text: /*
   * Copyright (c) 2018-2021, Arm Limited. All rights reserved.
   *
   * SPDX-License-Identifier: BSD-3-Clause
   *
   */
  /**
   * \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.
   */
  
  #ifndef PSA_CRYPTO_SIZES_H
  #define PSA_CRYPTO_SIZES_H
  
  #define PSA_BITS_TO_BYTES(bits) (((bits) + 7) / 8)
  #define PSA_BYTES_TO_BITS(bytes) ((bytes) * 8)
  
  #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_MD2 ? 16 :            \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD4 ? 16 :            \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 16 :            \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 20 :      \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 20 :          \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 28 :        \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 32 :        \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 48 :        \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 64 :        \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 28 :    \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 32 :    \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 28 :       \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 32 :       \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 48 :       \
          PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 64 :       \
          0)
  
  /** \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-SHA3-226,
   * 136 bytes for HMAC-SHA3-256, 104 bytes for SHA3-384, 72 bytes for
   * HMAC-SHA3-512. */
  #define PSA_HASH_MAX_SIZE 64
  #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128
  
  /** \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 tag size for an AEAD algorithm, in bytes.
   *
   * \param alg                 An AEAD algorithm
   *                            (\c PSA_ALG_XXX value such that
   *                            #PSA_ALG_IS_AEAD(\p alg) is true).
   *
   * \return                    The tag size for the specified algorithm.
   *                            If the AEAD algorithm does not have an identified
   *                            tag that can be distinguished from the rest of
   *                            the ciphertext, return 0.
   *                            If the AEAD algorithm is not recognized, return 0.
   */
  #define PSA_AEAD_TAG_LENGTH(alg)                                        \
      (PSA_ALG_IS_AEAD(alg) ?                                             \
       (((alg) & PSA_ALG_AEAD_TAG_LENGTH_MASK) >> PSA_AEAD_TAG_LENGTH_OFFSET) : \
       0)
  
  /** The maximum tag size for all supported AEAD algorithms, in bytes.
   *
   * See also #PSA_AEAD_TAG_LENGTH(\p alg).
   */
  #define PSA_AEAD_TAG_MAX_SIZE       16
  
  /* 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 4096
  
  /* The maximum size of an ECC key on this implementation, in bits */
  #define PSA_VENDOR_ECC_MAX_CURVE_BITS 521
  
  /** 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(\p 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 128
  
  /** The maximum size of a block cipher. */
  #define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16
  
  
  /** 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), 0))
  
  /** 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.
   *
   * \warning This macro may evaluate its arguments multiple times or
   *          zero times, so you should not pass arguments that contain
   *          side effects.
   *
   * \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 AEAD algorithm is not recognized, return 0.
   */
  #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(alg, plaintext_length)       \
      (PSA_AEAD_TAG_LENGTH(alg) != 0 ?                              \
       (plaintext_length) + PSA_AEAD_TAG_LENGTH(alg) :              \
       0)
  
  /** 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 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.
   *
   * \warning This macro may evaluate its arguments multiple times or
   *          zero times, so you should not pass arguments that contain
   *          side effects.
   *
   * \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 AEAD algorithm is not recognized, return 0.
   */
  #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(alg, ciphertext_length)      \
      (PSA_AEAD_TAG_LENGTH(alg) != 0 ?                              \
       (ciphertext_length) - PSA_AEAD_TAG_LENGTH(alg) :             \
       0)
  
  /** 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 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 && \
           (PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG(alg) == PSA_ALG_CCM || \
            PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG(alg) == PSA_ALG_GCM) ? 12 : \
       (key_type) == PSA_KEY_TYPE_CHACHA20 && \
            PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG(alg) == PSA_ALG_CHACHA20_POLY1305 ? 12 : \
       0)
  
  /** 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 12
  
  /** 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.
   *
   * \warning This macro may evaluate its arguments multiple times or
   *          zero times, so you should not pass arguments that contain
   *          side effects.
   *
   * \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 AEAD algorithm is not recognized, 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(alg, input_length)                              \
      (PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ?                                         \
       PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length)) :    \
       (input_length))
  
  /** 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 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.
   *
   * \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 AEAD algorithm is not recognized, return 0.
   */
  #define PSA_AEAD_FINISH_OUTPUT_SIZE(alg)                                \
      (PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ?                             \
       PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE :                                  \
       0)
  
  /** 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 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.
   *
   * \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 AEAD algorithm is not recognized, return 0.
   */
  #define PSA_AEAD_VERIFY_OUTPUT_SIZE(alg)                                \
      (PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ?                             \
       PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE :                                  \
       0)
  
  /** 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 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) ?                                   \
       2 * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1 :    \
       11 /*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) * 2)
  
  /** 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, 0))
  
  #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                               \
      (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE ? \
       PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) :                   \
       PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE)
  
  /** 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)) :                         \
       0)
  
  /** 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) :  \
       0)
  
  /** 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) / 8 + 5)
  
  /* 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) + 11)
  
  /* Maximum size of the export encoding of an RSA key pair.
   * Assumes thatthe 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)   \
      (9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14)
  
  /* 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-Parms  } -- 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) * 3 + 59)
  
  /* 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) * 3 + 75)
  
  /* 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)        \
      (2 * PSA_BITS_TO_BYTES(key_bits) + 1)
  
  /* 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))
  
  /** 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) :                         \
       (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) :  \
       0)
  
  /** 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) : \
       0)
  
  /** 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                                            \
      (PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) >        \
       PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ?      \
       PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) :        \
       PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS))
  
  /** 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                                          \
      (PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) >      \
       PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) ?    \
       PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_RSA_MAX_KEY_BITS) :      \
       PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS))
  
  /** 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.
   */
  /* FFDH is not yet supported in PSA. */
  #define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits)   \
      (PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ?                   \
       PSA_BITS_TO_BYTES(key_bits) :                              \
       0)
  
  /** 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   \
      (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS))
  
  /** 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 ? 12 : \
       0)
  
  /** The maximum IV size for all supported cipher algorithms, in bytes.
   *
   * See also #PSA_CIPHER_IV_LENGTH().
   */
  #define PSA_CIPHER_IV_MAX_SIZE 16
  
  /** 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_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type),          \
                                (input_length) + 1) +                             \
       PSA_CIPHER_IV_LENGTH((key_type), (alg)) :                                  \
       (PSA_ALG_IS_CIPHER(alg) ?                                                  \
        (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) :                \
       0))
  
  /** 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) + 1) +                             \
       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) :                                                               \
       0)
  
  /** 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) ?                                                   \
       (((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)) :                                                         \
       0)
  
  /** 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) :         \
        0) :                                              \
       0)
  
  /** 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 */
  