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 expected size of input passed to psa_tls12_ecjpake_to_pms_input, 243 * which is expected to work with P-256 curve only. */ 244 #define PSA_TLS12_ECJPAKE_TO_PMS_INPUT_SIZE 65 245 246 /* The size of a serialized K.X coordinate to be used in 247 * psa_tls12_ecjpake_to_pms_input. This function only accepts the P-256 248 * curve. */ 249 #define PSA_TLS12_ECJPAKE_TO_PMS_DATA_SIZE 32 250 251 /** The maximum size of a block cipher. */ 252 #define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16 253 254 /** The size of the output of psa_mac_sign_finish(), in bytes. 255 * 256 * This is also the MAC size that psa_mac_verify_finish() expects. 257 * 258 * \warning This macro may evaluate its arguments multiple times or 259 * zero times, so you should not pass arguments that contain 260 * side effects. 261 * 262 * \param key_type The type of the MAC key. 263 * \param key_bits The size of the MAC key in bits. 264 * \param alg A MAC algorithm (\c PSA_ALG_XXX value such that 265 * #PSA_ALG_IS_MAC(\p alg) is true). 266 * 267 * \return The MAC size for the specified algorithm with 268 * the specified key parameters. 269 * \return 0 if the MAC algorithm is not recognized. 270 * \return Either 0 or the correct size for a MAC algorithm that 271 * the implementation recognizes, but does not support. 272 * \return Unspecified if the key parameters are not consistent 273 * with the algorithm. 274 */ 275 #define PSA_MAC_LENGTH(key_type, key_bits, alg) \ 276 ((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \ 277 PSA_ALG_IS_HMAC(alg) ? PSA_HASH_LENGTH(PSA_ALG_HMAC_GET_HASH(alg)) : \ 278 PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 279 ((void) (key_type), (void) (key_bits), 0)) 280 281 /** The maximum size of the output of psa_aead_encrypt(), in bytes. 282 * 283 * If the size of the ciphertext buffer is at least this large, it is 284 * guaranteed that psa_aead_encrypt() will not fail due to an 285 * insufficient buffer size. Depending on the algorithm, the actual size of 286 * the ciphertext may be smaller. 287 * 288 * See also #PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(\p plaintext_length). 289 * 290 * \warning This macro may evaluate its arguments multiple times or 291 * zero times, so you should not pass arguments that contain 292 * side effects. 293 * 294 * \param key_type A symmetric key type that is 295 * compatible with algorithm \p alg. 296 * \param alg An AEAD algorithm 297 * (\c PSA_ALG_XXX value such that 298 * #PSA_ALG_IS_AEAD(\p alg) is true). 299 * \param plaintext_length Size of the plaintext in bytes. 300 * 301 * \return The AEAD ciphertext size for the specified 302 * algorithm. 303 * If the key type or AEAD algorithm is not 304 * recognized, or the parameters are incompatible, 305 * return 0. 306 */ 307 #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length) \ 308 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 309 (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 310 0) 311 312 /** A sufficient output buffer size for psa_aead_encrypt(), for any of the 313 * supported key types and AEAD algorithms. 314 * 315 * If the size of the ciphertext buffer is at least this large, it is guaranteed 316 * that psa_aead_encrypt() will not fail due to an insufficient buffer size. 317 * 318 * \note This macro returns a compile-time constant if its arguments are 319 * compile-time constants. 320 * 321 * See also #PSA_AEAD_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, 322 * \p plaintext_length). 323 * 324 * \param plaintext_length Size of the plaintext in bytes. 325 * 326 * \return A sufficient output buffer size for any of the 327 * supported key types and AEAD algorithms. 328 * 329 */ 330 #define PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length) \ 331 ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE) 332 333 334 /** The maximum size of the output of psa_aead_decrypt(), in bytes. 335 * 336 * If the size of the plaintext buffer is at least this large, it is 337 * guaranteed that psa_aead_decrypt() will not fail due to an 338 * insufficient buffer size. Depending on the algorithm, the actual size of 339 * the plaintext may be smaller. 340 * 341 * See also #PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(\p ciphertext_length). 342 * 343 * \warning This macro may evaluate its arguments multiple times or 344 * zero times, so you should not pass arguments that contain 345 * side effects. 346 * 347 * \param key_type A symmetric key type that is 348 * compatible with algorithm \p alg. 349 * \param alg An AEAD algorithm 350 * (\c PSA_ALG_XXX value such that 351 * #PSA_ALG_IS_AEAD(\p alg) is true). 352 * \param ciphertext_length Size of the plaintext in bytes. 353 * 354 * \return The AEAD ciphertext size for the specified 355 * algorithm. 356 * If the key type or AEAD algorithm is not 357 * recognized, or the parameters are incompatible, 358 * return 0. 359 */ 360 #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length) \ 361 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 362 (ciphertext_length) > PSA_ALG_AEAD_GET_TAG_LENGTH(alg) ? \ 363 (ciphertext_length) - PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 364 0) 365 366 /** A sufficient output buffer size for psa_aead_decrypt(), for any of the 367 * supported key types and AEAD algorithms. 368 * 369 * If the size of the plaintext buffer is at least this large, it is guaranteed 370 * that psa_aead_decrypt() will not fail due to an insufficient buffer size. 371 * 372 * \note This macro returns a compile-time constant if its arguments are 373 * compile-time constants. 374 * 375 * See also #PSA_AEAD_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, 376 * \p ciphertext_length). 377 * 378 * \param ciphertext_length Size of the ciphertext in bytes. 379 * 380 * \return A sufficient output buffer size for any of the 381 * supported key types and AEAD algorithms. 382 * 383 */ 384 #define PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(ciphertext_length) \ 385 (ciphertext_length) 386 387 /** The default nonce size for an AEAD algorithm, in bytes. 388 * 389 * This macro can be used to allocate a buffer of sufficient size to 390 * store the nonce output from #psa_aead_generate_nonce(). 391 * 392 * See also #PSA_AEAD_NONCE_MAX_SIZE. 393 * 394 * \note This is not the maximum size of nonce supported as input to 395 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 396 * just the default size that is generated by #psa_aead_generate_nonce(). 397 * 398 * \warning This macro may evaluate its arguments multiple times or 399 * zero times, so you should not pass arguments that contain 400 * side effects. 401 * 402 * \param key_type A symmetric key type that is compatible with 403 * algorithm \p alg. 404 * 405 * \param alg An AEAD algorithm (\c PSA_ALG_XXX value such that 406 * #PSA_ALG_IS_AEAD(\p alg) is true). 407 * 408 * \return The default nonce size for the specified key type and algorithm. 409 * If the key type or AEAD algorithm is not recognized, 410 * or the parameters are incompatible, return 0. 411 */ 412 #define PSA_AEAD_NONCE_LENGTH(key_type, alg) \ 413 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \ 414 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CCM) ? 13 : \ 415 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_GCM) ? 12 : \ 416 0 : \ 417 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 418 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12 : \ 419 0) 420 421 /** The maximum default nonce size among all supported pairs of key types and 422 * AEAD algorithms, in bytes. 423 * 424 * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH() 425 * may return. 426 * 427 * \note This is not the maximum size of nonce supported as input to 428 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 429 * just the largest size that may be generated by 430 * #psa_aead_generate_nonce(). 431 */ 432 #define PSA_AEAD_NONCE_MAX_SIZE 13 433 434 /** A sufficient output buffer size for psa_aead_update(). 435 * 436 * If the size of the output buffer is at least this large, it is 437 * guaranteed that psa_aead_update() will not fail due to an 438 * insufficient buffer size. The actual size of the output may be smaller 439 * in any given call. 440 * 441 * See also #PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 442 * 443 * \warning This macro may evaluate its arguments multiple times or 444 * zero times, so you should not pass arguments that contain 445 * side effects. 446 * 447 * \param key_type A symmetric key type that is 448 * compatible with algorithm \p alg. 449 * \param alg An AEAD algorithm 450 * (\c PSA_ALG_XXX value such that 451 * #PSA_ALG_IS_AEAD(\p alg) is true). 452 * \param input_length Size of the input in bytes. 453 * 454 * \return A sufficient output buffer size for the specified 455 * algorithm. 456 * If the key type or AEAD algorithm is not 457 * recognized, or the parameters are incompatible, 458 * return 0. 459 */ 460 /* For all the AEAD modes defined in this specification, it is possible 461 * to emit output without delay. However, hardware may not always be 462 * capable of this. So for modes based on a block cipher, allow the 463 * implementation to delay the output until it has a full block. */ 464 #define PSA_AEAD_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 465 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 466 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 467 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), (input_length)) : \ 468 (input_length) : \ 469 0) 470 471 /** A sufficient output buffer size for psa_aead_update(), for any of the 472 * supported key types and AEAD algorithms. 473 * 474 * If the size of the output buffer is at least this large, it is guaranteed 475 * that psa_aead_update() will not fail due to an insufficient buffer size. 476 * 477 * See also #PSA_AEAD_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 478 * 479 * \param input_length Size of the input in bytes. 480 */ 481 #define PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 482 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length))) 483 484 /** A sufficient ciphertext buffer size for psa_aead_finish(). 485 * 486 * If the size of the ciphertext buffer is at least this large, it is 487 * guaranteed that psa_aead_finish() will not fail due to an 488 * insufficient ciphertext buffer size. The actual size of the output may 489 * be smaller in any given call. 490 * 491 * See also #PSA_AEAD_FINISH_OUTPUT_MAX_SIZE. 492 * 493 * \param key_type A symmetric key type that is 494 compatible with algorithm \p alg. 495 * \param alg An AEAD algorithm 496 * (\c PSA_ALG_XXX value such that 497 * #PSA_ALG_IS_AEAD(\p alg) is true). 498 * 499 * \return A sufficient ciphertext buffer size for the 500 * specified algorithm. 501 * If the key type or AEAD algorithm is not 502 * recognized, or the parameters are incompatible, 503 * return 0. 504 */ 505 #define PSA_AEAD_FINISH_OUTPUT_SIZE(key_type, alg) \ 506 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 507 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 508 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 509 0) 510 511 /** A sufficient ciphertext buffer size for psa_aead_finish(), for any of the 512 * supported key types and AEAD algorithms. 513 * 514 * See also #PSA_AEAD_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 515 */ 516 #define PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 517 518 /** A sufficient plaintext buffer size for psa_aead_verify(). 519 * 520 * If the size of the plaintext buffer is at least this large, it is 521 * guaranteed that psa_aead_verify() will not fail due to an 522 * insufficient plaintext buffer size. The actual size of the output may 523 * be smaller in any given call. 524 * 525 * See also #PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE. 526 * 527 * \param key_type A symmetric key type that is 528 * compatible with algorithm \p alg. 529 * \param alg An AEAD algorithm 530 * (\c PSA_ALG_XXX value such that 531 * #PSA_ALG_IS_AEAD(\p alg) is true). 532 * 533 * \return A sufficient plaintext buffer size for the 534 * specified algorithm. 535 * If the key type or AEAD algorithm is not 536 * recognized, or the parameters are incompatible, 537 * return 0. 538 */ 539 #define PSA_AEAD_VERIFY_OUTPUT_SIZE(key_type, alg) \ 540 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 541 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 542 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 543 0) 544 545 /** A sufficient plaintext buffer size for psa_aead_verify(), for any of the 546 * supported key types and AEAD algorithms. 547 * 548 * See also #PSA_AEAD_VERIFY_OUTPUT_SIZE(\p key_type, \p alg). 549 */ 550 #define PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 551 552 #define PSA_RSA_MINIMUM_PADDING_SIZE(alg) \ 553 (PSA_ALG_IS_RSA_OAEP(alg) ? \ 554 2 * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1 : \ 555 11 /*PKCS#1v1.5*/) 556 557 /** 558 * \brief ECDSA signature size for a given curve bit size 559 * 560 * \param curve_bits Curve size in bits. 561 * \return Signature size in bytes. 562 * 563 * \note This macro returns a compile-time constant if its argument is one. 564 */ 565 #define PSA_ECDSA_SIGNATURE_SIZE(curve_bits) \ 566 (PSA_BITS_TO_BYTES(curve_bits) * 2) 567 568 /** Sufficient signature buffer size for psa_sign_hash(). 569 * 570 * This macro returns a sufficient buffer size for a signature using a key 571 * of the specified type and size, with the specified algorithm. 572 * Note that the actual size of the signature may be smaller 573 * (some algorithms produce a variable-size signature). 574 * 575 * \warning This function may call its arguments multiple times or 576 * zero times, so you should not pass arguments that contain 577 * side effects. 578 * 579 * \param key_type An asymmetric key type (this may indifferently be a 580 * key pair type or a public key type). 581 * \param key_bits The size of the key in bits. 582 * \param alg The signature algorithm. 583 * 584 * \return If the parameters are valid and supported, return 585 * a buffer size in bytes that guarantees that 586 * psa_sign_hash() will not fail with 587 * #PSA_ERROR_BUFFER_TOO_SMALL. 588 * If the parameters are a valid combination that is not supported, 589 * return either a sensible size or 0. 590 * If the parameters are not valid, the 591 * return value is unspecified. 592 */ 593 #define PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \ 594 (PSA_KEY_TYPE_IS_RSA(key_type) ? ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \ 595 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \ 596 ((void) alg, 0)) 597 598 #define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE \ 599 PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 600 601 /** \def PSA_SIGNATURE_MAX_SIZE 602 * 603 * Maximum size of an asymmetric signature. 604 * 605 * This macro expands to a compile-time constant integer. This value 606 * is the maximum size of a signature in bytes. 607 */ 608 #define PSA_SIGNATURE_MAX_SIZE \ 609 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE ? \ 610 PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 611 PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE) 612 613 /** Sufficient output buffer size for psa_asymmetric_encrypt(). 614 * 615 * This macro returns a sufficient buffer size for a ciphertext produced using 616 * a key of the specified type and size, with the specified algorithm. 617 * Note that the actual size of the ciphertext may be smaller, depending 618 * on the algorithm. 619 * 620 * \warning This function may call its arguments multiple times or 621 * zero times, so you should not pass arguments that contain 622 * side effects. 623 * 624 * \param key_type An asymmetric key type (this may indifferently be a 625 * key pair type or a public key type). 626 * \param key_bits The size of the key in bits. 627 * \param alg The asymmetric encryption algorithm. 628 * 629 * \return If the parameters are valid and supported, return 630 * a buffer size in bytes that guarantees that 631 * psa_asymmetric_encrypt() will not fail with 632 * #PSA_ERROR_BUFFER_TOO_SMALL. 633 * If the parameters are a valid combination that is not supported, 634 * return either a sensible size or 0. 635 * If the parameters are not valid, the 636 * return value is unspecified. 637 */ 638 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 639 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 640 ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \ 641 0) 642 643 /** A sufficient output buffer size for psa_asymmetric_encrypt(), for any 644 * supported asymmetric encryption. 645 * 646 * See also #PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 647 */ 648 /* This macro assumes that RSA is the only supported asymmetric encryption. */ 649 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE \ 650 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 651 652 /** Sufficient output buffer size for psa_asymmetric_decrypt(). 653 * 654 * This macro returns a sufficient buffer size for a plaintext produced using 655 * a key of the specified type and size, with the specified algorithm. 656 * Note that the actual size of the plaintext may be smaller, depending 657 * on the algorithm. 658 * 659 * \warning This function may call its arguments multiple times or 660 * zero times, so you should not pass arguments that contain 661 * side effects. 662 * 663 * \param key_type An asymmetric key type (this may indifferently be a 664 * key pair type or a public key type). 665 * \param key_bits The size of the key in bits. 666 * \param alg The asymmetric encryption algorithm. 667 * 668 * \return If the parameters are valid and supported, return 669 * a buffer size in bytes that guarantees that 670 * psa_asymmetric_decrypt() will not fail with 671 * #PSA_ERROR_BUFFER_TOO_SMALL. 672 * If the parameters are a valid combination that is not supported, 673 * return either a sensible size or 0. 674 * If the parameters are not valid, the 675 * return value is unspecified. 676 */ 677 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 678 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 679 PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \ 680 0) 681 682 /** A sufficient output buffer size for psa_asymmetric_decrypt(), for any 683 * supported asymmetric decryption. 684 * 685 * This macro assumes that RSA is the only supported asymmetric encryption. 686 * 687 * See also #PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 688 */ 689 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE \ 690 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 691 692 /* Maximum size of the ASN.1 encoding of an INTEGER with the specified 693 * number of bits. 694 * 695 * This definition assumes that bits <= 2^19 - 9 so that the length field 696 * is at most 3 bytes. The length of the encoding is the length of the 697 * bit string padded to a whole number of bytes plus: 698 * - 1 type byte; 699 * - 1 to 3 length bytes; 700 * - 0 to 1 bytes of leading 0 due to the sign bit. 701 */ 702 #define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \ 703 ((bits) / 8 + 5) 704 705 /* Maximum size of the export encoding of an RSA public key. 706 * Assumes that the public exponent is less than 2^32. 707 * 708 * RSAPublicKey ::= SEQUENCE { 709 * modulus INTEGER, -- n 710 * publicExponent INTEGER } -- e 711 * 712 * - 4 bytes of SEQUENCE overhead; 713 * - n : INTEGER; 714 * - 7 bytes for the public exponent. 715 */ 716 #define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 717 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11) 718 719 /* Maximum size of the export encoding of an RSA key pair. 720 * Assumes that the public exponent is less than 2^32 and that the size 721 * difference between the two primes is at most 1 bit. 722 * 723 * RSAPrivateKey ::= SEQUENCE { 724 * version Version, -- 0 725 * modulus INTEGER, -- N-bit 726 * publicExponent INTEGER, -- 32-bit 727 * privateExponent INTEGER, -- N-bit 728 * prime1 INTEGER, -- N/2-bit 729 * prime2 INTEGER, -- N/2-bit 730 * exponent1 INTEGER, -- N/2-bit 731 * exponent2 INTEGER, -- N/2-bit 732 * coefficient INTEGER, -- N/2-bit 733 * } 734 * 735 * - 4 bytes of SEQUENCE overhead; 736 * - 3 bytes of version; 737 * - 7 half-size INTEGERs plus 2 full-size INTEGERs, 738 * overapproximated as 9 half-size INTEGERS; 739 * - 7 bytes for the public exponent. 740 */ 741 #define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) \ 742 (9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14) 743 744 /* Maximum size of the export encoding of a DSA public key. 745 * 746 * SubjectPublicKeyInfo ::= SEQUENCE { 747 * algorithm AlgorithmIdentifier, 748 * subjectPublicKey BIT STRING } -- contains DSAPublicKey 749 * AlgorithmIdentifier ::= SEQUENCE { 750 * algorithm OBJECT IDENTIFIER, 751 * parameters Dss-Params } -- SEQUENCE of 3 INTEGERs 752 * DSAPublicKey ::= INTEGER -- public key, Y 753 * 754 * - 3 * 4 bytes of SEQUENCE overhead; 755 * - 1 + 1 + 7 bytes of algorithm (DSA OID); 756 * - 4 bytes of BIT STRING overhead; 757 * - 3 full-size INTEGERs (p, g, y); 758 * - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits). 759 */ 760 #define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 761 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 59) 762 763 /* Maximum size of the export encoding of a DSA key pair. 764 * 765 * DSAPrivateKey ::= SEQUENCE { 766 * version Version, -- 0 767 * prime INTEGER, -- p 768 * subprime INTEGER, -- q 769 * generator INTEGER, -- g 770 * public INTEGER, -- y 771 * private INTEGER, -- x 772 * } 773 * 774 * - 4 bytes of SEQUENCE overhead; 775 * - 3 bytes of version; 776 * - 3 full-size INTEGERs (p, g, y); 777 * - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits). 778 */ 779 #define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) \ 780 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 75) 781 782 /* Maximum size of the export encoding of an ECC public key. 783 * 784 * The representation of an ECC public key is: 785 * - The byte 0x04; 786 * - `x_P` as a `ceiling(m/8)`-byte string, big-endian; 787 * - `y_P` as a `ceiling(m/8)`-byte string, big-endian; 788 * - where m is the bit size associated with the curve. 789 * 790 * - 1 byte + 2 * point size. 791 */ 792 #define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \ 793 (2 * PSA_BITS_TO_BYTES(key_bits) + 1) 794 795 /* Maximum size of the export encoding of an ECC key pair. 796 * 797 * An ECC key pair is represented by the secret value. 798 */ 799 #define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) \ 800 (PSA_BITS_TO_BYTES(key_bits)) 801 802 /** Sufficient output buffer size for psa_export_key() or 803 * psa_export_public_key(). 804 * 805 * This macro returns a compile-time constant if its arguments are 806 * compile-time constants. 807 * 808 * \warning This macro may evaluate its arguments multiple times or 809 * zero times, so you should not pass arguments that contain 810 * side effects. 811 * 812 * The following code illustrates how to allocate enough memory to export 813 * a key by querying the key type and size at runtime. 814 * \code{c} 815 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 816 * psa_status_t status; 817 * status = psa_get_key_attributes(key, &attributes); 818 * if (status != PSA_SUCCESS) handle_error(...); 819 * psa_key_type_t key_type = psa_get_key_type(&attributes); 820 * size_t key_bits = psa_get_key_bits(&attributes); 821 * size_t buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits); 822 * psa_reset_key_attributes(&attributes); 823 * uint8_t *buffer = malloc(buffer_size); 824 * if (buffer == NULL) handle_error(...); 825 * size_t buffer_length; 826 * status = psa_export_key(key, buffer, buffer_size, &buffer_length); 827 * if (status != PSA_SUCCESS) handle_error(...); 828 * \endcode 829 * 830 * \param key_type A supported key type. 831 * \param key_bits The size of the key in bits. 832 * 833 * \return If the parameters are valid and supported, return 834 * a buffer size in bytes that guarantees that 835 * psa_export_key() or psa_export_public_key() will not fail with 836 * #PSA_ERROR_BUFFER_TOO_SMALL. 837 * If the parameters are a valid combination that is not supported, 838 * return either a sensible size or 0. 839 * If the parameters are not valid, the return value is unspecified. 840 */ 841 #define PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits) \ 842 (PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 843 (key_type) == PSA_KEY_TYPE_RSA_KEY_PAIR ? PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 844 (key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 845 (key_type) == PSA_KEY_TYPE_DSA_KEY_PAIR ? PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 846 (key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 847 PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) : \ 848 PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 849 0) 850 851 /** Sufficient output buffer size for psa_export_public_key(). 852 * 853 * This macro returns a compile-time constant if its arguments are 854 * compile-time constants. 855 * 856 * \warning This macro may evaluate its arguments multiple times or 857 * zero times, so you should not pass arguments that contain 858 * side effects. 859 * 860 * The following code illustrates how to allocate enough memory to export 861 * a public key by querying the key type and size at runtime. 862 * \code{c} 863 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 864 * psa_status_t status; 865 * status = psa_get_key_attributes(key, &attributes); 866 * if (status != PSA_SUCCESS) handle_error(...); 867 * psa_key_type_t key_type = psa_get_key_type(&attributes); 868 * size_t key_bits = psa_get_key_bits(&attributes); 869 * size_t buffer_size = PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits); 870 * psa_reset_key_attributes(&attributes); 871 * uint8_t *buffer = malloc(buffer_size); 872 * if (buffer == NULL) handle_error(...); 873 * size_t buffer_length; 874 * status = psa_export_public_key(key, buffer, buffer_size, &buffer_length); 875 * if (status != PSA_SUCCESS) handle_error(...); 876 * \endcode 877 * 878 * \param key_type A public key or key pair key type. 879 * \param key_bits The size of the key in bits. 880 * 881 * \return If the parameters are valid and supported, return 882 * a buffer size in bytes that guarantees that 883 * psa_export_public_key() will not fail with 884 * #PSA_ERROR_BUFFER_TOO_SMALL. 885 * If the parameters are a valid combination that is not 886 * supported, return either a sensible size or 0. 887 * If the parameters are not valid, 888 * the return value is unspecified. 889 * 890 * If the parameters are valid and supported, 891 * return the same result as 892 * #PSA_EXPORT_KEY_OUTPUT_SIZE( 893 * \p #PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(\p key_type), 894 * \p key_bits). 895 */ 896 #define PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits) \ 897 (PSA_KEY_TYPE_IS_RSA(key_type) ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 898 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 899 0) 900 901 /** Sufficient buffer size for exporting any asymmetric key pair. 902 * 903 * This macro expands to a compile-time constant integer. This value is 904 * a sufficient buffer size when calling psa_export_key() to export any 905 * asymmetric key pair, regardless of the exact key type and key size. 906 * 907 * See also #PSA_EXPORT_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 908 */ 909 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 910 (PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 911 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ? \ 912 PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 913 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 914 915 /** Sufficient buffer size for exporting any asymmetric public key. 916 * 917 * This macro expands to a compile-time constant integer. This value is 918 * a sufficient buffer size when calling psa_export_key() or 919 * psa_export_public_key() to export any asymmetric public key, 920 * regardless of the exact key type and key size. 921 * 922 * See also #PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 923 */ 924 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 925 (PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 926 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ? \ 927 PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 928 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 929 930 /** Sufficient output buffer size for psa_raw_key_agreement(). 931 * 932 * This macro returns a compile-time constant if its arguments are 933 * compile-time constants. 934 * 935 * \warning This macro may evaluate its arguments multiple times or 936 * zero times, so you should not pass arguments that contain 937 * side effects. 938 * 939 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE. 940 * 941 * \param key_type A supported key type. 942 * \param key_bits The size of the key in bits. 943 * 944 * \return If the parameters are valid and supported, return 945 * a buffer size in bytes that guarantees that 946 * psa_raw_key_agreement() will not fail with 947 * #PSA_ERROR_BUFFER_TOO_SMALL. 948 * If the parameters are a valid combination that 949 * is not supported, return either a sensible size or 0. 950 * If the parameters are not valid, 951 * the return value is unspecified. 952 */ 953 /* FFDH is not yet supported in PSA. */ 954 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits) \ 955 (PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? \ 956 PSA_BITS_TO_BYTES(key_bits) : \ 957 0) 958 959 /** Maximum size of the output from psa_raw_key_agreement(). 960 * 961 * This macro expands to a compile-time constant integer. This value is the 962 * maximum size of the output any raw key agreement algorithm, in bytes. 963 * 964 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(\p key_type, \p key_bits). 965 */ 966 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE \ 967 (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 968 969 /** The default IV size for a cipher algorithm, in bytes. 970 * 971 * The IV that is generated as part of a call to #psa_cipher_encrypt() is always 972 * the default IV length for the algorithm. 973 * 974 * This macro can be used to allocate a buffer of sufficient size to 975 * store the IV output from #psa_cipher_generate_iv() when using 976 * a multi-part cipher operation. 977 * 978 * See also #PSA_CIPHER_IV_MAX_SIZE. 979 * 980 * \warning This macro may evaluate its arguments multiple times or 981 * zero times, so you should not pass arguments that contain 982 * side effects. 983 * 984 * \param key_type A symmetric key type that is compatible with algorithm \p alg. 985 * 986 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true). 987 * 988 * \return The default IV size for the specified key type and algorithm. 989 * If the algorithm does not use an IV, return 0. 990 * If the key type or cipher algorithm is not recognized, 991 * or the parameters are incompatible, return 0. 992 */ 993 #define PSA_CIPHER_IV_LENGTH(key_type, alg) \ 994 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1 && \ 995 ((alg) == PSA_ALG_CTR || \ 996 (alg) == PSA_ALG_CFB || \ 997 (alg) == PSA_ALG_OFB || \ 998 (alg) == PSA_ALG_XTS || \ 999 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1000 (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1001 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 1002 (alg) == PSA_ALG_STREAM_CIPHER ? 12 : \ 1003 (alg) == PSA_ALG_CCM_STAR_NO_TAG ? 13 : \ 1004 0) 1005 1006 /** The maximum IV size for all supported cipher algorithms, in bytes. 1007 * 1008 * See also #PSA_CIPHER_IV_LENGTH(). 1009 */ 1010 #define PSA_CIPHER_IV_MAX_SIZE 16 1011 1012 /** The maximum size of the output of psa_cipher_encrypt(), in bytes. 1013 * 1014 * If the size of the output buffer is at least this large, it is guaranteed 1015 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1016 * Depending on the algorithm, the actual size of the output might be smaller. 1017 * 1018 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(\p input_length). 1019 * 1020 * \warning This macro may evaluate its arguments multiple times or 1021 * zero times, so you should not pass arguments that contain 1022 * side effects. 1023 * 1024 * \param key_type A symmetric key type that is compatible with algorithm 1025 * alg. 1026 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1027 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1028 * \param input_length Size of the input in bytes. 1029 * 1030 * \return A sufficient output size for the specified key type and 1031 * algorithm. If the key type or cipher algorithm is not 1032 * recognized, or the parameters are incompatible, 1033 * return 0. 1034 */ 1035 #define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1036 (alg == PSA_ALG_CBC_PKCS7 ? \ 1037 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1038 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1039 (input_length) + 1) + \ 1040 PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0) : \ 1041 (PSA_ALG_IS_CIPHER(alg) ? \ 1042 (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) : \ 1043 0)) 1044 1045 /** A sufficient output buffer size for psa_cipher_encrypt(), for any of the 1046 * supported key types and cipher algorithms. 1047 * 1048 * If the size of the output buffer is at least this large, it is guaranteed 1049 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1050 * 1051 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1052 * 1053 * \param input_length Size of the input in bytes. 1054 * 1055 */ 1056 #define PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(input_length) \ 1057 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, \ 1058 (input_length) + 1) + \ 1059 PSA_CIPHER_IV_MAX_SIZE) 1060 1061 /** The maximum size of the output of psa_cipher_decrypt(), in bytes. 1062 * 1063 * If the size of the output buffer is at least this large, it is guaranteed 1064 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1065 * Depending on the algorithm, the actual size of the output might be smaller. 1066 * 1067 * See also #PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(\p input_length). 1068 * 1069 * \param key_type A symmetric key type that is compatible with algorithm 1070 * alg. 1071 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1072 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1073 * \param input_length Size of the input in bytes. 1074 * 1075 * \return A sufficient output size for the specified key type and 1076 * algorithm. If the key type or cipher algorithm is not 1077 * recognized, or the parameters are incompatible, 1078 * return 0. 1079 */ 1080 #define PSA_CIPHER_DECRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1081 (PSA_ALG_IS_CIPHER(alg) && \ 1082 ((key_type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \ 1083 (input_length) : \ 1084 0) 1085 1086 /** A sufficient output buffer size for psa_cipher_decrypt(), for any of the 1087 * supported key types and cipher algorithms. 1088 * 1089 * If the size of the output buffer is at least this large, it is guaranteed 1090 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1091 * 1092 * See also #PSA_CIPHER_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1093 * 1094 * \param input_length Size of the input in bytes. 1095 */ 1096 #define PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(input_length) \ 1097 (input_length) 1098 1099 /** A sufficient output buffer size for psa_cipher_update(). 1100 * 1101 * If the size of the output buffer is at least this large, it is guaranteed 1102 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1103 * The actual size of the output might be smaller in any given call. 1104 * 1105 * See also #PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 1106 * 1107 * \param key_type A symmetric key type that is compatible with algorithm 1108 * alg. 1109 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1110 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1111 * \param input_length Size of the input in bytes. 1112 * 1113 * \return A sufficient output size for the specified key type and 1114 * algorithm. If the key type or cipher algorithm is not 1115 * recognized, or the parameters are incompatible, return 0. 1116 */ 1117 #define PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 1118 (PSA_ALG_IS_CIPHER(alg) ? \ 1119 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1120 (((alg) == PSA_ALG_CBC_PKCS7 || \ 1121 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1122 (alg) == PSA_ALG_ECB_NO_PADDING) ? \ 1123 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1124 input_length) : \ 1125 (input_length)) : 0) : \ 1126 0) 1127 1128 /** A sufficient output buffer size for psa_cipher_update(), for any of the 1129 * supported key types and cipher algorithms. 1130 * 1131 * If the size of the output buffer is at least this large, it is guaranteed 1132 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1133 * 1134 * See also #PSA_CIPHER_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1135 * 1136 * \param input_length Size of the input in bytes. 1137 */ 1138 #define PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 1139 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length)) 1140 1141 /** A sufficient ciphertext buffer size for psa_cipher_finish(). 1142 * 1143 * If the size of the ciphertext buffer is at least this large, it is 1144 * guaranteed that psa_cipher_finish() will not fail due to an insufficient 1145 * ciphertext buffer size. The actual size of the output might be smaller in 1146 * any given call. 1147 * 1148 * See also #PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE(). 1149 * 1150 * \param key_type A symmetric key type that is compatible with algorithm 1151 * alg. 1152 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1153 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1154 * \return A sufficient output size for the specified key type and 1155 * algorithm. If the key type or cipher algorithm is not 1156 * recognized, or the parameters are incompatible, return 0. 1157 */ 1158 #define PSA_CIPHER_FINISH_OUTPUT_SIZE(key_type, alg) \ 1159 (PSA_ALG_IS_CIPHER(alg) ? \ 1160 (alg == PSA_ALG_CBC_PKCS7 ? \ 1161 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1162 0) : \ 1163 0) 1164 1165 /** A sufficient ciphertext buffer size for psa_cipher_finish(), for any of the 1166 * supported key types and cipher algorithms. 1167 * 1168 * See also #PSA_CIPHER_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 1169 */ 1170 #define PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE \ 1171 (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 1172 1173 #endif /* PSA_CRYPTO_SIZES_H */ 1174
