1 /** @file 2 Diffie-Hellman Wrapper Implementation over OpenSSL. 3 4 Copyright (c) 2010 - 2015, 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/bn.h> 17 #include <openssl/dh.h> 18 19 20 /** 21 Allocates and Initializes one Diffie-Hellman Context for subsequent use. 22 23 @return Pointer to the Diffie-Hellman Context that has been initialized. 24 If the allocations fails, DhNew() returns NULL. 25 26 **/ 27 VOID * 28 EFIAPI 29 DhNew ( 30 VOID 31 ) 32 { 33 // 34 // Allocates & Initializes DH Context by OpenSSL DH_new() 35 // 36 return (VOID *) DH_new (); 37 } 38 39 /** 40 Release the specified DH context. 41 42 If DhContext is NULL, then return FALSE. 43 44 @param[in] DhContext Pointer to the DH context to be released. 45 46 **/ 47 VOID 48 EFIAPI 49 DhFree ( 50 IN VOID *DhContext 51 ) 52 { 53 // 54 // Free OpenSSL DH Context 55 // 56 DH_free ((DH *) DhContext); 57 } 58 59 /** 60 Generates DH parameter. 61 62 Given generator g, and length of prime number p in bits, this function generates p, 63 and sets DH context according to value of g and p. 64 65 Before this function can be invoked, pseudorandom number generator must be correctly 66 initialized by RandomSeed(). 67 68 If DhContext is NULL, then return FALSE. 69 If Prime is NULL, then return FALSE. 70 71 @param[in, out] DhContext Pointer to the DH context. 72 @param[in] Generator Value of generator. 73 @param[in] PrimeLength Length in bits of prime to be generated. 74 @param[out] Prime Pointer to the buffer to receive the generated prime number. 75 76 @retval TRUE DH pamameter generation succeeded. 77 @retval FALSE Value of Generator is not supported. 78 @retval FALSE PRNG fails to generate random prime number with PrimeLength. 79 80 **/ 81 BOOLEAN 82 EFIAPI 83 DhGenerateParameter ( 84 IN OUT VOID *DhContext, 85 IN UINTN Generator, 86 IN UINTN PrimeLength, 87 OUT UINT8 *Prime 88 ) 89 { 90 BOOLEAN RetVal; 91 92 // 93 // Check input parameters. 94 // 95 if (DhContext == NULL || Prime == NULL || PrimeLength > INT_MAX) { 96 return FALSE; 97 } 98 99 if (Generator != DH_GENERATOR_2 && Generator != DH_GENERATOR_5) { 100 return FALSE; 101 } 102 103 RetVal = (BOOLEAN) DH_generate_parameters_ex (DhContext, (UINT32) PrimeLength, (UINT32) Generator, NULL); 104 if (!RetVal) { 105 return FALSE; 106 } 107 108 BN_bn2bin (((DH *) DhContext)->p, Prime); 109 110 return TRUE; 111 } 112 113 /** 114 Sets generator and prime parameters for DH. 115 116 Given generator g, and prime number p, this function and sets DH 117 context accordingly. 118 119 If DhContext is NULL, then return FALSE. 120 If Prime is NULL, then return FALSE. 121 122 @param[in, out] DhContext Pointer to the DH context. 123 @param[in] Generator Value of generator. 124 @param[in] PrimeLength Length in bits of prime to be generated. 125 @param[in] Prime Pointer to the prime number. 126 127 @retval TRUE DH pamameter setting succeeded. 128 @retval FALSE Value of Generator is not supported. 129 @retval FALSE Value of Generator is not suitable for the Prime. 130 @retval FALSE Value of Prime is not a prime number. 131 @retval FALSE Value of Prime is not a safe prime number. 132 133 **/ 134 BOOLEAN 135 EFIAPI 136 DhSetParameter ( 137 IN OUT VOID *DhContext, 138 IN UINTN Generator, 139 IN UINTN PrimeLength, 140 IN CONST UINT8 *Prime 141 ) 142 { 143 DH *Dh; 144 BIGNUM *Bn; 145 146 // 147 // Check input parameters. 148 // 149 if (DhContext == NULL || Prime == NULL || PrimeLength > INT_MAX) { 150 return FALSE; 151 } 152 153 if (Generator != DH_GENERATOR_2 && Generator != DH_GENERATOR_5) { 154 return FALSE; 155 } 156 157 Bn = NULL; 158 159 Dh = (DH *) DhContext; 160 Dh->g = NULL; 161 Dh->p = BN_new (); 162 if (Dh->p == NULL) { 163 goto Error; 164 } 165 166 Dh->g = BN_new (); 167 if (Dh->g == NULL) { 168 goto Error; 169 } 170 171 Bn = BN_bin2bn (Prime, (UINT32) (PrimeLength / 8), Dh->p); 172 if (Bn == NULL) { 173 goto Error; 174 } 175 176 if (BN_set_word (Dh->g, (UINT32) Generator) == 0) { 177 goto Error; 178 } 179 180 return TRUE; 181 182 Error: 183 184 if (Dh->p != NULL) { 185 BN_free (Dh->p); 186 } 187 188 if (Dh->g != NULL) { 189 BN_free (Dh->g); 190 } 191 192 if (Bn != NULL) { 193 BN_free (Bn); 194 } 195 196 return FALSE; 197 } 198 199 /** 200 Generates DH public key. 201 202 This function generates random secret exponent, and computes the public key, which is 203 returned via parameter PublicKey and PublicKeySize. DH context is updated accordingly. 204 If the PublicKey buffer is too small to hold the public key, FALSE is returned and 205 PublicKeySize is set to the required buffer size to obtain the public key. 206 207 If DhContext is NULL, then return FALSE. 208 If PublicKeySize is NULL, then return FALSE. 209 If PublicKeySize is large enough but PublicKey is NULL, then return FALSE. 210 211 @param[in, out] DhContext Pointer to the DH context. 212 @param[out] PublicKey Pointer to the buffer to receive generated public key. 213 @param[in, out] PublicKeySize On input, the size of PublicKey buffer in bytes. 214 On output, the size of data returned in PublicKey buffer in bytes. 215 216 @retval TRUE DH public key generation succeeded. 217 @retval FALSE DH public key generation failed. 218 @retval FALSE PublicKeySize is not large enough. 219 220 **/ 221 BOOLEAN 222 EFIAPI 223 DhGenerateKey ( 224 IN OUT VOID *DhContext, 225 OUT UINT8 *PublicKey, 226 IN OUT UINTN *PublicKeySize 227 ) 228 { 229 BOOLEAN RetVal; 230 DH *Dh; 231 INTN Size; 232 233 // 234 // Check input parameters. 235 // 236 if (DhContext == NULL || PublicKeySize == NULL) { 237 return FALSE; 238 } 239 240 if (PublicKey == NULL && *PublicKeySize != 0) { 241 return FALSE; 242 } 243 244 Dh = (DH *) DhContext; 245 246 RetVal = (BOOLEAN) DH_generate_key (DhContext); 247 if (RetVal) { 248 Size = BN_num_bytes (Dh->pub_key); 249 if ((Size > 0) && (*PublicKeySize < (UINTN) Size)) { 250 *PublicKeySize = Size; 251 return FALSE; 252 } 253 254 BN_bn2bin (Dh->pub_key, PublicKey); 255 *PublicKeySize = Size; 256 } 257 258 return RetVal; 259 } 260 261 /** 262 Computes exchanged common key. 263 264 Given peer's public key, this function computes the exchanged common key, based on its own 265 context including value of prime modulus and random secret exponent. 266 267 If DhContext is NULL, then return FALSE. 268 If PeerPublicKey is NULL, then return FALSE. 269 If KeySize is NULL, then return FALSE. 270 If Key is NULL, then return FALSE. 271 If KeySize is not large enough, then return FALSE. 272 273 @param[in, out] DhContext Pointer to the DH context. 274 @param[in] PeerPublicKey Pointer to the peer's public key. 275 @param[in] PeerPublicKeySize Size of peer's public key in bytes. 276 @param[out] Key Pointer to the buffer to receive generated key. 277 @param[in, out] KeySize On input, the size of Key buffer in bytes. 278 On output, the size of data returned in Key buffer in bytes. 279 280 @retval TRUE DH exchanged key generation succeeded. 281 @retval FALSE DH exchanged key generation failed. 282 @retval FALSE KeySize is not large enough. 283 284 **/ 285 BOOLEAN 286 EFIAPI 287 DhComputeKey ( 288 IN OUT VOID *DhContext, 289 IN CONST UINT8 *PeerPublicKey, 290 IN UINTN PeerPublicKeySize, 291 OUT UINT8 *Key, 292 IN OUT UINTN *KeySize 293 ) 294 { 295 BIGNUM *Bn; 296 INTN Size; 297 298 // 299 // Check input parameters. 300 // 301 if (DhContext == NULL || PeerPublicKey == NULL || KeySize == NULL || Key == NULL) { 302 return FALSE; 303 } 304 305 if (PeerPublicKeySize > INT_MAX) { 306 return FALSE; 307 } 308 309 Bn = BN_bin2bn (PeerPublicKey, (UINT32) PeerPublicKeySize, NULL); 310 if (Bn == NULL) { 311 return FALSE; 312 } 313 314 Size = DH_compute_key (Key, Bn, DhContext); 315 if (Size < 0) { 316 BN_free (Bn); 317 return FALSE; 318 } 319 320 if (*KeySize < (UINTN) Size) { 321 *KeySize = Size; 322 BN_free (Bn); 323 return FALSE; 324 } 325 326 *KeySize = Size; 327 BN_free (Bn); 328 return TRUE; 329 } 330
