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 #if !defined(MBEDTLS_CONFIG_FILE) 46 #include "mbedtls/config.h" 47 #else 48 #include MBEDTLS_CONFIG_FILE 49 #endif 50 51 #define PSA_BITS_TO_BYTES(bits) (((bits) + 7) / 8) 52 #define PSA_BYTES_TO_BITS(bytes) ((bytes) * 8) 53 54 #define PSA_ROUND_UP_TO_MULTIPLE(block_size, length) \ 55 (((length) + (block_size) - 1) / (block_size) * (block_size)) 56 57 /** The size of the output of psa_hash_finish(), in bytes. 58 * 59 * This is also the hash size that psa_hash_verify() expects. 60 * 61 * \param alg A hash algorithm (\c PSA_ALG_XXX value such that 62 * #PSA_ALG_IS_HASH(\p alg) is true), or an HMAC algorithm 63 * (#PSA_ALG_HMAC(\c hash_alg) where \c hash_alg is a 64 * hash algorithm). 65 * 66 * \return The hash size for the specified hash algorithm. 67 * If the hash algorithm is not recognized, return 0. 68 */ 69 #define PSA_HASH_LENGTH(alg) \ 70 ( \ 71 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD2 ? 16 : \ 72 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD4 ? 16 : \ 73 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 16 : \ 74 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 20 : \ 75 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 20 : \ 76 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 28 : \ 77 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 32 : \ 78 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 48 : \ 79 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 64 : \ 80 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 28 : \ 81 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 32 : \ 82 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 28 : \ 83 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 32 : \ 84 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 48 : \ 85 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 64 : \ 86 0) 87 88 /** The input block size of a hash algorithm, in bytes. 89 * 90 * Hash algorithms process their input data in blocks. Hash operations will 91 * retain any partial blocks until they have enough input to fill the block or 92 * until the operation is finished. 93 * This affects the output from psa_hash_suspend(). 94 * 95 * \param alg A hash algorithm (\c PSA_ALG_XXX value such that 96 * PSA_ALG_IS_HASH(\p alg) is true). 97 * 98 * \return The block size in bytes for the specified hash algorithm. 99 * If the hash algorithm is not recognized, return 0. 100 * An implementation can return either 0 or the correct size for a 101 * hash algorithm that it recognizes, but does not support. 102 */ 103 #define PSA_HASH_BLOCK_LENGTH(alg) \ 104 ( \ 105 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD2 ? 16 : \ 106 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD4 ? 64 : \ 107 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 64 : \ 108 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 64 : \ 109 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 64 : \ 110 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 64 : \ 111 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 64 : \ 112 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 128 : \ 113 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 128 : \ 114 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 128 : \ 115 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 128 : \ 116 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 144 : \ 117 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 136 : \ 118 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 104 : \ 119 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 72 : \ 120 0) 121 122 /** \def PSA_HASH_MAX_SIZE 123 * 124 * Maximum size of a hash. 125 * 126 * This macro expands to a compile-time constant integer. This value 127 * is the maximum size of a hash in bytes. 128 */ 129 /* Note: for HMAC-SHA-3, the block size is 144 bytes for HMAC-SHA3-226, 130 * 136 bytes for HMAC-SHA3-256, 104 bytes for SHA3-384, 72 bytes for 131 * HMAC-SHA3-512. */ 132 #if defined(PSA_WANT_ALG_SHA_512) || defined(PSA_WANT_ALG_SHA_384) 133 #define PSA_HASH_MAX_SIZE 64 134 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128 135 #else 136 #define PSA_HASH_MAX_SIZE 32 137 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64 138 #endif 139 140 /** \def PSA_MAC_MAX_SIZE 141 * 142 * Maximum size of a MAC. 143 * 144 * This macro expands to a compile-time constant integer. This value 145 * is the maximum size of a MAC in bytes. 146 */ 147 /* All non-HMAC MACs have a maximum size that's smaller than the 148 * minimum possible value of PSA_HASH_MAX_SIZE in this implementation. */ 149 /* Note that the encoding of truncated MAC algorithms limits this value 150 * to 64 bytes. 151 */ 152 #define PSA_MAC_MAX_SIZE PSA_HASH_MAX_SIZE 153 154 /** The length of a tag for an AEAD algorithm, in bytes. 155 * 156 * This macro can be used to allocate a buffer of sufficient size to store the 157 * tag output from psa_aead_finish(). 158 * 159 * See also #PSA_AEAD_TAG_MAX_SIZE. 160 * 161 * \param key_type The type of the AEAD key. 162 * \param key_bits The size of the AEAD key in bits. 163 * \param alg An AEAD algorithm 164 * (\c PSA_ALG_XXX value such that 165 * #PSA_ALG_IS_AEAD(\p alg) is true). 166 * 167 * \return The tag length for the specified algorithm and key. 168 * If the AEAD algorithm does not have an identified 169 * tag that can be distinguished from the rest of 170 * the ciphertext, return 0. 171 * If the key type or AEAD algorithm is not 172 * recognized, or the parameters are incompatible, 173 * return 0. 174 */ 175 #define PSA_AEAD_TAG_LENGTH(key_type, key_bits, alg) \ 176 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 177 PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 178 ((void) (key_bits), 0)) 179 180 /** The maximum tag size for all supported AEAD algorithms, in bytes. 181 * 182 * See also #PSA_AEAD_TAG_LENGTH(\p key_type, \p key_bits, \p alg). 183 */ 184 #define PSA_AEAD_TAG_MAX_SIZE 16 185 186 /* The maximum size of an RSA key on this implementation, in bits. 187 * This is a vendor-specific macro. 188 * 189 * Mbed TLS does not set a hard limit on the size of RSA keys: any key 190 * whose parameters fit in a bignum is accepted. However large keys can 191 * induce a large memory usage and long computation times. Unlike other 192 * auxiliary macros in this file and in crypto.h, which reflect how the 193 * library is configured, this macro defines how the library is 194 * configured. This implementation refuses to import or generate an 195 * RSA key whose size is larger than the value defined here. 196 * 197 * Note that an implementation may set different size limits for different 198 * operations, and does not need to accept all key sizes up to the limit. */ 199 #define PSA_VENDOR_RSA_MAX_KEY_BITS 4096 200 201 /* The maximum size of an ECC key on this implementation, in bits. 202 * This is a vendor-specific macro. */ 203 #if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) 204 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 521 205 #elif defined(MBEDTLS_ECP_DP_BP512R1_ENABLED) 206 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 512 207 #elif defined(MBEDTLS_ECP_DP_CURVE448_ENABLED) 208 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 448 209 #elif defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED) 210 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384 211 #elif defined(MBEDTLS_ECP_DP_BP384R1_ENABLED) 212 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384 213 #elif defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED) 214 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 215 #elif defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED) 216 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 217 #elif defined(MBEDTLS_ECP_DP_BP256R1_ENABLED) 218 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 219 #elif defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) 220 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 255 221 #elif defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED) 222 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224 223 #elif defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED) 224 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224 225 #elif defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED) 226 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192 227 #elif defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED) 228 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192 229 #else 230 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 0 231 #endif 232 233 /** This macro returns the maximum supported length of the PSK for the 234 * TLS-1.2 PSK-to-MS key derivation 235 * (#PSA_ALG_TLS12_PSK_TO_MS(\c hash_alg)). 236 * 237 * The maximum supported length does not depend on the chosen hash algorithm. 238 * 239 * Quoting RFC 4279, Sect 5.3: 240 * TLS implementations supporting these ciphersuites MUST support 241 * arbitrary PSK identities up to 128 octets in length, and arbitrary 242 * PSKs up to 64 octets in length. Supporting longer identities and 243 * keys is RECOMMENDED. 244 * 245 * Therefore, no implementation should define a value smaller than 64 246 * for #PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE. 247 */ 248 #define PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128 249 250 /** The maximum size of a block cipher. */ 251 #define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16 252 253 /** The size of the output of psa_mac_sign_finish(), in bytes. 254 * 255 * This is also the MAC size that psa_mac_verify_finish() expects. 256 * 257 * \warning This macro may evaluate its arguments multiple times or 258 * zero times, so you should not pass arguments that contain 259 * side effects. 260 * 261 * \param key_type The type of the MAC key. 262 * \param key_bits The size of the MAC key in bits. 263 * \param alg A MAC algorithm (\c PSA_ALG_XXX value such that 264 * #PSA_ALG_IS_MAC(\p alg) is true). 265 * 266 * \return The MAC size for the specified algorithm with 267 * the specified key parameters. 268 * \return 0 if the MAC algorithm is not recognized. 269 * \return Either 0 or the correct size for a MAC algorithm that 270 * the implementation recognizes, but does not support. 271 * \return Unspecified if the key parameters are not consistent 272 * with the algorithm. 273 */ 274 #define PSA_MAC_LENGTH(key_type, key_bits, alg) \ 275 ((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \ 276 PSA_ALG_IS_HMAC(alg) ? PSA_HASH_LENGTH(PSA_ALG_HMAC_GET_HASH(alg)) : \ 277 PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 278 ((void)(key_type), (void)(key_bits), 0)) 279 280 /** The maximum size of the output of psa_aead_encrypt(), in bytes. 281 * 282 * If the size of the ciphertext buffer is at least this large, it is 283 * guaranteed that psa_aead_encrypt() will not fail due to an 284 * insufficient buffer size. Depending on the algorithm, the actual size of 285 * the ciphertext may be smaller. 286 * 287 * See also #PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(\p plaintext_length). 288 * 289 * \warning This macro may evaluate its arguments multiple times or 290 * zero times, so you should not pass arguments that contain 291 * side effects. 292 * 293 * \param key_type A symmetric key type that is 294 * compatible with algorithm \p alg. 295 * \param alg An AEAD algorithm 296 * (\c PSA_ALG_XXX value such that 297 * #PSA_ALG_IS_AEAD(\p alg) is true). 298 * \param plaintext_length Size of the plaintext in bytes. 299 * 300 * \return The AEAD ciphertext size for the specified 301 * algorithm. 302 * If the key type or AEAD algorithm is not 303 * recognized, or the parameters are incompatible, 304 * return 0. 305 */ 306 #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length) \ 307 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 308 (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 309 0) 310 311 /** A sufficient output buffer size for psa_aead_encrypt(), for any of the 312 * supported key types and AEAD algorithms. 313 * 314 * If the size of the ciphertext buffer is at least this large, it is guaranteed 315 * that psa_aead_encrypt() will not fail due to an insufficient buffer size. 316 * 317 * \note This macro returns a compile-time constant if its arguments are 318 * compile-time constants. 319 * 320 * See also #PSA_AEAD_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, 321 * \p plaintext_length). 322 * 323 * \param plaintext_length Size of the plaintext in bytes. 324 * 325 * \return A sufficient output buffer size for any of the 326 * supported key types and AEAD algorithms. 327 * 328 */ 329 #define PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length) \ 330 ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE) 331 332 333 /** The maximum size of the output of psa_aead_decrypt(), in bytes. 334 * 335 * If the size of the plaintext buffer is at least this large, it is 336 * guaranteed that psa_aead_decrypt() will not fail due to an 337 * insufficient buffer size. Depending on the algorithm, the actual size of 338 * the plaintext may be smaller. 339 * 340 * See also #PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(\p ciphertext_length). 341 * 342 * \warning This macro may evaluate its arguments multiple times or 343 * zero times, so you should not pass arguments that contain 344 * side effects. 345 * 346 * \param key_type A symmetric key type that is 347 * compatible with algorithm \p alg. 348 * \param alg An AEAD algorithm 349 * (\c PSA_ALG_XXX value such that 350 * #PSA_ALG_IS_AEAD(\p alg) is true). 351 * \param ciphertext_length Size of the plaintext in bytes. 352 * 353 * \return The AEAD ciphertext size for the specified 354 * algorithm. 355 * If the key type or AEAD algorithm is not 356 * recognized, or the parameters are incompatible, 357 * return 0. 358 */ 359 #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length) \ 360 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 361 (ciphertext_length) > PSA_ALG_AEAD_GET_TAG_LENGTH(alg) ? \ 362 (ciphertext_length) - PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 363 0) 364 365 /** A sufficient output buffer size for psa_aead_decrypt(), for any of the 366 * supported key types and AEAD algorithms. 367 * 368 * If the size of the plaintext buffer is at least this large, it is guaranteed 369 * that psa_aead_decrypt() will not fail due to an insufficient buffer size. 370 * 371 * \note This macro returns a compile-time constant if its arguments are 372 * compile-time constants. 373 * 374 * See also #PSA_AEAD_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, 375 * \p ciphertext_length). 376 * 377 * \param ciphertext_length Size of the ciphertext in bytes. 378 * 379 * \return A sufficient output buffer size for any of the 380 * supported key types and AEAD algorithms. 381 * 382 */ 383 #define PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(ciphertext_length) \ 384 (ciphertext_length) 385 386 /** The default nonce size for an AEAD algorithm, in bytes. 387 * 388 * This macro can be used to allocate a buffer of sufficient size to 389 * store the nonce output from #psa_aead_generate_nonce(). 390 * 391 * See also #PSA_AEAD_NONCE_MAX_SIZE. 392 * 393 * \note This is not the maximum size of nonce supported as input to 394 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 395 * just the default size that is generated by #psa_aead_generate_nonce(). 396 * 397 * \warning This macro may evaluate its arguments multiple times or 398 * zero times, so you should not pass arguments that contain 399 * side effects. 400 * 401 * \param key_type A symmetric key type that is compatible with 402 * algorithm \p alg. 403 * 404 * \param alg An AEAD algorithm (\c PSA_ALG_XXX value such that 405 * #PSA_ALG_IS_AEAD(\p alg) is true). 406 * 407 * \return The default nonce size for the specified key type and algorithm. 408 * If the key type or AEAD algorithm is not recognized, 409 * or the parameters are incompatible, return 0. 410 */ 411 #define PSA_AEAD_NONCE_LENGTH(key_type, alg) \ 412 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \ 413 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CCM) ? 13 : \ 414 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_GCM) ? 12 : \ 415 0 : \ 416 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 417 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12 : \ 418 0) 419 420 /** The maximum default nonce size among all supported pairs of key types and 421 * AEAD algorithms, in bytes. 422 * 423 * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH() 424 * may return. 425 * 426 * \note This is not the maximum size of nonce supported as input to 427 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 428 * just the largest size that may be generated by 429 * #psa_aead_generate_nonce(). 430 */ 431 #define PSA_AEAD_NONCE_MAX_SIZE 13 432 433 /** A sufficient output buffer size for psa_aead_update(). 434 * 435 * If the size of the output buffer is at least this large, it is 436 * guaranteed that psa_aead_update() will not fail due to an 437 * insufficient buffer size. The actual size of the output may be smaller 438 * in any given call. 439 * 440 * See also #PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 441 * 442 * \warning This macro may evaluate its arguments multiple times or 443 * zero times, so you should not pass arguments that contain 444 * side effects. 445 * 446 * \param key_type A symmetric key type that is 447 * compatible with algorithm \p alg. 448 * \param alg An AEAD algorithm 449 * (\c PSA_ALG_XXX value such that 450 * #PSA_ALG_IS_AEAD(\p alg) is true). 451 * \param input_length Size of the input in bytes. 452 * 453 * \return A sufficient output buffer size for the specified 454 * algorithm. 455 * If the key type or AEAD algorithm is not 456 * recognized, or the parameters are incompatible, 457 * return 0. 458 */ 459 /* For all the AEAD modes defined in this specification, it is possible 460 * to emit output without delay. However, hardware may not always be 461 * capable of this. So for modes based on a block cipher, allow the 462 * implementation to delay the output until it has a full block. */ 463 #define PSA_AEAD_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 464 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 465 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 466 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), (input_length)) : \ 467 (input_length) : \ 468 0) 469 470 /** A sufficient output buffer size for psa_aead_update(), for any of the 471 * supported key types and AEAD algorithms. 472 * 473 * If the size of the output buffer is at least this large, it is guaranteed 474 * that psa_aead_update() will not fail due to an insufficient buffer size. 475 * 476 * See also #PSA_AEAD_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 477 * 478 * \param input_length Size of the input in bytes. 479 */ 480 #define PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 481 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length))) 482 483 /** A sufficient ciphertext buffer size for psa_aead_finish(). 484 * 485 * If the size of the ciphertext buffer is at least this large, it is 486 * guaranteed that psa_aead_finish() will not fail due to an 487 * insufficient ciphertext buffer size. The actual size of the output may 488 * be smaller in any given call. 489 * 490 * See also #PSA_AEAD_FINISH_OUTPUT_MAX_SIZE. 491 * 492 * \param key_type A symmetric key type that is 493 compatible with algorithm \p alg. 494 * \param alg An AEAD algorithm 495 * (\c PSA_ALG_XXX value such that 496 * #PSA_ALG_IS_AEAD(\p alg) is true). 497 * 498 * \return A sufficient ciphertext buffer size for the 499 * specified algorithm. 500 * If the key type or AEAD algorithm is not 501 * recognized, or the parameters are incompatible, 502 * return 0. 503 */ 504 #define PSA_AEAD_FINISH_OUTPUT_SIZE(key_type, alg) \ 505 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 506 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 507 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 508 0) 509 510 /** A sufficient ciphertext buffer size for psa_aead_finish(), for any of the 511 * supported key types and AEAD algorithms. 512 * 513 * See also #PSA_AEAD_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 514 */ 515 #define PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 516 517 /** A sufficient plaintext buffer size for psa_aead_verify(). 518 * 519 * If the size of the plaintext buffer is at least this large, it is 520 * guaranteed that psa_aead_verify() will not fail due to an 521 * insufficient plaintext buffer size. The actual size of the output may 522 * be smaller in any given call. 523 * 524 * See also #PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE. 525 * 526 * \param key_type A symmetric key type that is 527 * compatible with algorithm \p alg. 528 * \param alg An AEAD algorithm 529 * (\c PSA_ALG_XXX value such that 530 * #PSA_ALG_IS_AEAD(\p alg) is true). 531 * 532 * \return A sufficient plaintext buffer size for the 533 * specified algorithm. 534 * If the key type or AEAD algorithm is not 535 * recognized, or the parameters are incompatible, 536 * return 0. 537 */ 538 #define PSA_AEAD_VERIFY_OUTPUT_SIZE(key_type, alg) \ 539 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 540 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 541 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 542 0) 543 544 /** A sufficient plaintext buffer size for psa_aead_verify(), for any of the 545 * supported key types and AEAD algorithms. 546 * 547 * See also #PSA_AEAD_VERIFY_OUTPUT_SIZE(\p key_type, \p alg). 548 */ 549 #define PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 550 551 #define PSA_RSA_MINIMUM_PADDING_SIZE(alg) \ 552 (PSA_ALG_IS_RSA_OAEP(alg) ? \ 553 2 * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1 : \ 554 11 /*PKCS#1v1.5*/) 555 556 /** 557 * \brief ECDSA signature size for a given curve bit size 558 * 559 * \param curve_bits Curve size in bits. 560 * \return Signature size in bytes. 561 * 562 * \note This macro returns a compile-time constant if its argument is one. 563 */ 564 #define PSA_ECDSA_SIGNATURE_SIZE(curve_bits) \ 565 (PSA_BITS_TO_BYTES(curve_bits) * 2) 566 567 /** Sufficient signature buffer size for psa_sign_hash(). 568 * 569 * This macro returns a sufficient buffer size for a signature using a key 570 * of the specified type and size, with the specified algorithm. 571 * Note that the actual size of the signature may be smaller 572 * (some algorithms produce a variable-size signature). 573 * 574 * \warning This function may call its arguments multiple times or 575 * zero times, so you should not pass arguments that contain 576 * side effects. 577 * 578 * \param key_type An asymmetric key type (this may indifferently be a 579 * key pair type or a public key type). 580 * \param key_bits The size of the key in bits. 581 * \param alg The signature algorithm. 582 * 583 * \return If the parameters are valid and supported, return 584 * a buffer size in bytes that guarantees that 585 * psa_sign_hash() will not fail with 586 * #PSA_ERROR_BUFFER_TOO_SMALL. 587 * If the parameters are a valid combination that is not supported, 588 * return either a sensible size or 0. 589 * If the parameters are not valid, the 590 * return value is unspecified. 591 */ 592 #define PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \ 593 (PSA_KEY_TYPE_IS_RSA(key_type) ? ((void)alg, PSA_BITS_TO_BYTES(key_bits)) : \ 594 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \ 595 ((void)alg, 0)) 596 597 #define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE \ 598 PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 599 600 /** \def PSA_SIGNATURE_MAX_SIZE 601 * 602 * Maximum size of an asymmetric signature. 603 * 604 * This macro expands to a compile-time constant integer. This value 605 * is the maximum size of a signature in bytes. 606 */ 607 #define PSA_SIGNATURE_MAX_SIZE \ 608 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE ? \ 609 PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 610 PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE) 611 612 /** Sufficient output buffer size for psa_asymmetric_encrypt(). 613 * 614 * This macro returns a sufficient buffer size for a ciphertext produced using 615 * a key of the specified type and size, with the specified algorithm. 616 * Note that the actual size of the ciphertext may be smaller, depending 617 * on the algorithm. 618 * 619 * \warning This function may call its arguments multiple times or 620 * zero times, so you should not pass arguments that contain 621 * side effects. 622 * 623 * \param key_type An asymmetric key type (this may indifferently be a 624 * key pair type or a public key type). 625 * \param key_bits The size of the key in bits. 626 * \param alg The asymmetric encryption algorithm. 627 * 628 * \return If the parameters are valid and supported, return 629 * a buffer size in bytes that guarantees that 630 * psa_asymmetric_encrypt() will not fail with 631 * #PSA_ERROR_BUFFER_TOO_SMALL. 632 * If the parameters are a valid combination that is not supported, 633 * return either a sensible size or 0. 634 * If the parameters are not valid, the 635 * return value is unspecified. 636 */ 637 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 638 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 639 ((void)alg, PSA_BITS_TO_BYTES(key_bits)) : \ 640 0) 641 642 /** A sufficient output buffer size for psa_asymmetric_encrypt(), for any 643 * supported asymmetric encryption. 644 * 645 * See also #PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 646 */ 647 /* This macro assumes that RSA is the only supported asymmetric encryption. */ 648 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE \ 649 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 650 651 /** Sufficient output buffer size for psa_asymmetric_decrypt(). 652 * 653 * This macro returns a sufficient buffer size for a plaintext produced using 654 * a key of the specified type and size, with the specified algorithm. 655 * Note that the actual size of the plaintext may be smaller, depending 656 * on the algorithm. 657 * 658 * \warning This function may call its arguments multiple times or 659 * zero times, so you should not pass arguments that contain 660 * side effects. 661 * 662 * \param key_type An asymmetric key type (this may indifferently be a 663 * key pair type or a public key type). 664 * \param key_bits The size of the key in bits. 665 * \param alg The asymmetric encryption algorithm. 666 * 667 * \return If the parameters are valid and supported, return 668 * a buffer size in bytes that guarantees that 669 * psa_asymmetric_decrypt() will not fail with 670 * #PSA_ERROR_BUFFER_TOO_SMALL. 671 * If the parameters are a valid combination that is not supported, 672 * return either a sensible size or 0. 673 * If the parameters are not valid, the 674 * return value is unspecified. 675 */ 676 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 677 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 678 PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \ 679 0) 680 681 /** A sufficient output buffer size for psa_asymmetric_decrypt(), for any 682 * supported asymmetric decryption. 683 * 684 * This macro assumes that RSA is the only supported asymmetric encryption. 685 * 686 * See also #PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 687 */ 688 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE \ 689 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 690 691 /* Maximum size of the ASN.1 encoding of an INTEGER with the specified 692 * number of bits. 693 * 694 * This definition assumes that bits <= 2^19 - 9 so that the length field 695 * is at most 3 bytes. The length of the encoding is the length of the 696 * bit string padded to a whole number of bytes plus: 697 * - 1 type byte; 698 * - 1 to 3 length bytes; 699 * - 0 to 1 bytes of leading 0 due to the sign bit. 700 */ 701 #define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \ 702 ((bits) / 8 + 5) 703 704 /* Maximum size of the export encoding of an RSA public key. 705 * Assumes that the public exponent is less than 2^32. 706 * 707 * RSAPublicKey ::= SEQUENCE { 708 * modulus INTEGER, -- n 709 * publicExponent INTEGER } -- e 710 * 711 * - 4 bytes of SEQUENCE overhead; 712 * - n : INTEGER; 713 * - 7 bytes for the public exponent. 714 */ 715 #define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 716 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11) 717 718 /* Maximum size of the export encoding of an RSA key pair. 719 * Assumes thatthe public exponent is less than 2^32 and that the size 720 * difference between the two primes is at most 1 bit. 721 * 722 * RSAPrivateKey ::= SEQUENCE { 723 * version Version, -- 0 724 * modulus INTEGER, -- N-bit 725 * publicExponent INTEGER, -- 32-bit 726 * privateExponent INTEGER, -- N-bit 727 * prime1 INTEGER, -- N/2-bit 728 * prime2 INTEGER, -- N/2-bit 729 * exponent1 INTEGER, -- N/2-bit 730 * exponent2 INTEGER, -- N/2-bit 731 * coefficient INTEGER, -- N/2-bit 732 * } 733 * 734 * - 4 bytes of SEQUENCE overhead; 735 * - 3 bytes of version; 736 * - 7 half-size INTEGERs plus 2 full-size INTEGERs, 737 * overapproximated as 9 half-size INTEGERS; 738 * - 7 bytes for the public exponent. 739 */ 740 #define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) \ 741 (9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14) 742 743 /* Maximum size of the export encoding of a DSA public key. 744 * 745 * SubjectPublicKeyInfo ::= SEQUENCE { 746 * algorithm AlgorithmIdentifier, 747 * subjectPublicKey BIT STRING } -- contains DSAPublicKey 748 * AlgorithmIdentifier ::= SEQUENCE { 749 * algorithm OBJECT IDENTIFIER, 750 * parameters Dss-Parms } -- SEQUENCE of 3 INTEGERs 751 * DSAPublicKey ::= INTEGER -- public key, Y 752 * 753 * - 3 * 4 bytes of SEQUENCE overhead; 754 * - 1 + 1 + 7 bytes of algorithm (DSA OID); 755 * - 4 bytes of BIT STRING overhead; 756 * - 3 full-size INTEGERs (p, g, y); 757 * - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits). 758 */ 759 #define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 760 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 59) 761 762 /* Maximum size of the export encoding of a DSA key pair. 763 * 764 * DSAPrivateKey ::= SEQUENCE { 765 * version Version, -- 0 766 * prime INTEGER, -- p 767 * subprime INTEGER, -- q 768 * generator INTEGER, -- g 769 * public INTEGER, -- y 770 * private INTEGER, -- x 771 * } 772 * 773 * - 4 bytes of SEQUENCE overhead; 774 * - 3 bytes of version; 775 * - 3 full-size INTEGERs (p, g, y); 776 * - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits). 777 */ 778 #define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) \ 779 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 75) 780 781 /* Maximum size of the export encoding of an ECC public key. 782 * 783 * The representation of an ECC public key is: 784 * - The byte 0x04; 785 * - `x_P` as a `ceiling(m/8)`-byte string, big-endian; 786 * - `y_P` as a `ceiling(m/8)`-byte string, big-endian; 787 * - where m is the bit size associated with the curve. 788 * 789 * - 1 byte + 2 * point size. 790 */ 791 #define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \ 792 (2 * PSA_BITS_TO_BYTES(key_bits) + 1) 793 794 /* Maximum size of the export encoding of an ECC key pair. 795 * 796 * An ECC key pair is represented by the secret value. 797 */ 798 #define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) \ 799 (PSA_BITS_TO_BYTES(key_bits)) 800 801 /** Sufficient output buffer size for psa_export_key() or 802 * psa_export_public_key(). 803 * 804 * This macro returns a compile-time constant if its arguments are 805 * compile-time constants. 806 * 807 * \warning This macro may evaluate its arguments multiple times or 808 * zero times, so you should not pass arguments that contain 809 * side effects. 810 * 811 * The following code illustrates how to allocate enough memory to export 812 * a key by querying the key type and size at runtime. 813 * \code{c} 814 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 815 * psa_status_t status; 816 * status = psa_get_key_attributes(key, &attributes); 817 * if (status != PSA_SUCCESS) handle_error(...); 818 * psa_key_type_t key_type = psa_get_key_type(&attributes); 819 * size_t key_bits = psa_get_key_bits(&attributes); 820 * size_t buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits); 821 * psa_reset_key_attributes(&attributes); 822 * uint8_t *buffer = malloc(buffer_size); 823 * if (buffer == NULL) handle_error(...); 824 * size_t buffer_length; 825 * status = psa_export_key(key, buffer, buffer_size, &buffer_length); 826 * if (status != PSA_SUCCESS) handle_error(...); 827 * \endcode 828 * 829 * \param key_type A supported key type. 830 * \param key_bits The size of the key in bits. 831 * 832 * \return If the parameters are valid and supported, return 833 * a buffer size in bytes that guarantees that 834 * psa_export_key() or psa_export_public_key() will not fail with 835 * #PSA_ERROR_BUFFER_TOO_SMALL. 836 * If the parameters are a valid combination that is not supported, 837 * return either a sensible size or 0. 838 * If the parameters are not valid, the return value is unspecified. 839 */ 840 #define PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits) \ 841 (PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 842 (key_type) == PSA_KEY_TYPE_RSA_KEY_PAIR ? PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 843 (key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 844 (key_type) == PSA_KEY_TYPE_DSA_KEY_PAIR ? PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 845 (key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 846 PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) : \ 847 PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 848 0) 849 850 /** Sufficient output buffer size for psa_export_public_key(). 851 * 852 * This macro returns a compile-time constant if its arguments are 853 * compile-time constants. 854 * 855 * \warning This macro may evaluate its arguments multiple times or 856 * zero times, so you should not pass arguments that contain 857 * side effects. 858 * 859 * The following code illustrates how to allocate enough memory to export 860 * a public key by querying the key type and size at runtime. 861 * \code{c} 862 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 863 * psa_status_t status; 864 * status = psa_get_key_attributes(key, &attributes); 865 * if (status != PSA_SUCCESS) handle_error(...); 866 * psa_key_type_t key_type = psa_get_key_type(&attributes); 867 * size_t key_bits = psa_get_key_bits(&attributes); 868 * size_t buffer_size = PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits); 869 * psa_reset_key_attributes(&attributes); 870 * uint8_t *buffer = malloc(buffer_size); 871 * if (buffer == NULL) handle_error(...); 872 * size_t buffer_length; 873 * status = psa_export_public_key(key, buffer, buffer_size, &buffer_length); 874 * if (status != PSA_SUCCESS) handle_error(...); 875 * \endcode 876 * 877 * \param key_type A public key or key pair key type. 878 * \param key_bits The size of the key in bits. 879 * 880 * \return If the parameters are valid and supported, return 881 * a buffer size in bytes that guarantees that 882 * psa_export_public_key() will not fail with 883 * #PSA_ERROR_BUFFER_TOO_SMALL. 884 * If the parameters are a valid combination that is not 885 * supported, return either a sensible size or 0. 886 * If the parameters are not valid, 887 * the return value is unspecified. 888 * 889 * If the parameters are valid and supported, 890 * return the same result as 891 * #PSA_EXPORT_KEY_OUTPUT_SIZE( 892 * \p #PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(\p key_type), 893 * \p key_bits). 894 */ 895 #define PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits) \ 896 (PSA_KEY_TYPE_IS_RSA(key_type) ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 897 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 898 0) 899 900 /** Sufficient buffer size for exporting any asymmetric key pair. 901 * 902 * This macro expands to a compile-time constant integer. This value is 903 * a sufficient buffer size when calling psa_export_key() to export any 904 * asymmetric key pair, regardless of the exact key type and key size. 905 * 906 * See also #PSA_EXPORT_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 907 */ 908 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 909 (PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 910 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ? \ 911 PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 912 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 913 914 /** Sufficient buffer size for exporting any asymmetric public key. 915 * 916 * This macro expands to a compile-time constant integer. This value is 917 * a sufficient buffer size when calling psa_export_key() or 918 * psa_export_public_key() to export any asymmetric public key, 919 * regardless of the exact key type and key size. 920 * 921 * See also #PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 922 */ 923 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 924 (PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 925 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ? \ 926 PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 927 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 928 929 /** Sufficient output buffer size for psa_raw_key_agreement(). 930 * 931 * This macro returns a compile-time constant if its arguments are 932 * compile-time constants. 933 * 934 * \warning This macro may evaluate its arguments multiple times or 935 * zero times, so you should not pass arguments that contain 936 * side effects. 937 * 938 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE. 939 * 940 * \param key_type A supported key type. 941 * \param key_bits The size of the key in bits. 942 * 943 * \return If the parameters are valid and supported, return 944 * a buffer size in bytes that guarantees that 945 * psa_raw_key_agreement() will not fail with 946 * #PSA_ERROR_BUFFER_TOO_SMALL. 947 * If the parameters are a valid combination that 948 * is not supported, return either a sensible size or 0. 949 * If the parameters are not valid, 950 * the return value is unspecified. 951 */ 952 /* FFDH is not yet supported in PSA. */ 953 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits) \ 954 (PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? \ 955 PSA_BITS_TO_BYTES(key_bits) : \ 956 0) 957 958 /** Maximum size of the output from psa_raw_key_agreement(). 959 * 960 * This macro expands to a compile-time constant integer. This value is the 961 * maximum size of the output any raw key agreement algorithm, in bytes. 962 * 963 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(\p key_type, \p key_bits). 964 */ 965 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE \ 966 (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 967 968 /** The default IV size for a cipher algorithm, in bytes. 969 * 970 * The IV that is generated as part of a call to #psa_cipher_encrypt() is always 971 * the default IV length for the algorithm. 972 * 973 * This macro can be used to allocate a buffer of sufficient size to 974 * store the IV output from #psa_cipher_generate_iv() when using 975 * a multi-part cipher operation. 976 * 977 * See also #PSA_CIPHER_IV_MAX_SIZE. 978 * 979 * \warning This macro may evaluate its arguments multiple times or 980 * zero times, so you should not pass arguments that contain 981 * side effects. 982 * 983 * \param key_type A symmetric key type that is compatible with algorithm \p alg. 984 * 985 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true). 986 * 987 * \return The default IV size for the specified key type and algorithm. 988 * If the algorithm does not use an IV, return 0. 989 * If the key type or cipher algorithm is not recognized, 990 * or the parameters are incompatible, return 0. 991 */ 992 #define PSA_CIPHER_IV_LENGTH(key_type, alg) \ 993 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1 && \ 994 ((alg) == PSA_ALG_CTR || \ 995 (alg) == PSA_ALG_CFB || \ 996 (alg) == PSA_ALG_OFB || \ 997 (alg) == PSA_ALG_XTS || \ 998 (alg) == PSA_ALG_CBC_NO_PADDING || \ 999 (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1000 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 1001 (alg) == PSA_ALG_STREAM_CIPHER ? 12 : \ 1002 0) 1003 1004 /** The maximum IV size for all supported cipher algorithms, in bytes. 1005 * 1006 * See also #PSA_CIPHER_IV_LENGTH(). 1007 */ 1008 #define PSA_CIPHER_IV_MAX_SIZE 16 1009 1010 /** The maximum size of the output of psa_cipher_encrypt(), in bytes. 1011 * 1012 * If the size of the output buffer is at least this large, it is guaranteed 1013 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1014 * Depending on the algorithm, the actual size of the output might be smaller. 1015 * 1016 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(\p input_length). 1017 * 1018 * \warning This macro may evaluate its arguments multiple times or 1019 * zero times, so you should not pass arguments that contain 1020 * side effects. 1021 * 1022 * \param key_type A symmetric key type that is compatible with algorithm 1023 * alg. 1024 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1025 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1026 * \param input_length Size of the input in bytes. 1027 * 1028 * \return A sufficient output size for the specified key type and 1029 * algorithm. If the key type or cipher algorithm is not 1030 * recognized, or the parameters are incompatible, 1031 * return 0. 1032 */ 1033 #define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1034 (alg == PSA_ALG_CBC_PKCS7 ? \ 1035 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1036 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1037 (input_length) + 1) + \ 1038 PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0) : \ 1039 (PSA_ALG_IS_CIPHER(alg) ? \ 1040 (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) : \ 1041 0)) 1042 1043 /** A sufficient output buffer size for psa_cipher_encrypt(), for any of the 1044 * supported key types and cipher algorithms. 1045 * 1046 * If the size of the output buffer is at least this large, it is guaranteed 1047 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1048 * 1049 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1050 * 1051 * \param input_length Size of the input in bytes. 1052 * 1053 */ 1054 #define PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(input_length) \ 1055 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, \ 1056 (input_length) + 1) + \ 1057 PSA_CIPHER_IV_MAX_SIZE) 1058 1059 /** The maximum size of the output of psa_cipher_decrypt(), in bytes. 1060 * 1061 * If the size of the output buffer is at least this large, it is guaranteed 1062 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1063 * Depending on the algorithm, the actual size of the output might be smaller. 1064 * 1065 * See also #PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(\p input_length). 1066 * 1067 * \param key_type A symmetric key type that is compatible with algorithm 1068 * alg. 1069 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1070 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1071 * \param input_length Size of the input in bytes. 1072 * 1073 * \return A sufficient output size for the specified key type and 1074 * algorithm. If the key type or cipher algorithm is not 1075 * recognized, or the parameters are incompatible, 1076 * return 0. 1077 */ 1078 #define PSA_CIPHER_DECRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1079 (PSA_ALG_IS_CIPHER(alg) && \ 1080 ((key_type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \ 1081 (input_length) : \ 1082 0) 1083 1084 /** A sufficient output buffer size for psa_cipher_decrypt(), for any of the 1085 * supported key types and cipher algorithms. 1086 * 1087 * If the size of the output buffer is at least this large, it is guaranteed 1088 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1089 * 1090 * See also #PSA_CIPHER_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1091 * 1092 * \param input_length Size of the input in bytes. 1093 */ 1094 #define PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(input_length) \ 1095 (input_length) 1096 1097 /** A sufficient output buffer size for psa_cipher_update(). 1098 * 1099 * If the size of the output buffer is at least this large, it is guaranteed 1100 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1101 * The actual size of the output might be smaller in any given call. 1102 * 1103 * See also #PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 1104 * 1105 * \param key_type A symmetric key type that is compatible with algorithm 1106 * alg. 1107 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1108 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1109 * \param input_length Size of the input in bytes. 1110 * 1111 * \return A sufficient output size for the specified key type and 1112 * algorithm. If the key type or cipher algorithm is not 1113 * recognized, or the parameters are incompatible, return 0. 1114 */ 1115 #define PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 1116 (PSA_ALG_IS_CIPHER(alg) ? \ 1117 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1118 (((alg) == PSA_ALG_CBC_PKCS7 || \ 1119 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1120 (alg) == PSA_ALG_ECB_NO_PADDING) ? \ 1121 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1122 input_length) : \ 1123 (input_length)) : 0) : \ 1124 0) 1125 1126 /** A sufficient output buffer size for psa_cipher_update(), for any of the 1127 * supported key types and cipher algorithms. 1128 * 1129 * If the size of the output buffer is at least this large, it is guaranteed 1130 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1131 * 1132 * See also #PSA_CIPHER_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1133 * 1134 * \param input_length Size of the input in bytes. 1135 */ 1136 #define PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 1137 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length)) 1138 1139 /** A sufficient ciphertext buffer size for psa_cipher_finish(). 1140 * 1141 * If the size of the ciphertext buffer is at least this large, it is 1142 * guaranteed that psa_cipher_finish() will not fail due to an insufficient 1143 * ciphertext buffer size. The actual size of the output might be smaller in 1144 * any given call. 1145 * 1146 * See also #PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE(). 1147 * 1148 * \param key_type A symmetric key type that is compatible with algorithm 1149 * alg. 1150 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1151 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1152 * \return A sufficient output size for the specified key type and 1153 * algorithm. If the key type or cipher algorithm is not 1154 * recognized, or the parameters are incompatible, return 0. 1155 */ 1156 #define PSA_CIPHER_FINISH_OUTPUT_SIZE(key_type, alg) \ 1157 (PSA_ALG_IS_CIPHER(alg) ? \ 1158 (alg == PSA_ALG_CBC_PKCS7 ? \ 1159 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1160 0) : \ 1161 0) 1162 1163 /** A sufficient ciphertext buffer size for psa_cipher_finish(), for any of the 1164 * supported key types and cipher algorithms. 1165 * 1166 * See also #PSA_CIPHER_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 1167 */ 1168 #define PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE \ 1169 (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 1170 1171 #endif /* PSA_CRYPTO_SIZES_H */ 1172
