PSA cryptography module: Mbed TLS buffer size macros. More...

#include "mbedtls/build_info.h"

Include dependency graph for crypto_sizes.h:

This graph shows which files directly or indirectly include this file:

Macros
#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))

#define	PSA_HASH_LENGTH(alg)

#define	PSA_HASH_BLOCK_LENGTH(alg)

#define	PSA_HASH_MAX_SIZE 64

#define	PSA_HMAC_MAX_HASH_BLOCK_SIZE 128

#define	PSA_MAC_MAX_SIZE PSA_HASH_MAX_SIZE

#define	PSA_AEAD_TAG_LENGTH(key_type, key_bits, alg)

#define	PSA_AEAD_TAG_MAX_SIZE 16

#define	PSA_VENDOR_RSA_MAX_KEY_BITS 4096

#define	PSA_VENDOR_ECC_MAX_CURVE_BITS 521

#define	PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128

#define	PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16

#define	PSA_MAC_LENGTH(key_type, key_bits, alg)

#define	PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length)

#define	PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length) ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE)

#define	PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length)

#define	PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE(ciphertext_length) (ciphertext_length)

#define	PSA_AEAD_NONCE_LENGTH(key_type, alg)

#define	PSA_AEAD_NONCE_MAX_SIZE 13

#define	PSA_AEAD_UPDATE_OUTPUT_SIZE(key_type, alg, input_length)

#define	PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE(input_length) (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length)))

#define	PSA_AEAD_FINISH_OUTPUT_SIZE(key_type, alg)

#define	PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)

#define	PSA_AEAD_VERIFY_OUTPUT_SIZE(key_type, alg)

#define	PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)

#define	PSA_RSA_MINIMUM_PADDING_SIZE(alg)

#define	PSA_ECDSA_SIGNATURE_SIZE(curve_bits) (PSA_BITS_TO_BYTES(curve_bits) * 2)
	ECDSA signature size for a given curve bit size. More...

#define	PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg)

#define	PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)

#define	PSA_SIGNATURE_MAX_SIZE

#define	PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg)

#define	PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS))

#define	PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg)

#define	PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS))

#define	PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) ((bits) / 8 + 5)

#define	PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11)

#define	PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) (9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14)

#define	PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 59)

#define	PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 75)

#define	PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) (2 * PSA_BITS_TO_BYTES(key_bits) + 1)

#define	PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) (PSA_BITS_TO_BYTES(key_bits))

#define	PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits)

#define	PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(key_type, key_bits)

#define	PSA_EXPORT_KEY_PAIR_MAX_SIZE

#define	PSA_EXPORT_PUBLIC_KEY_MAX_SIZE

#define	PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(key_type, key_bits)

#define	PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS))

#define	PSA_CIPHER_IV_LENGTH(key_type, alg)

#define	PSA_CIPHER_IV_MAX_SIZE 16

#define	PSA_CIPHER_ENCRYPT_OUTPUT_SIZE(key_type, alg, input_length)

#define	PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE(input_length)

#define	PSA_CIPHER_DECRYPT_OUTPUT_SIZE(key_type, alg, input_length)

#define	PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE(input_length) (input_length)

#define	PSA_CIPHER_UPDATE_OUTPUT_SIZE(key_type, alg, input_length)

#define	PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE(input_length) (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length))

#define	PSA_CIPHER_FINISH_OUTPUT_SIZE(key_type, alg)

#define	PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)

Detailed Description

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.

Definition in file crypto_sizes.h.

Macro Definition Documentation

#define PSA_AEAD_DECRYPT_OUTPUT_MAX_SIZE ( ciphertext_length ) (ciphertext_length)

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(key_type, alg, ciphertext_length).

Parameters

ciphertext_length Size of the ciphertext in bytes.

Returns: A sufficient output buffer size for any of the supported key types and AEAD algorithms.

Definition at line 375 of file crypto_sizes.h.

#define PSA_AEAD_DECRYPT_OUTPUT_SIZE	(	key_type,
		alg,
		ciphertext_length
	)

Value:

(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) :      \
     0)

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(ciphertext_length).

Warning: This macro may evaluate its arguments multiple times or zero times, so you should not pass arguments that contain side effects.

Parameters

key_type	A symmetric key type that is compatible with algorithm `alg`.
alg	An AEAD algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_AEAD(`alg`) is true).
ciphertext_length	Size of the plaintext in bytes.

Returns: 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.

Definition at line 351 of file crypto_sizes.h.

#define PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE ( plaintext_length ) ((plaintext_length) + PSA_AEAD_TAG_MAX_SIZE)

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(key_type, alg, plaintext_length).

Parameters

plaintext_length Size of the plaintext in bytes.

Returns: A sufficient output buffer size for any of the supported key types and AEAD algorithms.

Definition at line 321 of file crypto_sizes.h.

#define PSA_AEAD_ENCRYPT_OUTPUT_SIZE	(	key_type,
		alg,
		plaintext_length
	)

Value:

(PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 ?                      \
     (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) :          \
     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.

See also PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(plaintext_length).

Warning: This macro may evaluate its arguments multiple times or zero times, so you should not pass arguments that contain side effects.

Parameters

key_type	A symmetric key type that is compatible with algorithm `alg`.
alg	An AEAD algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_AEAD(`alg`) is true).
plaintext_length	Size of the plaintext in bytes.

Returns: 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.

Definition at line 298 of file crypto_sizes.h.

#define PSA_AEAD_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)

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(key_type, alg).

Definition at line 507 of file crypto_sizes.h.

#define PSA_AEAD_FINISH_OUTPUT_SIZE	(	key_type,
		alg
	)

Value:

(PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 &&  \
         PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ?    \
         PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \
     0)

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.

Parameters

key_type	A symmetric key type that is compatible with algorithm `alg`.
alg	An AEAD algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_AEAD(`alg`) is true).

Returns: 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.

Definition at line 496 of file crypto_sizes.h.

#define PSA_AEAD_NONCE_LENGTH	(	key_type,
		alg
	)

Value:

(PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \
          MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CCM) ? 13 : \
          MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_GCM) ? 12 : \
          0 : \
     (key_type) == PSA_KEY_TYPE_CHACHA20 && \
          MBEDTLS_PSA_ALG_AEAD_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12 : \
     0)

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_TAG_MAX_SIZE.

Parameters

key_type	The type of the AEAD key.
key_bits	The size of the AEAD key in bits.
alg	An AEAD algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_AEAD(`alg`) is true).

Returns: 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.

Definition at line 167 of file crypto_sizes.h.

#define PSA_AEAD_TAG_MAX_SIZE 16

The maximum tag size for all supported AEAD algorithms, in bytes.

See also PSA_AEAD_TAG_LENGTH(key_type, key_bits, alg).

Definition at line 176 of file crypto_sizes.h.

#define PSA_AEAD_UPDATE_OUTPUT_MAX_SIZE ( input_length ) (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (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(key_type, alg, input_length).

Parameters

input_length Size of the input in bytes.

Definition at line 472 of file crypto_sizes.h.

#define PSA_AEAD_UPDATE_OUTPUT_SIZE	(	key_type,
		alg,
		input_length
	)

Value:

(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) : \
     0)

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(input_length).

Warning: This macro may evaluate its arguments multiple times or zero times, so you should not pass arguments that contain side effects.

Parameters

key_type	A symmetric key type that is compatible with algorithm `alg`.
alg	An AEAD algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_AEAD(`alg`) is true).
input_length	Size of the input in bytes.

Returns: 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.

Definition at line 455 of file crypto_sizes.h.

#define PSA_AEAD_VERIFY_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)

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(key_type, alg).

Definition at line 541 of file crypto_sizes.h.

#define PSA_AEAD_VERIFY_OUTPUT_SIZE	(	key_type,
		alg
	)

Value:

(PSA_AEAD_NONCE_LENGTH(key_type, alg) != 0 &&  \
         PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ?    \
         PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \
     0)

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.

Parameters

key_type	A symmetric key type that is compatible with algorithm `alg`.
alg	An AEAD algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_AEAD(`alg`) is true).

Returns: 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.

Definition at line 530 of file crypto_sizes.h.

#define PSA_ASYMMETRIC_DECRYPT_OUTPUT_MAX_SIZE (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS))

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(key_type, key_bits, alg).

Definition at line 680 of file crypto_sizes.h.

#define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE	(	key_type,
		key_bits,
		alg
	)

Value:

(PSA_KEY_TYPE_IS_RSA(key_type) ?                                    \
     PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) :  \
     0)

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.

Parameters

key_type	An asymmetric key type (this may indifferently be a key pair type or a public key type).
key_bits	The size of the key in bits.
alg	The asymmetric encryption algorithm.

Returns: 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.

Definition at line 668 of file crypto_sizes.h.

#define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_MAX_SIZE (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS))

A sufficient output buffer size for psa_asymmetric_encrypt(), for any supported asymmetric encryption.

See also PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg).

Definition at line 640 of file crypto_sizes.h.

#define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE	(	key_type,
		key_bits,
		alg
	)

Value:

(PSA_KEY_TYPE_IS_RSA(key_type) ?                                    \
     ((void)alg, PSA_BITS_TO_BYTES(key_bits)) :                         \
     0)

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.

Parameters

key_type	An asymmetric key type (this may indifferently be a key pair type or a public key type).
key_bits	The size of the key in bits.
alg	The asymmetric encryption algorithm.

Returns: 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.

Definition at line 629 of file crypto_sizes.h.

#define PSA_BITS_TO_BYTES ( bits ) (((bits) + 7) / 8)

Definition at line 47 of file crypto_sizes.h.

#define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16

The maximum size of a block cipher.

Definition at line 243 of file crypto_sizes.h.

#define PSA_BYTES_TO_BITS ( bytes ) ((bytes) * 8)

Definition at line 48 of file crypto_sizes.h.

#define PSA_CIPHER_DECRYPT_OUTPUT_MAX_SIZE ( input_length ) (input_length)

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(key_type, alg, input_length).

Parameters

input_length Size of the input in bytes.

Definition at line 1087 of file crypto_sizes.h.

#define PSA_CIPHER_DECRYPT_OUTPUT_SIZE	(	key_type,
		alg,
		input_length
	)

Value:

(PSA_ALG_IS_CIPHER(alg) &&                                                      \
     ((key_type) & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC ? \
     (input_length) :                                                               \
     0)

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(input_length).

Parameters

key_type	A symmetric key type that is compatible with algorithm alg.
alg	A cipher algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_CIPHER(`alg`) is true).
input_length	Size of the input in bytes.

Returns: 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.

Definition at line 1071 of file crypto_sizes.h.

#define PSA_CIPHER_ENCRYPT_OUTPUT_MAX_SIZE ( input_length )

Value:

(PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE,                  \
                              (input_length) + 1) +                             \
     PSA_CIPHER_IV_MAX_SIZE)

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(key_type, alg, input_length).

Parameters

input_length Size of the input in bytes.

Definition at line 1047 of file crypto_sizes.h.

#define PSA_CIPHER_ENCRYPT_OUTPUT_SIZE	(	key_type,
		alg,
		input_length
	)

Value:

(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) + 1) +                             \
     PSA_CIPHER_IV_LENGTH((key_type), (alg)) : 0) :                             \
     (PSA_ALG_IS_CIPHER(alg) ?                                                  \
      (input_length) + PSA_CIPHER_IV_LENGTH((key_type), (alg)) :                \
     0))

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(input_length).

Warning: This macro may evaluate its arguments multiple times or zero times, so you should not pass arguments that contain side effects.

Parameters

key_type	A symmetric key type that is compatible with algorithm alg.
alg	A cipher algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_CIPHER(`alg`) is true).
input_length	Size of the input in bytes.

Returns: 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.

Definition at line 1026 of file crypto_sizes.h.

#define PSA_CIPHER_FINISH_OUTPUT_MAX_SIZE (PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE)

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(key_type, alg).

Definition at line 1161 of file crypto_sizes.h.

#define PSA_CIPHER_FINISH_OUTPUT_SIZE	(	key_type,
		alg
	)

Value:

(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().

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.

Parameters

key_type	A symmetric key type that is compatible with algorithm alg.
alg	A cipher algorithm (PSA_ALG_XXX value such that PSA_ALG_IS_CIPHER(`alg`) is true).

Returns: 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.

Definition at line 1149 of file crypto_sizes.h.

#define PSA_CIPHER_IV_LENGTH	(	key_type,
		alg
	)

Value:

(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 : \
         (alg) == PSA_ALG_CCM_STAR_NO_TAG ? 13 : \
         0)

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_LENGTH().

Definition at line 1001 of file crypto_sizes.h.

#define PSA_CIPHER_UPDATE_OUTPUT_MAX_SIZE ( input_length ) (PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, input_length))

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(key_type, alg, input_length).

Parameters

input_length Size of the input in bytes.

Definition at line 1129 of file crypto_sizes.h.

#define PSA_CIPHER_UPDATE_OUTPUT_SIZE	(	key_type,
		alg,
		input_length
	)

Value:

(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)) : 0) :                                                    \
     0)

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(input_length).

Parameters

key_type	A symmetric key type that is compatible with algorithm alg.
alg	A cipher algorithm (PSA_ALG_XXX value such that PSA_ALG_IS_CIPHER(`alg`) is true).
input_length	Size of the input in bytes.

Returns: 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.

Definition at line 1108 of file crypto_sizes.h.

#define PSA_ECDSA_SIGNATURE_SIZE ( curve_bits ) (PSA_BITS_TO_BYTES(curve_bits) * 2)

ECDSA signature size for a given curve bit size.

Parameters

curve_bits Curve size in bits.

Returns: Signature size in bytes.

Note: This macro returns a compile-time constant if its argument is one.

Definition at line 556 of file crypto_sizes.h.

#define PSA_EXPORT_KEY_OUTPUT_SIZE	(	key_type,
		key_bits
	)

Value:

(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_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.

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(...);

Parameters

key_type	A supported key type.
key_bits	The size of the key in bits.

Returns: 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.

Definition at line 832 of file crypto_sizes.h.

#define PSA_EXPORT_KEY_PAIR_MAX_SIZE

Value:

(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 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(key_type, key_bits).

Definition at line 900 of file crypto_sizes.h.

#define PSA_EXPORT_PUBLIC_KEY_MAX_SIZE

Value:

(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 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(key_type, key_bits).

Definition at line 915 of file crypto_sizes.h.

#define PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE	(	key_type,
		key_bits
	)

Value:

(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 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.

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(...);

Parameters

key_type	A public key or key pair key type.
key_bits	The size of the key in bits.

Returns: 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( PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(key_type), key_bits).

Definition at line 887 of file crypto_sizes.h.

#define PSA_HASH_BLOCK_LENGTH ( alg )

Value:

(                                                               \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 64 :            \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 64 :      \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 64 :          \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 64 :        \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 64 :        \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 128 :       \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 128 :       \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 128 :   \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 128 :   \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 144 :      \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 136 :      \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 104 :      \
        PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 72 :       \
        0)

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().

Parameters

alg	A hash algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_HASH(`alg`) is true).

Returns: 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.

Definition at line 97 of file crypto_sizes.h.

#define PSA_HASH_LENGTH ( alg )

Value:

(                                                               \
        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)

The size of the output of psa_hash_finish(), in bytes.

This is also the hash size that psa_hash_verify() expects.

Parameters

alg	A hash algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_HASH(`alg`) is true), or an HMAC algorithm (PSA_ALG_HMAC(`hash_alg`) where `hash_alg` is a hash algorithm).

Returns: The hash size for the specified hash algorithm. If the hash algorithm is not recognized, return 0.

Definition at line 65 of file crypto_sizes.h.

#define PSA_HASH_MAX_SIZE 64

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.

Definition at line 125 of file crypto_sizes.h.

#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128

Definition at line 126 of file crypto_sizes.h.

#define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE ( bits ) ((bits) / 8 + 5)

Definition at line 693 of file crypto_sizes.h.

#define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE ( key_bits ) (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 75)

Definition at line 770 of file crypto_sizes.h.

#define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE ( key_bits ) (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 59)

Definition at line 751 of file crypto_sizes.h.

#define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE ( key_bits ) (PSA_BITS_TO_BYTES(key_bits))

Definition at line 790 of file crypto_sizes.h.

#define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE ( key_bits ) (2 * PSA_BITS_TO_BYTES(key_bits) + 1)

Definition at line 783 of file crypto_sizes.h.

#define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE ( key_bits ) (9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14)

Definition at line 732 of file crypto_sizes.h.

#define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE ( key_bits ) (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11)

Definition at line 707 of file crypto_sizes.h.

#define PSA_MAC_LENGTH	(	key_type,
		key_bits,
		alg
	)

Value:

((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 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.

Parameters

key_type	The type of the MAC key.
key_bits	The size of the MAC key in bits.
alg	A MAC algorithm (`PSA_ALG_XXX` value such that PSA_ALG_IS_MAC(`alg`) is true).

Returns: The MAC size for the specified algorithm with the specified key parameters.; 0 if the MAC algorithm is not recognized.; Either 0 or the correct size for a MAC algorithm that the implementation recognizes, but does not support.; Unspecified if the key parameters are not consistent with the algorithm.

Definition at line 266 of file crypto_sizes.h.

#define PSA_MAC_MAX_SIZE PSA_HASH_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.

Definition at line 144 of file crypto_sizes.h.

#define PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE (PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS))

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(key_type, key_bits).

Definition at line 957 of file crypto_sizes.h.

#define PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE	(	key_type,
		key_bits
	)

Value:

(PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ?                   \
     PSA_BITS_TO_BYTES(key_bits) :                              \
     0)

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.

Parameters

key_type	A supported key type.
key_bits	The size of the key in bits.

Returns: 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.

Definition at line 945 of file crypto_sizes.h.

#define PSA_ROUND_UP_TO_MULTIPLE	(	block_size,
		length
	)	(((length) + (block_size) - 1) / (block_size) * (block_size))

Definition at line 50 of file crypto_sizes.h.

#define PSA_RSA_MINIMUM_PADDING_SIZE ( alg )

Value:

(PSA_ALG_IS_RSA_OAEP(alg) ?                                   \
     2 * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1 :    \
     11 /*PKCS#1v1.5*/)

Definition at line 543 of file crypto_sizes.h.

#define PSA_SIGN_OUTPUT_SIZE	(	key_type,
		key_bits,
		alg
	)

Value:

(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))

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.

Parameters

key_type	An asymmetric key type (this may indifferently be a key pair type or a public key type).
key_bits	The size of the key in bits.
alg	The signature algorithm.

Returns: 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.

Definition at line 584 of file crypto_sizes.h.

#define PSA_SIGNATURE_MAX_SIZE

Value:

(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)

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.

Definition at line 599 of file crypto_sizes.h.

#define PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128

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(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.

Definition at line 240 of file crypto_sizes.h.

#define PSA_VENDOR_ECC_MAX_CURVE_BITS 521

Definition at line 196 of file crypto_sizes.h.

#define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)

Definition at line 589 of file crypto_sizes.h.

#define PSA_VENDOR_RSA_MAX_KEY_BITS 4096

Definition at line 191 of file crypto_sizes.h.