d87);	/* 27 */
    GG(b, c, d, a, x[8], S24, 0x455a14ed);	/* 28 */
    GG(a, b, c, d, x[13], S21, 0xa9e3e905);	/* 29 */
    GG(d, a, b, c, x[2], S22, 0xfcefa3f8);	/* 30 */
    GG(c, d, a, b, x[7], S23, 0x676f02d9);	/* 31 */
    GG(b, c, d, a, x[12], S24, 0x8d2a4c8a);	/* 32 */

    /* Round 3 */
    HH(a, b, c, d, x[5], S31, 0xfffa3942);	/* 33 */
    HH(d, a, b, c, x[8], S32, 0x8771f681);	/* 34 */
    HH(c, d, a, b, x[11], S33, 0x6d9d6122);	/* 35 */
    HH(b, c, d, a, x[14], S34, 0xfde5380c);	/* 36 */
    HH(a, b, c, d, x[1], S31, 0xa4beea44);	/* 37 */
    HH(d, a, b, c, x[4], S32, 0x4bdecfa9);	/* 38 */
    HH(c, d, a, b, x[7], S33, 0xf6bb4b60);	/* 39 */
    HH(b, c, d, a, x[10], S34, 0xbebfbc70);	/* 40 */
    HH(a, b, c, d, x[13], S31, 0x289b7ec6);	/* 41 */
    HH(d, a, b, c, x[0], S32, 0xeaa127fa);	/* 42 */
    HH(c, d, a, b, x[3], S33, 0xd4ef3085);	/* 43 */
    HH(b, c, d, a, x[6], S34, 0x4881d05);	/* 44 */
    HH(a, b, c, d, x[9], S31, 0xd9d4d039);	/* 45 */
    HH(d, a, b, c, x[12], S32, 0xe6db99e5);	/* 46 */
    HH(c, d, a, b, x[15], S33, 0x1fa27cf8);	/* 47 */
    HH(b, c, d, a, x[2], S34, 0xc4ac5665);	/* 48 */

    /* Round 4 */
    II(a, b, c, d, x[0], S41, 0xf4292244);	/* 49 */
    II(d, a, b, c, x[7], S42, 0x432aff97);	/* 50 */
    II(c, d, a, b, x[14], S43, 0xab9423a7);	/* 51 */
    II(b, c, d, a, x[5], S44, 0xfc93a039);	/* 52 */
    II(a, b, c, d, x[12], S41, 0x655b59c3);	/* 53 */
    II(d, a, b, c, x[3], S42, 0x8f0ccc92);	/* 54 */
    II(c, d, a, b, x[10], S43, 0xffeff47d);	/* 55 */
    II(b, c, d, a, x[1], S44, 0x85845dd1);	/* 56 */
    II(a, b, c, d, x[8], S41, 0x6fa87e4f);	/* 57 */
    II(d, a, b, c, x[15], S42, 0xfe2ce6e0);	/* 58 */
    II(c, d, a, b, x[6], S43, 0xa3014314);	/* 59 */
    II(b, c, d, a, x[13], S44, 0x4e0811a1);	/* 60 */
    II(a, b, c, d, x[4], S41, 0xf7537e82);	/* 61 */
    II(d, a, b, c, x[11], S42, 0xbd3af235);	/* 62 */
    II(c, d, a, b, x[2], S43, 0x2ad7d2bb);	/* 63 */
    II(b, c, d, a, x[9], S44, 0xeb86d391);	/* 64 */

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;

    /* Zeroize sensitive information. */
    memset(x, 0, sizeof(x));
}

/* Encodes input (UINT4) into output (unsigned char). Assumes len is
   a multiple of 4.
 */
static void Encode(unsigned char *output, const UINT4 *input, unsigned int len)
{
    unsigned int i, j;
    UINT4 k;

    for (i = 0, j = 0; j < len; i++, j += 4) {
	k = input[i];
	output[j] = (unsigned char) (k & 0xff);
	output[j + 1] = (unsigned char) ((k >> 8) & 0xff);
	output[j + 2] = (unsigned char) ((k >> 16) & 0xff);
	output[j + 3] = (unsigned char) ((k >> 24) & 0xff);
    }
}

/* Decodes input (unsigned char) into output (UINT4). Assumes len is
 * a multiple of 4.
 */
static void Decode(UINT4 *output, const unsigned char *input, unsigned int len)
{
    unsigned int i, j;

    for (i = 0, j = 0; j < len; i++, j += 4)
	output[i] = ((UINT4) input[j]) | (((UINT4) input[j + 1]) << 8) |
	    (((UINT4) input[j + 2]) << 16) | (((UINT4) input[j + 3]) << 24);
}

#if APR_CHARSET_EBCDIC
APR_DECLARE(apr_status_t) apr_MD5InitEBCDIC(apr_xlate_t *xlate)
{
    xlate_ebcdic_to_ascii = xlate;
    return APR_SUCCESS;
}
#endif

/*
 * Define the Magic String prefix that identifies a password as being
 * hashed using our algorithm.
 */
static const char *apr1_id = "$apr1$";

/*
 * The following MD5 password encryption code was largely borrowed from
 * the FreeBSD 3.0 /usr/src/lib/libcrypt/crypt.c file, which is
 * licenced as stated at the top of this file.
 */

static void to64(char *s, unsigned long v, int n)
{
    static unsigned char itoa64[] =         /* 0 ... 63 => ASCII - 64 */
	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    while (--n >= 0) {
	*s++ = itoa64[v&0x3f];
	v >>= 6;
    }
}

APR_DECLARE(apr_status_t) apr_md5_encode(const char *pw, const char *salt,
                             char *result, size_t nbytes)
{
    /*
     * Minimum size is 8 bytes for salt, plus 1 for the trailing NUL,
     * plus 4 for the '$' separators, plus the password hash itself.
     * Let's leave a goodly amount of leeway.
     */

    char passwd[120], *p;
    const char *sp, *ep;
    unsigned char final[MD5_DIGESTSIZE];
    int sl, pl, i;
    apr_md5_ctx_t ctx, ctx1;
    unsigned long l;

    /* 
     * Refine the salt first.  It's possible we were given an already-hashed
     * string as the salt argument, so extract the actual salt value from it
     * if so.  Otherwise just use the string up to the first '$' as the salt.
     */
    sp = salt;

    /*
     * If it starts with the magic string, then skip that.
     */
    if (!strncmp(sp, apr1_id, strlen(apr1_id))) {
	sp += strlen(apr1_id);
    }

    /*
     * It stops at the first '$' or 8 chars, whichever comes first
     */
    for (ep = sp; (*ep != '\0') && (*ep != '$') && (ep < (sp + 8)); ep++) {
	continue;
    }

    /*
     * Get the length of the true salt
     */
    sl = ep - sp;

    /*
     * 'Time to make the doughnuts..'
     */
    apr_md5_init(&ctx);
#if APR_CHARSET_EBCDIC
    apr_md5_set_xlate(&ctx, xlate_ebcdic_to_ascii);
#endif
    
    /*
     * The password first, since that is what is most unknown
     */
    apr_md5_update(&ctx, (unsigned char *)pw, strlen(pw));

    /*
     * Then our magic string
     */
    apr_md5_update(&ctx, (unsigned char *)apr1_id, strlen(apr1_id));

    /*
     * Then the raw salt
     */
    apr_md5_update(&ctx, (unsigned char *)sp, sl);

    /*
     * Then just as many characters of the MD5(pw, salt, pw)
     */
    apr_md5_init(&ctx1);
    apr_md5_update(&ctx1, (unsigned char *)pw, strlen(pw));
    apr_md5_update(&ctx1, (unsigned char *)sp, sl);
    apr_md5_update(&ctx1, (unsigned char *)pw, strlen(pw));
    apr_md5_final(final, &ctx1);
    for (pl = strlen(pw); pl > 0; pl -= MD5_DIGESTSIZE) {
        apr_md5_update(&ctx, final, 
                      (pl > MD5_DIGESTSIZE) ? MD5_DIGESTSIZE : pl);
    }

    /*
     * Don't leave anything around in vm they could use.
     */
    memset(final, 0, sizeof(final));

    /*
     * Then something really weird...
     */
    for (i = strlen(pw); i != 0; i >>= 1) {
	if (i & 1) {
	    apr_md5_update(&ctx, final, 1);
	}
	else {
	    apr_md5_update(&ctx, (unsigned char *)pw, 1);
	}
    }

    /*
     * Now make the output string.  We know our limitations, so we
     * can use the string routines without bounds checking.
     */
    strcpy(passwd, apr1_id);
    strncat(passwd, sp, sl);
    strcat(passwd, "$");

    apr_md5_final(final, &ctx);

    /*
     * And now, just to make sure things don't run too fast..
     * On a 60 Mhz Pentium this takes 34 msec, so you would
     * need 30 seconds to build a 1000 entry dictionary...
     */
    for (i = 0; i < 1000; i++) {
	apr_md5_init(&ctx1);
	if (i & 1) {
	    apr_md5_update(&ctx1, (unsigned char *)pw, strlen(pw));
	}
	else {
	    apr_md5_update(&ctx1, final, MD5_DIGESTSIZE);
	}
	if (i % 3) {
	    apr_md5_update(&ctx1, (unsigned char *)sp, sl);
	}

	if (i % 7) {
	    apr_md5_update(&ctx1, (unsigned char *)pw, strlen(pw));
	}

	if (i & 1) {
	    apr_md5_update(&ctx1, final, MD5_DIGESTSIZE);
	}
	else {
	    apr_md5_update(&ctx1, (unsigned char *)pw, strlen(pw));
	}
	apr_md5_final(final,&ctx1);
    }

    p = passwd + strlen(passwd);

    l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; to64(p, l, 4); p += 4;
    l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; to64(p, l, 4); p += 4;
    l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; to64(p, l, 4); p += 4;
    l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; to64(p, l, 4); p += 4;
    l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; to64(p, l, 4); p += 4;
    l =                    final[11]                ; to64(p, l, 2); p += 2;
    *p = '\0';

    /*
     * Don't leave anything around in vm they could use.
     */
    memset(final, 0, sizeof(final));

    apr_cpystrn(result, passwd, nbytes - 1);
    return APR_SUCCESS;
}

/*
 * Validate a plaintext password against a smashed one.  Use either
 * crypt() (if available) or apr_md5_encode(), depending upon the format
 * of the smashed input password.  Return APR_SUCCESS if they match, or
 * APR_EMISMATCH if they don't.
 */

APR_DECLARE(apr_status_t) apr_password_validate(const char *passwd, 
                                               const char *hash)
{
    char sample[120];
#if !defined(WIN32) && !defined(BEOS)
    char *crypt_pw;
#endif
    if (!strncmp(hash, apr1_id, strlen(apr1_id))) {
	/*
	 * The hash was created using our custom algorithm.
	 */
	apr_md5_encode(passwd, hash, sample, sizeof(sample));
    }
    else {
	/*
	 * It's not our algorithm, so feed it to crypt() if possible.
	 */
#if defined(WIN32) || defined(BEOS)
	apr_cpystrn(sample, passwd, sizeof(sample) - 1);
#else
	crypt_pw = crypt(passwd, hash);
	apr_cpystrn(sample, crypt_pw, sizeof(sample) - 1);
#endif
    }
    return (strcmp(sample, hash) == 0) ? APR_SUCCESS : APR_EMISMATCH;
}