Home | History | Annotate | Line # | Download | only in krb5 
      1 /*	$NetBSD: prf.c,v 1.2 2017/01/28 21:31:46 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2007 Kungliga Tekniska Hgskolan
      5  * (Royal Institute of Technology, Stockholm, Sweden).
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  *
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  *
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * 3. Neither the name of the Institute nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include "gsskrb5_locl.h"
     37 
     38 OM_uint32 GSSAPI_CALLCONV
     39 _gsskrb5_pseudo_random(OM_uint32 *minor_status,
     40 		       gss_ctx_id_t context_handle,
     41 		       int prf_key,
     42 		       const gss_buffer_t prf_in,
     43 		       ssize_t desired_output_len,
     44 		       gss_buffer_t prf_out)
     45 {
     46     gsskrb5_ctx ctx = (gsskrb5_ctx)context_handle;
     47     krb5_context context;
     48     krb5_error_code ret;
     49     krb5_crypto crypto;
     50     krb5_data input, output;
     51     uint32_t num;
     52     OM_uint32 junk;
     53     unsigned char *p;
     54     krb5_keyblock *key = NULL;
     55     size_t dol;
     56 
     57     if (ctx == NULL) {
     58 	*minor_status = 0;
     59 	return GSS_S_NO_CONTEXT;
     60     }
     61 
     62     if (desired_output_len <= 0 || prf_in->length + 4 < prf_in->length) {
     63 	*minor_status = 0;
     64 	return GSS_S_FAILURE;
     65     }
     66     dol = desired_output_len;
     67 
     68     GSSAPI_KRB5_INIT (&context);
     69 
     70     switch(prf_key) {
     71     case GSS_C_PRF_KEY_FULL:
     72 	_gsskrb5i_get_acceptor_subkey(ctx, context, &key);
     73 	break;
     74     case GSS_C_PRF_KEY_PARTIAL:
     75 	_gsskrb5i_get_initiator_subkey(ctx, context, &key);
     76 	break;
     77     default:
     78 	_gsskrb5_set_status(EINVAL, "unknown kerberos prf_key");
     79 	*minor_status = EINVAL;
     80 	return GSS_S_FAILURE;
     81     }
     82 
     83     if (key == NULL) {
     84 	_gsskrb5_set_status(EINVAL, "no prf_key found");
     85 	*minor_status = EINVAL;
     86 	return GSS_S_FAILURE;
     87     }
     88 
     89     ret = krb5_crypto_init(context, key, 0, &crypto);
     90     krb5_free_keyblock (context, key);
     91     if (ret) {
     92 	*minor_status = ret;
     93 	return GSS_S_FAILURE;
     94     }
     95 
     96     prf_out->value = malloc(dol);
     97     if (prf_out->value == NULL) {
     98 	_gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
     99 	*minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
    100 	krb5_crypto_destroy(context, crypto);
    101 	return GSS_S_FAILURE;
    102     }
    103     prf_out->length = dol;
    104 
    105     HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
    106 
    107     input.length = prf_in->length + 4;
    108     input.data = malloc(prf_in->length + 4);
    109     if (input.data == NULL) {
    110 	_gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
    111 	*minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
    112 	gss_release_buffer(&junk, prf_out);
    113 	krb5_crypto_destroy(context, crypto);
    114 	HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
    115 	return GSS_S_FAILURE;
    116     }
    117     memcpy(((uint8_t *)input.data) + 4, prf_in->value, prf_in->length);
    118 
    119     num = 0;
    120     p = prf_out->value;
    121     while(dol > 0) {
    122 	size_t tsize;
    123 
    124 	_gsskrb5_encode_be_om_uint32(num, input.data);
    125 
    126 	ret = krb5_crypto_prf(context, crypto, &input, &output);
    127 	if (ret) {
    128 	    *minor_status = ret;
    129 	    free(input.data);
    130 	    gss_release_buffer(&junk, prf_out);
    131 	    krb5_crypto_destroy(context, crypto);
    132 	    HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
    133 	    return GSS_S_FAILURE;
    134 	}
    135 
    136 	tsize = min(dol, output.length);
    137 	memcpy(p, output.data, tsize);
    138 	p += tsize;
    139 	dol -= tsize;
    140 	krb5_data_free(&output);
    141 	num++;
    142     }
    143     free(input.data);
    144 
    145     krb5_crypto_destroy(context, crypto);
    146 
    147     HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
    148 
    149     return GSS_S_COMPLETE;
    150 }
    151