CryptoPkg/Library/BaseCryptLib/Pk/CryptDh.c

   1 /** @file
   2   Diffie-Hellman Wrapper Implementation over OpenSSL.
   3
   4 Copyright (c) 2010 - 2012, Intel Corporation. All rights reserved.<BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "InternalCryptLib.h"
  16 #include <openssl/dh.h>
  17
  18
  19 /**
  20   Allocates and Initializes one Diffie-Hellman Context for subsequent use.
  21
  22   @return  Pointer to the Diffie-Hellman Context that has been initialized.
  23            If the allocations fails, DhNew() returns NULL.
  24
  25 **/
  26 VOID *
  27 EFIAPI
  28 DhNew (
  29   VOID
  30   )
  31 {
  32   //
  33   // Allocates & Initializes DH Context by OpenSSL DH_new()
  34   //
  35   return (VOID *)DH_new ();
  36 }
  37
  38 /**
  39   Release the specified DH context.
  40
  41   If DhContext is NULL, then return FALSE.
  42
  43   @param[in]  DhContext  Pointer to the DH context to be released.
  44
  45 **/
  46 VOID
  47 EFIAPI
  48 DhFree (
  49   IN  VOID  *DhContext
  50   )
  51 {
  52   //
  53   // Free OpenSSL DH Context
  54   //
  55   DH_free ((DH *)DhContext);
  56 }
  57
  58 /**
  59   Generates DH parameter.
  60
  61   Given generator g, and length of prime number p in bits, this function generates p,
  62   and sets DH context according to value of g and p.
  63
  64   Before this function can be invoked, pseudorandom number generator must be correctly
  65   initialized by RandomSeed().
  66
  67   If DhContext is NULL, then return FALSE.
  68   If Prime is NULL, then return FALSE.
  69
  70   @param[in, out]  DhContext    Pointer to the DH context.
  71   @param[in]       Generator    Value of generator.
  72   @param[in]       PrimeLength  Length in bits of prime to be generated.
  73   @param[out]      Prime        Pointer to the buffer to receive the generated prime number.
  74
  75   @retval TRUE   DH pamameter generation succeeded.
  76   @retval FALSE  Value of Generator is not supported.
  77   @retval FALSE  PRNG fails to generate random prime number with PrimeLength.
  78
  79 **/
  80 BOOLEAN
  81 EFIAPI
  82 DhGenerateParameter (
  83   IN OUT  VOID   *DhContext,
  84   IN      UINTN  Generator,
  85   IN      UINTN  PrimeLength,
  86   OUT     UINT8  *Prime
  87   )
  88 {
  89   BOOLEAN RetVal;
  90
  91   //
  92   // Check input parameters.
  93   //
  94   if (DhContext == NULL || Prime == NULL) {
  95     return FALSE;
  96   }
  97
  98   if (Generator != DH_GENERATOR_2 && Generator != DH_GENERATOR_5) {
  99     return FALSE;
 100   }
 101
 102   RetVal = (BOOLEAN) DH_generate_parameters_ex (DhContext, (UINT32) PrimeLength, (UINT32) Generator, NULL);
 103   if (!RetVal) {
 104     return FALSE;
 105   }
 106
 107   BN_bn2bin (((DH *) DhContext)->p, Prime);
 108
 109   return TRUE;
 110 }
 111
 112 /**
 113   Sets generator and prime parameters for DH.
 114
 115   Given generator g, and prime number p, this function and sets DH
 116   context accordingly.
 117
 118   If DhContext is NULL, then return FALSE.
 119   If Prime is NULL, then return FALSE.
 120
 121   @param[in, out]  DhContext    Pointer to the DH context.
 122   @param[in]       Generator    Value of generator.
 123   @param[in]       PrimeLength  Length in bits of prime to be generated.
 124   @param[in]       Prime        Pointer to the prime number.
 125
 126   @retval TRUE   DH pamameter setting succeeded.
 127   @retval FALSE  Value of Generator is not supported.
 128   @retval FALSE  Value of Generator is not suitable for the Prime.
 129   @retval FALSE  Value of Prime is not a prime number.
 130   @retval FALSE  Value of Prime is not a safe prime number.
 131
 132 **/
 133 BOOLEAN
 134 EFIAPI
 135 DhSetParameter (
 136   IN OUT  VOID         *DhContext,
 137   IN      UINTN        Generator,
 138   IN      UINTN        PrimeLength,
 139   IN      CONST UINT8  *Prime
 140   )
 141 {
 142   DH  *Dh;
 143
 144   //
 145   // Check input parameters.
 146   //
 147   if (DhContext == NULL || Prime == NULL) {
 148     return FALSE;
 149   }
 150
 151   if (Generator != DH_GENERATOR_2 && Generator != DH_GENERATOR_5) {
 152     return FALSE;
 153   }
 154
 155   Dh = (DH *) DhContext;
 156   Dh->p = BN_new();
 157   Dh->g = BN_new();
 158
 159   BN_bin2bn (Prime, (UINT32) (PrimeLength / 8), Dh->p);
 160   BN_set_word (Dh->g, (UINT32) Generator);
 161
 162   return TRUE;
 163 }
 164
 165 /**
 166   Generates DH public key.
 167
 168   This function generates random secret exponent, and computes the public key, which is
 169   returned via parameter PublicKey and PublicKeySize. DH context is updated accordingly.
 170   If the PublicKey buffer is too small to hold the public key, FALSE is returned and
 171   PublicKeySize is set to the required buffer size to obtain the public key.
 172
 173   If DhContext is NULL, then return FALSE.
 174   If PublicKeySize is NULL, then return FALSE.
 175   If PublicKeySize is large enough but PublicKey is NULL, then return FALSE.
 176
 177   @param[in, out]  DhContext      Pointer to the DH context.
 178   @param[out]      PublicKey      Pointer to the buffer to receive generated public key.
 179   @param[in, out]  PublicKeySize  On input, the size of PublicKey buffer in bytes.
 180                                   On output, the size of data returned in PublicKey buffer in bytes.
 181
 182   @retval TRUE   DH public key generation succeeded.
 183   @retval FALSE  DH public key generation failed.
 184   @retval FALSE  PublicKeySize is not large enough.
 185
 186 **/
 187 BOOLEAN
 188 EFIAPI
 189 DhGenerateKey (
 190   IN OUT  VOID   *DhContext,
 191   OUT     UINT8  *PublicKey,
 192   IN OUT  UINTN  *PublicKeySize
 193   )
 194 {
 195   BOOLEAN RetVal;
 196   DH      *Dh;
 197
 198   //
 199   // Check input parameters.
 200   //
 201   if (DhContext == NULL || PublicKeySize == NULL) {
 202     return FALSE;
 203   }
 204
 205   if (PublicKey == NULL && *PublicKeySize != 0) {
 206     return FALSE;
 207   }
 208
 209   Dh = (DH *) DhContext;
 210   *PublicKeySize = 0;
 211
 212   RetVal = (BOOLEAN) DH_generate_key (DhContext);
 213   if (RetVal) {
 214     BN_bn2bin (Dh->pub_key, PublicKey);
 215     *PublicKeySize  = BN_num_bytes (Dh->pub_key);
 216   }
 217
 218   return RetVal;
 219 }
 220
 221 /**
 222   Computes exchanged common key.
 223
 224   Given peer's public key, this function computes the exchanged common key, based on its own
 225   context including value of prime modulus and random secret exponent.
 226
 227   If DhContext is NULL, then return FALSE.
 228   If PeerPublicKey is NULL, then return FALSE.
 229   If KeySize is NULL, then return FALSE.
 230   If KeySize is large enough but Key is NULL, then return FALSE.
 231
 232   @param[in, out]  DhContext          Pointer to the DH context.
 233   @param[in]       PeerPublicKey      Pointer to the peer's public key.
 234   @param[in]       PeerPublicKeySize  Size of peer's public key in bytes.
 235   @param[out]      Key                Pointer to the buffer to receive generated key.
 236   @param[in, out]  KeySize            On input, the size of Key buffer in bytes.
 237                                       On output, the size of data returned in Key buffer in bytes.
 238
 239   @retval TRUE   DH exchanged key generation succeeded.
 240   @retval FALSE  DH exchanged key generation failed.
 241   @retval FALSE  KeySize is not large enough.
 242
 243 **/
 244 BOOLEAN
 245 EFIAPI
 246 DhComputeKey (
 247   IN OUT  VOID         *DhContext,
 248   IN      CONST UINT8  *PeerPublicKey,
 249   IN      UINTN        PeerPublicKeySize,
 250   OUT     UINT8        *Key,
 251   IN OUT  UINTN        *KeySize
 252   )
 253 {
 254   BIGNUM  *Bn;
 255
 256   //
 257   // Check input parameters.
 258   //
 259   if (DhContext == NULL || PeerPublicKey == NULL || KeySize == NULL) {
 260     return FALSE;
 261   }
 262
 263   if (Key == NULL && *KeySize != 0) {
 264     return FALSE;
 265   }
 266
 267   Bn = BN_bin2bn (PeerPublicKey, (UINT32) PeerPublicKeySize, NULL);
 268
 269   *KeySize = (BOOLEAN) DH_compute_key (Key, Bn, DhContext);
 270
 271   BN_free (Bn);
 272
 273   return TRUE;
 274 }