ntlm.c

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	heim_ntlm_free_buf(key);
	return ret;
    }
    MD4_Init(&ctx);
    MD4_Update(&ctx, buf.data, buf.length);
    MD4_Final(key->data, &ctx);
    heim_ntlm_free_buf(&buf);
    return 0;
}

/**
 * Calculate NTLMv1 response hash
 *
 * @param key the ntlm v1 key
 * @param len length of key
 * @param challange sent by the server
 * @param answer calculated answer, should be freed with heim_ntlm_free_buf().
 *
 * @return In case of success 0 is return, an errors, a errno in what
 * went wrong.
 *
 * @ingroup ntlm_core
 */

int
heim_ntlm_calculate_ntlm1(void *key, size_t len,
			  unsigned char challange[8],
			  struct ntlm_buf *answer)
{
    unsigned char res[21];

    if (len != MD4_DIGEST_LENGTH)
	return EINVAL;

    memcpy(res, key, len);
    memset(&res[MD4_DIGEST_LENGTH], 0, sizeof(res) - MD4_DIGEST_LENGTH);

    answer->data = malloc(24);
    if (answer->data == NULL)
	return ENOMEM;
    answer->length = 24;

    splitandenc(&res[0],  challange, ((unsigned char *)answer->data) + 0);
    splitandenc(&res[7],  challange, ((unsigned char *)answer->data) + 8);
    splitandenc(&res[14], challange, ((unsigned char *)answer->data) + 16);

    return 0;
}

/**
 * Generates an NTLMv1 session random with assosited session master key.
 *
 * @param key the ntlm v1 key
 * @param len length of key
 * @param session generated session nonce, should be freed with heim_ntlm_free_buf().
 * @param master calculated session master key, should be freed with heim_ntlm_free_buf().
 *
 * @return In case of success 0 is return, an errors, a errno in what
 * went wrong.
 *
 * @ingroup ntlm_core
 */

int
heim_ntlm_build_ntlm1_master(void *key, size_t len,
			     struct ntlm_buf *session,
			     struct ntlm_buf *master)
{
    RC4_KEY rc4;

    memset(master, 0, sizeof(*master));
    memset(session, 0, sizeof(*session));

    if (len != MD4_DIGEST_LENGTH)
	return EINVAL;
    
    session->length = MD4_DIGEST_LENGTH;
    session->data = malloc(session->length);
    if (session->data == NULL) {
	session->length = 0;
	return EINVAL;
    }    
    master->length = MD4_DIGEST_LENGTH;
    master->data = malloc(master->length);
    if (master->data == NULL) {
	heim_ntlm_free_buf(master);
	heim_ntlm_free_buf(session);
	return EINVAL;
    }
    
    {
	unsigned char sessionkey[MD4_DIGEST_LENGTH];
	MD4_CTX ctx;
    
	MD4_Init(&ctx);
	MD4_Update(&ctx, key, len);
	MD4_Final(sessionkey, &ctx);
	
	RC4_set_key(&rc4, sizeof(sessionkey), sessionkey);
    }
    
    if (RAND_bytes(session->data, session->length) != 1) {
	heim_ntlm_free_buf(master);
	heim_ntlm_free_buf(session);
	return EINVAL;
    }
    
    RC4(&rc4, master->length, session->data, master->data);
    memset(&rc4, 0, sizeof(rc4));
    
    return 0;
}

/**
 * Generates an NTLMv2 session key.
 *
 * @param key the ntlm key
 * @param len length of key
 * @param username name of the user, as sent in the message, assumed to be in UTF8.
 * @param target the name of the target, assumed to be in UTF8.
 * @param ntlmv2 the ntlmv2 session key
 *
 * @ingroup ntlm_core
 */

void
heim_ntlm_ntlmv2_key(const void *key, size_t len,
		     const char *username,
		     const char *target,
		     unsigned char ntlmv2[16])
{
    unsigned int hmaclen;
    HMAC_CTX c;

    HMAC_CTX_init(&c);
    HMAC_Init_ex(&c, key, len, EVP_md5(), NULL);
    {
	struct ntlm_buf buf;
	/* uppercase username and turn it inte ucs2-le */
	ascii2ucs2le(username, 1, &buf);
	HMAC_Update(&c, buf.data, buf.length);
	free(buf.data);
	/* uppercase target and turn into ucs2-le */
	ascii2ucs2le(target, 1, &buf);
	HMAC_Update(&c, buf.data, buf.length);
	free(buf.data);
    }
    HMAC_Final(&c, ntlmv2, &hmaclen);
    HMAC_CTX_cleanup(&c);

}

/*
 *
 */

#define NTTIME_EPOCH 0x019DB1DED53E8000LL

static uint64_t
unix2nttime(time_t unix_time)
{
    long long wt;
    wt = unix_time * (uint64_t)10000000 + (uint64_t)NTTIME_EPOCH;
    return wt;
}

static time_t
nt2unixtime(uint64_t t)
{
    t = ((t - (uint64_t)NTTIME_EPOCH) / (uint64_t)10000000);
    if (t > (((time_t)(~(uint64_t)0)) >> 1))
	return 0;
    return (time_t)t;
}


/**
 * Calculate NTLMv2 response
 *
 * @param key the ntlm key
 * @param len length of key
 * @param username name of the user, as sent in the message, assumed to be in UTF8.
 * @param target the name of the target, assumed to be in UTF8.
 * @param serverchallange challange as sent by the server in the type2 message.
 * @param infotarget infotarget as sent by the server in the type2 message.
 * @param ntlmv2 calculated session key
 * @param answer ntlm response answer, should be freed with heim_ntlm_free_buf().
 *
 * @return In case of success 0 is return, an errors, a errno in what
 * went wrong.
 *
 * @ingroup ntlm_core
 */

int
heim_ntlm_calculate_ntlm2(const void *key, size_t len,
			  const char *username,
			  const char *target,
			  const unsigned char serverchallange[8],
			  const struct ntlm_buf *infotarget,
			  unsigned char ntlmv2[16],
			  struct ntlm_buf *answer)
{
    krb5_error_code ret;
    krb5_data data;
    unsigned int hmaclen;
    unsigned char ntlmv2answer[16];
    krb5_storage *sp;
    unsigned char clientchallange[8];
    HMAC_CTX c;
    uint64_t t;
    
    t = unix2nttime(time(NULL));

    if (RAND_bytes(clientchallange, sizeof(clientchallange)) != 1)
	return EINVAL;
    
    /* calculate ntlmv2 key */

    heim_ntlm_ntlmv2_key(key, len, username, target, ntlmv2);

    /* calculate and build ntlmv2 answer */

    sp = krb5_storage_emem();
    if (sp == NULL)
	return ENOMEM;
    krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);

    CHECK(krb5_store_uint32(sp, 0x00000101), 0);
    CHECK(krb5_store_uint32(sp, 0), 0);
    /* timestamp le 64 bit ts */
    CHECK(krb5_store_uint32(sp, t & 0xffffffff), 0);
    CHECK(krb5_store_uint32(sp, t >> 32), 0);

    CHECK(krb5_storage_write(sp, clientchallange, 8), 8);

    CHECK(krb5_store_uint32(sp, 0), 0);  /* unknown but zero will work */
    CHECK(krb5_storage_write(sp, infotarget->data, infotarget->length), 
	  infotarget->length);
    CHECK(krb5_store_uint32(sp, 0), 0); /* unknown but zero will work */
    
    CHECK(krb5_storage_to_data(sp, &data), 0);
    krb5_storage_free(sp);
    sp = NULL;

    HMAC_CTX_init(&c);
    HMAC_Init_ex(&c, ntlmv2, 16, EVP_md5(), NULL);
    HMAC_Update(&c, serverchallange, 8);
    HMAC_Update(&c, data.data, data.length);
    HMAC_Final(&c, ntlmv2answer, &hmaclen);
    HMAC_CTX_cleanup(&c);

    sp = krb5_storage_emem();
    if (sp == NULL) {
	krb5_data_free(&data);
	return ENOMEM;
    }

    CHECK(krb5_storage_write(sp, ntlmv2answer, 16), 16);
    CHECK(krb5_storage_write(sp, data.data, data.length), data.length);
    krb5_data_free(&data);
    
    CHECK(krb5_storage_to_data(sp, &data), 0);
    krb5_storage_free(sp);
    sp = NULL;

    answer->data = data.data;
    answer->length = data.length;

    return 0;
out:
    if (sp)
	krb5_storage_free(sp);
    return ret;
}

static const int authtimediff = 3600 * 2; /* 2 hours */

/**
 * Verify NTLMv2 response.
 *
 * @param key the ntlm key
 * @param len length of key
 * @param username name of the user, as sent in the message, assumed to be in UTF8.
 * @param target the name of the target, assumed to be in UTF8.
 * @param now the time now (0 if the library should pick it up itself)
 * @param serverchallange challange as sent by the server in the type2 message.
 * @param answer ntlm response answer, should be freed with heim_ntlm_free_buf().
 * @param infotarget infotarget as sent by the server in the type2 message.
 * @param ntlmv2 calculated session key
 *
 * @return In case of success 0 is return, an errors, a errno in what
 * went wrong.
 *
 * @ingroup ntlm_core
 */

int
heim_ntlm_verify_ntlm2(const void *key, size_t len,
		       const char *username,
		       const char *target,
		       time_t now,
		       const unsigned char serverchallange[8],
		       const struct ntlm_buf *answer,
		       struct ntlm_buf *infotarget,
		       unsigned char ntlmv2[16])
{
    krb5_error_code ret;
    unsigned int hmaclen;
    unsigned char clientanswer[16];
    unsigned char clientnonce[8];
    unsigned char serveranswer[16];
    krb5_storage *sp;
    HMAC_CTX c;
    uint64_t t;
    time_t authtime;
    uint32_t temp;

    infotarget->length = 0;    
    infotarget->data = NULL;    

    if (answer->length < 16)
	return EINVAL;

    if (now == 0)
	now = time(NULL);

    /* calculate ntlmv2 key */

    heim_ntlm_ntlmv2_key(key, len, username, target, ntlmv2);

    /* calculate and build ntlmv2 answer */

    sp = krb5_storage_from_readonly_mem(answer->data, answer->length);
    if (sp == NULL)
	return ENOMEM;
    krb5_storage_set_flags(sp, KRB5_STORAGE_BYTEORDER_LE);

    CHECK(krb5_storage_read(sp, clientanswer, 16), 16);

    CHECK(krb5_ret_uint32(sp, &temp), 0);
    CHECK(temp, 0x00000101);
    CHECK(krb5_ret_uint32(sp, &temp), 0);
    CHECK(temp, 0);
    /* timestamp le 64 bit ts */
    CHECK(krb5_ret_uint32(sp, &temp), 0);
    t = temp;
    CHECK(krb5_ret_uint32(sp, &temp), 0);
    t |= ((uint64_t)temp)<< 32;

    authtime = nt2unixtime(t);

    if (abs((int)(authtime - now)) > authtimediff) {
	ret = EINVAL;
	goto out;
    }

    /* client challange */
    CHECK(krb5_storage_read(sp, clientnonce, 8), 8);

    CHECK(krb5_ret_uint32(sp, &temp), 0); /* unknown */

    /* should really unparse the infotarget, but lets pick up everything */
    infotarget->length = answer->length - krb5_storage_seek(sp, 0, SEEK_CUR);
    infotarget->data = malloc(infotarget->length);
    if (infotarget->data == NULL) {
	ret = ENOMEM;
	goto out;
    }
    CHECK(krb5_storage_read(sp, infotarget->data, infotarget->length), 
	  infotarget->length);
    /* XXX remove the unknown ?? */
    krb5_storage_free(sp);
    sp = NULL;

    HMAC_CTX_init(&c);
    HMAC_Init_ex(&c, ntlmv2, 16, EVP_md5(), NULL);
    HMAC_Update(&c, serverchallange, 8);
    HMAC_Update(&c, ((unsigned char *)answer->data) + 16, answer->length - 16);
    HMAC_Final(&c, serveranswer, &hmaclen);
    HMAC_CTX_cleanup(&c);

    if (memcmp(serveranswer, clientanswer, 16) != 0) {
	heim_ntlm_free_buf(infotarget);
	return EINVAL;
    }

    return 0;
out:
    heim_ntlm_free_buf(infotarget);
    if (sp)
	krb5_storage_free(sp);
    return ret;
}


/*
 * Calculate the NTLM2 Session Response
 *
 * @param clnt_nonce client nonce
 * @param svr_chal server challage
 * @param ntlm2_hash ntlm hash
 * @param lm The LM response, should be freed with heim_ntlm_free_buf().
 * @param ntlm The NTLM response, should be freed with heim_ntlm_free_buf().
 *
 * @return In case of success 0 is return, an errors, a errno in what
 * went wrong.
 *
 * @ingroup ntlm_core
 */

int
heim_ntlm_calculate_ntlm2_sess(const unsigned char clnt_nonce[8],
			       const unsigned char svr_chal[8],
			       const unsigned char ntlm_hash[16],
			       struct ntlm_buf *lm,
			       struct ntlm_buf *ntlm)
{
    unsigned char ntlm2_sess_hash[MD5_DIGEST_LENGTH];
    unsigned char res[21], *resp;
    MD5_CTX md5;

    lm->data = malloc(24);
    if (lm->data == NULL)
	return ENOMEM;
    lm->length = 24;

    ntlm->data = malloc(24);
    if (ntlm->data == NULL) {
	free(lm->data);
	lm->data = NULL;
	return ENOMEM;
    }
    ntlm->length = 24;

    /* first setup the lm resp */
    memset(lm->data, 0, 24);
    memcpy(lm->data, clnt_nonce, 8);

    MD5_Init(&md5);
    MD5_Update(&md5, svr_chal, 8); /* session nonce part 1 */
    MD5_Update(&md5, clnt_nonce, 8); /* session nonce part 2 */
    MD5_Final(ntlm2_sess_hash, &md5); /* will only use first 8 bytes */

    memset(res, 0, sizeof(res));
    memcpy(res, ntlm_hash, 16);

    resp = ntlm->data;
    splitandenc(&res[0], ntlm2_sess_hash, resp + 0);
    splitandenc(&res[7], ntlm2_sess_hash, resp + 8);
    splitandenc(&res[14], ntlm2_sess_hash, resp + 16);

    return 0;
}