1 /* 2 * Copyright (c) 2018-2023, Arm Limited. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 */ 7 /** 8 * \file psa/crypto_sizes.h 9 * 10 * \brief PSA cryptography module: Mbed TLS buffer size macros 11 * 12 * \note This file may not be included directly. Applications must 13 * include psa/crypto.h. 14 * 15 * This file contains the definitions of macros that are useful to 16 * compute buffer sizes. The signatures and semantics of these macros 17 * are standardized, but the definitions are not, because they depend on 18 * the available algorithms and, in some cases, on permitted tolerances 19 * on buffer sizes. 20 * 21 * In implementations with isolation between the application and the 22 * cryptography module, implementers should take care to ensure that 23 * the definitions that are exposed to applications match what the 24 * module implements. 25 * 26 * Macros that compute sizes whose values do not depend on the 27 * implementation are in crypto.h. 28 */ 29 30 #ifndef PSA_CRYPTO_SIZES_H 31 #define PSA_CRYPTO_SIZES_H 32 33 #define PSA_BITS_TO_BYTES(bits) (((bits) + 7) / 8) 34 #define PSA_BYTES_TO_BITS(bytes) ((bytes) * 8) 35 36 #define PSA_ROUND_UP_TO_MULTIPLE(block_size, length) \ 37 (((length) + (block_size) - 1) / (block_size) * (block_size)) 38 39 /** The size of the output of psa_hash_finish(), in bytes. 40 * 41 * This is also the hash size that psa_hash_verify() expects. 42 * 43 * \param alg A hash algorithm (\c PSA_ALG_XXX value such that 44 * #PSA_ALG_IS_HASH(\p alg) is true), or an HMAC algorithm 45 * (#PSA_ALG_HMAC(\c hash_alg) where \c hash_alg is a 46 * hash algorithm). 47 * 48 * \return The hash size for the specified hash algorithm. 49 * If the hash algorithm is not recognized, return 0. 50 */ 51 #define PSA_HASH_LENGTH(alg) \ 52 ( \ 53 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 16 : \ 54 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 20 : \ 55 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 20 : \ 56 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 28 : \ 57 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 32 : \ 58 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 48 : \ 59 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 64 : \ 60 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 28 : \ 61 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 32 : \ 62 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 28 : \ 63 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 32 : \ 64 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 48 : \ 65 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 64 : \ 66 0) 67 68 /** The input block size of a hash algorithm, in bytes. 69 * 70 * Hash algorithms process their input data in blocks. Hash operations will 71 * retain any partial blocks until they have enough input to fill the block or 72 * until the operation is finished. 73 * This affects the output from psa_hash_suspend(). 74 * 75 * \param alg A hash algorithm (\c PSA_ALG_XXX value such that 76 * PSA_ALG_IS_HASH(\p alg) is true). 77 * 78 * \return The block size in bytes for the specified hash algorithm. 79 * If the hash algorithm is not recognized, return 0. 80 * An implementation can return either 0 or the correct size for a 81 * hash algorithm that it recognizes, but does not support. 82 */ 83 #define PSA_HASH_BLOCK_LENGTH(alg) \ 84 ( \ 85 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 64 : \ 86 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 64 : \ 87 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 64 : \ 88 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 64 : \ 89 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 64 : \ 90 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 128 : \ 91 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 128 : \ 92 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 128 : \ 93 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 128 : \ 94 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 144 : \ 95 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 136 : \ 96 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 104 : \ 97 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 72 : \ 98 0) 99 100 /** \def PSA_HASH_MAX_SIZE 101 * 102 * Maximum size of a hash. 103 * 104 * This macro expands to a compile-time constant integer. This value 105 * is the maximum size of a hash in bytes. 106 */ 107 /* Note: for HMAC-SHA-3, the block size is 144 bytes for HMAC-SHA3-226, 108 * 136 bytes for HMAC-SHA3-256, 104 bytes for SHA3-384, 72 bytes for 109 * HMAC-SHA3-512. */ 110 #if defined(PSA_WANT_ALG_SHA_512) || defined(PSA_WANT_ALG_SHA_384) 111 #define PSA_HASH_MAX_SIZE 64 112 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128 113 #else 114 #define PSA_HASH_MAX_SIZE 32 115 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64 116 #endif 117 118 /** \def PSA_MAC_MAX_SIZE 119 * 120 * Maximum size of a MAC. 121 * 122 * This macro expands to a compile-time constant integer. This value 123 * is the maximum size of a MAC in bytes. 124 */ 125 /* All non-HMAC MACs have a maximum size that's smaller than the 126 * minimum possible value of PSA_HASH_MAX_SIZE in this implementation. */ 127 /* Note that the encoding of truncated MAC algorithms limits this value 128 * to 64 bytes. 129 */ 130 #define PSA_MAC_MAX_SIZE PSA_HASH_MAX_SIZE 131 132 /** The length of a tag for an AEAD algorithm, in bytes. 133 * 134 * This macro can be used to allocate a buffer of sufficient size to store the 135 * tag output from psa_aead_finish(). 136 * 137 * See also #PSA_AEAD_TAG_MAX_SIZE. 138 * 139 * \param key_type The type of the AEAD key. 140 * \param key_bits The size of the AEAD key in bits. 141 * \param alg An AEAD algorithm 142 * (\c PSA_ALG_XXX value such that 143 * #PSA_ALG_IS_AEAD(\p alg) is true). 144 * 145 * \return The tag length for the specified algorithm and key. 146 * If the AEAD algorithm does not have an identified 147 * tag that can be distinguished from the rest of 148 * the ciphertext, return 0. 149 * If the key type or AEAD algorithm is not 150 * recognized, or the parameters are incompatible, 151 * return 0. 152 */ 153 #define PSA_AEAD_TAG_LENGTH(key_type, key_bits, alg) \ 154 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 155 PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 156 ((void) (key_bits), 0)) 157 158 /** The maximum tag size for all supported AEAD algorithms, in bytes. 159 * 160 * See also #PSA_AEAD_TAG_LENGTH(\p key_type, \p key_bits, \p alg). 161 */ 162 #define PSA_AEAD_TAG_MAX_SIZE 16 163 164 /* The maximum size of an RSA key on this implementation, in bits. 165 * This is a vendor-specific macro. 166 * 167 * Mbed TLS does not set a hard limit on the size of RSA keys: any key 168 * whose parameters fit in a bignum is accepted. However large keys can 169 * induce a large memory usage and long computation times. Unlike other 170 * auxiliary macros in this file and in crypto.h, which reflect how the 171 * library is configured, this macro defines how the library is 172 * configured. This implementation refuses to import or generate an 173 * RSA key whose size is larger than the value defined here. 174 * 175 * Note that an implementation may set different size limits for different 176 * operations, and does not need to accept all key sizes up to the limit. */ 177 #define PSA_VENDOR_RSA_MAX_KEY_BITS 4096 178 179 /* The maximum size of an ECC key on this implementation, in bits. 180 * This is a vendor-specific macro. */ 181 #if defined(MBEDTLS_PSA_CRYPTO_CONFIG) 182 #if defined(MBEDTLS_PSA_CRYPTO_CONFIG_FILE) 183 #include MBEDTLS_PSA_CRYPTO_CONFIG_FILE 184 #else 185 #include "crypto_config.h" 186 #endif 187 #if defined(PSA_WANT_ECC_SECP_R1_521) 188 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 521 189 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_512) 190 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 512 191 #elif defined(PSA_WANT_ECC_MONTGOMERY_448) 192 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 448 193 #elif defined(PSA_WANT_ECC_SECP_R1_384) 194 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384 195 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_384) 196 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384 197 #elif defined(PSA_WANT_ECC_SECP_R1_256) 198 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 199 #elif defined(PSA_WANT_ECC_SECP_K1_256) 200 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 201 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_256) 202 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 203 #elif defined(PSA_WANT_ECC_MONTGOMERY_255) 204 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 255 205 #elif defined(PSA_WANT_ECC_SECP_R1_224) 206 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224 207 #elif defined(PSA_WANT_ECC_SECP_K1_224) 208 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224 209 #elif defined(PSA_WANT_ECC_SECP_R1_192) 210 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192 211 #elif defined(PSA_WANT_ECC_SECP_K1_192) 212 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192 213 #else 214 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 0 215 #endif 216 #else /* defined(MBEDTLS_PSA_CRYPTO_CONFIG) */ 217 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 521 218 #endif /* defined(MBEDTLS_PSA_CRYPTO_CONFIG) */ 219 220 /** This macro returns the maximum supported length of the PSK for the 221 * TLS-1.2 PSK-to-MS key derivation 222 * (#PSA_ALG_TLS12_PSK_TO_MS(\c hash_alg)). 223 * 224 * The maximum supported length does not depend on the chosen hash algorithm. 225 * 226 * Quoting RFC 4279, Sect 5.3: 227 * TLS implementations supporting these ciphersuites MUST support 228 * arbitrary PSK identities up to 128 octets in length, and arbitrary 229 * PSKs up to 64 octets in length. Supporting longer identities and 230 * keys is RECOMMENDED. 231 * 232 * Therefore, no implementation should define a value smaller than 64 233 * for #PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE. 234 */ 235 #define PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128 236 237 /* The expected size of input passed to psa_tls12_ecjpake_to_pms_input, 238 * which is expected to work with P-256 curve only. */ 239 #define PSA_TLS12_ECJPAKE_TO_PMS_INPUT_SIZE 65 240 241 /* The size of a serialized K.X coordinate to be used in 242 * psa_tls12_ecjpake_to_pms_input. This function only accepts the P-256 243 * curve. */ 244 #define PSA_TLS12_ECJPAKE_TO_PMS_DATA_SIZE 32 245 246 /** The maximum size of a block cipher. */ 247 #define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16 248 249 /** The size of the output of psa_mac_sign_finish(), in bytes. 250 * 251 * This is also the MAC size that psa_mac_verify_finish() expects. 252 * 253 * \warning This macro may evaluate its arguments multiple times or 254 * zero times, so you should not pass arguments that contain 255 * side effects. 256 * 257 * \param key_type The type of the MAC key. 258 * \param key_bits The size of the MAC key in bits. 259 * \param alg A MAC algorithm (\c PSA_ALG_XXX value such that 260 * #PSA_ALG_IS_MAC(\p alg) is true). 261 * 262 * \return The MAC size for the specified algorithm with 263 * the specified key parameters. 264 * \return 0 if the MAC algorithm is not recognized. 265 * \return Either 0 or the correct size for a MAC algorithm that 266 * the implementation recognizes, but does not support. 267 * \return Unspecified if the key parameters are not consistent 268 * with the algorithm. 269 */ 270 #define PSA_MAC_LENGTH(key_type, key_bits, alg) \ 271 ((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \ 272 PSA_ALG_IS_HMAC(alg) ? PSA_HASH_LENGTH(PSA_ALG_HMAC_GET_HASH(alg)) : \ 273 PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 274 ((void) (key_type), (void) (key_bits), 0)) 275 276 /** The maximum size of the output of psa_aead_encrypt(), in bytes. 277 * 278 * If the size of the ciphertext buffer is at least this large, it is 279 * guaranteed that psa_aead_encrypt() will not fail due to an 280 * insufficient buffer size. Depending on the algorithm, the actual size of 281 * the ciphertext may be smaller. 282 * 283 * See also #PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(\p plaintext_length). 284 * 285 * \warning This macro may evaluate its arguments multiple times or 286 * zero times, so you should not pass arguments that contain 287 * side effects. 288 * 289 * \param key_type A symmetric key type that is 290 * compatible with algorithm \p alg. 291 * \param alg An AEAD algorithm 292 * (\c PSA_ALG_XXX value such that 293 * #PSA_ALG_IS_AEAD(\p alg) is true). 294 * \param plaintext_length Size of the plaintext in bytes. 295 * 296 * \return The AEAD ciphertext size for the specified 297 * algorithm. 298 * If the key type or AEAD algorithm is not 299 * recognized, or the parameters are incompatible, 300 * return 0. 301 */ 302 #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length) \ 303 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 304 (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 305 0) 306 307 /** A sufficient output buffer size for psa_aead_encrypt(), for any of the 308 * supported key types and AEAD algorithms. 309 * 310 * If the size of the ciphertext buffer is at least this large, it is guaranteed 311 * that psa_aead_encrypt() will not fail due to an insufficient buffer size. 312 * 313 * \note This macro returns a compile-time constant if its arguments are 314 * compile-time constants. 315 * 316 * See also #PSA_AEAD_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, 317 * \p plaintext_length). 318 * 319 * \param plaintext_length Size of the plaintext in bytes. 320 * 321 * \return A sufficient output buffer size for any of the 322 * supported key types and AEAD algorithms. 323 * 324 */ 325 #define PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length) \ 326 ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE) 327 328 329 /** The maximum size of the output of psa_aead_decrypt(), in bytes. 330 * 331 * If the size of the plaintext buffer is at least this large, it is 332 * guaranteed that psa_aead_decrypt() will not fail due to an 333 * insufficient buffer size. Depending on the algorithm, the actual size of 334 * the plaintext may be smaller. 335 * 336 * See also #PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(\p ciphertext_length). 337 * 338 * \warning This macro may evaluate its arguments multiple times or 339 * zero times, so you should not pass arguments that contain 340 * side effects. 341 * 342 * \param key_type A symmetric key type that is 343 * compatible with algorithm \p alg. 344 * \param alg An AEAD algorithm 345 * (\c PSA_ALG_XXX value such that 346 * #PSA_ALG_IS_AEAD(\p alg) is true). 347 * \param ciphertext_length Size of the plaintext in bytes. 348 * 349 * \return The AEAD ciphertext size for the specified 350 * algorithm. 351 * If the key type or AEAD algorithm is not 352 * recognized, or the parameters are incompatible, 353 * return 0. 354 */ 355 #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length) \ 356 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 357 (ciphertext_length) > PSA_ALG_AEAD_GET_TAG_LENGTH(alg) ? \ 358 (ciphertext_length) - PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 359 0) 360 361 /** A sufficient output buffer size for psa_aead_decrypt(), for any of the 362 * supported key types and AEAD algorithms. 363 * 364 * If the size of the plaintext buffer is at least this large, it is guaranteed 365 * that psa_aead_decrypt() will not fail due to an insufficient buffer size. 366 * 367 * \note This macro returns a compile-time constant if its arguments are 368 * compile-time constants. 369 * 370 * See also #PSA_AEAD_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, 371 * \p ciphertext_length). 372 * 373 * \param ciphertext_length Size of the ciphertext in bytes. 374 * 375 * \return A sufficient output buffer size for any of the 376 * supported key types and AEAD algorithms. 377 * 378 */ 379 #define PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(ciphertext_length) \ 380 (ciphertext_length) 381 382 /** The default nonce size for an AEAD algorithm, in bytes. 383 * 384 * This macro can be used to allocate a buffer of sufficient size to 385 * store the nonce output from #psa_aead_generate_nonce(). 386 * 387 * See also #PSA_AEAD_NONCE_MAX_SIZE. 388 * 389 * \note This is not the maximum size of nonce supported as input to 390 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 391 * just the default size that is generated by #psa_aead_generate_nonce(). 392 * 393 * \warning This macro may evaluate its arguments multiple times or 394 * zero times, so you should not pass arguments that contain 395 * side effects. 396 * 397 * \param key_type A symmetric key type that is compatible with 398 * algorithm \p alg. 399 * 400 * \param alg An AEAD algorithm (\c PSA_ALG_XXX value such that 401 * #PSA_ALG_IS_AEAD(\p alg) is true). 402 * 403 * \return The default nonce size for the specified key type and algorithm. 404 * If the key type or AEAD algorithm is not recognized, 405 * or the parameters are incompatible, return 0. 406 */ 407 #define PSA_AEAD_NONCE_LENGTH(key_type, alg) \ 408 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \ 409 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CCM) ? 13 : \ 410 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_GCM) ? 12 : \ 411 0 : \ 412 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 413 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12 : \ 414 0) 415 416 /** The maximum default nonce size among all supported pairs of key types and 417 * AEAD algorithms, in bytes. 418 * 419 * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH() 420 * may return. 421 * 422 * \note This is not the maximum size of nonce supported as input to 423 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 424 * just the largest size that may be generated by 425 * #psa_aead_generate_nonce(). 426 */ 427 #define PSA_AEAD_NONCE_MAX_SIZE 13 428 429 /** A sufficient output buffer size for psa_aead_update(). 430 * 431 * If the size of the output buffer is at least this large, it is 432 * guaranteed that psa_aead_update() will not fail due to an 433 * insufficient buffer size. The actual size of the output may be smaller 434 * in any given call. 435 * 436 * See also #PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 437 * 438 * \warning This macro may evaluate its arguments multiple times or 439 * zero times, so you should not pass arguments that contain 440 * side effects. 441 * 442 * \param key_type A symmetric key type that is 443 * compatible with algorithm \p alg. 444 * \param alg An AEAD algorithm 445 * (\c PSA_ALG_XXX value such that 446 * #PSA_ALG_IS_AEAD(\p alg) is true). 447 * \param input_length Size of the input in bytes. 448 * 449 * \return A sufficient output buffer size for the specified 450 * algorithm. 451 * If the key type or AEAD algorithm is not 452 * recognized, or the parameters are incompatible, 453 * return 0. 454 */ 455 /* For all the AEAD modes defined in this specification, it is possible 456 * to emit output without delay. However, hardware may not always be 457 * capable of this. So for modes based on a block cipher, allow the 458 * implementation to delay the output until it has a full block. */ 459 #define PSA_AEAD_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 460 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 461 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 462 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), (input_length)) : \ 463 (input_length) : \ 464 0) 465 466 /** A sufficient output buffer size for psa_aead_update(), for any of the 467 * supported key types and AEAD algorithms. 468 * 469 * If the size of the output buffer is at least this large, it is guaranteed 470 * that psa_aead_update() will not fail due to an insufficient buffer size. 471 * 472 * See also #PSA_AEAD_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 473 * 474 * \param input_length Size of the input in bytes. 475 */ 476 #define PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 477 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length))) 478 479 /** A sufficient ciphertext buffer size for psa_aead_finish(). 480 * 481 * If the size of the ciphertext buffer is at least this large, it is 482 * guaranteed that psa_aead_finish() will not fail due to an 483 * insufficient ciphertext buffer size. The actual size of the output may 484 * be smaller in any given call. 485 * 486 * See also #PSA_AEAD_FINISH_OUTPUT_MAX_SIZE. 487 * 488 * \param key_type A symmetric key type that is 489 compatible with algorithm \p alg. 490 * \param alg An AEAD algorithm 491 * (\c PSA_ALG_XXX value such that 492 * #PSA_ALG_IS_AEAD(\p alg) is true). 493 * 494 * \return A sufficient ciphertext buffer size for the 495 * specified algorithm. 496 * If the key type or AEAD algorithm is not 497 * recognized, or the parameters are incompatible, 498 * return 0. 499 */ 500 #define PSA_AEAD_FINISH_OUTPUT_SIZE(key_type, alg) \ 501 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 502 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 503 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 504 0) 505 506 /** A sufficient ciphertext buffer size for psa_aead_finish(), for any of the 507 * supported key types and AEAD algorithms. 508 * 509 * See also #PSA_AEAD_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 510 */ 511 #define PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 512 513 /** A sufficient plaintext buffer size for psa_aead_verify(). 514 * 515 * If the size of the plaintext buffer is at least this large, it is 516 * guaranteed that psa_aead_verify() will not fail due to an 517 * insufficient plaintext buffer size. The actual size of the output may 518 * be smaller in any given call. 519 * 520 * See also #PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE. 521 * 522 * \param key_type A symmetric key type that is 523 * compatible with algorithm \p alg. 524 * \param alg An AEAD algorithm 525 * (\c PSA_ALG_XXX value such that 526 * #PSA_ALG_IS_AEAD(\p alg) is true). 527 * 528 * \return A sufficient plaintext buffer size for the 529 * specified algorithm. 530 * If the key type or AEAD algorithm is not 531 * recognized, or the parameters are incompatible, 532 * return 0. 533 */ 534 #define PSA_AEAD_VERIFY_OUTPUT_SIZE(key_type, alg) \ 535 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 536 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 537 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 538 0) 539 540 /** A sufficient plaintext buffer size for psa_aead_verify(), for any of the 541 * supported key types and AEAD algorithms. 542 * 543 * See also #PSA_AEAD_VERIFY_OUTPUT_SIZE(\p key_type, \p alg). 544 */ 545 #define PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 546 547 #define PSA_RSA_MINIMUM_PADDING_SIZE(alg) \ 548 (PSA_ALG_IS_RSA_OAEP(alg) ? \ 549 2 * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1 : \ 550 11 /*PKCS#1v1.5*/) 551 552 /** 553 * \brief ECDSA signature size for a given curve bit size 554 * 555 * \param curve_bits Curve size in bits. 556 * \return Signature size in bytes. 557 * 558 * \note This macro returns a compile-time constant if its argument is one. 559 */ 560 #define PSA_ECDSA_SIGNATURE_SIZE(curve_bits) \ 561 (PSA_BITS_TO_BYTES(curve_bits) * 2) 562 563 /** Sufficient signature buffer size for psa_sign_hash(). 564 * 565 * This macro returns a sufficient buffer size for a signature using a key 566 * of the specified type and size, with the specified algorithm. 567 * Note that the actual size of the signature may be smaller 568 * (some algorithms produce a variable-size signature). 569 * 570 * \warning This function may call its arguments multiple times or 571 * zero times, so you should not pass arguments that contain 572 * side effects. 573 * 574 * \param key_type An asymmetric key type (this may indifferently be a 575 * key pair type or a public key type). 576 * \param key_bits The size of the key in bits. 577 * \param alg The signature algorithm. 578 * 579 * \return If the parameters are valid and supported, return 580 * a buffer size in bytes that guarantees that 581 * psa_sign_hash() will not fail with 582 * #PSA_ERROR_BUFFER_TOO_SMALL. 583 * If the parameters are a valid combination that is not supported, 584 * return either a sensible size or 0. 585 * If the parameters are not valid, the 586 * return value is unspecified. 587 */ 588 #define PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \ 589 (PSA_KEY_TYPE_IS_RSA(key_type) ? ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \ 590 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \ 591 ((void) alg, 0)) 592 593 #define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE \ 594 PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 595 596 /** \def PSA_SIGNATURE_MAX_SIZE 597 * 598 * Maximum size of an asymmetric signature. 599 * 600 * This macro expands to a compile-time constant integer. This value 601 * is the maximum size of a signature in bytes. 602 */ 603 #define PSA_SIGNATURE_MAX_SIZE \ 604 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE ? \ 605 PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 606 PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE) 607 608 /** Sufficient output buffer size for psa_asymmetric_encrypt(). 609 * 610 * This macro returns a sufficient buffer size for a ciphertext produced using 611 * a key of the specified type and size, with the specified algorithm. 612 * Note that the actual size of the ciphertext may be smaller, depending 613 * on the algorithm. 614 * 615 * \warning This function may call its arguments multiple times or 616 * zero times, so you should not pass arguments that contain 617 * side effects. 618 * 619 * \param key_type An asymmetric key type (this may indifferently be a 620 * key pair type or a public key type). 621 * \param key_bits The size of the key in bits. 622 * \param alg The asymmetric encryption algorithm. 623 * 624 * \return If the parameters are valid and supported, return 625 * a buffer size in bytes that guarantees that 626 * psa_asymmetric_encrypt() will not fail with 627 * #PSA_ERROR_BUFFER_TOO_SMALL. 628 * If the parameters are a valid combination that is not supported, 629 * return either a sensible size or 0. 630 * If the parameters are not valid, the 631 * return value is unspecified. 632 */ 633 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 634 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 635 ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \ 636 0) 637 638 /** A sufficient output buffer size for psa_asymmetric_encrypt(), for any 639 * supported asymmetric encryption. 640 * 641 * See also #PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 642 */ 643 /* This macro assumes that RSA is the only supported asymmetric encryption. */ 644 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE \ 645 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 646 647 /** Sufficient output buffer size for psa_asymmetric_decrypt(). 648 * 649 * This macro returns a sufficient buffer size for a plaintext produced using 650 * a key of the specified type and size, with the specified algorithm. 651 * Note that the actual size of the plaintext may be smaller, depending 652 * on the algorithm. 653 * 654 * \warning This function may call its arguments multiple times or 655 * zero times, so you should not pass arguments that contain 656 * side effects. 657 * 658 * \param key_type An asymmetric key type (this may indifferently be a 659 * key pair type or a public key type). 660 * \param key_bits The size of the key in bits. 661 * \param alg The asymmetric encryption algorithm. 662 * 663 * \return If the parameters are valid and supported, return 664 * a buffer size in bytes that guarantees that 665 * psa_asymmetric_decrypt() will not fail with 666 * #PSA_ERROR_BUFFER_TOO_SMALL. 667 * If the parameters are a valid combination that is not supported, 668 * return either a sensible size or 0. 669 * If the parameters are not valid, the 670 * return value is unspecified. 671 */ 672 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 673 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 674 PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \ 675 0) 676 677 /** A sufficient output buffer size for psa_asymmetric_decrypt(), for any 678 * supported asymmetric decryption. 679 * 680 * This macro assumes that RSA is the only supported asymmetric encryption. 681 * 682 * See also #PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 683 */ 684 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE \ 685 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 686 687 /* Maximum size of the ASN.1 encoding of an INTEGER with the specified 688 * number of bits. 689 * 690 * This definition assumes that bits <= 2^19 - 9 so that the length field 691 * is at most 3 bytes. The length of the encoding is the length of the 692 * bit string padded to a whole number of bytes plus: 693 * - 1 type byte; 694 * - 1 to 3 length bytes; 695 * - 0 to 1 bytes of leading 0 due to the sign bit. 696 */ 697 #define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \ 698 ((bits) / 8 + 5) 699 700 /* Maximum size of the export encoding of an RSA public key. 701 * Assumes that the public exponent is less than 2^32. 702 * 703 * RSAPublicKey ::= SEQUENCE { 704 * modulus INTEGER, -- n 705 * publicExponent INTEGER } -- e 706 * 707 * - 4 bytes of SEQUENCE overhead; 708 * - n : INTEGER; 709 * - 7 bytes for the public exponent. 710 */ 711 #define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 712 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11) 713 714 /* Maximum size of the export encoding of an RSA key pair. 715 * Assumes that the public exponent is less than 2^32 and that the size 716 * difference between the two primes is at most 1 bit. 717 * 718 * RSAPrivateKey ::= SEQUENCE { 719 * version Version, -- 0 720 * modulus INTEGER, -- N-bit 721 * publicExponent INTEGER, -- 32-bit 722 * privateExponent INTEGER, -- N-bit 723 * prime1 INTEGER, -- N/2-bit 724 * prime2 INTEGER, -- N/2-bit 725 * exponent1 INTEGER, -- N/2-bit 726 * exponent2 INTEGER, -- N/2-bit 727 * coefficient INTEGER, -- N/2-bit 728 * } 729 * 730 * - 4 bytes of SEQUENCE overhead; 731 * - 3 bytes of version; 732 * - 7 half-size INTEGERs plus 2 full-size INTEGERs, 733 * overapproximated as 9 half-size INTEGERS; 734 * - 7 bytes for the public exponent. 735 */ 736 #define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) \ 737 (9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14) 738 739 /* Maximum size of the export encoding of a DSA public key. 740 * 741 * SubjectPublicKeyInfo ::= SEQUENCE { 742 * algorithm AlgorithmIdentifier, 743 * subjectPublicKey BIT STRING } -- contains DSAPublicKey 744 * AlgorithmIdentifier ::= SEQUENCE { 745 * algorithm OBJECT IDENTIFIER, 746 * parameters Dss-Params } -- SEQUENCE of 3 INTEGERs 747 * DSAPublicKey ::= INTEGER -- public key, Y 748 * 749 * - 3 * 4 bytes of SEQUENCE overhead; 750 * - 1 + 1 + 7 bytes of algorithm (DSA OID); 751 * - 4 bytes of BIT STRING overhead; 752 * - 3 full-size INTEGERs (p, g, y); 753 * - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits). 754 */ 755 #define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 756 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 59) 757 758 /* Maximum size of the export encoding of a DSA key pair. 759 * 760 * DSAPrivateKey ::= SEQUENCE { 761 * version Version, -- 0 762 * prime INTEGER, -- p 763 * subprime INTEGER, -- q 764 * generator INTEGER, -- g 765 * public INTEGER, -- y 766 * private INTEGER, -- x 767 * } 768 * 769 * - 4 bytes of SEQUENCE overhead; 770 * - 3 bytes of version; 771 * - 3 full-size INTEGERs (p, g, y); 772 * - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits). 773 */ 774 #define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) \ 775 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 75) 776 777 /* Maximum size of the export encoding of an ECC public key. 778 * 779 * The representation of an ECC public key is: 780 * - The byte 0x04; 781 * - `x_P` as a `ceiling(m/8)`-byte string, big-endian; 782 * - `y_P` as a `ceiling(m/8)`-byte string, big-endian; 783 * - where m is the bit size associated with the curve. 784 * 785 * - 1 byte + 2 * point size. 786 */ 787 #define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \ 788 (2 * PSA_BITS_TO_BYTES(key_bits) + 1) 789 790 /* Maximum size of the export encoding of an ECC key pair. 791 * 792 * An ECC key pair is represented by the secret value. 793 */ 794 #define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) \ 795 (PSA_BITS_TO_BYTES(key_bits)) 796 797 /** Sufficient output buffer size for psa_export_key() or 798 * psa_export_public_key(). 799 * 800 * This macro returns a compile-time constant if its arguments are 801 * compile-time constants. 802 * 803 * \warning This macro may evaluate its arguments multiple times or 804 * zero times, so you should not pass arguments that contain 805 * side effects. 806 * 807 * The following code illustrates how to allocate enough memory to export 808 * a key by querying the key type and size at runtime. 809 * \code{c} 810 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 811 * psa_status_t status; 812 * status = psa_get_key_attributes(key, &attributes); 813 * if (status != PSA_SUCCESS) handle_error(...); 814 * psa_key_type_t key_type = psa_get_key_type(&attributes); 815 * size_t key_bits = psa_get_key_bits(&attributes); 816 * size_t buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits); 817 * psa_reset_key_attributes(&attributes); 818 * uint8_t *buffer = malloc(buffer_size); 819 * if (buffer == NULL) handle_error(...); 820 * size_t buffer_length; 821 * status = psa_export_key(key, buffer, buffer_size, &buffer_length); 822 * if (status != PSA_SUCCESS) handle_error(...); 823 * \endcode 824 * 825 * \param key_type A supported key type. 826 * \param key_bits The size of the key in bits. 827 * 828 * \return If the parameters are valid and supported, return 829 * a buffer size in bytes that guarantees that 830 * psa_export_key() or psa_export_public_key() will not fail with 831 * #PSA_ERROR_BUFFER_TOO_SMALL. 832 * If the parameters are a valid combination that is not supported, 833 * return either a sensible size or 0. 834 * If the parameters are not valid, the return value is unspecified. 835 */ 836 #define PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits) \ 837 (PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 838 (key_type) == PSA_KEY_TYPE_RSA_KEY_PAIR ? PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 839 (key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 840 (key_type) == PSA_KEY_TYPE_DSA_KEY_PAIR ? PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 841 (key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 842 PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) : \ 843 PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 844 0) 845 846 /** Sufficient output buffer size for psa_export_public_key(). 847 * 848 * This macro returns a compile-time constant if its arguments are 849 * compile-time constants. 850 * 851 * \warning This macro may evaluate its arguments multiple times or 852 * zero times, so you should not pass arguments that contain 853 * side effects. 854 * 855 * The following code illustrates how to allocate enough memory to export 856 * a public key by querying the key type and size at runtime. 857 * \code{c} 858 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 859 * psa_status_t status; 860 * status = psa_get_key_attributes(key, &attributes); 861 * if (status != PSA_SUCCESS) handle_error(...); 862 * psa_key_type_t key_type = psa_get_key_type(&attributes); 863 * size_t key_bits = psa_get_key_bits(&attributes); 864 * size_t buffer_size = PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits); 865 * psa_reset_key_attributes(&attributes); 866 * uint8_t *buffer = malloc(buffer_size); 867 * if (buffer == NULL) handle_error(...); 868 * size_t buffer_length; 869 * status = psa_export_public_key(key, buffer, buffer_size, &buffer_length); 870 * if (status != PSA_SUCCESS) handle_error(...); 871 * \endcode 872 * 873 * \param key_type A public key or key pair key type. 874 * \param key_bits The size of the key in bits. 875 * 876 * \return If the parameters are valid and supported, return 877 * a buffer size in bytes that guarantees that 878 * psa_export_public_key() will not fail with 879 * #PSA_ERROR_BUFFER_TOO_SMALL. 880 * If the parameters are a valid combination that is not 881 * supported, return either a sensible size or 0. 882 * If the parameters are not valid, 883 * the return value is unspecified. 884 * 885 * If the parameters are valid and supported, 886 * return the same result as 887 * #PSA_EXPORT_KEY_OUTPUT_SIZE( 888 * \p #PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(\p key_type), 889 * \p key_bits). 890 */ 891 #define PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits) \ 892 (PSA_KEY_TYPE_IS_RSA(key_type) ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 893 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 894 0) 895 896 /** Sufficient buffer size for exporting any asymmetric key pair. 897 * 898 * This macro expands to a compile-time constant integer. This value is 899 * a sufficient buffer size when calling psa_export_key() to export any 900 * asymmetric key pair, regardless of the exact key type and key size. 901 * 902 * See also #PSA_EXPORT_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 903 */ 904 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 905 (PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 906 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ? \ 907 PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 908 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 909 910 /** Sufficient buffer size for exporting any asymmetric public key. 911 * 912 * This macro expands to a compile-time constant integer. This value is 913 * a sufficient buffer size when calling psa_export_key() or 914 * psa_export_public_key() to export any asymmetric public key, 915 * regardless of the exact key type and key size. 916 * 917 * See also #PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 918 */ 919 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 920 (PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 921 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ? \ 922 PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ 923 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 924 925 /** Sufficient output buffer size for psa_raw_key_agreement(). 926 * 927 * This macro returns a compile-time constant if its arguments are 928 * compile-time constants. 929 * 930 * \warning This macro may evaluate its arguments multiple times or 931 * zero times, so you should not pass arguments that contain 932 * side effects. 933 * 934 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE. 935 * 936 * \param key_type A supported key type. 937 * \param key_bits The size of the key in bits. 938 * 939 * \return If the parameters are valid and supported, return 940 * a buffer size in bytes that guarantees that 941 * psa_raw_key_agreement() will not fail with 942 * #PSA_ERROR_BUFFER_TOO_SMALL. 943 * If the parameters are a valid combination that 944 * is not supported, return either a sensible size or 0. 945 * If the parameters are not valid, 946 * the return value is unspecified. 947 */ 948 /* FFDH is not yet supported in PSA. */ 949 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits) \ 950 (PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? \ 951 PSA_BITS_TO_BYTES(key_bits) : \ 952 0) 953 954 /** Maximum size of the output from psa_raw_key_agreement(). 955 * 956 * This macro expands to a compile-time constant integer. This value is the 957 * maximum size of the output any raw key agreement algorithm, in bytes. 958 * 959 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(\p key_type, \p key_bits). 960 */ 961 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE \ 962 (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS)) 963 964 /** The default IV size for a cipher algorithm, in bytes. 965 * 966 * The IV that is generated as part of a call to #psa_cipher_encrypt() is always 967 * the default IV length for the algorithm. 968 * 969 * This macro can be used to allocate a buffer of sufficient size to 970 * store the IV output from #psa_cipher_generate_iv() when using 971 * a multi-part cipher operation. 972 * 973 * See also #PSA_CIPHER_IV_MAX_SIZE. 974 * 975 * \warning This macro may evaluate its arguments multiple times or 976 * zero times, so you should not pass arguments that contain 977 * side effects. 978 * 979 * \param key_type A symmetric key type that is compatible with algorithm \p alg. 980 * 981 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true). 982 * 983 * \return The default IV size for the specified key type and algorithm. 984 * If the algorithm does not use an IV, return 0. 985 * If the key type or cipher algorithm is not recognized, 986 * or the parameters are incompatible, return 0. 987 */ 988 #define PSA_CIPHER_IV_LENGTH(key_type, alg) \ 989 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1 && \ 990 ((alg) == PSA_ALG_CTR || \ 991 (alg) == PSA_ALG_CFB || \ 992 (alg) == PSA_ALG_OFB || \ 993 (alg) == PSA_ALG_XTS || \ 994 (alg) == PSA_ALG_CBC_NO_PADDING || \ 995 (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 996 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 997 (alg) == PSA_ALG_STREAM_CIPHER ? 12 : \ 998 (alg) == PSA_ALG_CCM_STAR_NO_TAG ? 13 : \ 999 0) 1000 1001 /** The maximum IV size for all supported cipher algorithms, in bytes. 1002 * 1003 * See also #PSA_CIPHER_IV_LENGTH(). 1004 */ 1005 #define PSA_CIPHER_IV_MAX_SIZE 16 1006 1007 /** The maximum size of the output of psa_cipher_encrypt(), in bytes. 1008 * 1009 * If the size of the output buffer is at least this large, it is guaranteed 1010 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1011 * Depending on the algorithm, the actual size of the output might be smaller. 1012 * 1013 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(\p input_length). 1014 * 1015 * \warning This macro may evaluate its arguments multiple times or 1016 * zero times, so you should not pass arguments that contain 1017 * side effects. 1018 * 1019 * \param key_type A symmetric key type that is compatible with algorithm 1020 * alg. 1021 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1022 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1023 * \param input_length Size of the input in bytes. 1024 * 1025 * \return A sufficient output size for the specified key type and 1026 * algorithm. If the key type or cipher algorithm is not 1027 * recognized, or the parameters are incompatible, 1028 * return 0. 1029 */ 1030 #define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1031 (alg == PSA_ALG_CBC_PKCS7 ? \ 1032 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1033 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1034 (input_length) + 1) + \ 1035 PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0) : \ 1036 (PSA_ALG_IS_CIPHER(alg) ? \ 1037 (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) : \ 1038 0)) 1039 1040 /** A sufficient output buffer size for psa_cipher_encrypt(), for any of the 1041 * supported key types and cipher algorithms. 1042 * 1043 * If the size of the output buffer is at least this large, it is guaranteed 1044 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1045 * 1046 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1047 * 1048 * \param input_length Size of the input in bytes. 1049 * 1050 */ 1051 #define PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(input_length) \ 1052 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, \ 1053 (input_length) + 1) + \ 1054 PSA_CIPHER_IV_MAX_SIZE) 1055 1056 /** The maximum size of the output of psa_cipher_decrypt(), in bytes. 1057 * 1058 * If the size of the output buffer is at least this large, it is guaranteed 1059 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1060 * Depending on the algorithm, the actual size of the output might be smaller. 1061 * 1062 * See also #PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(\p input_length). 1063 * 1064 * \param key_type A symmetric key type that is compatible with algorithm 1065 * alg. 1066 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1067 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1068 * \param input_length Size of the input in bytes. 1069 * 1070 * \return A sufficient output size for the specified key type and 1071 * algorithm. If the key type or cipher algorithm is not 1072 * recognized, or the parameters are incompatible, 1073 * return 0. 1074 */ 1075 #define PSA_CIPHER_DECRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1076 (PSA_ALG_IS_CIPHER(alg) && \ 1077 ((key_type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \ 1078 (input_length) : \ 1079 0) 1080 1081 /** A sufficient output buffer size for psa_cipher_decrypt(), for any of the 1082 * supported key types and cipher algorithms. 1083 * 1084 * If the size of the output buffer is at least this large, it is guaranteed 1085 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1086 * 1087 * See also #PSA_CIPHER_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1088 * 1089 * \param input_length Size of the input in bytes. 1090 */ 1091 #define PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(input_length) \ 1092 (input_length) 1093 1094 /** A sufficient output buffer size for psa_cipher_update(). 1095 * 1096 * If the size of the output buffer is at least this large, it is guaranteed 1097 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1098 * The actual size of the output might be smaller in any given call. 1099 * 1100 * See also #PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 1101 * 1102 * \param key_type A symmetric key type that is compatible with algorithm 1103 * alg. 1104 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1105 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1106 * \param input_length Size of the input in bytes. 1107 * 1108 * \return A sufficient output size for the specified key type and 1109 * algorithm. If the key type or cipher algorithm is not 1110 * recognized, or the parameters are incompatible, return 0. 1111 */ 1112 #define PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 1113 (PSA_ALG_IS_CIPHER(alg) ? \ 1114 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1115 (((alg) == PSA_ALG_CBC_PKCS7 || \ 1116 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1117 (alg) == PSA_ALG_ECB_NO_PADDING) ? \ 1118 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1119 input_length) : \ 1120 (input_length)) : 0) : \ 1121 0) 1122 1123 /** A sufficient output buffer size for psa_cipher_update(), for any of the 1124 * supported key types and cipher algorithms. 1125 * 1126 * If the size of the output buffer is at least this large, it is guaranteed 1127 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1128 * 1129 * See also #PSA_CIPHER_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1130 * 1131 * \param input_length Size of the input in bytes. 1132 */ 1133 #define PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 1134 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length)) 1135 1136 /** A sufficient ciphertext buffer size for psa_cipher_finish(). 1137 * 1138 * If the size of the ciphertext buffer is at least this large, it is 1139 * guaranteed that psa_cipher_finish() will not fail due to an insufficient 1140 * ciphertext buffer size. The actual size of the output might be smaller in 1141 * any given call. 1142 * 1143 * See also #PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE(). 1144 * 1145 * \param key_type A symmetric key type that is compatible with algorithm 1146 * alg. 1147 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1148 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1149 * \return A sufficient output size for the specified key type and 1150 * algorithm. If the key type or cipher algorithm is not 1151 * recognized, or the parameters are incompatible, return 0. 1152 */ 1153 #define PSA_CIPHER_FINISH_OUTPUT_SIZE(key_type, alg) \ 1154 (PSA_ALG_IS_CIPHER(alg) ? \ 1155 (alg == PSA_ALG_CBC_PKCS7 ? \ 1156 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1157 0) : \ 1158 0) 1159 1160 /** A sufficient ciphertext buffer size for psa_cipher_finish(), for any of the 1161 * supported key types and cipher algorithms. 1162 * 1163 * See also #PSA_CIPHER_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 1164 */ 1165 #define PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE \ 1166 (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 1167 1168 #endif /* PSA_CRYPTO_SIZES_H */ 1169
