1 /** 2 * \file psa/crypto_sizes.h 3 * 4 * \brief PSA cryptography module: Mbed TLS buffer size macros 5 * 6 * \note This file may not be included directly. Applications must 7 * include psa/crypto.h. 8 * 9 * This file contains the definitions of macros that are useful to 10 * compute buffer sizes. The signatures and semantics of these macros 11 * are standardized, but the definitions are not, because they depend on 12 * the available algorithms and, in some cases, on permitted tolerances 13 * on buffer sizes. 14 * 15 * In implementations with isolation between the application and the 16 * cryptography module, implementers should take care to ensure that 17 * the definitions that are exposed to applications match what the 18 * module implements. 19 * 20 * Macros that compute sizes whose values do not depend on the 21 * implementation are in crypto.h. 22 */ 23 /* 24 * Copyright The Mbed TLS Contributors 25 * SPDX-License-Identifier: Apache-2.0 26 * 27 * Licensed under the Apache License, Version 2.0 (the "License"); you may 28 * not use this file except in compliance with the License. 29 * You may obtain a copy of the License at 30 * 31 * http://www.apache.org/licenses/LICENSE-2.0 32 * 33 * Unless required by applicable law or agreed to in writing, software 34 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 35 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 36 * See the License for the specific language governing permissions and 37 * limitations under the License. 38 */ 39 40 #ifndef PSA_CRYPTO_SIZES_H 41 #define PSA_CRYPTO_SIZES_H 42 43 /* Include the Mbed TLS configuration file, the way Mbed TLS does it 44 * in each of its header files. */ 45 #include "mbedtls/build_info.h" 46 47 #define PSA_BITS_TO_BYTES(bits) (((bits) + 7) / 8) 48 #define PSA_BYTES_TO_BITS(bytes) ((bytes) * 8) 49 50 #define PSA_ROUND_UP_TO_MULTIPLE(block_size, length) \ 51 (((length) + (block_size) - 1) / (block_size) * (block_size)) 52 53 /** The size of the output of psa_hash_finish(), in bytes. 54 * 55 * This is also the hash size that psa_hash_verify() expects. 56 * 57 * \param alg A hash algorithm (\c PSA_ALG_XXX value such that 58 * #PSA_ALG_IS_HASH(\p alg) is true), or an HMAC algorithm 59 * (#PSA_ALG_HMAC(\c hash_alg) where \c hash_alg is a 60 * hash algorithm). 61 * 62 * \return The hash size for the specified hash algorithm. 63 * If the hash algorithm is not recognized, return 0. 64 */ 65 #define PSA_HASH_LENGTH(alg) \ 66 ( \ 67 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 16 : \ 68 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 20 : \ 69 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 20 : \ 70 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 28 : \ 71 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 32 : \ 72 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 48 : \ 73 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 64 : \ 74 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 28 : \ 75 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 32 : \ 76 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 28 : \ 77 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 32 : \ 78 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 48 : \ 79 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 64 : \ 80 0) 81 82 /** The input block size of a hash algorithm, in bytes. 83 * 84 * Hash algorithms process their input data in blocks. Hash operations will 85 * retain any partial blocks until they have enough input to fill the block or 86 * until the operation is finished. 87 * This affects the output from psa_hash_suspend(). 88 * 89 * \param alg A hash algorithm (\c PSA_ALG_XXX value such that 90 * PSA_ALG_IS_HASH(\p alg) is true). 91 * 92 * \return The block size in bytes for the specified hash algorithm. 93 * If the hash algorithm is not recognized, return 0. 94 * An implementation can return either 0 or the correct size for a 95 * hash algorithm that it recognizes, but does not support. 96 */ 97 #define PSA_HASH_BLOCK_LENGTH(alg) \ 98 ( \ 99 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 64 : \ 100 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 64 : \ 101 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 64 : \ 102 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 64 : \ 103 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 64 : \ 104 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 128 : \ 105 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 128 : \ 106 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 128 : \ 107 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 128 : \ 108 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 144 : \ 109 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 136 : \ 110 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 104 : \ 111 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 72 : \ 112 0) 113 114 /** \def PSA_HASH_MAX_SIZE 115 * 116 * Maximum size of a hash. 117 * 118 * This macro expands to a compile-time constant integer. This value 119 * is the maximum size of a hash in bytes. 120 */ 121 /* Note: for HMAC-SHA-3, the block size is 144 bytes for HMAC-SHA3-226, 122 * 136 bytes for HMAC-SHA3-256, 104 bytes for SHA3-384, 72 bytes for 123 * HMAC-SHA3-512. */ 124 #if defined(PSA_WANT_ALG_SHA_512) || defined(PSA_WANT_ALG_SHA_384) 125 #define PSA_HASH_MAX_SIZE 64 126 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128 127 #else 128 #define PSA_HASH_MAX_SIZE 32 129 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64 130 #endif 131 132 /** \def PSA_MAC_MAX_SIZE 133 * 134 * Maximum size of a MAC. 135 * 136 * This macro expands to a compile-time constant integer. This value 137 * is the maximum size of a MAC in bytes. 138 */ 139 /* All non-HMAC MACs have a maximum size that's smaller than the 140 * minimum possible value of PSA_HASH_MAX_SIZE in this implementation. */ 141 /* Note that the encoding of truncated MAC algorithms limits this value 142 * to 64 bytes. 143 */ 144 #define PSA_MAC_MAX_SIZE PSA_HASH_MAX_SIZE 145 146 /** The length of a tag for an AEAD algorithm, in bytes. 147 * 148 * This macro can be used to allocate a buffer of sufficient size to store the 149 * tag output from psa_aead_finish(). 150 * 151 * See also #PSA_AEAD_TAG_MAX_SIZE. 152 * 153 * \param key_type The type of the AEAD key. 154 * \param key_bits The size of the AEAD key in bits. 155 * \param alg An AEAD algorithm 156 * (\c PSA_ALG_XXX value such that 157 * #PSA_ALG_IS_AEAD(\p alg) is true). 158 * 159 * \return The tag length for the specified algorithm and key. 160 * If the AEAD algorithm does not have an identified 161 * tag that can be distinguished from the rest of 162 * the ciphertext, return 0. 163 * If the key type or AEAD algorithm is not 164 * recognized, or the parameters are incompatible, 165 * return 0. 166 */ 167 #define PSA_AEAD_TAG_LENGTH(key_type, key_bits, alg) \ 168 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 169 PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 170 ((void) (key_bits), 0)) 171 172 /** The maximum tag size for all supported AEAD algorithms, in bytes. 173 * 174 * See also #PSA_AEAD_TAG_LENGTH(\p key_type, \p key_bits, \p alg). 175 */ 176 #define PSA_AEAD_TAG_MAX_SIZE 16 177 178 /* The maximum size of an RSA key on this implementation, in bits. 179 * This is a vendor-specific macro. 180 * 181 * Mbed TLS does not set a hard limit on the size of RSA keys: any key 182 * whose parameters fit in a bignum is accepted. However large keys can 183 * induce a large memory usage and long computation times. Unlike other 184 * auxiliary macros in this file and in crypto.h, which reflect how the 185 * library is configured, this macro defines how the library is 186 * configured. This implementation refuses to import or generate an 187 * RSA key whose size is larger than the value defined here. 188 * 189 * Note that an implementation may set different size limits for different 190 * operations, and does not need to accept all key sizes up to the limit. */ 191 #define PSA_VENDOR_RSA_MAX_KEY_BITS 4096 192 193 /* The maximum size of an ECC key on this implementation, in bits. 194 * This is a vendor-specific macro. */ 195 #if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) 196 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 521 197 #elif defined(MBEDTLS_ECP_DP_BP512R1_ENABLED) 198 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 512 199 #elif defined(MBEDTLS_ECP_DP_CURVE448_ENABLED) 200 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 448 201 #elif defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED) 202 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384 203 #elif defined(MBEDTLS_ECP_DP_BP384R1_ENABLED) 204 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384 205 #elif defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED) 206 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 207 #elif defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED) 208 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 209 #elif defined(MBEDTLS_ECP_DP_BP256R1_ENABLED) 210 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 211 #elif defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) 212 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 255 213 #elif defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED) 214 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224 215 #elif defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED) 216 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224 217 #elif defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED) 218 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192 219 #elif defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED) 220 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192 221 #else 222 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 0 223 #endif 224 225 /** This macro returns the maximum supported length of the PSK for the 226 * TLS-1.2 PSK-to-MS key derivation 227 * (#PSA_ALG_TLS12_PSK_TO_MS(\c hash_alg)). 228 * 229 * The maximum supported length does not depend on the chosen hash algorithm. 230 * 231 * Quoting RFC 4279, Sect 5.3: 232 * TLS implementations supporting these ciphersuites MUST support 233 * arbitrary PSK identities up to 128 octets in length, and arbitrary 234 * PSKs up to 64 octets in length. Supporting longer identities and 235 * keys is RECOMMENDED. 236 * 237 * Therefore, no implementation should define a value smaller than 64 238 * for #PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE. 239 */ 240 #define PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128 241 242 /** The maximum size of a block cipher. */ 243 #define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16 244 245 /** The size of the output of psa_mac_sign_finish(), in bytes. 246 * 247 * This is also the MAC size that psa_mac_verify_finish() expects. 248 * 249 * \warning This macro may evaluate its arguments multiple times or 250 * zero times, so you should not pass arguments that contain 251 * side effects. 252 * 253 * \param key_type The type of the MAC key. 254 * \param key_bits The size of the MAC key in bits. 255 * \param alg A MAC algorithm (\c PSA_ALG_XXX value such that 256 * #PSA_ALG_IS_MAC(\p alg) is true). 257 * 258 * \return The MAC size for the specified algorithm with 259 * the specified key parameters. 260 * \return 0 if the MAC algorithm is not recognized. 261 * \return Either 0 or the correct size for a MAC algorithm that 262 * the implementation recognizes, but does not support. 263 * \return Unspecified if the key parameters are not consistent 264 * with the algorithm. 265 */ 266 #define PSA_MAC_LENGTH(key_type, key_bits, alg) \ 267 ((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \ 268 PSA_ALG_IS_HMAC(alg) ? PSA_HASH_LENGTH(PSA_ALG_HMAC_GET_HASH(alg)) : \ 269 PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 270 ((void)(key_type), (void)(key_bits), 0)) 271 272 /** The maximum size of the output of psa_aead_encrypt(), in bytes. 273 * 274 * If the size of the ciphertext buffer is at least this large, it is 275 * guaranteed that psa_aead_encrypt() will not fail due to an 276 * insufficient buffer size. Depending on the algorithm, the actual size of 277 * the ciphertext may be smaller. 278 * 279 * See also #PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(\p plaintext_length). 280 * 281 * \warning This macro may evaluate its arguments multiple times or 282 * zero times, so you should not pass arguments that contain 283 * side effects. 284 * 285 * \param key_type A symmetric key type that is 286 * compatible with algorithm \p alg. 287 * \param alg An AEAD algorithm 288 * (\c PSA_ALG_XXX value such that 289 * #PSA_ALG_IS_AEAD(\p alg) is true). 290 * \param plaintext_length Size of the plaintext in bytes. 291 * 292 * \return The AEAD ciphertext size for the specified 293 * algorithm. 294 * If the key type or AEAD algorithm is not 295 * recognized, or the parameters are incompatible, 296 * return 0. 297 */ 298 #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length) \ 299 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 300 (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 301 0) 302 303 /** A sufficient output buffer size for psa_aead_encrypt(), for any of the 304 * supported key types and AEAD algorithms. 305 * 306 * If the size of the ciphertext buffer is at least this large, it is guaranteed 307 * that psa_aead_encrypt() will not fail due to an insufficient buffer size. 308 * 309 * \note This macro returns a compile-time constant if its arguments are 310 * compile-time constants. 311 * 312 * See also #PSA_AEAD_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, 313 * \p plaintext_length). 314 * 315 * \param plaintext_length Size of the plaintext in bytes. 316 * 317 * \return A sufficient output buffer size for any of the 318 * supported key types and AEAD algorithms. 319 * 320 */ 321 #define PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length) \ 322 ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE) 323 324 325 /** The maximum size of the output of psa_aead_decrypt(), in bytes. 326 * 327 * If the size of the plaintext buffer is at least this large, it is 328 * guaranteed that psa_aead_decrypt() will not fail due to an 329 * insufficient buffer size. Depending on the algorithm, the actual size of 330 * the plaintext may be smaller. 331 * 332 * See also #PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(\p ciphertext_length). 333 * 334 * \warning This macro may evaluate its arguments multiple times or 335 * zero times, so you should not pass arguments that contain 336 * side effects. 337 * 338 * \param key_type A symmetric key type that is 339 * compatible with algorithm \p alg. 340 * \param alg An AEAD algorithm 341 * (\c PSA_ALG_XXX value such that 342 * #PSA_ALG_IS_AEAD(\p alg) is true). 343 * \param ciphertext_length Size of the plaintext in bytes. 344 * 345 * \return The AEAD ciphertext size for the specified 346 * algorithm. 347 * If the key type or AEAD algorithm is not 348 * recognized, or the parameters are incompatible, 349 * return 0. 350 */ 351 #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length) \ 352 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 353 (ciphertext_length) > PSA_ALG_AEAD_GET_TAG_LENGTH(alg) ? \ 354 (ciphertext_length) - PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 355 0) 356 357 /** A sufficient output buffer size for psa_aead_decrypt(), for any of the 358 * supported key types and AEAD algorithms. 359 * 360 * If the size of the plaintext buffer is at least this large, it is guaranteed 361 * that psa_aead_decrypt() will not fail due to an insufficient buffer size. 362 * 363 * \note This macro returns a compile-time constant if its arguments are 364 * compile-time constants. 365 * 366 * See also #PSA_AEAD_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, 367 * \p ciphertext_length). 368 * 369 * \param ciphertext_length Size of the ciphertext in bytes. 370 * 371 * \return A sufficient output buffer size for any of the 372 * supported key types and AEAD algorithms. 373 * 374 */ 375 #define PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(ciphertext_length) \ 376 (ciphertext_length) 377 378 /** The default nonce size for an AEAD algorithm, in bytes. 379 * 380 * This macro can be used to allocate a buffer of sufficient size to 381 * store the nonce output from #psa_aead_generate_nonce(). 382 * 383 * See also #PSA_AEAD_NONCE_MAX_SIZE. 384 * 385 * \note This is not the maximum size of nonce supported as input to 386 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 387 * just the default size that is generated by #psa_aead_generate_nonce(). 388 * 389 * \warning This macro may evaluate its arguments multiple times or 390 * zero times, so you should not pass arguments that contain 391 * side effects. 392 * 393 * \param key_type A symmetric key type that is compatible with 394 * algorithm \p alg. 395 * 396 * \param alg An AEAD algorithm (\c PSA_ALG_XXX value such that 397 * #PSA_ALG_IS_AEAD(\p alg) is true). 398 * 399 * \return The default nonce size for the specified key type and algorithm. 400 * If the key type or AEAD algorithm is not recognized, 401 * or the parameters are incompatible, return 0. 402 */ 403 #define PSA_AEAD_NONCE_LENGTH(key_type, alg) \ 404 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \ 405 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CCM) ? 13 : \ 406 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_GCM) ? 12 : \ 407 0 : \ 408 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 409 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12 : \ 410 0) 411 412 /** The maximum default nonce size among all supported pairs of key types and 413 * AEAD algorithms, in bytes. 414 * 415 * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH() 416 * may return. 417 * 418 * \note This is not the maximum size of nonce supported as input to 419 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 420 * just the largest size that may be generated by 421 * #psa_aead_generate_nonce(). 422 */ 423 #define PSA_AEAD_NONCE_MAX_SIZE 13 424 425 /** A sufficient output buffer size for psa_aead_update(). 426 * 427 * If the size of the output buffer is at least this large, it is 428 * guaranteed that psa_aead_update() will not fail due to an 429 * insufficient buffer size. The actual size of the output may be smaller 430 * in any given call. 431 * 432 * See also #PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 433 * 434 * \warning This macro may evaluate its arguments multiple times or 435 * zero times, so you should not pass arguments that contain 436 * side effects. 437 * 438 * \param key_type A symmetric key type that is 439 * compatible with algorithm \p alg. 440 * \param alg An AEAD algorithm 441 * (\c PSA_ALG_XXX value such that 442 * #PSA_ALG_IS_AEAD(\p alg) is true). 443 * \param input_length Size of the input in bytes. 444 * 445 * \return A sufficient output buffer size for the specified 446 * algorithm. 447 * If the key type or AEAD algorithm is not 448 * recognized, or the parameters are incompatible, 449 * return 0. 450 */ 451 /* For all the AEAD modes defined in this specification, it is possible 452 * to emit output without delay. However, hardware may not always be 453 * capable of this. So for modes based on a block cipher, allow the 454 * implementation to delay the output until it has a full block. */ 455 #define PSA_AEAD_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 456 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 457 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 458 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), (input_length)) : \ 459 (input_length) : \ 460 0) 461 462 /** A sufficient output buffer size for psa_aead_update(), for any of the 463 * supported key types and AEAD algorithms. 464 * 465 * If the size of the output buffer is at least this large, it is guaranteed 466 * that psa_aead_update() will not fail due to an insufficient buffer size. 467 * 468 * See also #PSA_AEAD_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 469 * 470 * \param input_length Size of the input in bytes. 471 */ 472 #define PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 473 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length))) 474 475 /** A sufficient ciphertext buffer size for psa_aead_finish(). 476 * 477 * If the size of the ciphertext buffer is at least this large, it is 478 * guaranteed that psa_aead_finish() will not fail due to an 479 * insufficient ciphertext buffer size. The actual size of the output may 480 * be smaller in any given call. 481 * 482 * See also #PSA_AEAD_FINISH_OUTPUT_MAX_SIZE. 483 * 484 * \param key_type A symmetric key type that is 485 compatible with algorithm \p alg. 486 * \param alg An AEAD algorithm 487 * (\c PSA_ALG_XXX value such that 488 * #PSA_ALG_IS_AEAD(\p alg) is true). 489 * 490 * \return A sufficient ciphertext buffer size for the 491 * specified algorithm. 492 * If the key type or AEAD algorithm is not 493 * recognized, or the parameters are incompatible, 494 * return 0. 495 */ 496 #define PSA_AEAD_FINISH_OUTPUT_SIZE(key_type, alg) \ 497 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 498 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 499 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 500 0) 501 502 /** A sufficient ciphertext buffer size for psa_aead_finish(), for any of the 503 * supported key types and AEAD algorithms. 504 * 505 * See also #PSA_AEAD_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 506 */ 507 #define PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 508 509 /** A sufficient plaintext buffer size for psa_aead_verify(). 510 * 511 * If the size of the plaintext buffer is at least this large, it is 512 * guaranteed that psa_aead_verify() will not fail due to an 513 * insufficient plaintext buffer size. The actual size of the output may 514 * be smaller in any given call. 515 * 516 * See also #PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE. 517 * 518 * \param key_type A symmetric key type that is 519 * compatible with algorithm \p alg. 520 * \param alg An AEAD algorithm 521 * (\c PSA_ALG_XXX value such that 522 * #PSA_ALG_IS_AEAD(\p alg) is true). 523 * 524 * \return A sufficient plaintext buffer size for the 525 * specified algorithm. 526 * If the key type or AEAD algorithm is not 527 * recognized, or the parameters are incompatible, 528 * return 0. 529 */ 530 #define PSA_AEAD_VERIFY_OUTPUT_SIZE(key_type, alg) \ 531 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 532 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 533 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 534 0) 535 536 /** A sufficient plaintext buffer size for psa_aead_verify(), for any of the 537 * supported key types and AEAD algorithms. 538 * 539 * See also #PSA_AEAD_VERIFY_OUTPUT_SIZE(\p key_type, \p alg). 540 */ 541 #define PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 542 543 #define PSA_RSA_MINIMUM_PADDING_SIZE(alg) \ 544 (PSA_ALG_IS_RSA_OAEP(alg) ? \ 545 2 * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1 : \ 546 11 /*PKCS#1v1.5*/) 547 548 /** 549 * \brief ECDSA signature size for a given curve bit size 550 * 551 * \param curve_bits Curve size in bits. 552 * \return Signature size in bytes. 553 * 554 * \note This macro returns a compile-time constant if its argument is one. 555 */ 556 #define PSA_ECDSA_SIGNATURE_SIZE(curve_bits) \ 557 (PSA_BITS_TO_BYTES(curve_bits) * 2) 558 559 /** Sufficient signature buffer size for psa_sign_hash(). 560 * 561 * This macro returns a sufficient buffer size for a signature using a key 562 * of the specified type and size, with the specified algorithm. 563 * Note that the actual size of the signature may be smaller 564 * (some algorithms produce a variable-size signature). 565 * 566 * \warning This function may call its arguments multiple times or 567 * zero times, so you should not pass arguments that contain 568 * side effects. 569 * 570 * \param key_type An asymmetric key type (this may indifferently be a 571 * key pair type or a public key type). 572 * \param key_bits The size of the key in bits. 573 * \param alg The signature algorithm. 574 * 575 * \return If the parameters are valid and supported, return 576 * a buffer size in bytes that guarantees that 577 * psa_sign_hash() will not fail with 578 * #PSA_ERROR_BUFFER_TOO_SMALL. 579 * If the parameters are a valid combination that is not supported, 580 * return either a sensible size or 0. 581 * If the parameters are not valid, the 582 * return value is unspecified. 583 */ 584 #define PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \ 585 (PSA_KEY_TYPE_IS_RSA(key_type) ? ((void)alg, PSA_BITS_TO_BYTES(key_bits)) : \ 586 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \ 587 ((void)alg, 0)) 588 589 #define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE \ 590 PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 591 592 /** \def PSA_SIGNATURE_MAX_SIZE 593 * 594 * Maximum size of an asymmetric signature. 595 * 596 * This macro expands to a compile-time constant integer. This value 597 * is the maximum size of a signature in bytes. 598 */ 599 #define PSA_SIGNATURE_MAX_SIZE \ 600 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE ? \ 601 PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 602 PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE) 603 604 /** Sufficient output buffer size for psa_asymmetric_encrypt(). 605 * 606 * This macro returns a sufficient buffer size for a ciphertext produced using 607 * a key of the specified type and size, with the specified algorithm. 608 * Note that the actual size of the ciphertext may be smaller, depending 609 * on the algorithm. 610 * 611 * \warning This function may call its arguments multiple times or 612 * zero times, so you should not pass arguments that contain 613 * side effects. 614 * 615 * \param key_type An asymmetric key type (this may indifferently be a 616 * key pair type or a public key type). 617 * \param key_bits The size of the key in bits. 618 * \param alg The asymmetric encryption algorithm. 619 * 620 * \return If the parameters are valid and supported, return 621 * a buffer size in bytes that guarantees that 622 * psa_asymmetric_encrypt() will not fail with 623 * #PSA_ERROR_BUFFER_TOO_SMALL. 624 * If the parameters are a valid combination that is not supported, 625 * return either a sensible size or 0. 626 * If the parameters are not valid, the 627 * return value is unspecified. 628 */ 629 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 630 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 631 ((void)alg, PSA_BITS_TO_BYTES(key_bits)) : \ 632 0) 633 634 /** A sufficient output buffer size for psa_asymmetric_encrypt(), for any 635 * supported asymmetric encryption. 636 * 637 * See also #PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 638 */ 639 /* This macro assumes that RSA is the only supported asymmetric encryption. */ 640 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE \ 641 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 642 643 /** Sufficient output buffer size for psa_asymmetric_decrypt(). 644 * 645 * This macro returns a sufficient buffer size for a plaintext produced using 646 * a key of the specified type and size, with the specified algorithm. 647 * Note that the actual size of the plaintext may be smaller, depending 648 * on the algorithm. 649 * 650 * \warning This function may call its arguments multiple times or 651 * zero times, so you should not pass arguments that contain 652 * side effects. 653 * 654 * \param key_type An asymmetric key type (this may indifferently be a 655 * key pair type or a public key type). 656 * \param key_bits The size of the key in bits. 657 * \param alg The asymmetric encryption algorithm. 658 * 659 * \return If the parameters are valid and supported, return 660 * a buffer size in bytes that guarantees that 661 * psa_asymmetric_decrypt() will not fail with 662 * #PSA_ERROR_BUFFER_TOO_SMALL. 663 * If the parameters are a valid combination that is not supported, 664 * return either a sensible size or 0. 665 * If the parameters are not valid, the 666 * return value is unspecified. 667 */ 668 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 669 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 670 PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \ 671 0) 672 673 /** A sufficient output buffer size for psa_asymmetric_decrypt(), for any 674 * supported asymmetric decryption. 675 * 676 * This macro assumes that RSA is the only supported asymmetric encryption. 677 * 678 * See also #PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 679 */ 680 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE \ 681 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 682 683 /* Maximum size of the ASN.1 encoding of an INTEGER with the specified 684 * number of bits. 685 * 686 * This definition assumes that bits <= 2^19 - 9 so that the length field 687 * is at most 3 bytes. The length of the encoding is the length of the 688 * bit string padded to a whole number of bytes plus: 689 * - 1 type byte; 690 * - 1 to 3 length bytes; 691 * - 0 to 1 bytes of leading 0 due to the sign bit. 692 */ 693 #define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \ 694 ((bits) / 8 + 5) 695 696 /* Maximum size of the export encoding of an RSA public key. 697 * Assumes that the public exponent is less than 2^32. 698 * 699 * RSAPublicKey ::= SEQUENCE { 700 * modulus INTEGER, -- n 701 * publicExponent INTEGER } -- e 702 * 703 * - 4 bytes of SEQUENCE overhead; 704 * - n : INTEGER; 705 * - 7 bytes for the public exponent. 706 */ 707 #define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 708 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11) 709 710 /* Maximum size of the export encoding of an RSA key pair. 711 * Assumes thatthe public exponent is less than 2^32 and that the size 712 * difference between the two primes is at most 1 bit. 713 * 714 * RSAPrivateKey ::= SEQUENCE { 715 * version Version, -- 0 716 * modulus INTEGER, -- N-bit 717 * publicExponent INTEGER, -- 32-bit 718 * privateExponent INTEGER, -- N-bit 719 * prime1 INTEGER, -- N/2-bit 720 * prime2 INTEGER, -- N/2-bit 721 * exponent1 INTEGER, -- N/2-bit 722 * exponent2 INTEGER, -- N/2-bit 723 * coefficient INTEGER, -- N/2-bit 724 * } 725 * 726 * - 4 bytes of SEQUENCE overhead; 727 * - 3 bytes of version; 728 * - 7 half-size INTEGERs plus 2 full-size INTEGERs, 729 * overapproximated as 9 half-size INTEGERS; 730 * - 7 bytes for the public exponent. 731 */ 732 #define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) \ 733 (9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14) 734 735 /* Maximum size of the export encoding of a DSA public key. 736 * 737 * SubjectPublicKeyInfo ::= SEQUENCE { 738 * algorithm AlgorithmIdentifier, 739 * subjectPublicKey BIT STRING } -- contains DSAPublicKey 740 * AlgorithmIdentifier ::= SEQUENCE { 741 * algorithm OBJECT IDENTIFIER, 742 * parameters Dss-Parms } -- SEQUENCE of 3 INTEGERs 743 * DSAPublicKey ::= INTEGER -- public key, Y 744 * 745 * - 3 * 4 bytes of SEQUENCE overhead; 746 * - 1 + 1 + 7 bytes of algorithm (DSA OID); 747 * - 4 bytes of BIT STRING overhead; 748 * - 3 full-size INTEGERs (p, g, y); 749 * - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits). 750 */ 751 #define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 752 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 59) 753 754 /* Maximum size of the export encoding of a DSA key pair. 755 * 756 * DSAPrivateKey ::= SEQUENCE { 757 * version Version, -- 0 758 * prime INTEGER, -- p 759 * subprime INTEGER, -- q 760 * generator INTEGER, -- g 761 * public INTEGER, -- y 762 * private INTEGER, -- x 763 * } 764 * 765 * - 4 bytes of SEQUENCE overhead; 766 * - 3 bytes of version; 767 * - 3 full-size INTEGERs (p, g, y); 768 * - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits). 769 */ 770 #define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) \ 771 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 75) 772 773 /* Maximum size of the export encoding of an ECC public key. 774 * 775 * The representation of an ECC public key is: 776 * - The byte 0x04; 777 * - `x_P` as a `ceiling(m/8)`-byte string, big-endian; 778 * - `y_P` as a `ceiling(m/8)`-byte string, big-endian; 779 * - where m is the bit size associated with the curve. 780 * 781 * - 1 byte + 2 * point size. 782 */ 783 #define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \ 784 (2 * PSA_BITS_TO_BYTES(key_bits) + 1) 785 786 /* Maximum size of the export encoding of an ECC key pair. 787 * 788 * An ECC key pair is represented by the secret value. 789 */ 790 #define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) \ 791 (PSA_BITS_TO_BYTES(key_bits)) 792 793 /** Sufficient output buffer size for psa_export_key() or 794 * psa_export_public_key(). 795 * 796 * This macro returns a compile-time constant if its arguments are 797 * compile-time constants. 798 * 799 * \warning This macro may evaluate its arguments multiple times or 800 * zero times, so you should not pass arguments that contain 801 * side effects. 802 * 803 * The following code illustrates how to allocate enough memory to export 804 * a key by querying the key type and size at runtime. 805 * \code{c} 806 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 807 * psa_status_t status; 808 * status = psa_get_key_attributes(key, &attributes); 809 * if (status != PSA_SUCCESS) handle_error(...); 810 * psa_key_type_t key_type = psa_get_key_type(&attributes); 811 * size_t key_bits = psa_get_key_bits(&attributes); 812 * size_t buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits); 813 * psa_reset_key_attributes(&attributes); 814 * uint8_t *buffer = malloc(buffer_size); 815 * if (buffer == NULL) handle_error(...); 816 * size_t buffer_length; 817 * status = psa_export_key(key, buffer, buffer_size, &buffer_length); 818 * if (status != PSA_SUCCESS) handle_error(...); 819 * \endcode 820 * 821 * \param key_type A supported key type. 822 * \param key_bits The size of the key in bits. 823 * 824 * \return If the parameters are valid and supported, return 825 * a buffer size in bytes that guarantees that 826 * psa_export_key() or psa_export_public_key() will not fail with 827 * #PSA_ERROR_BUFFER_TOO_SMALL. 828 * If the parameters are a valid combination that is not supported, 829 * return either a sensible size or 0. 830 * If the parameters are not valid, the return value is unspecified. 831 */ 832 #define PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits) \ 833 (PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 834 (key_type) == PSA_KEY_TYPE_RSA_KEY_PAIR ? PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 835 (key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 836 (key_type) == PSA_KEY_TYPE_DSA_KEY_PAIR ? PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 837 (key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 838 PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) : \ 839 PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 840 0) 841 842 /** Sufficient output buffer size for psa_export_public_key(). 843 * 844 * This macro returns a compile-time constant if its arguments are 845 * compile-time constants. 846 * 847 * \warning This macro may evaluate its arguments multiple times or 848 * zero times, so you should not pass arguments that contain 849 * side effects. 850 * 851 * The following code illustrates how to allocate enough memory to export 852 * a public key by querying the key type and size at runtime. 853 * \code{c} 854 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 855 * psa_status_t status; 856 * status = psa_get_key_attributes(key, &attributes); 857 * if (status != PSA_SUCCESS) handle_error(...); 858 * psa_key_type_t key_type = psa_get_key_type(&attributes); 859 * size_t key_bits = psa_get_key_bits(&attributes); 860 * size_t buffer_size = PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits); 861 * psa_reset_key_attributes(&attributes); 862 * uint8_t *buffer = malloc(buffer_size); 863 * if (buffer == NULL) handle_error(...); 864 * size_t buffer_length; 865 * status = psa_export_public_key(key, buffer, buffer_size, &buffer_length); 866 * if (status != PSA_SUCCESS) handle_error(...); 867 * \endcode 868 * 869 * \param key_type A public key or key pair key type. 870 * \param key_bits The size of the key in bits. 871 * 872 * \return If the parameters are valid and supported, return 873 * a buffer size in bytes that guarantees that 874 * psa_export_public_key() will not fail with 875 * #PSA_ERROR_BUFFER_TOO_SMALL. 876 * If the parameters are a valid combination that is not 877 * supported, return either a sensible size or 0. 878 * If the parameters are not valid, 879 * the return value is unspecified. 880 * 881 * If the parameters are valid and supported, 882 * return the same result as 883 * #PSA_EXPORT_KEY_OUTPUT_SIZE( 884 * \p #PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(\p key_type), 885 * \p key_bits). 886 */ 887 #define PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits) \ 888 (PSA_KEY_TYPE_IS_RSA(key_type) ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 889 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 890 0) 891 892 /** Sufficient buffer size for exporting any asymmetric key pair. 893 * 894 * This macro expands to a compile-time constant integer. This value is 895 * a sufficient buffer size when calling psa_export_key() to export any 896 * asymmetric key pair, regardless of the exact key type and key size. 897 * 898 * See also #PSA_EXPORT_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 899 */ 900 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 901 (PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 902 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ? \ 903 PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 904 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 905 906 /** Sufficient buffer size for exporting any asymmetric public key. 907 * 908 * This macro expands to a compile-time constant integer. This value is 909 * a sufficient buffer size when calling psa_export_key() or 910 * psa_export_public_key() to export any asymmetric public key, 911 * regardless of the exact key type and key size. 912 * 913 * See also #PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 914 */ 915 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 916 (PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 917 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ? \ 918 PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 919 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 920 921 /** Sufficient output buffer size for psa_raw_key_agreement(). 922 * 923 * This macro returns a compile-time constant if its arguments are 924 * compile-time constants. 925 * 926 * \warning This macro may evaluate its arguments multiple times or 927 * zero times, so you should not pass arguments that contain 928 * side effects. 929 * 930 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE. 931 * 932 * \param key_type A supported key type. 933 * \param key_bits The size of the key in bits. 934 * 935 * \return If the parameters are valid and supported, return 936 * a buffer size in bytes that guarantees that 937 * psa_raw_key_agreement() will not fail with 938 * #PSA_ERROR_BUFFER_TOO_SMALL. 939 * If the parameters are a valid combination that 940 * is not supported, return either a sensible size or 0. 941 * If the parameters are not valid, 942 * the return value is unspecified. 943 */ 944 /* FFDH is not yet supported in PSA. */ 945 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits) \ 946 (PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? \ 947 PSA_BITS_TO_BYTES(key_bits) : \ 948 0) 949 950 /** Maximum size of the output from psa_raw_key_agreement(). 951 * 952 * This macro expands to a compile-time constant integer. This value is the 953 * maximum size of the output any raw key agreement algorithm, in bytes. 954 * 955 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(\p key_type, \p key_bits). 956 */ 957 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE \ 958 (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 959 960 /** The default IV size for a cipher algorithm, in bytes. 961 * 962 * The IV that is generated as part of a call to #psa_cipher_encrypt() is always 963 * the default IV length for the algorithm. 964 * 965 * This macro can be used to allocate a buffer of sufficient size to 966 * store the IV output from #psa_cipher_generate_iv() when using 967 * a multi-part cipher operation. 968 * 969 * See also #PSA_CIPHER_IV_MAX_SIZE. 970 * 971 * \warning This macro may evaluate its arguments multiple times or 972 * zero times, so you should not pass arguments that contain 973 * side effects. 974 * 975 * \param key_type A symmetric key type that is compatible with algorithm \p alg. 976 * 977 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true). 978 * 979 * \return The default IV size for the specified key type and algorithm. 980 * If the algorithm does not use an IV, return 0. 981 * If the key type or cipher algorithm is not recognized, 982 * or the parameters are incompatible, return 0. 983 */ 984 #define PSA_CIPHER_IV_LENGTH(key_type, alg) \ 985 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1 && \ 986 ((alg) == PSA_ALG_CTR || \ 987 (alg) == PSA_ALG_CFB || \ 988 (alg) == PSA_ALG_OFB || \ 989 (alg) == PSA_ALG_XTS || \ 990 (alg) == PSA_ALG_CBC_NO_PADDING || \ 991 (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 992 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 993 (alg) == PSA_ALG_STREAM_CIPHER ? 12 : \ 994 (alg) == PSA_ALG_CCM_STAR_NO_TAG ? 13 : \ 995 0) 996 997 /** The maximum IV size for all supported cipher algorithms, in bytes. 998 * 999 * See also #PSA_CIPHER_IV_LENGTH(). 1000 */ 1001 #define PSA_CIPHER_IV_MAX_SIZE 16 1002 1003 /** The maximum size of the output of psa_cipher_encrypt(), in bytes. 1004 * 1005 * If the size of the output buffer is at least this large, it is guaranteed 1006 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1007 * Depending on the algorithm, the actual size of the output might be smaller. 1008 * 1009 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(\p input_length). 1010 * 1011 * \warning This macro may evaluate its arguments multiple times or 1012 * zero times, so you should not pass arguments that contain 1013 * side effects. 1014 * 1015 * \param key_type A symmetric key type that is compatible with algorithm 1016 * alg. 1017 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1018 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1019 * \param input_length Size of the input in bytes. 1020 * 1021 * \return A sufficient output size for the specified key type and 1022 * algorithm. If the key type or cipher algorithm is not 1023 * recognized, or the parameters are incompatible, 1024 * return 0. 1025 */ 1026 #define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1027 (alg == PSA_ALG_CBC_PKCS7 ? \ 1028 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1029 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1030 (input_length) + 1) + \ 1031 PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0) : \ 1032 (PSA_ALG_IS_CIPHER(alg) ? \ 1033 (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) : \ 1034 0)) 1035 1036 /** A sufficient output buffer size for psa_cipher_encrypt(), for any of the 1037 * supported key types and cipher algorithms. 1038 * 1039 * If the size of the output buffer is at least this large, it is guaranteed 1040 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1041 * 1042 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1043 * 1044 * \param input_length Size of the input in bytes. 1045 * 1046 */ 1047 #define PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(input_length) \ 1048 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, \ 1049 (input_length) + 1) + \ 1050 PSA_CIPHER_IV_MAX_SIZE) 1051 1052 /** The maximum size of the output of psa_cipher_decrypt(), in bytes. 1053 * 1054 * If the size of the output buffer is at least this large, it is guaranteed 1055 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1056 * Depending on the algorithm, the actual size of the output might be smaller. 1057 * 1058 * See also #PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(\p input_length). 1059 * 1060 * \param key_type A symmetric key type that is compatible with algorithm 1061 * alg. 1062 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1063 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1064 * \param input_length Size of the input in bytes. 1065 * 1066 * \return A sufficient output size for the specified key type and 1067 * algorithm. If the key type or cipher algorithm is not 1068 * recognized, or the parameters are incompatible, 1069 * return 0. 1070 */ 1071 #define PSA_CIPHER_DECRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1072 (PSA_ALG_IS_CIPHER(alg) && \ 1073 ((key_type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \ 1074 (input_length) : \ 1075 0) 1076 1077 /** A sufficient output buffer size for psa_cipher_decrypt(), for any of the 1078 * supported key types and cipher algorithms. 1079 * 1080 * If the size of the output buffer is at least this large, it is guaranteed 1081 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1082 * 1083 * See also #PSA_CIPHER_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1084 * 1085 * \param input_length Size of the input in bytes. 1086 */ 1087 #define PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(input_length) \ 1088 (input_length) 1089 1090 /** A sufficient output buffer size for psa_cipher_update(). 1091 * 1092 * If the size of the output buffer is at least this large, it is guaranteed 1093 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1094 * The actual size of the output might be smaller in any given call. 1095 * 1096 * See also #PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 1097 * 1098 * \param key_type A symmetric key type that is compatible with algorithm 1099 * alg. 1100 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1101 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1102 * \param input_length Size of the input in bytes. 1103 * 1104 * \return A sufficient output size for the specified key type and 1105 * algorithm. If the key type or cipher algorithm is not 1106 * recognized, or the parameters are incompatible, return 0. 1107 */ 1108 #define PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 1109 (PSA_ALG_IS_CIPHER(alg) ? \ 1110 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1111 (((alg) == PSA_ALG_CBC_PKCS7 || \ 1112 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1113 (alg) == PSA_ALG_ECB_NO_PADDING) ? \ 1114 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1115 input_length) : \ 1116 (input_length)) : 0) : \ 1117 0) 1118 1119 /** A sufficient output buffer size for psa_cipher_update(), for any of the 1120 * supported key types and cipher algorithms. 1121 * 1122 * If the size of the output buffer is at least this large, it is guaranteed 1123 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1124 * 1125 * See also #PSA_CIPHER_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1126 * 1127 * \param input_length Size of the input in bytes. 1128 */ 1129 #define PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 1130 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length)) 1131 1132 /** A sufficient ciphertext buffer size for psa_cipher_finish(). 1133 * 1134 * If the size of the ciphertext buffer is at least this large, it is 1135 * guaranteed that psa_cipher_finish() will not fail due to an insufficient 1136 * ciphertext buffer size. The actual size of the output might be smaller in 1137 * any given call. 1138 * 1139 * See also #PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE(). 1140 * 1141 * \param key_type A symmetric key type that is compatible with algorithm 1142 * alg. 1143 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1144 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1145 * \return A sufficient output size for the specified key type and 1146 * algorithm. If the key type or cipher algorithm is not 1147 * recognized, or the parameters are incompatible, return 0. 1148 */ 1149 #define PSA_CIPHER_FINISH_OUTPUT_SIZE(key_type, alg) \ 1150 (PSA_ALG_IS_CIPHER(alg) ? \ 1151 (alg == PSA_ALG_CBC_PKCS7 ? \ 1152 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1153 0) : \ 1154 0) 1155 1156 /** A sufficient ciphertext buffer size for psa_cipher_finish(), for any of the 1157 * supported key types and cipher algorithms. 1158 * 1159 * See also #PSA_CIPHER_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 1160 */ 1161 #define PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE \ 1162 (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 1163 1164 #endif /* PSA_CRYPTO_SIZES_H */ 1165