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+/**
+ * \file psa/crypto_sizes.h
+ *
+ * \brief PSA cryptography module: Mbed TLS buffer size macros
+ *
+ * \note This file may not be included directly. Applications must
+ * include psa/crypto.h.
+ *
+ * This file contains the definitions of macros that are useful to
+ * compute buffer sizes. The signatures and semantics of these macros
+ * are standardized, but the definitions are not, because they depend on
+ * the available algorithms and, in some cases, on permitted tolerances
+ * on buffer sizes.
+ *
+ * In implementations with isolation between the application and the
+ * cryptography module, implementers should take care to ensure that
+ * the definitions that are exposed to applications match what the
+ * module implements.
+ *
+ * Macros that compute sizes whose values do not depend on the
+ * implementation are in crypto.h.
+ */
+/*
+ * Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+
+#ifndef PSA_CRYPTO_SIZES_H
+#define PSA_CRYPTO_SIZES_H
+
+/*
+ * Include the build-time configuration information file. Here, we do not
+ * include `"mbedtls/build_info.h"` directly but `"psa/build_info.h"`, which
+ * is basically just an alias to it. This is to ease the maintenance of the
+ * PSA cryptography repository which has a different build system and
+ * configuration.
+ */
+#include "psa/build_info.h"
+
+#define PSA_BITS_TO_BYTES(bits) (((bits) + 7u) / 8u)
+#define PSA_BYTES_TO_BITS(bytes) ((bytes) * 8u)
+#define PSA_MAX_OF_THREE(a, b, c) ((a) <= (b) ? (b) <= (c) ? \
+ (c) : (b) : (a) <= (c) ? (c) : (a))
+
+#define PSA_ROUND_UP_TO_MULTIPLE(block_size, length) \
+ (((length) + (block_size) - 1) / (block_size) * (block_size))
+
+/** The size of the output of psa_hash_finish(), in bytes.
+ *
+ * This is also the hash size that psa_hash_verify() expects.
+ *
+ * \param alg A hash algorithm (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_HASH(\p alg) is true), or an HMAC algorithm
+ * (#PSA_ALG_HMAC(\c hash_alg) where \c hash_alg is a
+ * hash algorithm).
+ *
+ * \return The hash size for the specified hash algorithm.
+ * If the hash algorithm is not recognized, return 0.
+ */
+#define PSA_HASH_LENGTH(alg) \
+ ( \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 16u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 20u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 20u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 28u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 32u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 48u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 64u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 28u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 32u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 28u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 32u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 48u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 64u : \
+ 0u)
+
+/** The input block size of a hash algorithm, in bytes.
+ *
+ * Hash algorithms process their input data in blocks. Hash operations will
+ * retain any partial blocks until they have enough input to fill the block or
+ * until the operation is finished.
+ * This affects the output from psa_hash_suspend().
+ *
+ * \param alg A hash algorithm (\c PSA_ALG_XXX value such that
+ * PSA_ALG_IS_HASH(\p alg) is true).
+ *
+ * \return The block size in bytes for the specified hash algorithm.
+ * If the hash algorithm is not recognized, return 0.
+ * An implementation can return either 0 or the correct size for a
+ * hash algorithm that it recognizes, but does not support.
+ */
+#define PSA_HASH_BLOCK_LENGTH(alg) \
+ ( \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 64u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 64u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 64u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 64u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 64u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 128u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 128u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 128u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 128u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 144u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 136u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 104u : \
+ PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 72u : \
+ 0u)
+
+/** \def PSA_HASH_MAX_SIZE
+ *
+ * Maximum size of a hash.
+ *
+ * This macro expands to a compile-time constant integer. This value
+ * is the maximum size of a hash in bytes.
+ */
+/* Note: for HMAC-SHA-3, the block size is 144 bytes for HMAC-SHA3-224,
+ * 136 bytes for HMAC-SHA3-256, 104 bytes for SHA3-384, 72 bytes for
+ * HMAC-SHA3-512. */
+/* Note: PSA_HASH_MAX_SIZE should be kept in sync with MBEDTLS_MD_MAX_SIZE,
+ * see the note on MBEDTLS_MD_MAX_SIZE for details. */
+#if defined(PSA_WANT_ALG_SHA3_224)
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 144u
+#elif defined(PSA_WANT_ALG_SHA3_256)
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 136u
+#elif defined(PSA_WANT_ALG_SHA_512)
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128u
+#elif defined(PSA_WANT_ALG_SHA_384)
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128u
+#elif defined(PSA_WANT_ALG_SHA3_384)
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 104u
+#elif defined(PSA_WANT_ALG_SHA3_512)
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 72u
+#elif defined(PSA_WANT_ALG_SHA_256)
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64u
+#elif defined(PSA_WANT_ALG_SHA_224)
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64u
+#else /* SHA-1 or smaller */
+#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64u
+#endif
+
+#if defined(PSA_WANT_ALG_SHA_512) || defined(PSA_WANT_ALG_SHA3_512)
+#define PSA_HASH_MAX_SIZE 64u
+#elif defined(PSA_WANT_ALG_SHA_384) || defined(PSA_WANT_ALG_SHA3_384)
+#define PSA_HASH_MAX_SIZE 48u
+#elif defined(PSA_WANT_ALG_SHA_256) || defined(PSA_WANT_ALG_SHA3_256)
+#define PSA_HASH_MAX_SIZE 32u
+#elif defined(PSA_WANT_ALG_SHA_224) || defined(PSA_WANT_ALG_SHA3_224)
+#define PSA_HASH_MAX_SIZE 28u
+#else /* SHA-1 or smaller */
+#define PSA_HASH_MAX_SIZE 20u
+#endif
+
+/** \def PSA_MAC_MAX_SIZE
+ *
+ * Maximum size of a MAC.
+ *
+ * This macro expands to a compile-time constant integer. This value
+ * is the maximum size of a MAC in bytes.
+ */
+/* All non-HMAC MACs have a maximum size that's smaller than the
+ * minimum possible value of PSA_HASH_MAX_SIZE in this implementation. */
+/* Note that the encoding of truncated MAC algorithms limits this value
+ * to 64 bytes.
+ */
+#define PSA_MAC_MAX_SIZE PSA_HASH_MAX_SIZE
+
+/** The length of a tag for an AEAD algorithm, in bytes.
+ *
+ * This macro can be used to allocate a buffer of sufficient size to store the
+ * tag output from psa_aead_finish().
+ *
+ * See also #PSA_AEAD_TAG_MAX_SIZE.
+ *
+ * \param key_type The type of the AEAD key.
+ * \param key_bits The size of the AEAD key in bits.
+ * \param alg An AEAD algorithm
+ * (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_AEAD(\p alg) is true).
+ *
+ * \return The tag length for the specified algorithm and key.
+ * If the AEAD algorithm does not have an identified
+ * tag that can be distinguished from the rest of
+ * the ciphertext, return 0.
+ * If the key type or AEAD algorithm is not
+ * recognized, or the parameters are incompatible,
+ * return 0.
+ */
+#define PSA_AEAD_TAG_LENGTH(key_type, key_bits, alg) \
+ (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \
+ PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \
+ ((void) (key_bits), 0u))
+
+/** The maximum tag size for all supported AEAD algorithms, in bytes.
+ *
+ * See also #PSA_AEAD_TAG_LENGTH(\p key_type, \p key_bits, \p alg).
+ */
+#define PSA_AEAD_TAG_MAX_SIZE 16u
+
+/* The maximum size of an RSA key on this implementation, in bits.
+ * This is a vendor-specific macro.
+ *
+ * Mbed TLS does not set a hard limit on the size of RSA keys: any key
+ * whose parameters fit in a bignum is accepted. However large keys can
+ * induce a large memory usage and long computation times. Unlike other
+ * auxiliary macros in this file and in crypto.h, which reflect how the
+ * library is configured, this macro defines how the library is
+ * configured. This implementation refuses to import or generate an
+ * RSA key whose size is larger than the value defined here.
+ *
+ * Note that an implementation may set different size limits for different
+ * operations, and does not need to accept all key sizes up to the limit. */
+#define PSA_VENDOR_RSA_MAX_KEY_BITS 4096u
+
+/* The minimum size of an RSA key on this implementation, in bits.
+ * This is a vendor-specific macro.
+ *
+ * Limits RSA key generation to a minimum due to avoid accidental misuse.
+ * This value cannot be less than 128 bits.
+ */
+#if defined(MBEDTLS_RSA_GEN_KEY_MIN_BITS)
+#define PSA_VENDOR_RSA_GENERATE_MIN_KEY_BITS MBEDTLS_RSA_GEN_KEY_MIN_BITS
+#else
+#define PSA_VENDOR_RSA_GENERATE_MIN_KEY_BITS 1024
+#endif
+
+/* The maximum size of an DH key on this implementation, in bits.
+ *
+ * Note that an implementation may set different size limits for different
+ * operations, and does not need to accept all key sizes up to the limit. */
+#define PSA_VENDOR_FFDH_MAX_KEY_BITS 8192u
+
+/* The maximum size of an ECC key on this implementation, in bits.
+ * This is a vendor-specific macro. */
+#if defined(PSA_WANT_ECC_SECP_R1_521)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 521u
+#elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_512)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 512u
+#elif defined(PSA_WANT_ECC_MONTGOMERY_448)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 448u
+#elif defined(PSA_WANT_ECC_SECP_R1_384)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 384u
+#elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_384)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 384u
+#elif defined(PSA_WANT_ECC_SECP_R1_256)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u
+#elif defined(PSA_WANT_ECC_SECP_K1_256)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u
+#elif defined(PSA_WANT_ECC_BRAINPOOL_P_R1_256)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 256u
+#elif defined(PSA_WANT_ECC_MONTGOMERY_255)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 255u
+#elif defined(PSA_WANT_ECC_SECP_R1_224)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 224u
+#elif defined(PSA_WANT_ECC_SECP_K1_224)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 224u
+#elif defined(PSA_WANT_ECC_SECP_R1_192)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 192u
+#elif defined(PSA_WANT_ECC_SECP_K1_192)
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 192u
+#else
+#define PSA_VENDOR_ECC_MAX_CURVE_BITS 0u
+#endif
+
+/** This macro returns the maximum supported length of the PSK for the
+ * TLS-1.2 PSK-to-MS key derivation
+ * (#PSA_ALG_TLS12_PSK_TO_MS(\c hash_alg)).
+ *
+ * The maximum supported length does not depend on the chosen hash algorithm.
+ *
+ * Quoting RFC 4279, Sect 5.3:
+ * TLS implementations supporting these ciphersuites MUST support
+ * arbitrary PSK identities up to 128 octets in length, and arbitrary
+ * PSKs up to 64 octets in length. Supporting longer identities and
+ * keys is RECOMMENDED.
+ *
+ * Therefore, no implementation should define a value smaller than 64
+ * for #PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE.
+ */
+#define PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128u
+
+/* The expected size of input passed to psa_tls12_ecjpake_to_pms_input,
+ * which is expected to work with P-256 curve only. */
+#define PSA_TLS12_ECJPAKE_TO_PMS_INPUT_SIZE 65u
+
+/* The size of a serialized K.X coordinate to be used in
+ * psa_tls12_ecjpake_to_pms_input. This function only accepts the P-256
+ * curve. */
+#define PSA_TLS12_ECJPAKE_TO_PMS_DATA_SIZE 32u
+
+/* The maximum number of iterations for PBKDF2 on this implementation, in bits.
+ * This is a vendor-specific macro. This can be configured if necessary */
+#define PSA_VENDOR_PBKDF2_MAX_ITERATIONS 0xffffffffU
+
+/** The maximum size of a block cipher. */
+#define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16u
+
+/** The size of the output of psa_mac_sign_finish(), in bytes.
+ *
+ * This is also the MAC size that psa_mac_verify_finish() expects.
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type The type of the MAC key.
+ * \param key_bits The size of the MAC key in bits.
+ * \param alg A MAC algorithm (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_MAC(\p alg) is true).
+ *
+ * \return The MAC size for the specified algorithm with
+ * the specified key parameters.
+ * \return 0 if the MAC algorithm is not recognized.
+ * \return Either 0 or the correct size for a MAC algorithm that
+ * the implementation recognizes, but does not support.
+ * \return Unspecified if the key parameters are not consistent
+ * with the algorithm.
+ */
+#define PSA_MAC_LENGTH(key_type, key_bits, alg) \
+ ((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \
+ PSA_ALG_IS_HMAC(alg) ? PSA_HASH_LENGTH(PSA_ALG_HMAC_GET_HASH(alg)) : \
+ PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \
+ ((void) (key_type), (void) (key_bits), 0u))
+
+/** The maximum size of the output of psa_aead_encrypt(), in bytes.
+ *
+ * If the size of the ciphertext buffer is at least this large, it is
+ * guaranteed that psa_aead_encrypt() will not fail due to an
+ * insufficient buffer size. Depending on the algorithm, the actual size of
+ * the ciphertext may be smaller.
+ *
+ * See also #PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(\p plaintext_length).
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type A symmetric key type that is
+ * compatible with algorithm \p alg.
+ * \param alg An AEAD algorithm
+ * (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_AEAD(\p alg) is true).
+ * \param plaintext_length Size of the plaintext in bytes.
+ *
+ * \return The AEAD ciphertext size for the specified
+ * algorithm.
+ * If the key type or AEAD algorithm is not
+ * recognized, or the parameters are incompatible,
+ * return 0.
+ */
+#define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length) \
+ (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \
+ (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \
+ 0u)
+
+/** A sufficient output buffer size for psa_aead_encrypt(), for any of the
+ * supported key types and AEAD algorithms.
+ *
+ * If the size of the ciphertext buffer is at least this large, it is guaranteed
+ * that psa_aead_encrypt() will not fail due to an insufficient buffer size.
+ *
+ * \note This macro returns a compile-time constant if its arguments are
+ * compile-time constants.
+ *
+ * See also #PSA_AEAD_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg,
+ * \p plaintext_length).
+ *
+ * \param plaintext_length Size of the plaintext in bytes.
+ *
+ * \return A sufficient output buffer size for any of the
+ * supported key types and AEAD algorithms.
+ *
+ */
+#define PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length) \
+ ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE)
+
+
+/** The maximum size of the output of psa_aead_decrypt(), in bytes.
+ *
+ * If the size of the plaintext buffer is at least this large, it is
+ * guaranteed that psa_aead_decrypt() will not fail due to an
+ * insufficient buffer size. Depending on the algorithm, the actual size of
+ * the plaintext may be smaller.
+ *
+ * See also #PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(\p ciphertext_length).
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type A symmetric key type that is
+ * compatible with algorithm \p alg.
+ * \param alg An AEAD algorithm
+ * (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_AEAD(\p alg) is true).
+ * \param ciphertext_length Size of the plaintext in bytes.
+ *
+ * \return The AEAD ciphertext size for the specified
+ * algorithm.
+ * If the key type or AEAD algorithm is not
+ * recognized, or the parameters are incompatible,
+ * return 0.
+ */
+#define PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length) \
+ (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \
+ (ciphertext_length) > PSA_ALG_AEAD_GET_TAG_LENGTH(alg) ? \
+ (ciphertext_length) - PSA_ALG_AEAD_GET_TAG_LENGTH(alg) : \
+ 0u)
+
+/** A sufficient output buffer size for psa_aead_decrypt(), for any of the
+ * supported key types and AEAD algorithms.
+ *
+ * If the size of the plaintext buffer is at least this large, it is guaranteed
+ * that psa_aead_decrypt() will not fail due to an insufficient buffer size.
+ *
+ * \note This macro returns a compile-time constant if its arguments are
+ * compile-time constants.
+ *
+ * See also #PSA_AEAD_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg,
+ * \p ciphertext_length).
+ *
+ * \param ciphertext_length Size of the ciphertext in bytes.
+ *
+ * \return A sufficient output buffer size for any of the
+ * supported key types and AEAD algorithms.
+ *
+ */
+#define PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(ciphertext_length) \
+ (ciphertext_length)
+
+/** The default nonce size for an AEAD algorithm, in bytes.
+ *
+ * This macro can be used to allocate a buffer of sufficient size to
+ * store the nonce output from #psa_aead_generate_nonce().
+ *
+ * See also #PSA_AEAD_NONCE_MAX_SIZE.
+ *
+ * \note This is not the maximum size of nonce supported as input to
+ * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(),
+ * just the default size that is generated by #psa_aead_generate_nonce().
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type A symmetric key type that is compatible with
+ * algorithm \p alg.
+ *
+ * \param alg An AEAD algorithm (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_AEAD(\p alg) is true).
+ *
+ * \return The default nonce size for the specified key type and algorithm.
+ * If the key type or AEAD algorithm is not recognized,
+ * or the parameters are incompatible, return 0.
+ */
+#define PSA_AEAD_NONCE_LENGTH(key_type, alg) \
+ (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \
+ MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CCM) ? 13u : \
+ MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_GCM) ? 12u : \
+ 0u : \
+ (key_type) == PSA_KEY_TYPE_CHACHA20 && \
+ MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12u : \
+ 0u)
+
+/** The maximum default nonce size among all supported pairs of key types and
+ * AEAD algorithms, in bytes.
+ *
+ * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH()
+ * may return.
+ *
+ * \note This is not the maximum size of nonce supported as input to
+ * #psa_aead_set_nonce(), #psa_aead_encrypt() or #psa_aead_decrypt(),
+ * just the largest size that may be generated by
+ * #psa_aead_generate_nonce().
+ */
+#define PSA_AEAD_NONCE_MAX_SIZE 13u
+
+/** A sufficient output buffer size for psa_aead_update().
+ *
+ * If the size of the output buffer is at least this large, it is
+ * guaranteed that psa_aead_update() will not fail due to an
+ * insufficient buffer size. The actual size of the output may be smaller
+ * in any given call.
+ *
+ * See also #PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(\p input_length).
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type A symmetric key type that is
+ * compatible with algorithm \p alg.
+ * \param alg An AEAD algorithm
+ * (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_AEAD(\p alg) is true).
+ * \param input_length Size of the input in bytes.
+ *
+ * \return A sufficient output buffer size for the specified
+ * algorithm.
+ * If the key type or AEAD algorithm is not
+ * recognized, or the parameters are incompatible,
+ * return 0.
+ */
+/* For all the AEAD modes defined in this specification, it is possible
+ * to emit output without delay. However, hardware may not always be
+ * capable of this. So for modes based on a block cipher, allow the
+ * implementation to delay the output until it has a full block. */
+#define PSA_AEAD_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \
+ (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ? \
+ PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \
+ PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), (input_length)) : \
+ (input_length) : \
+ 0u)
+
+/** A sufficient output buffer size for psa_aead_update(), for any of the
+ * supported key types and AEAD algorithms.
+ *
+ * If the size of the output buffer is at least this large, it is guaranteed
+ * that psa_aead_update() will not fail due to an insufficient buffer size.
+ *
+ * See also #PSA_AEAD_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length).
+ *
+ * \param input_length Size of the input in bytes.
+ */
+#define PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(input_length) \
+ (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length)))
+
+/** A sufficient ciphertext buffer size for psa_aead_finish().
+ *
+ * If the size of the ciphertext buffer is at least this large, it is
+ * guaranteed that psa_aead_finish() will not fail due to an
+ * insufficient ciphertext buffer size. The actual size of the output may
+ * be smaller in any given call.
+ *
+ * See also #PSA_AEAD_FINISH_OUTPUT_MAX_SIZE.
+ *
+ * \param key_type A symmetric key type that is
+ compatible with algorithm \p alg.
+ * \param alg An AEAD algorithm
+ * (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_AEAD(\p alg) is true).
+ *
+ * \return A sufficient ciphertext buffer size for the
+ * specified algorithm.
+ * If the key type or AEAD algorithm is not
+ * recognized, or the parameters are incompatible,
+ * return 0.
+ */
+#define PSA_AEAD_FINISH_OUTPUT_SIZE(key_type, alg) \
+ (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \
+ PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \
+ PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \
+ 0u)
+
+/** A sufficient ciphertext buffer size for psa_aead_finish(), for any of the
+ * supported key types and AEAD algorithms.
+ *
+ * See also #PSA_AEAD_FINISH_OUTPUT_SIZE(\p key_type, \p alg).
+ */
+#define PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)
+
+/** A sufficient plaintext buffer size for psa_aead_verify().
+ *
+ * If the size of the plaintext buffer is at least this large, it is
+ * guaranteed that psa_aead_verify() will not fail due to an
+ * insufficient plaintext buffer size. The actual size of the output may
+ * be smaller in any given call.
+ *
+ * See also #PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE.
+ *
+ * \param key_type A symmetric key type that is
+ * compatible with algorithm \p alg.
+ * \param alg An AEAD algorithm
+ * (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_AEAD(\p alg) is true).
+ *
+ * \return A sufficient plaintext buffer size for the
+ * specified algorithm.
+ * If the key type or AEAD algorithm is not
+ * recognized, or the parameters are incompatible,
+ * return 0.
+ */
+#define PSA_AEAD_VERIFY_OUTPUT_SIZE(key_type, alg) \
+ (PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 && \
+ PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \
+ PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \
+ 0u)
+
+/** A sufficient plaintext buffer size for psa_aead_verify(), for any of the
+ * supported key types and AEAD algorithms.
+ *
+ * See also #PSA_AEAD_VERIFY_OUTPUT_SIZE(\p key_type, \p alg).
+ */
+#define PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)
+
+#define PSA_RSA_MINIMUM_PADDING_SIZE(alg) \
+ (PSA_ALG_IS_RSA_OAEP(alg) ? \
+ 2u * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1u : \
+ 11u /*PKCS#1v1.5*/)
+
+/**
+ * \brief ECDSA signature size for a given curve bit size
+ *
+ * \param curve_bits Curve size in bits.
+ * \return Signature size in bytes.
+ *
+ * \note This macro returns a compile-time constant if its argument is one.
+ */
+#define PSA_ECDSA_SIGNATURE_SIZE(curve_bits) \
+ (PSA_BITS_TO_BYTES(curve_bits) * 2u)
+
+/** Sufficient signature buffer size for psa_sign_hash().
+ *
+ * This macro returns a sufficient buffer size for a signature using a key
+ * of the specified type and size, with the specified algorithm.
+ * Note that the actual size of the signature may be smaller
+ * (some algorithms produce a variable-size signature).
+ *
+ * \warning This function may call its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type An asymmetric key type (this may indifferently be a
+ * key pair type or a public key type).
+ * \param key_bits The size of the key in bits.
+ * \param alg The signature algorithm.
+ *
+ * \return If the parameters are valid and supported, return
+ * a buffer size in bytes that guarantees that
+ * psa_sign_hash() will not fail with
+ * #PSA_ERROR_BUFFER_TOO_SMALL.
+ * If the parameters are a valid combination that is not supported,
+ * return either a sensible size or 0.
+ * If the parameters are not valid, the
+ * return value is unspecified.
+ */
+#define PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \
+ (PSA_KEY_TYPE_IS_RSA(key_type) ? ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \
+ PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \
+ ((void) alg, 0u))
+
+#define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE \
+ PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)
+
+/** \def PSA_SIGNATURE_MAX_SIZE
+ *
+ * Maximum size of an asymmetric signature.
+ *
+ * This macro expands to a compile-time constant integer. This value
+ * is the maximum size of a signature in bytes.
+ */
+#define PSA_SIGNATURE_MAX_SIZE 1
+
+#if (defined(PSA_WANT_ALG_ECDSA) || defined(PSA_WANT_ALG_DETERMINISTIC_ECDSA)) && \
+ (PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE > PSA_SIGNATURE_MAX_SIZE)
+#undef PSA_SIGNATURE_MAX_SIZE
+#define PSA_SIGNATURE_MAX_SIZE PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE
+#endif
+#if (defined(PSA_WANT_ALG_RSA_PKCS1V15_SIGN) || defined(PSA_WANT_ALG_RSA_PSS)) && \
+ (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_SIGNATURE_MAX_SIZE)
+#undef PSA_SIGNATURE_MAX_SIZE
+#define PSA_SIGNATURE_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS)
+#endif
+
+/** Sufficient output buffer size for psa_asymmetric_encrypt().
+ *
+ * This macro returns a sufficient buffer size for a ciphertext produced using
+ * a key of the specified type and size, with the specified algorithm.
+ * Note that the actual size of the ciphertext may be smaller, depending
+ * on the algorithm.
+ *
+ * \warning This function may call its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type An asymmetric key type (this may indifferently be a
+ * key pair type or a public key type).
+ * \param key_bits The size of the key in bits.
+ * \param alg The asymmetric encryption algorithm.
+ *
+ * \return If the parameters are valid and supported, return
+ * a buffer size in bytes that guarantees that
+ * psa_asymmetric_encrypt() will not fail with
+ * #PSA_ERROR_BUFFER_TOO_SMALL.
+ * If the parameters are a valid combination that is not supported,
+ * return either a sensible size or 0.
+ * If the parameters are not valid, the
+ * return value is unspecified.
+ */
+#define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \
+ (PSA_KEY_TYPE_IS_RSA(key_type) ? \
+ ((void) alg, PSA_BITS_TO_BYTES(key_bits)) : \
+ 0u)
+
+/** A sufficient output buffer size for psa_asymmetric_encrypt(), for any
+ * supported asymmetric encryption.
+ *
+ * See also #PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg).
+ */
+/* This macro assumes that RSA is the only supported asymmetric encryption. */
+#define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE \
+ (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS))
+
+/** Sufficient output buffer size for psa_asymmetric_decrypt().
+ *
+ * This macro returns a sufficient buffer size for a plaintext produced using
+ * a key of the specified type and size, with the specified algorithm.
+ * Note that the actual size of the plaintext may be smaller, depending
+ * on the algorithm.
+ *
+ * \warning This function may call its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type An asymmetric key type (this may indifferently be a
+ * key pair type or a public key type).
+ * \param key_bits The size of the key in bits.
+ * \param alg The asymmetric encryption algorithm.
+ *
+ * \return If the parameters are valid and supported, return
+ * a buffer size in bytes that guarantees that
+ * psa_asymmetric_decrypt() will not fail with
+ * #PSA_ERROR_BUFFER_TOO_SMALL.
+ * If the parameters are a valid combination that is not supported,
+ * return either a sensible size or 0.
+ * If the parameters are not valid, the
+ * return value is unspecified.
+ */
+#define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \
+ (PSA_KEY_TYPE_IS_RSA(key_type) ? \
+ PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \
+ 0u)
+
+/** A sufficient output buffer size for psa_asymmetric_decrypt(), for any
+ * supported asymmetric decryption.
+ *
+ * This macro assumes that RSA is the only supported asymmetric encryption.
+ *
+ * See also #PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(\p key_type, \p key_bits, \p alg).
+ */
+#define PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE \
+ (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS))
+
+/* Maximum size of the ASN.1 encoding of an INTEGER with the specified
+ * number of bits.
+ *
+ * This definition assumes that bits <= 2^19 - 9 so that the length field
+ * is at most 3 bytes. The length of the encoding is the length of the
+ * bit string padded to a whole number of bytes plus:
+ * - 1 type byte;
+ * - 1 to 3 length bytes;
+ * - 0 to 1 bytes of leading 0 due to the sign bit.
+ */
+#define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \
+ ((bits) / 8u + 5u)
+
+/* Maximum size of the export encoding of an RSA public key.
+ * Assumes that the public exponent is less than 2^32.
+ *
+ * RSAPublicKey ::= SEQUENCE {
+ * modulus INTEGER, -- n
+ * publicExponent INTEGER } -- e
+ *
+ * - 4 bytes of SEQUENCE overhead;
+ * - n : INTEGER;
+ * - 7 bytes for the public exponent.
+ */
+#define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \
+ (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11u)
+
+/* Maximum size of the export encoding of an RSA key pair.
+ * Assumes that the public exponent is less than 2^32 and that the size
+ * difference between the two primes is at most 1 bit.
+ *
+ * RSAPrivateKey ::= SEQUENCE {
+ * version Version, -- 0
+ * modulus INTEGER, -- N-bit
+ * publicExponent INTEGER, -- 32-bit
+ * privateExponent INTEGER, -- N-bit
+ * prime1 INTEGER, -- N/2-bit
+ * prime2 INTEGER, -- N/2-bit
+ * exponent1 INTEGER, -- N/2-bit
+ * exponent2 INTEGER, -- N/2-bit
+ * coefficient INTEGER, -- N/2-bit
+ * }
+ *
+ * - 4 bytes of SEQUENCE overhead;
+ * - 3 bytes of version;
+ * - 7 half-size INTEGERs plus 2 full-size INTEGERs,
+ * overapproximated as 9 half-size INTEGERS;
+ * - 7 bytes for the public exponent.
+ */
+#define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) \
+ (9u * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2u + 1u) + 14u)
+
+/* Maximum size of the export encoding of a DSA public key.
+ *
+ * SubjectPublicKeyInfo ::= SEQUENCE {
+ * algorithm AlgorithmIdentifier,
+ * subjectPublicKey BIT STRING } -- contains DSAPublicKey
+ * AlgorithmIdentifier ::= SEQUENCE {
+ * algorithm OBJECT IDENTIFIER,
+ * parameters Dss-Params } -- SEQUENCE of 3 INTEGERs
+ * DSAPublicKey ::= INTEGER -- public key, Y
+ *
+ * - 3 * 4 bytes of SEQUENCE overhead;
+ * - 1 + 1 + 7 bytes of algorithm (DSA OID);
+ * - 4 bytes of BIT STRING overhead;
+ * - 3 full-size INTEGERs (p, g, y);
+ * - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits).
+ */
+#define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \
+ (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3u + 59u)
+
+/* Maximum size of the export encoding of a DSA key pair.
+ *
+ * DSAPrivateKey ::= SEQUENCE {
+ * version Version, -- 0
+ * prime INTEGER, -- p
+ * subprime INTEGER, -- q
+ * generator INTEGER, -- g
+ * public INTEGER, -- y
+ * private INTEGER, -- x
+ * }
+ *
+ * - 4 bytes of SEQUENCE overhead;
+ * - 3 bytes of version;
+ * - 3 full-size INTEGERs (p, g, y);
+ * - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits).
+ */
+#define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) \
+ (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3u + 75u)
+
+/* Maximum size of the export encoding of an ECC public key.
+ *
+ * The representation of an ECC public key is:
+ * - The byte 0x04;
+ * - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
+ * - `y_P` as a `ceiling(m/8)`-byte string, big-endian;
+ * - where m is the bit size associated with the curve.
+ *
+ * - 1 byte + 2 * point size.
+ */
+#define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \
+ (2u * PSA_BITS_TO_BYTES(key_bits) + 1u)
+
+/* Maximum size of the export encoding of an ECC key pair.
+ *
+ * An ECC key pair is represented by the secret value.
+ */
+#define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) \
+ (PSA_BITS_TO_BYTES(key_bits))
+
+/* Maximum size of the export encoding of an DH key pair.
+ *
+ * An DH key pair is represented by the secret value.
+ */
+#define PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(key_bits) \
+ (PSA_BITS_TO_BYTES(key_bits))
+
+/* Maximum size of the export encoding of an DH public key.
+ */
+#define PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(key_bits) \
+ (PSA_BITS_TO_BYTES(key_bits))
+
+/** Sufficient output buffer size for psa_export_key() or
+ * psa_export_public_key().
+ *
+ * This macro returns a compile-time constant if its arguments are
+ * compile-time constants.
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * The following code illustrates how to allocate enough memory to export
+ * a key by querying the key type and size at runtime.
+ * \code{c}
+ * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+ * psa_status_t status;
+ * status = psa_get_key_attributes(key, &attributes);
+ * if (status != PSA_SUCCESS) handle_error(...);
+ * psa_key_type_t key_type = psa_get_key_type(&attributes);
+ * size_t key_bits = psa_get_key_bits(&attributes);
+ * size_t buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits);
+ * psa_reset_key_attributes(&attributes);
+ * uint8_t *buffer = malloc(buffer_size);
+ * if (buffer == NULL) handle_error(...);
+ * size_t buffer_length;
+ * status = psa_export_key(key, buffer, buffer_size, &buffer_length);
+ * if (status != PSA_SUCCESS) handle_error(...);
+ * \endcode
+ *
+ * \param key_type A supported key type.
+ * \param key_bits The size of the key in bits.
+ *
+ * \return If the parameters are valid and supported, return
+ * a buffer size in bytes that guarantees that
+ * psa_export_key() or psa_export_public_key() will not fail with
+ * #PSA_ERROR_BUFFER_TOO_SMALL.
+ * If the parameters are a valid combination that is not supported,
+ * return either a sensible size or 0.
+ * If the parameters are not valid, the return value is unspecified.
+ */
+#define PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits) \
+ (PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \
+ PSA_KEY_TYPE_IS_DH(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \
+ (key_type) == PSA_KEY_TYPE_RSA_KEY_PAIR ? PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) : \
+ (key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \
+ (key_type) == PSA_KEY_TYPE_DSA_KEY_PAIR ? PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) : \
+ (key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \
+ PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) : \
+ PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \
+ 0u)
+
+/** Sufficient output buffer size for psa_export_public_key().
+ *
+ * This macro returns a compile-time constant if its arguments are
+ * compile-time constants.
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * The following code illustrates how to allocate enough memory to export
+ * a public key by querying the key type and size at runtime.
+ * \code{c}
+ * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+ * psa_status_t status;
+ * status = psa_get_key_attributes(key, &attributes);
+ * if (status != PSA_SUCCESS) handle_error(...);
+ * psa_key_type_t key_type = psa_get_key_type(&attributes);
+ * size_t key_bits = psa_get_key_bits(&attributes);
+ * size_t buffer_size = PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits);
+ * psa_reset_key_attributes(&attributes);
+ * uint8_t *buffer = malloc(buffer_size);
+ * if (buffer == NULL) handle_error(...);
+ * size_t buffer_length;
+ * status = psa_export_public_key(key, buffer, buffer_size, &buffer_length);
+ * if (status != PSA_SUCCESS) handle_error(...);
+ * \endcode
+ *
+ * \param key_type A public key or key pair key type.
+ * \param key_bits The size of the key in bits.
+ *
+ * \return If the parameters are valid and supported, return
+ * a buffer size in bytes that guarantees that
+ * psa_export_public_key() will not fail with
+ * #PSA_ERROR_BUFFER_TOO_SMALL.
+ * If the parameters are a valid combination that is not
+ * supported, return either a sensible size or 0.
+ * If the parameters are not valid,
+ * the return value is unspecified.
+ *
+ * If the parameters are valid and supported,
+ * return the same result as
+ * #PSA_EXPORT_KEY_OUTPUT_SIZE(
+ * \p #PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(\p key_type),
+ * \p key_bits).
+ */
+#define PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits) \
+ (PSA_KEY_TYPE_IS_RSA(key_type) ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \
+ PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \
+ PSA_KEY_TYPE_IS_DH(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \
+ 0u)
+
+/** Sufficient buffer size for exporting any asymmetric key pair.
+ *
+ * This macro expands to a compile-time constant integer. This value is
+ * a sufficient buffer size when calling psa_export_key() to export any
+ * asymmetric key pair, regardless of the exact key type and key size.
+ *
+ * See also #PSA_EXPORT_KEY_OUTPUT_SIZE(\p key_type, \p key_bits).
+ */
+#define PSA_EXPORT_KEY_PAIR_MAX_SIZE 1
+
+#if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_BASIC) && \
+ (PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) > \
+ PSA_EXPORT_KEY_PAIR_MAX_SIZE)
+#undef PSA_EXPORT_KEY_PAIR_MAX_SIZE
+#define PSA_EXPORT_KEY_PAIR_MAX_SIZE \
+ PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)
+#endif
+#if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_BASIC) && \
+ (PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \
+ PSA_EXPORT_KEY_PAIR_MAX_SIZE)
+#undef PSA_EXPORT_KEY_PAIR_MAX_SIZE
+#define PSA_EXPORT_KEY_PAIR_MAX_SIZE \
+ PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS)
+#endif
+#if defined(PSA_WANT_KEY_TYPE_DH_KEY_PAIR_BASIC) && \
+ (PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) > \
+ PSA_EXPORT_KEY_PAIR_MAX_SIZE)
+#undef PSA_EXPORT_KEY_PAIR_MAX_SIZE
+#define PSA_EXPORT_KEY_PAIR_MAX_SIZE \
+ PSA_KEY_EXPORT_FFDH_KEY_PAIR_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS)
+#endif
+
+/** Sufficient buffer size for exporting any asymmetric public key.
+ *
+ * This macro expands to a compile-time constant integer. This value is
+ * a sufficient buffer size when calling psa_export_key() or
+ * psa_export_public_key() to export any asymmetric public key,
+ * regardless of the exact key type and key size.
+ *
+ * See also #PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(\p key_type, \p key_bits).
+ */
+#define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE 1
+
+#if defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY) && \
+ (PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) > \
+ PSA_EXPORT_PUBLIC_KEY_MAX_SIZE)
+#undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE
+#define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \
+ PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)
+#endif
+#if defined(PSA_WANT_KEY_TYPE_RSA_PUBLIC_KEY) && \
+ (PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) > \
+ PSA_EXPORT_PUBLIC_KEY_MAX_SIZE)
+#undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE
+#define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \
+ PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS)
+#endif
+#if defined(PSA_WANT_KEY_TYPE_DH_PUBLIC_KEY) && \
+ (PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS) > \
+ PSA_EXPORT_PUBLIC_KEY_MAX_SIZE)
+#undef PSA_EXPORT_PUBLIC_KEY_MAX_SIZE
+#define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE \
+ PSA_KEY_EXPORT_FFDH_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_FFDH_MAX_KEY_BITS)
+#endif
+
+/** Sufficient output buffer size for psa_raw_key_agreement().
+ *
+ * This macro returns a compile-time constant if its arguments are
+ * compile-time constants.
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE.
+ *
+ * \param key_type A supported key type.
+ * \param key_bits The size of the key in bits.
+ *
+ * \return If the parameters are valid and supported, return
+ * a buffer size in bytes that guarantees that
+ * psa_raw_key_agreement() will not fail with
+ * #PSA_ERROR_BUFFER_TOO_SMALL.
+ * If the parameters are a valid combination that
+ * is not supported, return either a sensible size or 0.
+ * If the parameters are not valid,
+ * the return value is unspecified.
+ */
+#define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits) \
+ ((PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) || \
+ PSA_KEY_TYPE_IS_DH_KEY_PAIR(key_type)) ? PSA_BITS_TO_BYTES(key_bits) : 0u)
+
+/** Maximum size of the output from psa_raw_key_agreement().
+ *
+ * This macro expands to a compile-time constant integer. This value is the
+ * maximum size of the output any raw key agreement algorithm, in bytes.
+ *
+ * See also #PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(\p key_type, \p key_bits).
+ */
+#define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE 1
+
+#if defined(PSA_WANT_ALG_ECDH) && \
+ (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS) > PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE)
+#undef PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE
+#define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS)
+#endif
+#if defined(PSA_WANT_ALG_FFDH) && \
+ (PSA_BITS_TO_BYTES(PSA_VENDOR_FFDH_MAX_KEY_BITS) > PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE)
+#undef PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE
+#define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE PSA_BITS_TO_BYTES(PSA_VENDOR_FFDH_MAX_KEY_BITS)
+#endif
+
+/** The default IV size for a cipher algorithm, in bytes.
+ *
+ * The IV that is generated as part of a call to #psa_cipher_encrypt() is always
+ * the default IV length for the algorithm.
+ *
+ * This macro can be used to allocate a buffer of sufficient size to
+ * store the IV output from #psa_cipher_generate_iv() when using
+ * a multi-part cipher operation.
+ *
+ * See also #PSA_CIPHER_IV_MAX_SIZE.
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type A symmetric key type that is compatible with algorithm \p alg.
+ *
+ * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true).
+ *
+ * \return The default IV size for the specified key type and algorithm.
+ * If the algorithm does not use an IV, return 0.
+ * If the key type or cipher algorithm is not recognized,
+ * or the parameters are incompatible, return 0.
+ */
+#define PSA_CIPHER_IV_LENGTH(key_type, alg) \
+ (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1 && \
+ ((alg) == PSA_ALG_CTR || \
+ (alg) == PSA_ALG_CFB || \
+ (alg) == PSA_ALG_OFB || \
+ (alg) == PSA_ALG_XTS || \
+ (alg) == PSA_ALG_CBC_NO_PADDING || \
+ (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \
+ (key_type) == PSA_KEY_TYPE_CHACHA20 && \
+ (alg) == PSA_ALG_STREAM_CIPHER ? 12u : \
+ (alg) == PSA_ALG_CCM_STAR_NO_TAG ? 13u : \
+ 0u)
+
+/** The maximum IV size for all supported cipher algorithms, in bytes.
+ *
+ * See also #PSA_CIPHER_IV_LENGTH().
+ */
+#define PSA_CIPHER_IV_MAX_SIZE 16u
+
+/** The maximum size of the output of psa_cipher_encrypt(), in bytes.
+ *
+ * If the size of the output buffer is at least this large, it is guaranteed
+ * that psa_cipher_encrypt() will not fail due to an insufficient buffer size.
+ * Depending on the algorithm, the actual size of the output might be smaller.
+ *
+ * See also #PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(\p input_length).
+ *
+ * \warning This macro may evaluate its arguments multiple times or
+ * zero times, so you should not pass arguments that contain
+ * side effects.
+ *
+ * \param key_type A symmetric key type that is compatible with algorithm
+ * alg.
+ * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_CIPHER(\p alg) is true).
+ * \param input_length Size of the input in bytes.
+ *
+ * \return A sufficient output size for the specified key type and
+ * algorithm. If the key type or cipher algorithm is not
+ * recognized, or the parameters are incompatible,
+ * return 0.
+ */
+#define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length) \
+ (alg == PSA_ALG_CBC_PKCS7 ? \
+ (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \
+ PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \
+ (input_length) + 1u) + \
+ PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0u) : \
+ (PSA_ALG_IS_CIPHER(alg) ? \
+ (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) : \
+ 0u))
+
+/** A sufficient output buffer size for psa_cipher_encrypt(), for any of the
+ * supported key types and cipher algorithms.
+ *
+ * If the size of the output buffer is at least this large, it is guaranteed
+ * that psa_cipher_encrypt() will not fail due to an insufficient buffer size.
+ *
+ * See also #PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length).
+ *
+ * \param input_length Size of the input in bytes.
+ *
+ */
+#define PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(input_length) \
+ (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, \
+ (input_length) + 1u) + \
+ PSA_CIPHER_IV_MAX_SIZE)
+
+/** The maximum size of the output of psa_cipher_decrypt(), in bytes.
+ *
+ * If the size of the output buffer is at least this large, it is guaranteed
+ * that psa_cipher_decrypt() will not fail due to an insufficient buffer size.
+ * Depending on the algorithm, the actual size of the output might be smaller.
+ *
+ * See also #PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(\p input_length).
+ *
+ * \param key_type A symmetric key type that is compatible with algorithm
+ * alg.
+ * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_CIPHER(\p alg) is true).
+ * \param input_length Size of the input in bytes.
+ *
+ * \return A sufficient output size for the specified key type and
+ * algorithm. If the key type or cipher algorithm is not
+ * recognized, or the parameters are incompatible,
+ * return 0.
+ */
+#define PSA_CIPHER_DECRYPT_OUTPUT_SIZE(key_type, alg, input_length) \
+ (PSA_ALG_IS_CIPHER(alg) && \
+ ((key_type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \
+ (input_length) : \
+ 0u)
+
+/** A sufficient output buffer size for psa_cipher_decrypt(), for any of the
+ * supported key types and cipher algorithms.
+ *
+ * If the size of the output buffer is at least this large, it is guaranteed
+ * that psa_cipher_decrypt() will not fail due to an insufficient buffer size.
+ *
+ * See also #PSA_CIPHER_DECRYPT_OUTPUT_SIZE(\p key_type, \p alg, \p input_length).
+ *
+ * \param input_length Size of the input in bytes.
+ */
+#define PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(input_length) \
+ (input_length)
+
+/** A sufficient output buffer size for psa_cipher_update().
+ *
+ * If the size of the output buffer is at least this large, it is guaranteed
+ * that psa_cipher_update() will not fail due to an insufficient buffer size.
+ * The actual size of the output might be smaller in any given call.
+ *
+ * See also #PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(\p input_length).
+ *
+ * \param key_type A symmetric key type that is compatible with algorithm
+ * alg.
+ * \param alg A cipher algorithm (PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_CIPHER(\p alg) is true).
+ * \param input_length Size of the input in bytes.
+ *
+ * \return A sufficient output size for the specified key type and
+ * algorithm. If the key type or cipher algorithm is not
+ * recognized, or the parameters are incompatible, return 0.
+ */
+#define PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length) \
+ (PSA_ALG_IS_CIPHER(alg) ? \
+ (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) != 0 ? \
+ (((alg) == PSA_ALG_CBC_PKCS7 || \
+ (alg) == PSA_ALG_CBC_NO_PADDING || \
+ (alg) == PSA_ALG_ECB_NO_PADDING) ? \
+ PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type), \
+ input_length) : \
+ (input_length)) : 0u) : \
+ 0u)
+
+/** A sufficient output buffer size for psa_cipher_update(), for any of the
+ * supported key types and cipher algorithms.
+ *
+ * If the size of the output buffer is at least this large, it is guaranteed
+ * that psa_cipher_update() will not fail due to an insufficient buffer size.
+ *
+ * See also #PSA_CIPHER_UPDATE_OUTPUT_SIZE(\p key_type, \p alg, \p input_length).
+ *
+ * \param input_length Size of the input in bytes.
+ */
+#define PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(input_length) \
+ (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length))
+
+/** A sufficient ciphertext buffer size for psa_cipher_finish().
+ *
+ * If the size of the ciphertext buffer is at least this large, it is
+ * guaranteed that psa_cipher_finish() will not fail due to an insufficient
+ * ciphertext buffer size. The actual size of the output might be smaller in
+ * any given call.
+ *
+ * See also #PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE().
+ *
+ * \param key_type A symmetric key type that is compatible with algorithm
+ * alg.
+ * \param alg A cipher algorithm (PSA_ALG_XXX value such that
+ * #PSA_ALG_IS_CIPHER(\p alg) is true).
+ * \return A sufficient output size for the specified key type and
+ * algorithm. If the key type or cipher algorithm is not
+ * recognized, or the parameters are incompatible, return 0.
+ */
+#define PSA_CIPHER_FINISH_OUTPUT_SIZE(key_type, alg) \
+ (PSA_ALG_IS_CIPHER(alg) ? \
+ (alg == PSA_ALG_CBC_PKCS7 ? \
+ PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \
+ 0u) : \
+ 0u)
+
+/** A sufficient ciphertext buffer size for psa_cipher_finish(), for any of the
+ * supported key types and cipher algorithms.
+ *
+ * See also #PSA_CIPHER_FINISH_OUTPUT_SIZE(\p key_type, \p alg).
+ */
+#define PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE \
+ (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)
+
+#endif /* PSA_CRYPTO_SIZES_H */