fips/rand/fips_rand_lib.c

   1 /* ====================================================================
   2  * Copyright (c) 2011 The OpenSSL Project.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in
  13  *    the documentation and/or other materials provided with the
  14  *    distribution.
  15  *
  16  * 3. All advertising materials mentioning features or use of this
  17  *    software must display the following acknowledgment:
  18  *    "This product includes software developed by the OpenSSL Project
  19  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  20  *
  21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  22  *    endorse or promote products derived from this software without
  23  *    prior written permission. For written permission, please contact
  24  *    openssl-core@openssl.org.
  25  *
  26  * 5. Products derived from this software may not be called "OpenSSL"
  27  *    nor may "OpenSSL" appear in their names without prior written
  28  *    permission of the OpenSSL Project.
  29  *
  30  * 6. Redistributions of any form whatsoever must retain the following
  31  *    acknowledgment:
  32  *    "This product includes software developed by the OpenSSL Project
  33  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  46  * OF THE POSSIBILITY OF SUCH DAMAGE.
  47  *
  48  */
  49
  50 #define OPENSSL_FIPSAPI
  51
  52 #include <openssl/crypto.h>
  53 #include <openssl/rand.h>
  54 #include <openssl/err.h>
  55 #include <openssl/fips.h>
  56 #include <openssl/fips_rand.h>
  57 #include "e_os.h"
  58
  59 /* FIPS API for PRNG use. Similar to RAND functionality but without
  60  * ENGINE and additional checking for non-FIPS rand methods.
  61  */
  62
  63 static const RAND_METHOD *fips_rand_meth = NULL;
  64 static int fips_approved_rand_meth = 0;
  65 static int fips_rand_bits = 0;
  66
  67 /* Allows application to override number of bits and uses non-FIPS methods */
  68 void FIPS_rand_set_bits(int nbits)
  69         {
  70         fips_rand_bits = nbits;
  71         }
  72
  73 int FIPS_rand_set_method(const RAND_METHOD *meth)
  74         {
  75         if (!fips_rand_bits)
  76                 {
  77                 if (meth == FIPS_drbg_method())
  78                         fips_approved_rand_meth = 1;
  79                 else if (meth == FIPS_x931_method())
  80                         fips_approved_rand_meth = 2;
  81                 else
  82                         {
  83                         fips_approved_rand_meth = 0;
  84                         if (FIPS_module_mode())
  85                                 {
  86                                 FIPSerr(FIPS_F_FIPS_RAND_SET_METHOD,
  87                                                 FIPS_R_NON_FIPS_METHOD);
  88                                 return 0;
  89                                 }
  90                         }
  91                 }
  92         fips_rand_meth = meth;
  93         return 1;
  94         }
  95
  96 const RAND_METHOD *FIPS_rand_get_method(void)
  97         {
  98         return fips_rand_meth;
  99         }
 100
 101 void FIPS_rand_seed(const void *buf, int num)
 102         {
 103         if (!fips_approved_rand_meth && FIPS_module_mode())
 104                 {
 105                 FIPSerr(FIPS_F_FIPS_RAND_SEED, FIPS_R_NON_FIPS_METHOD);
 106                 return;
 107                 }
 108         if (fips_rand_meth && fips_rand_meth->seed)
 109                 fips_rand_meth->seed(buf,num);
 110         }
 111
 112 void FIPS_rand_add(const void *buf, int num, double entropy)
 113         {
 114         if (!fips_approved_rand_meth && FIPS_module_mode())
 115                 {
 116                 FIPSerr(FIPS_F_FIPS_RAND_ADD, FIPS_R_NON_FIPS_METHOD);
 117                 return;
 118                 }
 119         if (fips_rand_meth && fips_rand_meth->add)
 120                 fips_rand_meth->add(buf,num,entropy);
 121         }
 122
 123 int FIPS_rand_bytes(unsigned char *buf, int num)
 124         {
 125         if (!fips_approved_rand_meth && FIPS_module_mode())
 126                 {
 127                 FIPSerr(FIPS_F_FIPS_RAND_BYTES, FIPS_R_NON_FIPS_METHOD);
 128                 return 0;
 129                 }
 130         if (fips_rand_meth && fips_rand_meth->bytes)
 131                 return fips_rand_meth->bytes(buf,num);
 132         return 0;
 133         }
 134
 135 int FIPS_rand_pseudo_bytes(unsigned char *buf, int num)
 136         {
 137         if (!fips_approved_rand_meth && FIPS_module_mode())
 138                 {
 139                 FIPSerr(FIPS_F_FIPS_RAND_PSEUDO_BYTES, FIPS_R_NON_FIPS_METHOD);
 140                 return 0;
 141                 }
 142         if (fips_rand_meth && fips_rand_meth->pseudorand)
 143                 return fips_rand_meth->pseudorand(buf,num);
 144         return -1;
 145         }
 146
 147 int FIPS_rand_status(void)
 148         {
 149         if (!fips_approved_rand_meth && FIPS_module_mode())
 150                 {
 151                 FIPSerr(FIPS_F_FIPS_RAND_STATUS, FIPS_R_NON_FIPS_METHOD);
 152                 return 0;
 153                 }
 154         if (fips_rand_meth && fips_rand_meth->status)
 155                 return fips_rand_meth->status();
 156         return 0;
 157         }
 158
 159 /* Return instantiated strength of PRNG. For DRBG this is an internal
 160  * parameter. For X9.31 PRNG it is 80 bits (from SP800-131). Any other
 161  * type of PRNG is not approved and returns 0 in FIPS mode and maximum
 162  * 256 outside FIPS mode.
 163  */
 164
 165 int FIPS_rand_strength(void)
 166         {
 167         if (fips_rand_bits)
 168                 return fips_rand_bits;
 169         if (fips_approved_rand_meth == 1)
 170                 return FIPS_drbg_get_strength(FIPS_get_default_drbg());
 171         else if (fips_approved_rand_meth == 2)
 172                 return 80;
 173         else if (fips_approved_rand_meth == 0)
 174                 {
 175                 if (FIPS_module_mode())
 176                         return 0;
 177                 else
 178                         return 256;
 179                 }
 180         return 0;
 181         }