lib/gssapi/krb5/prf.c

   1 /*
   2  * Copyright (c) 2007 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "gsskrb5_locl.h"
  35
  36 OM_uint32
  37 _gsskrb5_pseudo_random(OM_uint32 *minor_status,
  38                        gss_ctx_id_t context_handle,
  39                        int prf_key,
  40                        const gss_buffer_t prf_in,
  41                        ssize_t desired_output_len,
  42                        gss_buffer_t prf_out)
  43 {
  44     gsskrb5_ctx ctx = (gsskrb5_ctx)context_handle;
  45     krb5_context context;
  46     krb5_error_code ret;
  47     krb5_crypto crypto;
  48     krb5_data input, output;
  49     uint32_t num;
  50     unsigned char *p;
  51     krb5_keyblock *key = NULL;
  52
  53     if (ctx == NULL) {
  54         *minor_status = 0;
  55         return GSS_S_NO_CONTEXT;
  56     }
  57
  58     if (desired_output_len <= 0) {
  59         *minor_status = 0;
  60         return GSS_S_FAILURE;
  61     }
  62
  63     GSSAPI_KRB5_INIT (&context);
  64
  65     switch(prf_key) {
  66     case GSS_C_PRF_KEY_FULL:
  67         _gsskrb5i_get_acceptor_subkey(ctx, context, &key);
  68         break;
  69     case GSS_C_PRF_KEY_PARTIAL:
  70         _gsskrb5i_get_initiator_subkey(ctx, context, &key);
  71         break;
  72     default:
  73         _gsskrb5_set_status(EINVAL, "unknown kerberos prf_key");
  74         *minor_status = EINVAL;
  75         return GSS_S_FAILURE;
  76     }
  77
  78     if (key == NULL) {
  79         _gsskrb5_set_status(EINVAL, "no prf_key found");
  80         *minor_status = EINVAL;
  81         return GSS_S_FAILURE;
  82     }
  83
  84     ret = krb5_crypto_init(context, key, 0, &crypto);
  85     krb5_free_keyblock (context, key);
  86     if (ret) {
  87         *minor_status = ret;
  88         return GSS_S_FAILURE;
  89     }
  90
  91     prf_out->value = malloc(desired_output_len);
  92     if (prf_out->value == NULL) {
  93         _gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
  94         *minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
  95         krb5_crypto_destroy(context, crypto);
  96         return GSS_S_FAILURE;
  97     }
  98     prf_out->length = desired_output_len;
  99
 100     HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
 101
 102     input.length = prf_in->length + 4;
 103     input.data = malloc(prf_in->length + 4);
 104     if (input.data == NULL) {
 105         OM_uint32 junk;
 106         _gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
 107         *minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
 108         gss_release_buffer(&junk, prf_out);
 109         krb5_crypto_destroy(context, crypto);
 110         HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 111         return GSS_S_FAILURE;
 112     }
 113     memcpy(((unsigned char *)input.data) + 4, prf_in->value, prf_in->length);
 114
 115     num = 0;
 116     p = prf_out->value;
 117     while(desired_output_len > 0) {
 118         _gsskrb5_encode_om_uint32(num, input.data);
 119         ret = krb5_crypto_prf(context, crypto, &input, &output);
 120         if (ret) {
 121             OM_uint32 junk;
 122             *minor_status = ret;
 123             free(input.data);
 124             gss_release_buffer(&junk, prf_out);
 125             krb5_crypto_destroy(context, crypto);
 126             HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 127             return GSS_S_FAILURE;
 128         }
 129         memcpy(p, output.data, min(desired_output_len, output.length));
 130         p += output.length;
 131         desired_output_len -= output.length;
 132         krb5_data_free(&output);
 133         num++;
 134     }
 135
 136     krb5_crypto_destroy(context, crypto);
 137
 138     HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 139
 140     return GSS_S_COMPLETE;
 141 }