1 /* Copyright (c) 2020, Google Inc. 2 * 3 * Permission to use, copy, modify, and/or distribute this software for any 4 * purpose with or without fee is hereby granted, provided that the above 5 * copyright notice and this permission notice appear in all copies. 6 * 7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ 14 15 #ifndef OPENSSL_HEADER_CRYPTO_HPKE_INTERNAL_H 16 #define OPENSSL_HEADER_CRYPTO_HPKE_INTERNAL_H 17 18 #include <openssl/aead.h> 19 #include <openssl/base.h> 20 #include <openssl/curve25519.h> 21 #include <openssl/digest.h> 22 23 #if defined(__cplusplus) 24 extern "C" { 25 #endif 26 27 28 // Hybrid Public Key Encryption. 29 // 30 // Hybrid Public Key Encryption (HPKE) enables a sender to encrypt messages to a 31 // receiver with a public key. 32 // 33 // See RFC 9180. 34 35 36 // Parameters. 37 // 38 // An HPKE context is parameterized by KEM, KDF, and AEAD algorithms, 39 // represented by |EVP_HPKE_KEM|, |EVP_HPKE_KDF|, and |EVP_HPKE_AEAD| types, 40 // respectively. 41 42 // The following constants are KEM identifiers. 43 #define EVP_HPKE_DHKEM_X25519_HKDF_SHA256 0x0020 44 45 // The following functions are KEM algorithms which may be used with HPKE. Note 46 // that, while some HPKE KEMs use KDFs internally, this is separate from the 47 // |EVP_HPKE_KDF| selection. 48 OPENSSL_EXPORT const EVP_HPKE_KEM *EVP_hpke_x25519_hkdf_sha256(void); 49 50 // EVP_HPKE_KEM_id returns the HPKE KEM identifier for |kem|, which 51 // will be one of the |EVP_HPKE_KEM_*| constants. 52 OPENSSL_EXPORT uint16_t EVP_HPKE_KEM_id(const EVP_HPKE_KEM *kem); 53 54 // EVP_HPKE_MAX_PUBLIC_KEY_LENGTH is the maximum length of an encoded public key 55 // for all KEMs currently supported by this library. 56 #define EVP_HPKE_MAX_PUBLIC_KEY_LENGTH 32 57 58 // EVP_HPKE_KEM_public_key_len returns the length of a public key for |kem|. 59 // This value will be at most |EVP_HPKE_MAX_PUBLIC_KEY_LENGTH|. 60 OPENSSL_EXPORT size_t EVP_HPKE_KEM_public_key_len(const EVP_HPKE_KEM *kem); 61 62 // EVP_HPKE_MAX_PRIVATE_KEY_LENGTH is the maximum length of an encoded private 63 // key for all KEMs currently supported by this library. 64 #define EVP_HPKE_MAX_PRIVATE_KEY_LENGTH 32 65 66 // EVP_HPKE_KEM_private_key_len returns the length of a private key for |kem|. 67 // This value will be at most |EVP_HPKE_MAX_PRIVATE_KEY_LENGTH|. 68 OPENSSL_EXPORT size_t EVP_HPKE_KEM_private_key_len(const EVP_HPKE_KEM *kem); 69 70 // EVP_HPKE_MAX_ENC_LENGTH is the maximum length of "enc", the encapsulated 71 // shared secret, for all KEMs currently supported by this library. 72 #define EVP_HPKE_MAX_ENC_LENGTH 32 73 74 // EVP_HPKE_KEM_enc_len returns the length of the "enc", the encapsulated shared 75 // secret, for |kem|. This value will be at most |EVP_HPKE_MAX_ENC_LENGTH|. 76 OPENSSL_EXPORT size_t EVP_HPKE_KEM_enc_len(const EVP_HPKE_KEM *kem); 77 78 // The following constants are KDF identifiers. 79 #define EVP_HPKE_HKDF_SHA256 0x0001 80 81 // The following functions are KDF algorithms which may be used with HPKE. 82 OPENSSL_EXPORT const EVP_HPKE_KDF *EVP_hpke_hkdf_sha256(void); 83 84 // EVP_HPKE_KDF_id returns the HPKE KDF identifier for |kdf|. 85 OPENSSL_EXPORT uint16_t EVP_HPKE_KDF_id(const EVP_HPKE_KDF *kdf); 86 87 // EVP_HPKE_KDF_hkdf_md returns the HKDF hash function corresponding to |kdf|, 88 // or NULL if |kdf| is not an HKDF-based KDF. All currently supported KDFs are 89 // HKDF-based. 90 OPENSSL_EXPORT const EVP_MD *EVP_HPKE_KDF_hkdf_md(const EVP_HPKE_KDF *kdf); 91 92 // The following constants are AEAD identifiers. 93 #define EVP_HPKE_AES_128_GCM 0x0001 94 #define EVP_HPKE_AES_256_GCM 0x0002 95 #define EVP_HPKE_CHACHA20_POLY1305 0x0003 96 97 // The following functions are AEAD algorithms which may be used with HPKE. 98 OPENSSL_EXPORT const EVP_HPKE_AEAD *EVP_hpke_aes_128_gcm(void); 99 OPENSSL_EXPORT const EVP_HPKE_AEAD *EVP_hpke_aes_256_gcm(void); 100 OPENSSL_EXPORT const EVP_HPKE_AEAD *EVP_hpke_chacha20_poly1305(void); 101 102 // EVP_HPKE_AEAD_id returns the HPKE AEAD identifier for |aead|. 103 OPENSSL_EXPORT uint16_t EVP_HPKE_AEAD_id(const EVP_HPKE_AEAD *aead); 104 105 // EVP_HPKE_AEAD_aead returns the |EVP_AEAD| corresponding to |aead|. 106 OPENSSL_EXPORT const EVP_AEAD *EVP_HPKE_AEAD_aead(const EVP_HPKE_AEAD *aead); 107 108 109 // Recipient keys. 110 // 111 // An HPKE recipient maintains a long-term KEM key. This library represents keys 112 // with the |EVP_HPKE_KEY| type. 113 114 // EVP_HPKE_KEY_zero sets an uninitialized |EVP_HPKE_KEY| to the zero state. The 115 // caller should then use |EVP_HPKE_KEY_init|, |EVP_HPKE_KEY_copy|, or 116 // |EVP_HPKE_KEY_generate| to finish initializing |key|. 117 // 118 // It is safe, but not necessary to call |EVP_HPKE_KEY_cleanup| in this state. 119 // This may be used for more uniform cleanup of |EVP_HPKE_KEY|. 120 OPENSSL_EXPORT void EVP_HPKE_KEY_zero(EVP_HPKE_KEY *key); 121 122 // EVP_HPKE_KEY_cleanup releases memory referenced by |key|. 123 OPENSSL_EXPORT void EVP_HPKE_KEY_cleanup(EVP_HPKE_KEY *key); 124 125 // EVP_HPKE_KEY_new returns a newly-allocated |EVP_HPKE_KEY|, or NULL on error. 126 // The caller must call |EVP_HPKE_KEY_free| on the result to release it. 127 // 128 // This is a convenience function for callers that need a heap-allocated 129 // |EVP_HPKE_KEY|. 130 OPENSSL_EXPORT EVP_HPKE_KEY *EVP_HPKE_KEY_new(void); 131 132 // EVP_HPKE_KEY_free releases memory associated with |key|, which must have been 133 // created with |EVP_HPKE_KEY_new|. 134 OPENSSL_EXPORT void EVP_HPKE_KEY_free(EVP_HPKE_KEY *key); 135 136 // EVP_HPKE_KEY_copy sets |dst| to a copy of |src|. It returns one on success 137 // and zero on error. On success, the caller must call |EVP_HPKE_KEY_cleanup| to 138 // release |dst|. On failure, calling |EVP_HPKE_KEY_cleanup| is safe, but not 139 // necessary. 140 OPENSSL_EXPORT int EVP_HPKE_KEY_copy(EVP_HPKE_KEY *dst, 141 const EVP_HPKE_KEY *src); 142 143 // EVP_HPKE_KEY_move sets |out|, which must be initialized or in the zero state, 144 // to the key in |in|. |in| is mutated and left in the zero state. 145 OPENSSL_EXPORT void EVP_HPKE_KEY_move(EVP_HPKE_KEY *out, EVP_HPKE_KEY *in); 146 147 // EVP_HPKE_KEY_init decodes |priv_key| as a private key for |kem| and 148 // initializes |key| with the result. It returns one on success and zero if 149 // |priv_key| was invalid. On success, the caller must call 150 // |EVP_HPKE_KEY_cleanup| to release the key. On failure, calling 151 // |EVP_HPKE_KEY_cleanup| is safe, but not necessary. 152 OPENSSL_EXPORT int EVP_HPKE_KEY_init(EVP_HPKE_KEY *key, const EVP_HPKE_KEM *kem, 153 const uint8_t *priv_key, 154 size_t priv_key_len); 155 156 // EVP_HPKE_KEY_generate sets |key| to a newly-generated key using |kem|. 157 OPENSSL_EXPORT int EVP_HPKE_KEY_generate(EVP_HPKE_KEY *key, 158 const EVP_HPKE_KEM *kem); 159 160 // EVP_HPKE_KEY_kem returns the HPKE KEM used by |key|. 161 OPENSSL_EXPORT const EVP_HPKE_KEM *EVP_HPKE_KEY_kem(const EVP_HPKE_KEY *key); 162 163 // EVP_HPKE_KEY_public_key writes |key|'s public key to |out| and sets 164 // |*out_len| to the number of bytes written. On success, it returns one and 165 // writes at most |max_out| bytes. If |max_out| is too small, it returns zero. 166 // Setting |max_out| to |EVP_HPKE_MAX_PUBLIC_KEY_LENGTH| will ensure the public 167 // key fits. An exact size can also be determined by 168 // |EVP_HPKE_KEM_public_key_len|. 169 OPENSSL_EXPORT int EVP_HPKE_KEY_public_key(const EVP_HPKE_KEY *key, 170 uint8_t *out, size_t *out_len, 171 size_t max_out); 172 173 // EVP_HPKE_KEY_private_key writes |key|'s private key to |out| and sets 174 // |*out_len| to the number of bytes written. On success, it returns one and 175 // writes at most |max_out| bytes. If |max_out| is too small, it returns zero. 176 // Setting |max_out| to |EVP_HPKE_MAX_PRIVATE_KEY_LENGTH| will ensure the 177 // private key fits. An exact size can also be determined by 178 // |EVP_HPKE_KEM_private_key_len|. 179 OPENSSL_EXPORT int EVP_HPKE_KEY_private_key(const EVP_HPKE_KEY *key, 180 uint8_t *out, size_t *out_len, 181 size_t max_out); 182 183 184 // Encryption contexts. 185 // 186 // An HPKE encryption context is represented by the |EVP_HPKE_CTX| type. 187 188 // EVP_HPKE_CTX_zero sets an uninitialized |EVP_HPKE_CTX| to the zero state. The 189 // caller should then use one of the |EVP_HPKE_CTX_setup_*| functions to finish 190 // setting up |ctx|. 191 // 192 // It is safe, but not necessary to call |EVP_HPKE_CTX_cleanup| in this state. 193 // This may be used for more uniform cleanup of |EVP_HPKE_CTX|. 194 OPENSSL_EXPORT void EVP_HPKE_CTX_zero(EVP_HPKE_CTX *ctx); 195 196 // EVP_HPKE_CTX_cleanup releases memory referenced by |ctx|. |ctx| must have 197 // been initialized with |EVP_HPKE_CTX_zero| or one of the 198 // |EVP_HPKE_CTX_setup_*| functions. 199 OPENSSL_EXPORT void EVP_HPKE_CTX_cleanup(EVP_HPKE_CTX *ctx); 200 201 // EVP_HPKE_CTX_new returns a newly-allocated |EVP_HPKE_CTX|, or NULL on error. 202 // The caller must call |EVP_HPKE_CTX_free| on the result to release it. 203 // 204 // This is a convenience function for callers that need a heap-allocated 205 // |EVP_HPKE_CTX|. 206 OPENSSL_EXPORT EVP_HPKE_CTX *EVP_HPKE_CTX_new(void); 207 208 // EVP_HPKE_CTX_free releases memory associated with |ctx|, which must have been 209 // created with |EVP_HPKE_CTX_new|. 210 OPENSSL_EXPORT void EVP_HPKE_CTX_free(EVP_HPKE_CTX *ctx); 211 212 // EVP_HPKE_CTX_setup_sender implements the SetupBaseS HPKE operation. It 213 // encapsulates a shared secret for |peer_public_key| and sets up |ctx| as a 214 // sender context. It writes the encapsulated shared secret to |out_enc| and 215 // sets |*out_enc_len| to the number of bytes written. It writes at most 216 // |max_enc| bytes and fails if the buffer is too small. Setting |max_enc| to at 217 // least |EVP_HPKE_MAX_ENC_LENGTH| will ensure the buffer is large enough. An 218 // exact size may also be determined by |EVP_PKEY_KEM_enc_len|. 219 // 220 // This function returns one on success and zero on error. Note that 221 // |peer_public_key| may be invalid, in which case this function will return an 222 // error. 223 // 224 // On success, callers may call |EVP_HPKE_CTX_seal| to encrypt messages for the 225 // recipient. Callers must then call |EVP_HPKE_CTX_cleanup| when done. On 226 // failure, calling |EVP_HPKE_CTX_cleanup| is safe, but not required. 227 OPENSSL_EXPORT int EVP_HPKE_CTX_setup_sender( 228 EVP_HPKE_CTX *ctx, uint8_t *out_enc, size_t *out_enc_len, size_t max_enc, 229 const EVP_HPKE_KEM *kem, const EVP_HPKE_KDF *kdf, const EVP_HPKE_AEAD *aead, 230 const uint8_t *peer_public_key, size_t peer_public_key_len, 231 const uint8_t *info, size_t info_len); 232 233 // EVP_HPKE_CTX_setup_sender_with_seed_for_testing behaves like 234 // |EVP_HPKE_CTX_setup_sender|, but takes a seed to behave deterministically. 235 // The seed's format depends on |kem|. For X25519, it is the sender's 236 // ephemeral private key. 237 OPENSSL_EXPORT int EVP_HPKE_CTX_setup_sender_with_seed_for_testing( 238 EVP_HPKE_CTX *ctx, uint8_t *out_enc, size_t *out_enc_len, size_t max_enc, 239 const EVP_HPKE_KEM *kem, const EVP_HPKE_KDF *kdf, const EVP_HPKE_AEAD *aead, 240 const uint8_t *peer_public_key, size_t peer_public_key_len, 241 const uint8_t *info, size_t info_len, const uint8_t *seed, size_t seed_len); 242 243 // EVP_HPKE_CTX_setup_recipient implements the SetupBaseR HPKE operation. It 244 // decapsulates the shared secret in |enc| with |key| and sets up |ctx| as a 245 // recipient context. It returns one on success and zero on failure. Note that 246 // |enc| may be invalid, in which case this function will return an error. 247 // 248 // On success, callers may call |EVP_HPKE_CTX_open| to decrypt messages from the 249 // sender. Callers must then call |EVP_HPKE_CTX_cleanup| when done. On failure, 250 // calling |EVP_HPKE_CTX_cleanup| is safe, but not required. 251 OPENSSL_EXPORT int EVP_HPKE_CTX_setup_recipient( 252 EVP_HPKE_CTX *ctx, const EVP_HPKE_KEY *key, const EVP_HPKE_KDF *kdf, 253 const EVP_HPKE_AEAD *aead, const uint8_t *enc, size_t enc_len, 254 const uint8_t *info, size_t info_len); 255 256 // EVP_HPKE_CTX_setup_auth_sender implements the SetupAuthS HPKE operation. It 257 // behaves like |EVP_HPKE_CTX_setup_sender| but authenticates the resulting 258 // context with |key|. 259 OPENSSL_EXPORT int EVP_HPKE_CTX_setup_auth_sender( 260 EVP_HPKE_CTX *ctx, uint8_t *out_enc, size_t *out_enc_len, size_t max_enc, 261 const EVP_HPKE_KEY *key, const EVP_HPKE_KDF *kdf, const EVP_HPKE_AEAD *aead, 262 const uint8_t *peer_public_key, size_t peer_public_key_len, 263 const uint8_t *info, size_t info_len); 264 265 // EVP_HPKE_CTX_setup_auth_sender_with_seed_for_testing behaves like 266 // |EVP_HPKE_CTX_setup_auth_sender|, but takes a seed to behave 267 // deterministically. The seed's format depends on |kem|. For X25519, it is the 268 // sender's ephemeral private key. 269 OPENSSL_EXPORT int EVP_HPKE_CTX_setup_auth_sender_with_seed_for_testing( 270 EVP_HPKE_CTX *ctx, uint8_t *out_enc, size_t *out_enc_len, size_t max_enc, 271 const EVP_HPKE_KEY *key, const EVP_HPKE_KDF *kdf, const EVP_HPKE_AEAD *aead, 272 const uint8_t *peer_public_key, size_t peer_public_key_len, 273 const uint8_t *info, size_t info_len, const uint8_t *seed, size_t seed_len); 274 275 // EVP_HPKE_CTX_setup_auth_recipient implements the SetupAuthR HPKE operation. 276 // It behaves like |EVP_HPKE_CTX_setup_recipient| but checks the resulting 277 // context was authenticated with |peer_public_key|. 278 OPENSSL_EXPORT int EVP_HPKE_CTX_setup_auth_recipient( 279 EVP_HPKE_CTX *ctx, const EVP_HPKE_KEY *key, const EVP_HPKE_KDF *kdf, 280 const EVP_HPKE_AEAD *aead, const uint8_t *enc, size_t enc_len, 281 const uint8_t *info, size_t info_len, const uint8_t *peer_public_key, 282 size_t peer_public_key_len); 283 284 285 // Using an HPKE context. 286 // 287 // Once set up, callers may encrypt or decrypt with an |EVP_HPKE_CTX| using the 288 // following functions. 289 290 // EVP_HPKE_CTX_open uses the HPKE context |ctx| to authenticate |in_len| bytes 291 // from |in| and |ad_len| bytes from |ad| and to decrypt at most |in_len| bytes 292 // into |out|. It returns one on success, and zero otherwise. 293 // 294 // This operation will fail if the |ctx| context is not set up as a receiver. 295 // 296 // Note that HPKE encryption is stateful and ordered. The sender's first call to 297 // |EVP_HPKE_CTX_seal| must correspond to the recipient's first call to 298 // |EVP_HPKE_CTX_open|, etc. 299 // 300 // At most |in_len| bytes are written to |out|. In order to ensure success, 301 // |max_out_len| should be at least |in_len|. On successful return, |*out_len| 302 // is set to the actual number of bytes written. 303 OPENSSL_EXPORT int EVP_HPKE_CTX_open(EVP_HPKE_CTX *ctx, uint8_t *out, 304 size_t *out_len, size_t max_out_len, 305 const uint8_t *in, size_t in_len, 306 const uint8_t *ad, size_t ad_len); 307 308 // EVP_HPKE_CTX_seal uses the HPKE context |ctx| to encrypt and authenticate 309 // |in_len| bytes of ciphertext |in| and authenticate |ad_len| bytes from |ad|, 310 // writing the result to |out|. It returns one on success and zero otherwise. 311 // 312 // This operation will fail if the |ctx| context is not set up as a sender. 313 // 314 // Note that HPKE encryption is stateful and ordered. The sender's first call to 315 // |EVP_HPKE_CTX_seal| must correspond to the recipient's first call to 316 // |EVP_HPKE_CTX_open|, etc. 317 // 318 // At most, |max_out_len| encrypted bytes are written to |out|. On successful 319 // return, |*out_len| is set to the actual number of bytes written. 320 // 321 // To ensure success, |max_out_len| should be |in_len| plus the result of 322 // |EVP_HPKE_CTX_max_overhead| or |EVP_HPKE_MAX_OVERHEAD|. 323 OPENSSL_EXPORT int EVP_HPKE_CTX_seal(EVP_HPKE_CTX *ctx, uint8_t *out, 324 size_t *out_len, size_t max_out_len, 325 const uint8_t *in, size_t in_len, 326 const uint8_t *ad, size_t ad_len); 327 328 // EVP_HPKE_CTX_export uses the HPKE context |ctx| to export a secret of 329 // |secret_len| bytes into |out|. This function uses |context_len| bytes from 330 // |context| as a context string for the secret. This is necessary to separate 331 // different uses of exported secrets and bind relevant caller-specific context 332 // into the output. It returns one on success and zero otherwise. 333 OPENSSL_EXPORT int EVP_HPKE_CTX_export(const EVP_HPKE_CTX *ctx, uint8_t *out, 334 size_t secret_len, 335 const uint8_t *context, 336 size_t context_len); 337 338 // EVP_HPKE_MAX_OVERHEAD contains the largest value that 339 // |EVP_HPKE_CTX_max_overhead| would ever return for any context. 340 #define EVP_HPKE_MAX_OVERHEAD EVP_AEAD_MAX_OVERHEAD 341 342 // EVP_HPKE_CTX_max_overhead returns the maximum number of additional bytes 343 // added by sealing data with |EVP_HPKE_CTX_seal|. The |ctx| context must be set 344 // up as a sender. 345 OPENSSL_EXPORT size_t EVP_HPKE_CTX_max_overhead(const EVP_HPKE_CTX *ctx); 346 347 // EVP_HPKE_CTX_kem returns |ctx|'s configured KEM, or NULL if the context has 348 // not been set up. 349 OPENSSL_EXPORT const EVP_HPKE_KEM *EVP_HPKE_CTX_kem(const EVP_HPKE_CTX *ctx); 350 351 // EVP_HPKE_CTX_aead returns |ctx|'s configured AEAD, or NULL if the context has 352 // not been set up. 353 OPENSSL_EXPORT const EVP_HPKE_AEAD *EVP_HPKE_CTX_aead(const EVP_HPKE_CTX *ctx); 354 355 // EVP_HPKE_CTX_kdf returns |ctx|'s configured KDF, or NULL if the context has 356 // not been set up. 357 OPENSSL_EXPORT const EVP_HPKE_KDF *EVP_HPKE_CTX_kdf(const EVP_HPKE_CTX *ctx); 358 359 360 // Private structures. 361 // 362 // The following structures are exported so their types are stack-allocatable, 363 // but accessing or modifying their fields is forbidden. 364 365 struct evp_hpke_ctx_st { 366 const EVP_HPKE_KEM *kem; 367 const EVP_HPKE_AEAD *aead; 368 const EVP_HPKE_KDF *kdf; 369 EVP_AEAD_CTX aead_ctx; 370 uint8_t base_nonce[EVP_AEAD_MAX_NONCE_LENGTH]; 371 uint8_t exporter_secret[EVP_MAX_MD_SIZE]; 372 uint64_t seq; 373 int is_sender; 374 }; 375 376 struct evp_hpke_key_st { 377 const EVP_HPKE_KEM *kem; 378 uint8_t private_key[X25519_PRIVATE_KEY_LEN]; 379 uint8_t public_key[X25519_PUBLIC_VALUE_LEN]; 380 }; 381 382 383 #if defined(__cplusplus) 384 } // extern C 385 #endif 386 387 #if !defined(BORINGSSL_NO_CXX) 388 extern "C++" { 389 390 BSSL_NAMESPACE_BEGIN 391 392 using ScopedEVP_HPKE_CTX = 393 internal::StackAllocated<EVP_HPKE_CTX, void, EVP_HPKE_CTX_zero, 394 EVP_HPKE_CTX_cleanup>; 395 using ScopedEVP_HPKE_KEY = 396 internal::StackAllocatedMovable<EVP_HPKE_KEY, void, EVP_HPKE_KEY_zero, 397 EVP_HPKE_KEY_cleanup, EVP_HPKE_KEY_move>; 398 399 BORINGSSL_MAKE_DELETER(EVP_HPKE_CTX, EVP_HPKE_CTX_free) 400 BORINGSSL_MAKE_DELETER(EVP_HPKE_KEY, EVP_HPKE_KEY_free) 401 402 BSSL_NAMESPACE_END 403 404 } // extern C++ 405 #endif 406 407 #endif // OPENSSL_HEADER_CRYPTO_HPKE_INTERNAL_H 408