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 OR GPL-2.0-or-later 26 */ 27 28 #ifndef PSA_CRYPTO_SIZES_H 29 #define PSA_CRYPTO_SIZES_H 30 31 /* 32 * Include the build-time configuration information file. Here, we do not 33 * include `"mbedtls/build_info.h"` directly but `"psa/build_info.h"`, which 34 * is basically just an alias to it. This is to ease the maintenance of the 35 * PSA cryptography repository which has a different build system and 36 * configuration. 37 */ 38 #include "psa/build_info.h" 39 40 #define PSA_BITS_TO_BYTES(bits) (((bits) + 7u) / 8u) 41 #define PSA_BYTES_TO_BITS(bytes) ((bytes) * 8u) 42 #define PSA_MAX_OF_THREE(a, b, c) ((a) <= (b) ? (b) <= (c) ? \ 43 (c) : (b) : (a) <= (c) ? (c) : (a)) 44 45 #define PSA_ROUND_UP_TO_MULTIPLE(block_size, length) \ 46 (((length) + (block_size) - 1) / (block_size) * (block_size)) 47 48 /** The size of the output of psa_hash_finish(), in bytes. 49 * 50 * This is also the hash size that psa_hash_verify() expects. 51 * 52 * \param alg A hash algorithm (\c PSA_ALG_XXX value such that 53 * #PSA_ALG_IS_HASH(\p alg) is true), or an HMAC algorithm 54 * (#PSA_ALG_HMAC(\c hash_alg) where \c hash_alg is a 55 * hash algorithm). 56 * 57 * \return The hash size for the specified hash algorithm. 58 * If the hash algorithm is not recognized, return 0. 59 */ 60 #define PSA_HASH_LENGTH(alg) \ 61 ( \ 62 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 16u : \ 63 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 20u : \ 64 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 20u : \ 65 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 28u : \ 66 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 32u : \ 67 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 48u : \ 68 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 64u : \ 69 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 28u : \ 70 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 32u : \ 71 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 28u : \ 72 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 32u : \ 73 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 48u : \ 74 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 64u : \ 75 0u) 76 77 /** The input block size of a hash algorithm, in bytes. 78 * 79 * Hash algorithms process their input data in blocks. Hash operations will 80 * retain any partial blocks until they have enough input to fill the block or 81 * until the operation is finished. 82 * This affects the output from psa_hash_suspend(). 83 * 84 * \param alg A hash algorithm (\c PSA_ALG_XXX value such that 85 * PSA_ALG_IS_HASH(\p alg) is true). 86 * 87 * \return The block size in bytes for the specified hash algorithm. 88 * If the hash algorithm is not recognized, return 0. 89 * An implementation can return either 0 or the correct size for a 90 * hash algorithm that it recognizes, but does not support. 91 */ 92 #define PSA_HASH_BLOCK_LENGTH(alg) \ 93 ( \ 94 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 64u : \ 95 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 64u : \ 96 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 64u : \ 97 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 64u : \ 98 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 64u : \ 99 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 128u : \ 100 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 128u : \ 101 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 128u : \ 102 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 128u : \ 103 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 144u : \ 104 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 136u : \ 105 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 104u : \ 106 PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 72u : \ 107 0u) 108 109 /** \def PSA_HASH_MAX_SIZE 110 * 111 * Maximum size of a hash. 112 * 113 * This macro expands to a compile-time constant integer. This value 114 * is the maximum size of a hash in bytes. 115 */ 116 /* Note: for HMAC-SHA-3, the block size is 144 bytes for HMAC-SHA3-224, 117 * 136 bytes for HMAC-SHA3-256, 104 bytes for SHA3-384, 72 bytes for 118 * HMAC-SHA3-512. */ 119 /* Note: PSA_HASH_MAX_SIZE should be kept in sync with MBEDTLS_MD_MAX_SIZE, 120 * see the note on MBEDTLS_MD_MAX_SIZE for details. */ 121 #if defined(PSA_WANT_ALG_SHA3_224) 122 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 144u 123 #elif defined(PSA_WANT_ALG_SHA3_256) 124 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 136u 125 #elif defined(PSA_WANT_ALG_SHA_512) 126 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128u 127 #elif defined(PSA_WANT_ALG_SHA_384) 128 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128u 129 #elif defined(PSA_WANT_ALG_SHA3_384) 130 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 104u 131 #elif defined(PSA_WANT_ALG_SHA3_512) 132 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 72u 133 #elif defined(PSA_WANT_ALG_SHA_256) 134 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64u 135 #elif defined(PSA_WANT_ALG_SHA_224) 136 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64u 137 #else /* SHA-1 or smaller */ 138 #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64u 139 #endif 140 141 #if defined(PSA_WANT_ALG_SHA_512) || defined(PSA_WANT_ALG_SHA3_512) 142 #define PSA_HASH_MAX_SIZE 64u 143 #elif defined(PSA_WANT_ALG_SHA_384) || defined(PSA_WANT_ALG_SHA3_384) 144 #define PSA_HASH_MAX_SIZE 48u 145 #elif defined(PSA_WANT_ALG_SHA_256) || defined(PSA_WANT_ALG_SHA3_256) 146 #define PSA_HASH_MAX_SIZE 32u 147 #elif defined(PSA_WANT_ALG_SHA_224) || defined(PSA_WANT_ALG_SHA3_224) 148 #define PSA_HASH_MAX_SIZE 28u 149 #else /* SHA-1 or smaller */ 150 #define PSA_HASH_MAX_SIZE 20u 151 #endif 152 153 /** \def PSA_MAC_MAX_SIZE 154 * 155 * Maximum size of a MAC. 156 * 157 * This macro expands to a compile-time constant integer. This value 158 * is the maximum size of a MAC in bytes. 159 */ 160 /* All non-HMAC MACs have a maximum size that's smaller than the 161 * minimum possible value of PSA_HASH_MAX_SIZE in this implementation. */ 162 /* Note that the encoding of truncated MAC algorithms limits this value 163 * to 64 bytes. 164 */ 165 #define PSA_MAC_MAX_SIZE PSA_HASH_MAX_SIZE 166 167 /** The length of a tag for an AEAD algorithm, in bytes. 168 * 169 * This macro can be used to allocate a buffer of sufficient size to store the 170 * tag output from psa_aead_finish(). 171 * 172 * See also #PSA_AEAD_TAG_MAX_SIZE. 173 * 174 * \param key_type The type of the AEAD key. 175 * \param key_bits The size of the AEAD key in bits. 176 * \param alg An AEAD algorithm 177 * (\c PSA_ALG_XXX value such that 178 * #PSA_ALG_IS_AEAD(\p alg) is true). 179 * 180 * \return The tag length for the specified algorithm and key. 181 * If the AEAD algorithm does not have an identified 182 * tag that can be distinguished from the rest of 183 * the ciphertext, return 0. 184 * If the key type or AEAD algorithm is not 185 * recognized, or the parameters are incompatible, 186 * return 0. 187 */ 188 #define PSA_AEAD_TAG_LENGTH(key_type, key_bits, alg) \ 189 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 190 PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 191 ((void) (key_bits), 0u)) 192 193 /** The maximum tag size for all supported AEAD algorithms, in bytes. 194 * 195 * See also #PSA_AEAD_TAG_LENGTH(\p key_type, \p key_bits, \p alg). 196 */ 197 #define PSA_AEAD_TAG_MAX_SIZE 16u 198 199 /* The maximum size of an RSA key on this implementation, in bits. 200 * This is a vendor-specific macro. 201 * 202 * Mbed TLS does not set a hard limit on the size of RSA keys: any key 203 * whose parameters fit in a bignum is accepted. However large keys can 204 * induce a large memory usage and long computation times. Unlike other 205 * auxiliary macros in this file and in crypto.h, which reflect how the 206 * library is configured, this macro defines how the library is 207 * configured. This implementation refuses to import or generate an 208 * RSA key whose size is larger than the value defined here. 209 * 210 * Note that an implementation may set different size limits for different 211 * operations, and does not need to accept all key sizes up to the limit. */ 212 #define PSA_VENDOR_RSA_MAX_KEY_BITS 4096u 213 214 /* The minimum size of an RSA key on this implementation, in bits. 215 * This is a vendor-specific macro. 216 * 217 * Limits RSA key generation to a minimum due to avoid accidental misuse. 218 * This value cannot be less than 128 bits. 219 */ 220 #if defined(MBEDTLS_RSA_GEN_KEY_MIN_BITS) 221 #define PSA_VENDOR_RSA_GENERATE_MIN_KEY_BITS MBEDTLS_RSA_GEN_KEY_MIN_BITS 222 #else 223 #define PSA_VENDOR_RSA_GENERATE_MIN_KEY_BITS 1024 224 #endif 225 226 /* The maximum size of an DH key on this implementation, in bits. 227 * 228 * Note that an implementation may set different size limits for different 229 * operations, and does not need to accept all key sizes up to the limit. */ 230 #define PSA_VENDOR_FFDH_MAX_KEY_BITS 8192u 231 232 /* The maximum size of an ECC key on this implementation, in bits. 233 * This is a vendor-specific macro. */ 234 #if defined(PSA_WANT_ECC_SECP_R1_521) 235 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 521u 236 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_512) 237 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 512u 238 #elif defined(PSA_WANT_ECC_MONTGOMERY_448) 239 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 448u 240 #elif defined(PSA_WANT_ECC_SECP_R1_384) 241 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384u 242 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_384) 243 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384u 244 #elif defined(PSA_WANT_ECC_SECP_R1_256) 245 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u 246 #elif defined(PSA_WANT_ECC_SECP_K1_256) 247 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u 248 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_256) 249 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u 250 #elif defined(PSA_WANT_ECC_MONTGOMERY_255) 251 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 255u 252 #elif defined(PSA_WANT_ECC_SECP_R1_224) 253 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224u 254 #elif defined(PSA_WANT_ECC_SECP_K1_224) 255 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224u 256 #elif defined(PSA_WANT_ECC_SECP_R1_192) 257 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192u 258 #elif defined(PSA_WANT_ECC_SECP_K1_192) 259 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192u 260 #else 261 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 0u 262 #endif 263 264 /** This macro returns the maximum supported length of the PSK for the 265 * TLS-1.2 PSK-to-MS key derivation 266 * (#PSA_ALG_TLS12_PSK_TO_MS(\c hash_alg)). 267 * 268 * The maximum supported length does not depend on the chosen hash algorithm. 269 * 270 * Quoting RFC 4279, Sect 5.3: 271 * TLS implementations supporting these ciphersuites MUST support 272 * arbitrary PSK identities up to 128 octets in length, and arbitrary 273 * PSKs up to 64 octets in length. Supporting longer identities and 274 * keys is RECOMMENDED. 275 * 276 * Therefore, no implementation should define a value smaller than 64 277 * for #PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE. 278 */ 279 #define PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128u 280 281 /* The expected size of input passed to psa_tls12_ecjpake_to_pms_input, 282 * which is expected to work with P-256 curve only. */ 283 #define PSA_TLS12_ECJPAKE_TO_PMS_INPUT_SIZE 65u 284 285 /* The size of a serialized K.X coordinate to be used in 286 * psa_tls12_ecjpake_to_pms_input. This function only accepts the P-256 287 * curve. */ 288 #define PSA_TLS12_ECJPAKE_TO_PMS_DATA_SIZE 32u 289 290 /* The maximum number of iterations for PBKDF2 on this implementation, in bits. 291 * This is a vendor-specific macro. This can be configured if necessary */ 292 #define PSA_VENDOR_PBKDF2_MAX_ITERATIONS 0xffffffffU 293 294 /** The maximum size of a block cipher. */ 295 #define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16u 296 297 /** The size of the output of psa_mac_sign_finish(), in bytes. 298 * 299 * This is also the MAC size that psa_mac_verify_finish() expects. 300 * 301 * \warning This macro may evaluate its arguments multiple times or 302 * zero times, so you should not pass arguments that contain 303 * side effects. 304 * 305 * \param key_type The type of the MAC key. 306 * \param key_bits The size of the MAC key in bits. 307 * \param alg A MAC algorithm (\c PSA_ALG_XXX value such that 308 * #PSA_ALG_IS_MAC(\p alg) is true). 309 * 310 * \return The MAC size for the specified algorithm with 311 * the specified key parameters. 312 * \return 0 if the MAC algorithm is not recognized. 313 * \return Either 0 or the correct size for a MAC algorithm that 314 * the implementation recognizes, but does not support. 315 * \return Unspecified if the key parameters are not consistent 316 * with the algorithm. 317 */ 318 #define PSA_MAC_LENGTH(key_type, key_bits, alg) \ 319 ((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \ 320 PSA_ALG_IS_HMAC(alg) ? PSA_HASH_LENGTH(PSA_ALG_HMAC_GET_HASH(alg)) : \ 321 PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 322 ((void) (key_type), (void) (key_bits), 0u)) 323 324 /** The maximum size of the output of psa_aead_encrypt(), in bytes. 325 * 326 * If the size of the ciphertext buffer is at least this large, it is 327 * guaranteed that psa_aead_encrypt() will not fail due to an 328 * insufficient buffer size. Depending on the algorithm, the actual size of 329 * the ciphertext may be smaller. 330 * 331 * See also #PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(\p plaintext_length). 332 * 333 * \warning This macro may evaluate its arguments multiple times or 334 * zero times, so you should not pass arguments that contain 335 * side effects. 336 * 337 * \param key_type A symmetric key type that is 338 * compatible with algorithm \p alg. 339 * \param alg An AEAD algorithm 340 * (\c PSA_ALG_XXX value such that 341 * #PSA_ALG_IS_AEAD(\p alg) is true). 342 * \param plaintext_length Size of the plaintext in bytes. 343 * 344 * \return The AEAD ciphertext size for the specified 345 * algorithm. 346 * If the key type or AEAD algorithm is not 347 * recognized, or the parameters are incompatible, 348 * return 0. 349 */ 350 #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length) \ 351 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 352 (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 353 0u) 354 355 /** A sufficient output buffer size for psa_aead_encrypt(), for any of the 356 * supported key types and AEAD algorithms. 357 * 358 * If the size of the ciphertext buffer is at least this large, it is guaranteed 359 * that psa_aead_encrypt() will not fail due to an insufficient buffer size. 360 * 361 * \note This macro returns a compile-time constant if its arguments are 362 * compile-time constants. 363 * 364 * See also #PSA_AEAD_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, 365 * \p plaintext_length). 366 * 367 * \param plaintext_length Size of the plaintext in bytes. 368 * 369 * \return A sufficient output buffer size for any of the 370 * supported key types and AEAD algorithms. 371 * 372 */ 373 #define PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length) \ 374 ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE) 375 376 377 /** The maximum size of the output of psa_aead_decrypt(), in bytes. 378 * 379 * If the size of the plaintext buffer is at least this large, it is 380 * guaranteed that psa_aead_decrypt() will not fail due to an 381 * insufficient buffer size. Depending on the algorithm, the actual size of 382 * the plaintext may be smaller. 383 * 384 * See also #PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(\p ciphertext_length). 385 * 386 * \warning This macro may evaluate its arguments multiple times or 387 * zero times, so you should not pass arguments that contain 388 * side effects. 389 * 390 * \param key_type A symmetric key type that is 391 * compatible with algorithm \p alg. 392 * \param alg An AEAD algorithm 393 * (\c PSA_ALG_XXX value such that 394 * #PSA_ALG_IS_AEAD(\p alg) is true). 395 * \param ciphertext_length Size of the plaintext in bytes. 396 * 397 * \return The AEAD ciphertext size for the specified 398 * algorithm. 399 * If the key type or AEAD algorithm is not 400 * recognized, or the parameters are incompatible, 401 * return 0. 402 */ 403 #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length) \ 404 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 405 (ciphertext_length) > PSA_ALG_AEAD_GET_TAG_LENGTH(alg) ? \ 406 (ciphertext_length) - PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 407 0u) 408 409 /** A sufficient output buffer size for psa_aead_decrypt(), for any of the 410 * supported key types and AEAD algorithms. 411 * 412 * If the size of the plaintext buffer is at least this large, it is guaranteed 413 * that psa_aead_decrypt() will not fail due to an insufficient buffer size. 414 * 415 * \note This macro returns a compile-time constant if its arguments are 416 * compile-time constants. 417 * 418 * See also #PSA_AEAD_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, 419 * \p ciphertext_length). 420 * 421 * \param ciphertext_length Size of the ciphertext in bytes. 422 * 423 * \return A sufficient output buffer size for any of the 424 * supported key types and AEAD algorithms. 425 * 426 */ 427 #define PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(ciphertext_length) \ 428 (ciphertext_length) 429 430 /** The default nonce size for an AEAD algorithm, in bytes. 431 * 432 * This macro can be used to allocate a buffer of sufficient size to 433 * store the nonce output from #psa_aead_generate_nonce(). 434 * 435 * See also #PSA_AEAD_NONCE_MAX_SIZE. 436 * 437 * \note This is not the maximum size of nonce supported as input to 438 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 439 * just the default size that is generated by #psa_aead_generate_nonce(). 440 * 441 * \warning This macro may evaluate its arguments multiple times or 442 * zero times, so you should not pass arguments that contain 443 * side effects. 444 * 445 * \param key_type A symmetric key type that is compatible with 446 * algorithm \p alg. 447 * 448 * \param alg An AEAD algorithm (\c PSA_ALG_XXX value such that 449 * #PSA_ALG_IS_AEAD(\p alg) is true). 450 * 451 * \return The default nonce size for the specified key type and algorithm. 452 * If the key type or AEAD algorithm is not recognized, 453 * or the parameters are incompatible, return 0. 454 */ 455 #define PSA_AEAD_NONCE_LENGTH(key_type, alg) \ 456 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \ 457 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CCM) ? 13u : \ 458 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_GCM) ? 12u : \ 459 0u : \ 460 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 461 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12u : \ 462 0u) 463 464 /** The maximum default nonce size among all supported pairs of key types and 465 * AEAD algorithms, in bytes. 466 * 467 * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH() 468 * may return. 469 * 470 * \note This is not the maximum size of nonce supported as input to 471 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 472 * just the largest size that may be generated by 473 * #psa_aead_generate_nonce(). 474 */ 475 #define PSA_AEAD_NONCE_MAX_SIZE 13u 476 477 /** A sufficient output buffer size for psa_aead_update(). 478 * 479 * If the size of the output buffer is at least this large, it is 480 * guaranteed that psa_aead_update() will not fail due to an 481 * insufficient buffer size. The actual size of the output may be smaller 482 * in any given call. 483 * 484 * See also #PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 485 * 486 * \warning This macro may evaluate its arguments multiple times or 487 * zero times, so you should not pass arguments that contain 488 * side effects. 489 * 490 * \param key_type A symmetric key type that is 491 * compatible with algorithm \p alg. 492 * \param alg An AEAD algorithm 493 * (\c PSA_ALG_XXX value such that 494 * #PSA_ALG_IS_AEAD(\p alg) is true). 495 * \param input_length Size of the input in bytes. 496 * 497 * \return A sufficient output buffer size for the specified 498 * algorithm. 499 * If the key type or AEAD algorithm is not 500 * recognized, or the parameters are incompatible, 501 * return 0. 502 */ 503 /* For all the AEAD modes defined in this specification, it is possible 504 * to emit output without delay. However, hardware may not always be 505 * capable of this. So for modes based on a block cipher, allow the 506 * implementation to delay the output until it has a full block. */ 507 #define PSA_AEAD_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 508 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 509 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 510 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), (input_length)) : \ 511 (input_length) : \ 512 0u) 513 514 /** A sufficient output buffer size for psa_aead_update(), for any of the 515 * supported key types and AEAD algorithms. 516 * 517 * If the size of the output buffer is at least this large, it is guaranteed 518 * that psa_aead_update() will not fail due to an insufficient buffer size. 519 * 520 * See also #PSA_AEAD_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 521 * 522 * \param input_length Size of the input in bytes. 523 */ 524 #define PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 525 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length))) 526 527 /** A sufficient ciphertext buffer size for psa_aead_finish(). 528 * 529 * If the size of the ciphertext buffer is at least this large, it is 530 * guaranteed that psa_aead_finish() will not fail due to an 531 * insufficient ciphertext buffer size. The actual size of the output may 532 * be smaller in any given call. 533 * 534 * See also #PSA_AEAD_FINISH_OUTPUT_MAX_SIZE. 535 * 536 * \param key_type A symmetric key type that is 537 compatible with algorithm \p alg. 538 * \param alg An AEAD algorithm 539 * (\c PSA_ALG_XXX value such that 540 * #PSA_ALG_IS_AEAD(\p alg) is true). 541 * 542 * \return A sufficient ciphertext buffer size for the 543 * specified algorithm. 544 * If the key type or AEAD algorithm is not 545 * recognized, or the parameters are incompatible, 546 * return 0. 547 */ 548 #define PSA_AEAD_FINISH_OUTPUT_SIZE(key_type, alg) \ 549 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 550 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 551 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 552 0u) 553 554 /** A sufficient ciphertext buffer size for psa_aead_finish(), for any of the 555 * supported key types and AEAD algorithms. 556 * 557 * See also #PSA_AEAD_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 558 */ 559 #define PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 560 561 /** A sufficient plaintext buffer size for psa_aead_verify(). 562 * 563 * If the size of the plaintext buffer is at least this large, it is 564 * guaranteed that psa_aead_verify() will not fail due to an 565 * insufficient plaintext buffer size. The actual size of the output may 566 * be smaller in any given call. 567 * 568 * See also #PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE. 569 * 570 * \param key_type A symmetric key type that is 571 * compatible with algorithm \p alg. 572 * \param alg An AEAD algorithm 573 * (\c PSA_ALG_XXX value such that 574 * #PSA_ALG_IS_AEAD(\p alg) is true). 575 * 576 * \return A sufficient plaintext buffer size for the 577 * specified algorithm. 578 * If the key type or AEAD algorithm is not 579 * recognized, or the parameters are incompatible, 580 * return 0. 581 */ 582 #define PSA_AEAD_VERIFY_OUTPUT_SIZE(key_type, alg) \ 583 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 584 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 585 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 586 0u) 587 588 /** A sufficient plaintext buffer size for psa_aead_verify(), for any of the 589 * supported key types and AEAD algorithms. 590 * 591 * See also #PSA_AEAD_VERIFY_OUTPUT_SIZE(\p key_type, \p alg). 592 */ 593 #define PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 594 595 #define PSA_RSA_MINIMUM_PADDING_SIZE(alg) \ 596 (PSA_ALG_IS_RSA_OAEP(alg) ? \ 597 2u * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1u : \ 598 11u /*PKCS#1v1.5*/) 599 600 /** 601 * \brief ECDSA signature size for a given curve bit size 602 * 603 * \param curve_bits Curve size in bits. 604 * \return Signature size in bytes. 605 * 606 * \note This macro returns a compile-time constant if its argument is one. 607 */ 608 #define PSA_ECDSA_SIGNATURE_SIZE(curve_bits) \ 609 (PSA_BITS_TO_BYTES(curve_bits) * 2u) 610 611 /** Sufficient signature buffer size for psa_sign_hash(). 612 * 613 * This macro returns a sufficient buffer size for a signature using a key 614 * of the specified type and size, with the specified algorithm. 615 * Note that the actual size of the signature may be smaller 616 * (some algorithms produce a variable-size signature). 617 * 618 * \warning This function may call its arguments multiple times or 619 * zero times, so you should not pass arguments that contain 620 * side effects. 621 * 622 * \param key_type An asymmetric key type (this may indifferently be a 623 * key pair type or a public key type). 624 * \param key_bits The size of the key in bits. 625 * \param alg The signature algorithm. 626 * 627 * \return If the parameters are valid and supported, return 628 * a buffer size in bytes that guarantees that 629 * psa_sign_hash() will not fail with 630 * #PSA_ERROR_BUFFER_TOO_SMALL. 631 * If the parameters are a valid combination that is not supported, 632 * return either a sensible size or 0. 633 * If the parameters are not valid, the 634 * return value is unspecified. 635 */ 636 #define PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \ 637 (PSA_KEY_TYPE_IS_RSA(key_type) ? ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \ 638 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \ 639 ((void) alg, 0u)) 640 641 #define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE \ 642 PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 643 644 /** \def PSA_SIGNATURE_MAX_SIZE 645 * 646 * Maximum size of an asymmetric signature. 647 * 648 * This macro expands to a compile-time constant integer. This value 649 * is the maximum size of a signature in bytes. 650 */ 651 #define PSA_SIGNATURE_MAX_SIZE 1 652 653 #if (defined(PSA_WANT_ALG_ECDSA) || defined(PSA_WANT_ALG_DETERMINISTIC_ECDSA)) && \ 654 (PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE > PSA_SIGNATURE_MAX_SIZE) 655 #undef PSA_SIGNATURE_MAX_SIZE 656 #define PSA_SIGNATURE_MAX_SIZE PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE 657 #endif 658 #if (defined(PSA_WANT_ALG_RSA_PKCS1V15_SIGN) || defined(PSA_WANT_ALG_RSA_PSS)) && \ 659 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_SIGNATURE_MAX_SIZE) 660 #undef PSA_SIGNATURE_MAX_SIZE 661 #define PSA_SIGNATURE_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) 662 #endif 663 664 /** Sufficient output buffer size for psa_asymmetric_encrypt(). 665 * 666 * This macro returns a sufficient buffer size for a ciphertext produced using 667 * a key of the specified type and size, with the specified algorithm. 668 * Note that the actual size of the ciphertext may be smaller, depending 669 * on the algorithm. 670 * 671 * \warning This function may call its arguments multiple times or 672 * zero times, so you should not pass arguments that contain 673 * side effects. 674 * 675 * \param key_type An asymmetric key type (this may indifferently be a 676 * key pair type or a public key type). 677 * \param key_bits The size of the key in bits. 678 * \param alg The asymmetric encryption algorithm. 679 * 680 * \return If the parameters are valid and supported, return 681 * a buffer size in bytes that guarantees that 682 * psa_asymmetric_encrypt() will not fail with 683 * #PSA_ERROR_BUFFER_TOO_SMALL. 684 * If the parameters are a valid combination that is not supported, 685 * return either a sensible size or 0. 686 * If the parameters are not valid, the 687 * return value is unspecified. 688 */ 689 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 690 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 691 ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \ 692 0u) 693 694 /** A sufficient output buffer size for psa_asymmetric_encrypt(), for any 695 * supported asymmetric encryption. 696 * 697 * See also #PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 698 */ 699 /* This macro assumes that RSA is the only supported asymmetric encryption. */ 700 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE \ 701 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 702 703 /** Sufficient output buffer size for psa_asymmetric_decrypt(). 704 * 705 * This macro returns a sufficient buffer size for a plaintext produced using 706 * a key of the specified type and size, with the specified algorithm. 707 * Note that the actual size of the plaintext may be smaller, depending 708 * on the algorithm. 709 * 710 * \warning This function may call its arguments multiple times or 711 * zero times, so you should not pass arguments that contain 712 * side effects. 713 * 714 * \param key_type An asymmetric key type (this may indifferently be a 715 * key pair type or a public key type). 716 * \param key_bits The size of the key in bits. 717 * \param alg The asymmetric encryption algorithm. 718 * 719 * \return If the parameters are valid and supported, return 720 * a buffer size in bytes that guarantees that 721 * psa_asymmetric_decrypt() will not fail with 722 * #PSA_ERROR_BUFFER_TOO_SMALL. 723 * If the parameters are a valid combination that is not supported, 724 * return either a sensible size or 0. 725 * If the parameters are not valid, the 726 * return value is unspecified. 727 */ 728 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 729 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 730 PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \ 731 0u) 732 733 /** A sufficient output buffer size for psa_asymmetric_decrypt(), for any 734 * supported asymmetric decryption. 735 * 736 * This macro assumes that RSA is the only supported asymmetric encryption. 737 * 738 * See also #PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 739 */ 740 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE \ 741 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 742 743 /* Maximum size of the ASN.1 encoding of an INTEGER with the specified 744 * number of bits. 745 * 746 * This definition assumes that bits <= 2^19 - 9 so that the length field 747 * is at most 3 bytes. The length of the encoding is the length of the 748 * bit string padded to a whole number of bytes plus: 749 * - 1 type byte; 750 * - 1 to 3 length bytes; 751 * - 0 to 1 bytes of leading 0 due to the sign bit. 752 */ 753 #define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \ 754 ((bits) / 8u + 5u) 755 756 /* Maximum size of the export encoding of an RSA public key. 757 * Assumes that the public exponent is less than 2^32. 758 * 759 * RSAPublicKey ::= SEQUENCE { 760 * modulus INTEGER, -- n 761 * publicExponent INTEGER } -- e 762 * 763 * - 4 bytes of SEQUENCE overhead; 764 * - n : INTEGER; 765 * - 7 bytes for the public exponent. 766 */ 767 #define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 768 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11u) 769 770 /* Maximum size of the export encoding of an RSA key pair. 771 * Assumes that the public exponent is less than 2^32 and that the size 772 * difference between the two primes is at most 1 bit. 773 * 774 * RSAPrivateKey ::= SEQUENCE { 775 * version Version, -- 0 776 * modulus INTEGER, -- N-bit 777 * publicExponent INTEGER, -- 32-bit 778 * privateExponent INTEGER, -- N-bit 779 * prime1 INTEGER, -- N/2-bit 780 * prime2 INTEGER, -- N/2-bit 781 * exponent1 INTEGER, -- N/2-bit 782 * exponent2 INTEGER, -- N/2-bit 783 * coefficient INTEGER, -- N/2-bit 784 * } 785 * 786 * - 4 bytes of SEQUENCE overhead; 787 * - 3 bytes of version; 788 * - 7 half-size INTEGERs plus 2 full-size INTEGERs, 789 * overapproximated as 9 half-size INTEGERS; 790 * - 7 bytes for the public exponent. 791 */ 792 #define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) \ 793 (9u * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2u + 1u) + 14u) 794 795 /* Maximum size of the export encoding of a DSA public key. 796 * 797 * SubjectPublicKeyInfo ::= SEQUENCE { 798 * algorithm AlgorithmIdentifier, 799 * subjectPublicKey BIT STRING } -- contains DSAPublicKey 800 * AlgorithmIdentifier ::= SEQUENCE { 801 * algorithm OBJECT IDENTIFIER, 802 * parameters Dss-Params } -- SEQUENCE of 3 INTEGERs 803 * DSAPublicKey ::= INTEGER -- public key, Y 804 * 805 * - 3 * 4 bytes of SEQUENCE overhead; 806 * - 1 + 1 + 7 bytes of algorithm (DSA OID); 807 * - 4 bytes of BIT STRING overhead; 808 * - 3 full-size INTEGERs (p, g, y); 809 * - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits). 810 */ 811 #define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 812 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3u + 59u) 813 814 /* Maximum size of the export encoding of a DSA key pair. 815 * 816 * DSAPrivateKey ::= SEQUENCE { 817 * version Version, -- 0 818 * prime INTEGER, -- p 819 * subprime INTEGER, -- q 820 * generator INTEGER, -- g 821 * public INTEGER, -- y 822 * private INTEGER, -- x 823 * } 824 * 825 * - 4 bytes of SEQUENCE overhead; 826 * - 3 bytes of version; 827 * - 3 full-size INTEGERs (p, g, y); 828 * - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits). 829 */ 830 #define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) \ 831 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3u + 75u) 832 833 /* Maximum size of the export encoding of an ECC public key. 834 * 835 * The representation of an ECC public key is: 836 * - The byte 0x04; 837 * - `x_P` as a `ceiling(m/8)`-byte string, big-endian; 838 * - `y_P` as a `ceiling(m/8)`-byte string, big-endian; 839 * - where m is the bit size associated with the curve. 840 * 841 * - 1 byte + 2 * point size. 842 */ 843 #define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \ 844 (2u * PSA_BITS_TO_BYTES(key_bits) + 1u) 845 846 /* Maximum size of the export encoding of an ECC key pair. 847 * 848 * An ECC key pair is represented by the secret value. 849 */ 850 #define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) \ 851 (PSA_BITS_TO_BYTES(key_bits)) 852 853 /* Maximum size of the export encoding of an DH key pair. 854 * 855 * An DH key pair is represented by the secret value. 856 */ 857 #define PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(key_bits) \ 858 (PSA_BITS_TO_BYTES(key_bits)) 859 860 /* Maximum size of the export encoding of an DH public key. 861 */ 862 #define PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(key_bits) \ 863 (PSA_BITS_TO_BYTES(key_bits)) 864 865 /** Sufficient output buffer size for psa_export_key() or 866 * psa_export_public_key(). 867 * 868 * This macro returns a compile-time constant if its arguments are 869 * compile-time constants. 870 * 871 * \warning This macro may evaluate its arguments multiple times or 872 * zero times, so you should not pass arguments that contain 873 * side effects. 874 * 875 * The following code illustrates how to allocate enough memory to export 876 * a key by querying the key type and size at runtime. 877 * \code{c} 878 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 879 * psa_status_t status; 880 * status = psa_get_key_attributes(key, &attributes); 881 * if (status != PSA_SUCCESS) handle_error(...); 882 * psa_key_type_t key_type = psa_get_key_type(&attributes); 883 * size_t key_bits = psa_get_key_bits(&attributes); 884 * size_t buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits); 885 * psa_reset_key_attributes(&attributes); 886 * uint8_t *buffer = malloc(buffer_size); 887 * if (buffer == NULL) handle_error(...); 888 * size_t buffer_length; 889 * status = psa_export_key(key, buffer, buffer_size, &buffer_length); 890 * if (status != PSA_SUCCESS) handle_error(...); 891 * \endcode 892 * 893 * \param key_type A supported key type. 894 * \param key_bits The size of the key in bits. 895 * 896 * \return If the parameters are valid and supported, return 897 * a buffer size in bytes that guarantees that 898 * psa_export_key() or psa_export_public_key() will not fail with 899 * #PSA_ERROR_BUFFER_TOO_SMALL. 900 * If the parameters are a valid combination that is not supported, 901 * return either a sensible size or 0. 902 * If the parameters are not valid, the return value is unspecified. 903 */ 904 #define PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits) \ 905 (PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 906 PSA_KEY_TYPE_IS_DH(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 907 (key_type) == PSA_KEY_TYPE_RSA_KEY_PAIR ? PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 908 (key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 909 (key_type) == PSA_KEY_TYPE_DSA_KEY_PAIR ? PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 910 (key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 911 PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) : \ 912 PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 913 0u) 914 915 /** Sufficient output buffer size for psa_export_public_key(). 916 * 917 * This macro returns a compile-time constant if its arguments are 918 * compile-time constants. 919 * 920 * \warning This macro may evaluate its arguments multiple times or 921 * zero times, so you should not pass arguments that contain 922 * side effects. 923 * 924 * The following code illustrates how to allocate enough memory to export 925 * a public key by querying the key type and size at runtime. 926 * \code{c} 927 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 928 * psa_status_t status; 929 * status = psa_get_key_attributes(key, &attributes); 930 * if (status != PSA_SUCCESS) handle_error(...); 931 * psa_key_type_t key_type = psa_get_key_type(&attributes); 932 * size_t key_bits = psa_get_key_bits(&attributes); 933 * size_t buffer_size = PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits); 934 * psa_reset_key_attributes(&attributes); 935 * uint8_t *buffer = malloc(buffer_size); 936 * if (buffer == NULL) handle_error(...); 937 * size_t buffer_length; 938 * status = psa_export_public_key(key, buffer, buffer_size, &buffer_length); 939 * if (status != PSA_SUCCESS) handle_error(...); 940 * \endcode 941 * 942 * \param key_type A public key or key pair key type. 943 * \param key_bits The size of the key in bits. 944 * 945 * \return If the parameters are valid and supported, return 946 * a buffer size in bytes that guarantees that 947 * psa_export_public_key() will not fail with 948 * #PSA_ERROR_BUFFER_TOO_SMALL. 949 * If the parameters are a valid combination that is not 950 * supported, return either a sensible size or 0. 951 * If the parameters are not valid, 952 * the return value is unspecified. 953 * 954 * If the parameters are valid and supported, 955 * return the same result as 956 * #PSA_EXPORT_KEY_OUTPUT_SIZE( 957 * \p #PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(\p key_type), 958 * \p key_bits). 959 */ 960 #define PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits) \ 961 (PSA_KEY_TYPE_IS_RSA(key_type) ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 962 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 963 PSA_KEY_TYPE_IS_DH(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 964 0u) 965 966 /** Sufficient buffer size for exporting any asymmetric key pair. 967 * 968 * This macro expands to a compile-time constant integer. This value is 969 * a sufficient buffer size when calling psa_export_key() to export any 970 * asymmetric key pair, regardless of the exact key type and key size. 971 * 972 * See also #PSA_EXPORT_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 973 */ 974 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE 1 975 976 #if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_BASIC) && \ 977 (PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) > \ 978 PSA_EXPORT_KEY_PAIR_MAX_SIZE) 979 #undef PSA_EXPORT_KEY_PAIR_MAX_SIZE 980 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 981 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 982 #endif 983 #if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_BASIC) && \ 984 (PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 985 PSA_EXPORT_KEY_PAIR_MAX_SIZE) 986 #undef PSA_EXPORT_KEY_PAIR_MAX_SIZE 987 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 988 PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) 989 #endif 990 #if defined(PSA_WANT_KEY_TYPE_DH_KEY_PAIR_BASIC) && \ 991 (PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) > \ 992 PSA_EXPORT_KEY_PAIR_MAX_SIZE) 993 #undef PSA_EXPORT_KEY_PAIR_MAX_SIZE 994 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 995 PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) 996 #endif 997 998 /** Sufficient buffer size for exporting any asymmetric public key. 999 * 1000 * This macro expands to a compile-time constant integer. This value is 1001 * a sufficient buffer size when calling psa_export_key() or 1002 * psa_export_public_key() to export any asymmetric public key, 1003 * regardless of the exact key type and key size. 1004 * 1005 * See also #PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 1006 */ 1007 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1 1008 1009 #if defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY) && \ 1010 (PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) > \ 1011 PSA_EXPORT_PUBLIC_KEY_MAX_SIZE) 1012 #undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1013 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 1014 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 1015 #endif 1016 #if defined(PSA_WANT_KEY_TYPE_RSA_PUBLIC_KEY) && \ 1017 (PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 1018 PSA_EXPORT_PUBLIC_KEY_MAX_SIZE) 1019 #undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1020 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 1021 PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) 1022 #endif 1023 #if defined(PSA_WANT_KEY_TYPE_DH_PUBLIC_KEY) && \ 1024 (PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) > \ 1025 PSA_EXPORT_PUBLIC_KEY_MAX_SIZE) 1026 #undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1027 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 1028 PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) 1029 #endif 1030 1031 /** Sufficient output buffer size for psa_raw_key_agreement(). 1032 * 1033 * This macro returns a compile-time constant if its arguments are 1034 * compile-time constants. 1035 * 1036 * \warning This macro may evaluate its arguments multiple times or 1037 * zero times, so you should not pass arguments that contain 1038 * side effects. 1039 * 1040 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE. 1041 * 1042 * \param key_type A supported key type. 1043 * \param key_bits The size of the key in bits. 1044 * 1045 * \return If the parameters are valid and supported, return 1046 * a buffer size in bytes that guarantees that 1047 * psa_raw_key_agreement() will not fail with 1048 * #PSA_ERROR_BUFFER_TOO_SMALL. 1049 * If the parameters are a valid combination that 1050 * is not supported, return either a sensible size or 0. 1051 * If the parameters are not valid, 1052 * the return value is unspecified. 1053 */ 1054 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits) \ 1055 ((PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) || \ 1056 PSA_KEY_TYPE_IS_DH_KEY_PAIR(key_type)) ? PSA_BITS_TO_BYTES(key_bits) : 0u) 1057 1058 /** Maximum size of the output from psa_raw_key_agreement(). 1059 * 1060 * This macro expands to a compile-time constant integer. This value is the 1061 * maximum size of the output any raw key agreement algorithm, in bytes. 1062 * 1063 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(\p key_type, \p key_bits). 1064 */ 1065 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE 1 1066 1067 #if defined(PSA_WANT_ALG_ECDH) && \ 1068 (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS) > PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE) 1069 #undef PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE 1070 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS) 1071 #endif 1072 #if defined(PSA_WANT_ALG_FFDH) && \ 1073 (PSA_BITS_TO_BYTES(PSA_VENDOR_FFDH_MAX_KEY_BITS) > PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE) 1074 #undef PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE 1075 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_FFDH_MAX_KEY_BITS) 1076 #endif 1077 1078 /** The default IV size for a cipher algorithm, in bytes. 1079 * 1080 * The IV that is generated as part of a call to #psa_cipher_encrypt() is always 1081 * the default IV length for the algorithm. 1082 * 1083 * This macro can be used to allocate a buffer of sufficient size to 1084 * store the IV output from #psa_cipher_generate_iv() when using 1085 * a multi-part cipher operation. 1086 * 1087 * See also #PSA_CIPHER_IV_MAX_SIZE. 1088 * 1089 * \warning This macro may evaluate its arguments multiple times or 1090 * zero times, so you should not pass arguments that contain 1091 * side effects. 1092 * 1093 * \param key_type A symmetric key type that is compatible with algorithm \p alg. 1094 * 1095 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true). 1096 * 1097 * \return The default IV size for the specified key type and algorithm. 1098 * If the algorithm does not use an IV, return 0. 1099 * If the key type or cipher algorithm is not recognized, 1100 * or the parameters are incompatible, return 0. 1101 */ 1102 #define PSA_CIPHER_IV_LENGTH(key_type, alg) \ 1103 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1 && \ 1104 ((alg) == PSA_ALG_CTR || \ 1105 (alg) == PSA_ALG_CFB || \ 1106 (alg) == PSA_ALG_OFB || \ 1107 (alg) == PSA_ALG_XTS || \ 1108 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1109 (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1110 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 1111 (alg) == PSA_ALG_STREAM_CIPHER ? 12u : \ 1112 (alg) == PSA_ALG_CCM_STAR_NO_TAG ? 13u : \ 1113 0u) 1114 1115 /** The maximum IV size for all supported cipher algorithms, in bytes. 1116 * 1117 * See also #PSA_CIPHER_IV_LENGTH(). 1118 */ 1119 #define PSA_CIPHER_IV_MAX_SIZE 16u 1120 1121 /** The maximum size of the output of psa_cipher_encrypt(), in bytes. 1122 * 1123 * If the size of the output buffer is at least this large, it is guaranteed 1124 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1125 * Depending on the algorithm, the actual size of the output might be smaller. 1126 * 1127 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(\p input_length). 1128 * 1129 * \warning This macro may evaluate its arguments multiple times or 1130 * zero times, so you should not pass arguments that contain 1131 * side effects. 1132 * 1133 * \param key_type A symmetric key type that is compatible with algorithm 1134 * alg. 1135 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1136 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1137 * \param input_length Size of the input in bytes. 1138 * 1139 * \return A sufficient output size for the specified key type and 1140 * algorithm. If the key type or cipher algorithm is not 1141 * recognized, or the parameters are incompatible, 1142 * return 0. 1143 */ 1144 #define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1145 (alg == PSA_ALG_CBC_PKCS7 ? \ 1146 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1147 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1148 (input_length) + 1u) + \ 1149 PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0u) : \ 1150 (PSA_ALG_IS_CIPHER(alg) ? \ 1151 (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) : \ 1152 0u)) 1153 1154 /** A sufficient output buffer size for psa_cipher_encrypt(), for any of the 1155 * supported key types and cipher algorithms. 1156 * 1157 * If the size of the output buffer is at least this large, it is guaranteed 1158 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1159 * 1160 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1161 * 1162 * \param input_length Size of the input in bytes. 1163 * 1164 */ 1165 #define PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(input_length) \ 1166 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, \ 1167 (input_length) + 1u) + \ 1168 PSA_CIPHER_IV_MAX_SIZE) 1169 1170 /** The maximum size of the output of psa_cipher_decrypt(), in bytes. 1171 * 1172 * If the size of the output buffer is at least this large, it is guaranteed 1173 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1174 * Depending on the algorithm, the actual size of the output might be smaller. 1175 * 1176 * See also #PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(\p input_length). 1177 * 1178 * \param key_type A symmetric key type that is compatible with algorithm 1179 * alg. 1180 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1181 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1182 * \param input_length Size of the input in bytes. 1183 * 1184 * \return A sufficient output size for the specified key type and 1185 * algorithm. If the key type or cipher algorithm is not 1186 * recognized, or the parameters are incompatible, 1187 * return 0. 1188 */ 1189 #define PSA_CIPHER_DECRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1190 (PSA_ALG_IS_CIPHER(alg) && \ 1191 ((key_type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \ 1192 (input_length) : \ 1193 0u) 1194 1195 /** A sufficient output buffer size for psa_cipher_decrypt(), for any of the 1196 * supported key types and cipher algorithms. 1197 * 1198 * If the size of the output buffer is at least this large, it is guaranteed 1199 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1200 * 1201 * See also #PSA_CIPHER_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1202 * 1203 * \param input_length Size of the input in bytes. 1204 */ 1205 #define PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(input_length) \ 1206 (input_length) 1207 1208 /** A sufficient output buffer size for psa_cipher_update(). 1209 * 1210 * If the size of the output buffer is at least this large, it is guaranteed 1211 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1212 * The actual size of the output might be smaller in any given call. 1213 * 1214 * See also #PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 1215 * 1216 * \param key_type A symmetric key type that is compatible with algorithm 1217 * alg. 1218 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1219 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1220 * \param input_length Size of the input in bytes. 1221 * 1222 * \return A sufficient output size for the specified key type and 1223 * algorithm. If the key type or cipher algorithm is not 1224 * recognized, or the parameters are incompatible, return 0. 1225 */ 1226 #define PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 1227 (PSA_ALG_IS_CIPHER(alg) ? \ 1228 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1229 (((alg) == PSA_ALG_CBC_PKCS7 || \ 1230 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1231 (alg) == PSA_ALG_ECB_NO_PADDING) ? \ 1232 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1233 input_length) : \ 1234 (input_length)) : 0u) : \ 1235 0u) 1236 1237 /** A sufficient output buffer size for psa_cipher_update(), for any of the 1238 * supported key types and cipher algorithms. 1239 * 1240 * If the size of the output buffer is at least this large, it is guaranteed 1241 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1242 * 1243 * See also #PSA_CIPHER_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1244 * 1245 * \param input_length Size of the input in bytes. 1246 */ 1247 #define PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 1248 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length)) 1249 1250 /** A sufficient ciphertext buffer size for psa_cipher_finish(). 1251 * 1252 * If the size of the ciphertext buffer is at least this large, it is 1253 * guaranteed that psa_cipher_finish() will not fail due to an insufficient 1254 * ciphertext buffer size. The actual size of the output might be smaller in 1255 * any given call. 1256 * 1257 * See also #PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE(). 1258 * 1259 * \param key_type A symmetric key type that is compatible with algorithm 1260 * alg. 1261 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1262 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1263 * \return A sufficient output size for the specified key type and 1264 * algorithm. If the key type or cipher algorithm is not 1265 * recognized, or the parameters are incompatible, return 0. 1266 */ 1267 #define PSA_CIPHER_FINISH_OUTPUT_SIZE(key_type, alg) \ 1268 (PSA_ALG_IS_CIPHER(alg) ? \ 1269 (alg == PSA_ALG_CBC_PKCS7 ? \ 1270 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1271 0u) : \ 1272 0u) 1273 1274 /** A sufficient ciphertext buffer size for psa_cipher_finish(), for any of the 1275 * supported key types and cipher algorithms. 1276 * 1277 * See also #PSA_CIPHER_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 1278 */ 1279 #define PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE \ 1280 (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 1281 1282 #endif /* PSA_CRYPTO_SIZES_H */ 1283
