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 header. 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 * TF-PSA-Crypto 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 * This is a vendor-specific macro.*/ 228 #if defined(PSA_WANT_DH_RFC7919_8192) 229 #define PSA_VENDOR_FFDH_MAX_KEY_BITS 8192u 230 #elif defined(PSA_WANT_DH_RFC7919_6144) 231 #define PSA_VENDOR_FFDH_MAX_KEY_BITS 6144u 232 #elif defined(PSA_WANT_DH_RFC7919_4096) 233 #define PSA_VENDOR_FFDH_MAX_KEY_BITS 4096u 234 #elif defined(PSA_WANT_DH_RFC7919_3072) 235 #define PSA_VENDOR_FFDH_MAX_KEY_BITS 3072u 236 #elif defined(PSA_WANT_DH_RFC7919_2048) 237 #define PSA_VENDOR_FFDH_MAX_KEY_BITS 2048u 238 #else 239 #define PSA_VENDOR_FFDH_MAX_KEY_BITS 0u 240 #endif 241 242 /* The maximum size of an ECC key on this implementation, in bits. 243 * This is a vendor-specific macro. */ 244 #if defined(PSA_WANT_ECC_SECP_R1_521) 245 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 521u 246 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_512) 247 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 512u 248 #elif defined(PSA_WANT_ECC_MONTGOMERY_448) 249 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 448u 250 #elif defined(PSA_WANT_ECC_SECP_R1_384) 251 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384u 252 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_384) 253 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384u 254 #elif defined(PSA_WANT_ECC_SECP_R1_256) 255 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u 256 #elif defined(PSA_WANT_ECC_SECP_K1_256) 257 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u 258 #elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_256) 259 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u 260 #elif defined(PSA_WANT_ECC_MONTGOMERY_255) 261 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 255u 262 #elif defined(PSA_WANT_ECC_SECP_R1_224) 263 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224u 264 #elif defined(PSA_WANT_ECC_SECP_K1_224) 265 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224u 266 #elif defined(PSA_WANT_ECC_SECP_R1_192) 267 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192u 268 #elif defined(PSA_WANT_ECC_SECP_K1_192) 269 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192u 270 #else 271 #define PSA_VENDOR_ECC_MAX_CURVE_BITS 0u 272 #endif 273 274 /** This macro returns the maximum supported length of the PSK for the 275 * TLS-1.2 PSK-to-MS key derivation 276 * (#PSA_ALG_TLS12_PSK_TO_MS(\c hash_alg)). 277 * 278 * The maximum supported length does not depend on the chosen hash algorithm. 279 * 280 * Quoting RFC 4279, Sect 5.3: 281 * TLS implementations supporting these ciphersuites MUST support 282 * arbitrary PSK identities up to 128 octets in length, and arbitrary 283 * PSKs up to 64 octets in length. Supporting longer identities and 284 * keys is RECOMMENDED. 285 * 286 * Therefore, no implementation should define a value smaller than 64 287 * for #PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE. 288 */ 289 #define PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128u 290 291 /* The expected size of input passed to psa_tls12_ecjpake_to_pms_input, 292 * which is expected to work with P-256 curve only. */ 293 #define PSA_TLS12_ECJPAKE_TO_PMS_INPUT_SIZE 65u 294 295 /* The size of a serialized K.X coordinate to be used in 296 * psa_tls12_ecjpake_to_pms_input. This function only accepts the P-256 297 * curve. */ 298 #define PSA_TLS12_ECJPAKE_TO_PMS_DATA_SIZE 32u 299 300 /* The maximum number of iterations for PBKDF2 on this implementation, in bits. 301 * This is a vendor-specific macro. This can be configured if necessary */ 302 #define PSA_VENDOR_PBKDF2_MAX_ITERATIONS 0xffffffffU 303 304 /** The maximum size of a block cipher. */ 305 #define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16u 306 307 /** The size of the output of psa_mac_sign_finish(), in bytes. 308 * 309 * This is also the MAC size that psa_mac_verify_finish() expects. 310 * 311 * \warning This macro may evaluate its arguments multiple times or 312 * zero times, so you should not pass arguments that contain 313 * side effects. 314 * 315 * \param key_type The type of the MAC key. 316 * \param key_bits The size of the MAC key in bits. 317 * \param alg A MAC algorithm (\c PSA_ALG_XXX value such that 318 * #PSA_ALG_IS_MAC(\p alg) is true). 319 * 320 * \return The MAC size for the specified algorithm with 321 * the specified key parameters. 322 * \return 0 if the MAC algorithm is not recognized. 323 * \return Either 0 or the correct size for a MAC algorithm that 324 * the implementation recognizes, but does not support. 325 * \return Unspecified if the key parameters are not consistent 326 * with the algorithm. 327 */ 328 #define PSA_MAC_LENGTH(key_type, key_bits, alg) \ 329 ((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \ 330 PSA_ALG_IS_HMAC(alg) ? PSA_HASH_LENGTH(PSA_ALG_HMAC_GET_HASH(alg)) : \ 331 PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 332 ((void) (key_type), (void) (key_bits), 0u)) 333 334 /** The maximum size of the output of psa_aead_encrypt(), in bytes. 335 * 336 * If the size of the ciphertext buffer is at least this large, it is 337 * guaranteed that psa_aead_encrypt() will not fail due to an 338 * insufficient buffer size. Depending on the algorithm, the actual size of 339 * the ciphertext may be smaller. 340 * 341 * See also #PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(\p plaintext_length). 342 * 343 * \warning This macro may evaluate its arguments multiple times or 344 * zero times, so you should not pass arguments that contain 345 * side effects. 346 * 347 * \param key_type A symmetric key type that is 348 * compatible with algorithm \p alg. 349 * \param alg An AEAD algorithm 350 * (\c PSA_ALG_XXX value such that 351 * #PSA_ALG_IS_AEAD(\p alg) is true). 352 * \param plaintext_length Size of the plaintext in bytes. 353 * 354 * \return The AEAD ciphertext size for the specified 355 * algorithm. 356 * If the key type or AEAD algorithm is not 357 * recognized, or the parameters are incompatible, 358 * return 0. 359 */ 360 #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length) \ 361 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 362 (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 363 0u) 364 365 /** A sufficient output buffer size for psa_aead_encrypt(), for any of the 366 * supported key types and AEAD algorithms. 367 * 368 * If the size of the ciphertext buffer is at least this large, it is guaranteed 369 * that psa_aead_encrypt() will not fail due to an insufficient buffer size. 370 * 371 * \note This macro returns a compile-time constant if its arguments are 372 * compile-time constants. 373 * 374 * See also #PSA_AEAD_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, 375 * \p plaintext_length). 376 * 377 * \param plaintext_length Size of the plaintext in bytes. 378 * 379 * \return A sufficient output buffer size for any of the 380 * supported key types and AEAD algorithms. 381 * 382 */ 383 #define PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length) \ 384 ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE) 385 386 387 /** The maximum size of the output of psa_aead_decrypt(), in bytes. 388 * 389 * If the size of the plaintext buffer is at least this large, it is 390 * guaranteed that psa_aead_decrypt() will not fail due to an 391 * insufficient buffer size. Depending on the algorithm, the actual size of 392 * the plaintext may be smaller. 393 * 394 * See also #PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(\p ciphertext_length). 395 * 396 * \warning This macro may evaluate its arguments multiple times or 397 * zero times, so you should not pass arguments that contain 398 * side effects. 399 * 400 * \param key_type A symmetric key type that is 401 * compatible with algorithm \p alg. 402 * \param alg An AEAD algorithm 403 * (\c PSA_ALG_XXX value such that 404 * #PSA_ALG_IS_AEAD(\p alg) is true). 405 * \param ciphertext_length Size of the plaintext in bytes. 406 * 407 * \return The AEAD ciphertext size for the specified 408 * algorithm. 409 * If the key type or AEAD algorithm is not 410 * recognized, or the parameters are incompatible, 411 * return 0. 412 */ 413 #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length) \ 414 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 415 (ciphertext_length) > PSA_ALG_AEAD_GET_TAG_LENGTH(alg) ? \ 416 (ciphertext_length) - PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \ 417 0u) 418 419 /** A sufficient output buffer size for psa_aead_decrypt(), for any of the 420 * supported key types and AEAD algorithms. 421 * 422 * If the size of the plaintext buffer is at least this large, it is guaranteed 423 * that psa_aead_decrypt() will not fail due to an insufficient buffer size. 424 * 425 * \note This macro returns a compile-time constant if its arguments are 426 * compile-time constants. 427 * 428 * See also #PSA_AEAD_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, 429 * \p ciphertext_length). 430 * 431 * \param ciphertext_length Size of the ciphertext in bytes. 432 * 433 * \return A sufficient output buffer size for any of the 434 * supported key types and AEAD algorithms. 435 * 436 */ 437 #define PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(ciphertext_length) \ 438 (ciphertext_length) 439 440 /** The default nonce size for an AEAD algorithm, in bytes. 441 * 442 * This macro can be used to allocate a buffer of sufficient size to 443 * store the nonce output from #psa_aead_generate_nonce(). 444 * 445 * See also #PSA_AEAD_NONCE_MAX_SIZE. 446 * 447 * \note This is not the maximum size of nonce supported as input to 448 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 449 * just the default size that is generated by #psa_aead_generate_nonce(). 450 * 451 * \warning This macro may evaluate its arguments multiple times or 452 * zero times, so you should not pass arguments that contain 453 * side effects. 454 * 455 * \param key_type A symmetric key type that is compatible with 456 * algorithm \p alg. 457 * 458 * \param alg An AEAD algorithm (\c PSA_ALG_XXX value such that 459 * #PSA_ALG_IS_AEAD(\p alg) is true). 460 * 461 * \return The default nonce size for the specified key type and algorithm. 462 * If the key type or AEAD algorithm is not recognized, 463 * or the parameters are incompatible, return 0. 464 */ 465 #define PSA_AEAD_NONCE_LENGTH(key_type, alg) \ 466 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \ 467 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CCM) ? 13u : \ 468 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_GCM) ? 12u : \ 469 0u : \ 470 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 471 MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12u : \ 472 0u) 473 474 /** The maximum default nonce size among all supported pairs of key types and 475 * AEAD algorithms, in bytes. 476 * 477 * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH() 478 * may return. 479 * 480 * \note This is not the maximum size of nonce supported as input to 481 * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(), 482 * just the largest size that may be generated by 483 * #psa_aead_generate_nonce(). 484 */ 485 #define PSA_AEAD_NONCE_MAX_SIZE 13u 486 487 /** A sufficient output buffer size for psa_aead_update(). 488 * 489 * If the size of the output buffer is at least this large, it is 490 * guaranteed that psa_aead_update() will not fail due to an 491 * insufficient buffer size. The actual size of the output may be smaller 492 * in any given call. 493 * 494 * See also #PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 495 * 496 * \warning This macro may evaluate its arguments multiple times or 497 * zero times, so you should not pass arguments that contain 498 * side effects. 499 * 500 * \param key_type A symmetric key type that is 501 * compatible with algorithm \p alg. 502 * \param alg An AEAD algorithm 503 * (\c PSA_ALG_XXX value such that 504 * #PSA_ALG_IS_AEAD(\p alg) is true). 505 * \param input_length Size of the input in bytes. 506 * 507 * \return A sufficient output buffer size for the specified 508 * algorithm. 509 * If the key type or AEAD algorithm is not 510 * recognized, or the parameters are incompatible, 511 * return 0. 512 */ 513 /* For all the AEAD modes defined in this specification, it is possible 514 * to emit output without delay. However, hardware may not always be 515 * capable of this. So for modes based on a block cipher, allow the 516 * implementation to delay the output until it has a full block. */ 517 #define PSA_AEAD_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 518 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \ 519 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 520 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), (input_length)) : \ 521 (input_length) : \ 522 0u) 523 524 /** A sufficient output buffer size for psa_aead_update(), for any of the 525 * supported key types and AEAD algorithms. 526 * 527 * If the size of the output buffer is at least this large, it is guaranteed 528 * that psa_aead_update() will not fail due to an insufficient buffer size. 529 * 530 * See also #PSA_AEAD_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 531 * 532 * \param input_length Size of the input in bytes. 533 */ 534 #define PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 535 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length))) 536 537 /** A sufficient ciphertext buffer size for psa_aead_finish(). 538 * 539 * If the size of the ciphertext buffer is at least this large, it is 540 * guaranteed that psa_aead_finish() will not fail due to an 541 * insufficient ciphertext buffer size. The actual size of the output may 542 * be smaller in any given call. 543 * 544 * See also #PSA_AEAD_FINISH_OUTPUT_MAX_SIZE. 545 * 546 * \param key_type A symmetric key type that is 547 compatible with algorithm \p alg. 548 * \param alg An AEAD algorithm 549 * (\c PSA_ALG_XXX value such that 550 * #PSA_ALG_IS_AEAD(\p alg) is true). 551 * 552 * \return A sufficient ciphertext buffer size for the 553 * specified algorithm. 554 * If the key type or AEAD algorithm is not 555 * recognized, or the parameters are incompatible, 556 * return 0. 557 */ 558 #define PSA_AEAD_FINISH_OUTPUT_SIZE(key_type, alg) \ 559 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 560 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 561 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 562 0u) 563 564 /** A sufficient ciphertext buffer size for psa_aead_finish(), for any of the 565 * supported key types and AEAD algorithms. 566 * 567 * See also #PSA_AEAD_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 568 */ 569 #define PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 570 571 /** A sufficient plaintext buffer size for psa_aead_verify(). 572 * 573 * If the size of the plaintext buffer is at least this large, it is 574 * guaranteed that psa_aead_verify() will not fail due to an 575 * insufficient plaintext buffer size. The actual size of the output may 576 * be smaller in any given call. 577 * 578 * See also #PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE. 579 * 580 * \param key_type A symmetric key type that is 581 * compatible with algorithm \p alg. 582 * \param alg An AEAD algorithm 583 * (\c PSA_ALG_XXX value such that 584 * #PSA_ALG_IS_AEAD(\p alg) is true). 585 * 586 * \return A sufficient plaintext buffer size for the 587 * specified algorithm. 588 * If the key type or AEAD algorithm is not 589 * recognized, or the parameters are incompatible, 590 * return 0. 591 */ 592 #define PSA_AEAD_VERIFY_OUTPUT_SIZE(key_type, alg) \ 593 (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \ 594 PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ 595 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 596 0u) 597 598 /** A sufficient plaintext buffer size for psa_aead_verify(), for any of the 599 * supported key types and AEAD algorithms. 600 * 601 * See also #PSA_AEAD_VERIFY_OUTPUT_SIZE(\p key_type, \p alg). 602 */ 603 #define PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 604 605 #define PSA_RSA_MINIMUM_PADDING_SIZE(alg) \ 606 (PSA_ALG_IS_RSA_OAEP(alg) ? \ 607 2u * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1u : \ 608 11u /*PKCS#1v1.5*/) 609 610 /** 611 * \brief ECDSA signature size for a given curve bit size 612 * 613 * \param curve_bits Curve size in bits. 614 * \return Signature size in bytes. 615 * 616 * \note This macro returns a compile-time constant if its argument is one. 617 */ 618 #define PSA_ECDSA_SIGNATURE_SIZE(curve_bits) \ 619 (PSA_BITS_TO_BYTES(curve_bits) * 2u) 620 621 /** Sufficient signature buffer size for psa_sign_hash(). 622 * 623 * This macro returns a sufficient buffer size for a signature using a key 624 * of the specified type and size, with the specified algorithm. 625 * Note that the actual size of the signature may be smaller 626 * (some algorithms produce a variable-size signature). 627 * 628 * \warning This function may call its arguments multiple times or 629 * zero times, so you should not pass arguments that contain 630 * side effects. 631 * 632 * \param key_type An asymmetric key type (this may indifferently be a 633 * key pair type or a public key type). 634 * \param key_bits The size of the key in bits. 635 * \param alg The signature algorithm. 636 * 637 * \return If the parameters are valid and supported, return 638 * a buffer size in bytes that guarantees that 639 * psa_sign_hash() will not fail with 640 * #PSA_ERROR_BUFFER_TOO_SMALL. 641 * If the parameters are a valid combination that is not supported, 642 * return either a sensible size or 0. 643 * If the parameters are not valid, the 644 * return value is unspecified. 645 */ 646 #define PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \ 647 (PSA_KEY_TYPE_IS_RSA(key_type) ? ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \ 648 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \ 649 ((void) alg, 0u)) 650 651 #define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE \ 652 PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 653 654 /** \def PSA_SIGNATURE_MAX_SIZE 655 * 656 * Maximum size of an asymmetric signature. 657 * 658 * This macro expands to a compile-time constant integer. This value 659 * is the maximum size of a signature in bytes. 660 */ 661 #define PSA_SIGNATURE_MAX_SIZE 1 662 663 #if (defined(PSA_WANT_ALG_ECDSA) || defined(PSA_WANT_ALG_DETERMINISTIC_ECDSA)) && \ 664 (PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE > PSA_SIGNATURE_MAX_SIZE) 665 #undef PSA_SIGNATURE_MAX_SIZE 666 #define PSA_SIGNATURE_MAX_SIZE PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE 667 #endif 668 #if (defined(PSA_WANT_ALG_RSA_PKCS1V15_SIGN) || defined(PSA_WANT_ALG_RSA_PSS)) && \ 669 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_SIGNATURE_MAX_SIZE) 670 #undef PSA_SIGNATURE_MAX_SIZE 671 #define PSA_SIGNATURE_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) 672 #endif 673 674 /** Sufficient output buffer size for psa_asymmetric_encrypt(). 675 * 676 * This macro returns a sufficient buffer size for a ciphertext produced using 677 * a key of the specified type and size, with the specified algorithm. 678 * Note that the actual size of the ciphertext may be smaller, depending 679 * on the algorithm. 680 * 681 * \warning This function may call its arguments multiple times or 682 * zero times, so you should not pass arguments that contain 683 * side effects. 684 * 685 * \param key_type An asymmetric key type (this may indifferently be a 686 * key pair type or a public key type). 687 * \param key_bits The size of the key in bits. 688 * \param alg The asymmetric encryption algorithm. 689 * 690 * \return If the parameters are valid and supported, return 691 * a buffer size in bytes that guarantees that 692 * psa_asymmetric_encrypt() will not fail with 693 * #PSA_ERROR_BUFFER_TOO_SMALL. 694 * If the parameters are a valid combination that is not supported, 695 * return either a sensible size or 0. 696 * If the parameters are not valid, the 697 * return value is unspecified. 698 */ 699 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 700 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 701 ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \ 702 0u) 703 704 /** A sufficient output buffer size for psa_asymmetric_encrypt(), for any 705 * supported asymmetric encryption. 706 * 707 * See also #PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 708 */ 709 /* This macro assumes that RSA is the only supported asymmetric encryption. */ 710 #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE \ 711 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 712 713 /** Sufficient output buffer size for psa_asymmetric_decrypt(). 714 * 715 * This macro returns a sufficient buffer size for a plaintext produced using 716 * a key of the specified type and size, with the specified algorithm. 717 * Note that the actual size of the plaintext may be smaller, depending 718 * on the algorithm. 719 * 720 * \warning This function may call its arguments multiple times or 721 * zero times, so you should not pass arguments that contain 722 * side effects. 723 * 724 * \param key_type An asymmetric key type (this may indifferently be a 725 * key pair type or a public key type). 726 * \param key_bits The size of the key in bits. 727 * \param alg The asymmetric encryption algorithm. 728 * 729 * \return If the parameters are valid and supported, return 730 * a buffer size in bytes that guarantees that 731 * psa_asymmetric_decrypt() will not fail with 732 * #PSA_ERROR_BUFFER_TOO_SMALL. 733 * If the parameters are a valid combination that is not supported, 734 * return either a sensible size or 0. 735 * If the parameters are not valid, the 736 * return value is unspecified. 737 */ 738 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ 739 (PSA_KEY_TYPE_IS_RSA(key_type) ? \ 740 PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \ 741 0u) 742 743 /** A sufficient output buffer size for psa_asymmetric_decrypt(), for any 744 * supported asymmetric decryption. 745 * 746 * This macro assumes that RSA is the only supported asymmetric encryption. 747 * 748 * See also #PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg). 749 */ 750 #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE \ 751 (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)) 752 753 /* Maximum size of the ASN.1 encoding of an INTEGER with the specified 754 * number of bits. 755 * 756 * This definition assumes that bits <= 2^19 - 9 so that the length field 757 * is at most 3 bytes. The length of the encoding is the length of the 758 * bit string padded to a whole number of bytes plus: 759 * - 1 type byte; 760 * - 1 to 3 length bytes; 761 * - 0 to 1 bytes of leading 0 due to the sign bit. 762 */ 763 #define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \ 764 ((bits) / 8u + 5u) 765 766 /* Maximum size of the export encoding of an RSA public key. 767 * Assumes that the public exponent is less than 2^32. 768 * 769 * RSAPublicKey ::= SEQUENCE { 770 * modulus INTEGER, -- n 771 * publicExponent INTEGER } -- e 772 * 773 * - 4 bytes of SEQUENCE overhead; 774 * - n : INTEGER; 775 * - 7 bytes for the public exponent. 776 */ 777 #define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 778 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11u) 779 780 /* Maximum size of the export encoding of an RSA key pair. 781 * Assumes that the public exponent is less than 2^32 and that the size 782 * difference between the two primes is at most 1 bit. 783 * 784 * RSAPrivateKey ::= SEQUENCE { 785 * version Version, -- 0 786 * modulus INTEGER, -- N-bit 787 * publicExponent INTEGER, -- 32-bit 788 * privateExponent INTEGER, -- N-bit 789 * prime1 INTEGER, -- N/2-bit 790 * prime2 INTEGER, -- N/2-bit 791 * exponent1 INTEGER, -- N/2-bit 792 * exponent2 INTEGER, -- N/2-bit 793 * coefficient INTEGER, -- N/2-bit 794 * } 795 * 796 * - 4 bytes of SEQUENCE overhead; 797 * - 3 bytes of version; 798 * - 7 half-size INTEGERs plus 2 full-size INTEGERs, 799 * overapproximated as 9 half-size INTEGERS; 800 * - 7 bytes for the public exponent. 801 */ 802 #define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) \ 803 (9u * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2u + 1u) + 14u) 804 805 /* Maximum size of the export encoding of a DSA public key. 806 * 807 * SubjectPublicKeyInfo ::= SEQUENCE { 808 * algorithm AlgorithmIdentifier, 809 * subjectPublicKey BIT STRING } -- contains DSAPublicKey 810 * AlgorithmIdentifier ::= SEQUENCE { 811 * algorithm OBJECT IDENTIFIER, 812 * parameters Dss-Params } -- SEQUENCE of 3 INTEGERs 813 * DSAPublicKey ::= INTEGER -- public key, Y 814 * 815 * - 3 * 4 bytes of SEQUENCE overhead; 816 * - 1 + 1 + 7 bytes of algorithm (DSA OID); 817 * - 4 bytes of BIT STRING overhead; 818 * - 3 full-size INTEGERs (p, g, y); 819 * - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits). 820 */ 821 #define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ 822 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3u + 59u) 823 824 /* Maximum size of the export encoding of a DSA key pair. 825 * 826 * DSAPrivateKey ::= SEQUENCE { 827 * version Version, -- 0 828 * prime INTEGER, -- p 829 * subprime INTEGER, -- q 830 * generator INTEGER, -- g 831 * public INTEGER, -- y 832 * private INTEGER, -- x 833 * } 834 * 835 * - 4 bytes of SEQUENCE overhead; 836 * - 3 bytes of version; 837 * - 3 full-size INTEGERs (p, g, y); 838 * - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits). 839 */ 840 #define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) \ 841 (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3u + 75u) 842 843 /* Maximum size of the export encoding of an ECC public key. 844 * 845 * The representation of an ECC public key is: 846 * - The byte 0x04; 847 * - `x_P` as a `ceiling(m/8)`-byte string, big-endian; 848 * - `y_P` as a `ceiling(m/8)`-byte string, big-endian; 849 * - where m is the bit size associated with the curve. 850 * 851 * - 1 byte + 2 * point size. 852 */ 853 #define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \ 854 (2u * PSA_BITS_TO_BYTES(key_bits) + 1u) 855 856 /* Maximum size of the export encoding of an ECC key pair. 857 * 858 * An ECC key pair is represented by the secret value. 859 */ 860 #define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) \ 861 (PSA_BITS_TO_BYTES(key_bits)) 862 863 /* Maximum size of the export encoding of an DH key pair. 864 * 865 * An DH key pair is represented by the secret value. 866 */ 867 #define PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(key_bits) \ 868 (PSA_BITS_TO_BYTES(key_bits)) 869 870 /* Maximum size of the export encoding of an DH public key. 871 */ 872 #define PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(key_bits) \ 873 (PSA_BITS_TO_BYTES(key_bits)) 874 875 /** Sufficient output buffer size for psa_export_key() or 876 * psa_export_public_key(). 877 * 878 * This macro returns a compile-time constant if its arguments are 879 * compile-time constants. 880 * 881 * \warning This macro may evaluate its arguments multiple times or 882 * zero times, so you should not pass arguments that contain 883 * side effects. 884 * 885 * The following code illustrates how to allocate enough memory to export 886 * a key by querying the key type and size at runtime. 887 * \code{c} 888 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 889 * psa_status_t status; 890 * status = psa_get_key_attributes(key, &attributes); 891 * if (status != PSA_SUCCESS) handle_error(...); 892 * psa_key_type_t key_type = psa_get_key_type(&attributes); 893 * size_t key_bits = psa_get_key_bits(&attributes); 894 * size_t buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits); 895 * psa_reset_key_attributes(&attributes); 896 * uint8_t *buffer = malloc(buffer_size); 897 * if (buffer == NULL) handle_error(...); 898 * size_t buffer_length; 899 * status = psa_export_key(key, buffer, buffer_size, &buffer_length); 900 * if (status != PSA_SUCCESS) handle_error(...); 901 * \endcode 902 * 903 * \param key_type A supported key type. 904 * \param key_bits The size of the key in bits. 905 * 906 * \return If the parameters are valid and supported, return 907 * a buffer size in bytes that guarantees that 908 * psa_export_key() or psa_export_public_key() will not fail with 909 * #PSA_ERROR_BUFFER_TOO_SMALL. 910 * If the parameters are a valid combination that is not supported, 911 * return either a sensible size or 0. 912 * If the parameters are not valid, the return value is unspecified. 913 */ 914 #define PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits) \ 915 (PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 916 PSA_KEY_TYPE_IS_DH(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 917 (key_type) == PSA_KEY_TYPE_RSA_KEY_PAIR ? PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 918 (key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 919 (key_type) == PSA_KEY_TYPE_DSA_KEY_PAIR ? PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) : \ 920 (key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 921 PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) : \ 922 PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 923 0u) 924 925 /** Sufficient output buffer size for psa_export_public_key(). 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 * The following code illustrates how to allocate enough memory to export 935 * a public key by querying the key type and size at runtime. 936 * \code{c} 937 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; 938 * psa_status_t status; 939 * status = psa_get_key_attributes(key, &attributes); 940 * if (status != PSA_SUCCESS) handle_error(...); 941 * psa_key_type_t key_type = psa_get_key_type(&attributes); 942 * size_t key_bits = psa_get_key_bits(&attributes); 943 * size_t buffer_size = PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits); 944 * psa_reset_key_attributes(&attributes); 945 * uint8_t *buffer = malloc(buffer_size); 946 * if (buffer == NULL) handle_error(...); 947 * size_t buffer_length; 948 * status = psa_export_public_key(key, buffer, buffer_size, &buffer_length); 949 * if (status != PSA_SUCCESS) handle_error(...); 950 * \endcode 951 * 952 * \param key_type A public key or key pair key type. 953 * \param key_bits The size of the key in bits. 954 * 955 * \return If the parameters are valid and supported, return 956 * a buffer size in bytes that guarantees that 957 * psa_export_public_key() will not fail with 958 * #PSA_ERROR_BUFFER_TOO_SMALL. 959 * If the parameters are a valid combination that is not 960 * supported, return either a sensible size or 0. 961 * If the parameters are not valid, 962 * the return value is unspecified. 963 * 964 * If the parameters are valid and supported, 965 * return the same result as 966 * #PSA_EXPORT_KEY_OUTPUT_SIZE( 967 * \p #PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(\p key_type), 968 * \p key_bits). 969 */ 970 #define PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits) \ 971 (PSA_KEY_TYPE_IS_RSA(key_type) ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 972 PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ 973 PSA_KEY_TYPE_IS_DH(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ 974 0u) 975 976 /** Sufficient buffer size for exporting any asymmetric key pair. 977 * 978 * This macro expands to a compile-time constant integer. This value is 979 * a sufficient buffer size when calling psa_export_key() to export any 980 * asymmetric key pair, regardless of the exact key type and key size. 981 * 982 * See also #PSA_EXPORT_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 983 */ 984 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE 1 985 986 #if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_BASIC) && \ 987 (PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) > \ 988 PSA_EXPORT_KEY_PAIR_MAX_SIZE) 989 #undef PSA_EXPORT_KEY_PAIR_MAX_SIZE 990 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 991 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 992 #endif 993 #if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_BASIC) && \ 994 (PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 995 PSA_EXPORT_KEY_PAIR_MAX_SIZE) 996 #undef PSA_EXPORT_KEY_PAIR_MAX_SIZE 997 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 998 PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) 999 #endif 1000 #if defined(PSA_WANT_KEY_TYPE_DH_KEY_PAIR_BASIC) && \ 1001 (PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) > \ 1002 PSA_EXPORT_KEY_PAIR_MAX_SIZE) 1003 #undef PSA_EXPORT_KEY_PAIR_MAX_SIZE 1004 #define PSA_EXPORT_KEY_PAIR_MAX_SIZE \ 1005 PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) 1006 #endif 1007 1008 /** Sufficient buffer size for exporting any asymmetric public key. 1009 * 1010 * This macro expands to a compile-time constant integer. This value is 1011 * a sufficient buffer size when calling psa_export_key() or 1012 * psa_export_public_key() to export any asymmetric public key, 1013 * regardless of the exact key type and key size. 1014 * 1015 * See also #PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(\p key_type, \p key_bits). 1016 */ 1017 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1 1018 1019 #if defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY) && \ 1020 (PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) > \ 1021 PSA_EXPORT_PUBLIC_KEY_MAX_SIZE) 1022 #undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1023 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 1024 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) 1025 #endif 1026 #if defined(PSA_WANT_KEY_TYPE_RSA_PUBLIC_KEY) && \ 1027 (PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \ 1028 PSA_EXPORT_PUBLIC_KEY_MAX_SIZE) 1029 #undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1030 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 1031 PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) 1032 #endif 1033 #if defined(PSA_WANT_KEY_TYPE_DH_PUBLIC_KEY) && \ 1034 (PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) > \ 1035 PSA_EXPORT_PUBLIC_KEY_MAX_SIZE) 1036 #undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1037 #define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \ 1038 PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) 1039 #endif 1040 1041 /** Sufficient output buffer size for psa_raw_key_agreement(). 1042 * 1043 * This macro returns a compile-time constant if its arguments are 1044 * compile-time constants. 1045 * 1046 * \warning This macro may evaluate its arguments multiple times or 1047 * zero times, so you should not pass arguments that contain 1048 * side effects. 1049 * 1050 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE. 1051 * 1052 * \param key_type A supported key type. 1053 * \param key_bits The size of the key in bits. 1054 * 1055 * \return If the parameters are valid and supported, return 1056 * a buffer size in bytes that guarantees that 1057 * psa_raw_key_agreement() will not fail with 1058 * #PSA_ERROR_BUFFER_TOO_SMALL. 1059 * If the parameters are a valid combination that 1060 * is not supported, return either a sensible size or 0. 1061 * If the parameters are not valid, 1062 * the return value is unspecified. 1063 */ 1064 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits) \ 1065 ((PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) || \ 1066 PSA_KEY_TYPE_IS_DH_KEY_PAIR(key_type)) ? PSA_BITS_TO_BYTES(key_bits) : 0u) 1067 1068 /** Maximum size of the output from psa_raw_key_agreement(). 1069 * 1070 * This macro expands to a compile-time constant integer. This value is the 1071 * maximum size of the output any raw key agreement algorithm, in bytes. 1072 * 1073 * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(\p key_type, \p key_bits). 1074 */ 1075 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE 1 1076 1077 #if defined(PSA_WANT_ALG_ECDH) && \ 1078 (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS) > PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE) 1079 #undef PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE 1080 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS) 1081 #endif 1082 #if defined(PSA_WANT_ALG_FFDH) && \ 1083 (PSA_BITS_TO_BYTES(PSA_VENDOR_FFDH_MAX_KEY_BITS) > PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE) 1084 #undef PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE 1085 #define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_FFDH_MAX_KEY_BITS) 1086 #endif 1087 1088 /** The default IV size for a cipher algorithm, in bytes. 1089 * 1090 * The IV that is generated as part of a call to #psa_cipher_encrypt() is always 1091 * the default IV length for the algorithm. 1092 * 1093 * This macro can be used to allocate a buffer of sufficient size to 1094 * store the IV output from #psa_cipher_generate_iv() when using 1095 * a multi-part cipher operation. 1096 * 1097 * See also #PSA_CIPHER_IV_MAX_SIZE. 1098 * 1099 * \warning This macro may evaluate its arguments multiple times or 1100 * zero times, so you should not pass arguments that contain 1101 * side effects. 1102 * 1103 * \param key_type A symmetric key type that is compatible with algorithm \p alg. 1104 * 1105 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true). 1106 * 1107 * \return The default IV size for the specified key type and algorithm. 1108 * If the algorithm does not use an IV, return 0. 1109 * If the key type or cipher algorithm is not recognized, 1110 * or the parameters are incompatible, return 0. 1111 */ 1112 #define PSA_CIPHER_IV_LENGTH(key_type, alg) \ 1113 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1 && \ 1114 ((alg) == PSA_ALG_CTR || \ 1115 (alg) == PSA_ALG_CFB || \ 1116 (alg) == PSA_ALG_OFB || \ 1117 (alg) == PSA_ALG_XTS || \ 1118 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1119 (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1120 (key_type) == PSA_KEY_TYPE_CHACHA20 && \ 1121 (alg) == PSA_ALG_STREAM_CIPHER ? 12u : \ 1122 (alg) == PSA_ALG_CCM_STAR_NO_TAG ? 13u : \ 1123 0u) 1124 1125 /** The maximum IV size for all supported cipher algorithms, in bytes. 1126 * 1127 * See also #PSA_CIPHER_IV_LENGTH(). 1128 */ 1129 #define PSA_CIPHER_IV_MAX_SIZE 16u 1130 1131 /** The maximum size of the output of psa_cipher_encrypt(), in bytes. 1132 * 1133 * If the size of the output buffer is at least this large, it is guaranteed 1134 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1135 * Depending on the algorithm, the actual size of the output might be smaller. 1136 * 1137 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(\p input_length). 1138 * 1139 * \warning This macro may evaluate its arguments multiple times or 1140 * zero times, so you should not pass arguments that contain 1141 * side effects. 1142 * 1143 * \param key_type A symmetric key type that is compatible with algorithm 1144 * alg. 1145 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1146 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1147 * \param input_length Size of the input in bytes. 1148 * 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, 1152 * return 0. 1153 */ 1154 #define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1155 (alg == PSA_ALG_CBC_PKCS7 ? \ 1156 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1157 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1158 (input_length) + 1u) + \ 1159 PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0u) : \ 1160 (PSA_ALG_IS_CIPHER(alg) ? \ 1161 (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) : \ 1162 0u)) 1163 1164 /** A sufficient output buffer size for psa_cipher_encrypt(), for any of the 1165 * supported key types and cipher algorithms. 1166 * 1167 * If the size of the output buffer is at least this large, it is guaranteed 1168 * that psa_cipher_encrypt() will not fail due to an insufficient buffer size. 1169 * 1170 * See also #PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1171 * 1172 * \param input_length Size of the input in bytes. 1173 * 1174 */ 1175 #define PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(input_length) \ 1176 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, \ 1177 (input_length) + 1u) + \ 1178 PSA_CIPHER_IV_MAX_SIZE) 1179 1180 /** The maximum size of the output of psa_cipher_decrypt(), in bytes. 1181 * 1182 * If the size of the output buffer is at least this large, it is guaranteed 1183 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1184 * Depending on the algorithm, the actual size of the output might be smaller. 1185 * 1186 * See also #PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(\p input_length). 1187 * 1188 * \param key_type A symmetric key type that is compatible with algorithm 1189 * alg. 1190 * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that 1191 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1192 * \param input_length Size of the input in bytes. 1193 * 1194 * \return A sufficient output size for the specified key type and 1195 * algorithm. If the key type or cipher algorithm is not 1196 * recognized, or the parameters are incompatible, 1197 * return 0. 1198 */ 1199 #define PSA_CIPHER_DECRYPT_OUTPUT_SIZE(key_type, alg, input_length) \ 1200 (PSA_ALG_IS_CIPHER(alg) && \ 1201 ((key_type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \ 1202 (input_length) : \ 1203 0u) 1204 1205 /** A sufficient output buffer size for psa_cipher_decrypt(), for any of the 1206 * supported key types and cipher algorithms. 1207 * 1208 * If the size of the output buffer is at least this large, it is guaranteed 1209 * that psa_cipher_decrypt() will not fail due to an insufficient buffer size. 1210 * 1211 * See also #PSA_CIPHER_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1212 * 1213 * \param input_length Size of the input in bytes. 1214 */ 1215 #define PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(input_length) \ 1216 (input_length) 1217 1218 /** A sufficient output buffer size for psa_cipher_update(). 1219 * 1220 * If the size of the output buffer is at least this large, it is guaranteed 1221 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1222 * The actual size of the output might be smaller in any given call. 1223 * 1224 * See also #PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(\p input_length). 1225 * 1226 * \param key_type A symmetric key type that is compatible with algorithm 1227 * alg. 1228 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1229 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1230 * \param input_length Size of the input in bytes. 1231 * 1232 * \return A sufficient output size for the specified key type and 1233 * algorithm. If the key type or cipher algorithm is not 1234 * recognized, or the parameters are incompatible, return 0. 1235 */ 1236 #define PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \ 1237 (PSA_ALG_IS_CIPHER(alg) ? \ 1238 (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \ 1239 (((alg) == PSA_ALG_CBC_PKCS7 || \ 1240 (alg) == PSA_ALG_CBC_NO_PADDING || \ 1241 (alg) == PSA_ALG_ECB_NO_PADDING) ? \ 1242 PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \ 1243 input_length) : \ 1244 (input_length)) : 0u) : \ 1245 0u) 1246 1247 /** A sufficient output buffer size for psa_cipher_update(), for any of the 1248 * supported key types and cipher algorithms. 1249 * 1250 * If the size of the output buffer is at least this large, it is guaranteed 1251 * that psa_cipher_update() will not fail due to an insufficient buffer size. 1252 * 1253 * See also #PSA_CIPHER_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length). 1254 * 1255 * \param input_length Size of the input in bytes. 1256 */ 1257 #define PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(input_length) \ 1258 (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length)) 1259 1260 /** A sufficient ciphertext buffer size for psa_cipher_finish(). 1261 * 1262 * If the size of the ciphertext buffer is at least this large, it is 1263 * guaranteed that psa_cipher_finish() will not fail due to an insufficient 1264 * ciphertext buffer size. The actual size of the output might be smaller in 1265 * any given call. 1266 * 1267 * See also #PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE(). 1268 * 1269 * \param key_type A symmetric key type that is compatible with algorithm 1270 * alg. 1271 * \param alg A cipher algorithm (PSA_ALG_XXX value such that 1272 * #PSA_ALG_IS_CIPHER(\p alg) is true). 1273 * \return A sufficient output size for the specified key type and 1274 * algorithm. If the key type or cipher algorithm is not 1275 * recognized, or the parameters are incompatible, return 0. 1276 */ 1277 #define PSA_CIPHER_FINISH_OUTPUT_SIZE(key_type, alg) \ 1278 (PSA_ALG_IS_CIPHER(alg) ? \ 1279 (alg == PSA_ALG_CBC_PKCS7 ? \ 1280 PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ 1281 0u) : \ 1282 0u) 1283 1284 /** A sufficient ciphertext buffer size for psa_cipher_finish(), for any of the 1285 * supported key types and cipher algorithms. 1286 * 1287 * See also #PSA_CIPHER_FINISH_OUTPUT_SIZE(\p key_type, \p alg). 1288 */ 1289 #define PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE \ 1290 (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE) 1291 1292 #endif /* PSA_CRYPTO_SIZES_H */ 1293
