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 GSSAPI_CALLCONV
  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     OM_uint32 junk;
  51     unsigned char *p;
  52     krb5_keyblock *key = NULL;
  53     size_t dol;
  54
  55     if (ctx == NULL) {
  56         *minor_status = 0;
  57         return GSS_S_NO_CONTEXT;
  58     }
  59
  60     if (desired_output_len <= 0 || prf_in->length + 4 < prf_in->length) {
  61         *minor_status = 0;
  62         return GSS_S_FAILURE;
  63     }
  64     dol = desired_output_len;
  65
  66     GSSAPI_KRB5_INIT (&context);
  67
  68     switch(prf_key) {
  69     case GSS_C_PRF_KEY_FULL:
  70         _gsskrb5i_get_acceptor_subkey(ctx, context, &key);
  71         break;
  72     case GSS_C_PRF_KEY_PARTIAL:
  73         _gsskrb5i_get_initiator_subkey(ctx, context, &key);
  74         break;
  75     default:
  76         _gsskrb5_set_status(EINVAL, "unknown kerberos prf_key");
  77         *minor_status = EINVAL;
  78         return GSS_S_FAILURE;
  79     }
  80
  81     if (key == NULL) {
  82         _gsskrb5_set_status(EINVAL, "no prf_key found");
  83         *minor_status = EINVAL;
  84         return GSS_S_FAILURE;
  85     }
  86
  87     ret = krb5_crypto_init(context, key, 0, &crypto);
  88     krb5_free_keyblock (context, key);
  89     if (ret) {
  90         *minor_status = ret;
  91         return GSS_S_FAILURE;
  92     }
  93
  94     prf_out->value = malloc(dol);
  95     if (prf_out->value == NULL) {
  96         _gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
  97         *minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
  98         krb5_crypto_destroy(context, crypto);
  99         return GSS_S_FAILURE;
 100     }
 101     prf_out->length = dol;
 102
 103     HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
 104
 105     input.length = prf_in->length + 4;
 106     input.data = malloc(prf_in->length + 4);
 107     if (input.data == NULL) {
 108         _gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
 109         *minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
 110         gss_release_buffer(&junk, prf_out);
 111         krb5_crypto_destroy(context, crypto);
 112         HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 113         return GSS_S_FAILURE;
 114     }
 115     memcpy(((uint8_t *)input.data) + 4, prf_in->value, prf_in->length);
 116
 117     num = 0;
 118     p = prf_out->value;
 119     while(dol > 0) {
 120         size_t tsize;
 121
 122         _gss_mg_encode_be_uint32(num, input.data);
 123
 124         ret = krb5_crypto_prf(context, crypto, &input, &output);
 125         if (ret) {
 126             *minor_status = ret;
 127             free(input.data);
 128             gss_release_buffer(&junk, prf_out);
 129             krb5_crypto_destroy(context, crypto);
 130             HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 131             return GSS_S_FAILURE;
 132         }
 133
 134         tsize = min(dol, output.length);
 135         memcpy(p, output.data, tsize);
 136         p += tsize;
 137         dol -= tsize;
 138         krb5_data_free(&output);
 139         num++;
 140     }
 141     free(input.data);
 142
 143     krb5_crypto_destroy(context, crypto);
 144
 145     HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 146
 147     return GSS_S_COMPLETE;
 148 }