Key and algorithm types#

psa_key_type_t#

typedef uint16_t psa_key_type_t

Encoding of a key type.

Values of this type are generally constructed by macros called PSA_KEY_TYPE_xxx.

Note

• Values of this type are encoded in the persistent key store. Any changes to existing values will require bumping the storage format version and providing a translation when reading the old format.

psa_ecc_family_t#

typedef uint8_t psa_ecc_family_t

The type of PSA elliptic curve family identifiers.

Values of this type are generally constructed by macros called PSA_ECC_FAMILY_xxx.

The curve identifier is required to create an ECC key using the PSA_KEY_TYPE_ECC_KEY_PAIR() or PSA_KEY_TYPE_ECC_PUBLIC_KEY() macros.

Values defined by this standard will never be in the range 0x80-0xff. Vendors who define additional families must use an encoding in this range.

Note

• Values of this type are encoded in the persistent key store. Any changes to existing values will require bumping the storage format version and providing a translation when reading the old format.

psa_dh_family_t#

typedef uint8_t psa_dh_family_t

The type of PSA Diffie-Hellman group family identifiers.

Values of this type are generally constructed by macros called PSA_DH_FAMILY_xxx.

The group identifier is required to create a Diffie-Hellman key using the PSA_KEY_TYPE_DH_KEY_PAIR() or PSA_KEY_TYPE_DH_PUBLIC_KEY() macros.

Values defined by this standard will never be in the range 0x80-0xff. Vendors who define additional families must use an encoding in this range.

Note

• Values of this type are encoded in the persistent key store. Any changes to existing values will require bumping the storage format version and providing a translation when reading the old format.

psa_algorithm_t#

typedef uint32_t psa_algorithm_t

Encoding of a cryptographic algorithm.

Values of this type are generally constructed by macros called PSA_ALG_xxx.

For algorithms that can be applied to multiple key types, this type does not encode the key type. For example, for symmetric ciphers based on a block cipher, psa_algorithm_t encodes the block cipher mode and the padding mode while the block cipher itself is encoded via psa_key_type_t.

Note

• Values of this type are encoded in the persistent key store. Any changes to existing values will require bumping the storage format version and providing a translation when reading the old format.

psa_key_type_t#

typedef uint16_t psa_key_type_t

Encoding of a key type.

Values of this type are generally constructed by macros called PSA_KEY_TYPE_xxx.

Note

• Values of this type are encoded in the persistent key store. Any changes to existing values will require bumping the storage format version and providing a translation when reading the old format.

psa_ecc_family_t#

typedef uint8_t psa_ecc_family_t

The type of PSA elliptic curve family identifiers.

Values of this type are generally constructed by macros called PSA_ECC_FAMILY_xxx.

The curve identifier is required to create an ECC key using the PSA_KEY_TYPE_ECC_KEY_PAIR() or PSA_KEY_TYPE_ECC_PUBLIC_KEY() macros.

Values defined by this standard will never be in the range 0x80-0xff. Vendors who define additional families must use an encoding in this range.

Note

• Values of this type are encoded in the persistent key store. Any changes to existing values will require bumping the storage format version and providing a translation when reading the old format.

psa_dh_family_t#

typedef uint8_t psa_dh_family_t

The type of PSA Diffie-Hellman group family identifiers.

Values of this type are generally constructed by macros called PSA_DH_FAMILY_xxx.

The group identifier is required to create a Diffie-Hellman key using the PSA_KEY_TYPE_DH_KEY_PAIR() or PSA_KEY_TYPE_DH_PUBLIC_KEY() macros.

Values defined by this standard will never be in the range 0x80-0xff. Vendors who define additional families must use an encoding in this range.

Note

• Values of this type are encoded in the persistent key store. Any changes to existing values will require bumping the storage format version and providing a translation when reading the old format.

psa_algorithm_t#

typedef uint32_t psa_algorithm_t

Encoding of a cryptographic algorithm.

Values of this type are generally constructed by macros called PSA_ALG_xxx.

For algorithms that can be applied to multiple key types, this type does not encode the key type. For example, for symmetric ciphers based on a block cipher, psa_algorithm_t encodes the block cipher mode and the padding mode while the block cipher itself is encoded via psa_key_type_t.

Note

• Values of this type are encoded in the persistent key store. Any changes to existing values will require bumping the storage format version and providing a translation when reading the old format.

PSA_KEY_TYPE_DSA_PUBLIC_KEY#

#define PSA_KEY_TYPE_DSA_PUBLIC_KEY

((psa_key_type_t)0x4002)

DSA public key.

The import and export format is the representation of the public key y = g^x mod p as a big-endian byte string. The length of the byte string is the length of the base prime p in bytes.

PSA_KEY_TYPE_DSA_KEY_PAIR#

#define PSA_KEY_TYPE_DSA_KEY_PAIR

((psa_key_type_t)0x7002)

DSA key pair (private and public key).

The import and export format is the representation of the private key x as a big-endian byte string. The length of the byte string is the private key size in bytes (leading zeroes are not stripped).

Determinstic DSA key derivation with psa_generate_derived_key follows FIPS 186-4 §B.1.2: interpret the byte string as integer in big-endian order. Discard it if it is not in the range [0, N - 2] where N is the boundary of the private key domain (the prime p for Diffie-Hellman, the subprime q for DSA, or the order of the curve's base point for ECC). Add 1 to the resulting integer and use this as the private key x.

PSA_KEY_TYPE_IS_DSA#

#define PSA_KEY_TYPE_IS_DSA

(type)

Whether a key type is an DSA key (pair or public-only).

PSA_ALG_DSA_BASE#

#define PSA_ALG_DSA_BASE

((psa_algorithm_t)0x06000400)

PSA_ALG_DSA#

#define PSA_ALG_DSA

(hash_alg)

DSA signature with hashing.

This is the signature scheme defined by FIPS 186-4, with a random per-message secret number (k).

Returns

• The corresponding DSA signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_DETERMINISTIC_DSA_BASE#

#define PSA_ALG_DETERMINISTIC_DSA_BASE

((psa_algorithm_t)0x06000500)

PSA_ALG_DSA_DETERMINISTIC_FLAG#

#define PSA_ALG_DSA_DETERMINISTIC_FLAG

PSA_ALG_ECDSA_DETERMINISTIC_FLAG

PSA_ALG_DETERMINISTIC_DSA#

#define PSA_ALG_DETERMINISTIC_DSA

(hash_alg)

Deterministic DSA signature with hashing.

This is the deterministic variant defined by RFC 6979 of the signature scheme defined by FIPS 186-4.

Returns

• The corresponding DSA signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_IS_DSA#

#define PSA_ALG_IS_DSA

PSA_ALG_DSA_IS_DETERMINISTIC#

#define PSA_ALG_DSA_IS_DETERMINISTIC

(alg)

PSA_ALG_IS_DETERMINISTIC_DSA#

#define PSA_ALG_IS_DETERMINISTIC_DSA

(alg)

PSA_ALG_IS_RANDOMIZED_DSA#

#define PSA_ALG_IS_RANDOMIZED_DSA

(alg)

PSA_ALG_IS_VENDOR_HASH_AND_SIGN#

#define PSA_ALG_IS_VENDOR_HASH_AND_SIGN

(alg)

PSA_ALG_CATEGORY_PAKE#

#define PSA_ALG_CATEGORY_PAKE

((psa_algorithm_t) 0x0a000000)

PSA_ALG_IS_PAKE#

#define PSA_ALG_IS_PAKE

(alg)

Whether the specified algorithm is a password-authenticated key exchange.

Returns

• 1 if alg is a password-authenticated key exchange (PAKE) algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_JPAKE#

#define PSA_ALG_JPAKE

((psa_algorithm_t) 0x0a000100)

The Password-authenticated key exchange by juggling (J-PAKE) algorithm.

This is J-PAKE as defined by RFC 8236, instantiated with the following parameters:

• The group can be either an elliptic curve or defined over a finite field.

• Schnorr NIZK proof as defined by RFC 8235 and using the same group as the J-PAKE algorithm.

• A cryptographic hash function.

To select these parameters and set up the cipher suite, call these functions in any order:

psa_pake_cs_set_algorithm(cipher_suite, PSA_ALG_JPAKE);
psa_pake_cs_set_primitive(cipher_suite,
                          PSA_PAKE_PRIMITIVE(type, family, bits));
psa_pake_cs_set_hash(cipher_suite, hash);

For more information on how to set a specific curve or field, refer to the documentation of the individual PSA_PAKE_PRIMITIVE_TYPE_XXX constants.

After initializing a J-PAKE operation, call

psa_pake_setup(operation, cipher_suite);
psa_pake_set_user(operation, ...);
psa_pake_set_peer(operation, ...);
psa_pake_set_password_key(operation, ...);

The password is provided as a key. This can be the password text itself, in an agreed character encoding, or some value derived from the password as required by a higher level protocol.

(The implementation converts the key material to a number as described in Section 2.3.8 of SEC 1: Elliptic Curve Cryptography (https://www.secg.org/sec1-v2.pdf), before reducing it modulo q. Here q is order of the group defined by the primitive set in the cipher suite. The psa_pake_set_password_key() function returns an error if the result of the reduction is 0.)

The key exchange flow for J-PAKE is as follows:

1. To get the first round data that needs to be sent to the peer, call

   // Get g1
   psa_pake_output(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Get the ZKP public key for x1
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Get the ZKP proof for x1
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   // Get g2
   psa_pake_output(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Get the ZKP public key for x2
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Get the ZKP proof for x2
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   

2. To provide the first round data received from the peer to the operation, call

   // Set g3
   psa_pake_input(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Set the ZKP public key for x3
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Set the ZKP proof for x3
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   // Set g4
   psa_pake_input(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Set the ZKP public key for x4
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Set the ZKP proof for x4
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   

3. To get the second round data that needs to be sent to the peer, call

   // Get A
   psa_pake_output(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Get ZKP public key for x2*s
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Get ZKP proof for x2*s
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   

4. To provide the second round data received from the peer to the operation, call

   // Set B
   psa_pake_input(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Set ZKP public key for x4*s
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Set ZKP proof for x4*s
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   

5. To access the shared secret call

   // Get Ka=Kb=K
   psa_pake_get_implicit_key()
   

For more information consult the documentation of the individual PSA_PAKE_STEP_XXX constants.

At this point there is a cryptographic guarantee that only the authenticated party who used the same password is able to compute the key. But there is no guarantee that the peer is the party it claims to be and was able to do so.

That is, the authentication is only implicit (the peer is not authenticated at this point, and no action should be taken that assume that they are - like for example accessing restricted files).

To make the authentication explicit there are various methods, see Section 5 of RFC 8236 for two examples.

PSA_KEY_TYPE_DSA_PUBLIC_KEY#

#define PSA_KEY_TYPE_DSA_PUBLIC_KEY

((psa_key_type_t) 0x4002)

DSA public key.

The import and export format is the representation of the public key y = g^x mod p as a big-endian byte string. The length of the byte string is the length of the base prime p in bytes.

PSA_KEY_TYPE_DSA_KEY_PAIR#

#define PSA_KEY_TYPE_DSA_KEY_PAIR

((psa_key_type_t) 0x7002)

DSA key pair (private and public key).

The import and export format is the representation of the private key x as a big-endian byte string. The length of the byte string is the private key size in bytes (leading zeroes are not stripped).

Deterministic DSA key derivation with psa_generate_derived_key follows FIPS 186-4 §B.1.2: interpret the byte string as integer in big-endian order. Discard it if it is not in the range [0, N - 2] where N is the boundary of the private key domain (the prime p for Diffie-Hellman, the subprime q for DSA, or the order of the curve's base point for ECC). Add 1 to the resulting integer and use this as the private key x.

PSA_KEY_TYPE_IS_DSA#

#define PSA_KEY_TYPE_IS_DSA

(type)

Whether a key type is a DSA key (pair or public-only).

PSA_ALG_DSA_BASE#

#define PSA_ALG_DSA_BASE

((psa_algorithm_t) 0x06000400)

PSA_ALG_DSA#

#define PSA_ALG_DSA

(hash_alg)

DSA signature with hashing.

This is the signature scheme defined by FIPS 186-4, with a random per-message secret number (k).

Returns

• The corresponding DSA signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_DETERMINISTIC_DSA_BASE#

#define PSA_ALG_DETERMINISTIC_DSA_BASE

((psa_algorithm_t) 0x06000500)

PSA_ALG_DSA_DETERMINISTIC_FLAG#

#define PSA_ALG_DSA_DETERMINISTIC_FLAG

PSA_ALG_ECDSA_DETERMINISTIC_FLAG

PSA_ALG_DETERMINISTIC_DSA#

#define PSA_ALG_DETERMINISTIC_DSA

(hash_alg)

Deterministic DSA signature with hashing.

This is the deterministic variant defined by RFC 6979 of the signature scheme defined by FIPS 186-4.

Returns

• The corresponding DSA signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_IS_DSA#

#define PSA_ALG_IS_DSA

PSA_ALG_DSA_IS_DETERMINISTIC#

#define PSA_ALG_DSA_IS_DETERMINISTIC

(alg)

PSA_ALG_IS_DETERMINISTIC_DSA#

#define PSA_ALG_IS_DETERMINISTIC_DSA

(alg)

PSA_ALG_IS_RANDOMIZED_DSA#

#define PSA_ALG_IS_RANDOMIZED_DSA

(alg)

PSA_ALG_IS_VENDOR_HASH_AND_SIGN#

#define PSA_ALG_IS_VENDOR_HASH_AND_SIGN

(alg)

PSA_ALG_CATEGORY_PAKE#

#define PSA_ALG_CATEGORY_PAKE

((psa_algorithm_t) 0x0a000000)

PSA_ALG_IS_PAKE#

#define PSA_ALG_IS_PAKE

(alg)

Whether the specified algorithm is a password-authenticated key exchange.

Returns

• 1 if alg is a password-authenticated key exchange (PAKE) algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_JPAKE#

#define PSA_ALG_JPAKE

((psa_algorithm_t) 0x0a000100)

The Password-authenticated key exchange by juggling (J-PAKE) algorithm.

This is J-PAKE as defined by RFC 8236, instantiated with the following parameters:

• The group can be either an elliptic curve or defined over a finite field.

• Schnorr NIZK proof as defined by RFC 8235 and using the same group as the J-PAKE algorithm.

• A cryptographic hash function.

To select these parameters and set up the cipher suite, call these functions in any order:

psa_pake_cs_set_algorithm(cipher_suite, PSA_ALG_JPAKE);
psa_pake_cs_set_primitive(cipher_suite,
                          PSA_PAKE_PRIMITIVE(type, family, bits));
psa_pake_cs_set_hash(cipher_suite, hash);

For more information on how to set a specific curve or field, refer to the documentation of the individual PSA_PAKE_PRIMITIVE_TYPE_XXX constants.

After initializing a J-PAKE operation, call

psa_pake_setup(operation, cipher_suite);
psa_pake_set_user(operation, ...);
psa_pake_set_peer(operation, ...);
psa_pake_set_password_key(operation, ...);

The password is provided as a key. This can be the password text itself, in an agreed character encoding, or some value derived from the password as required by a higher level protocol.

(The implementation converts the key material to a number as described in Section 2.3.8 of SEC 1: Elliptic Curve Cryptography (https://www.secg.org/sec1-v2.pdf), before reducing it modulo q. Here q is order of the group defined by the primitive set in the cipher suite. The psa_pake_set_password_key() function returns an error if the result of the reduction is 0.)

The key exchange flow for J-PAKE is as follows:

1. To get the first round data that needs to be sent to the peer, call

   // Get g1
   psa_pake_output(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Get the ZKP public key for x1
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Get the ZKP proof for x1
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   // Get g2
   psa_pake_output(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Get the ZKP public key for x2
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Get the ZKP proof for x2
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   

2. To provide the first round data received from the peer to the operation, call

   // Set g3
   psa_pake_input(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Set the ZKP public key for x3
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Set the ZKP proof for x3
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   // Set g4
   psa_pake_input(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Set the ZKP public key for x4
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Set the ZKP proof for x4
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   

3. To get the second round data that needs to be sent to the peer, call

   // Get A
   psa_pake_output(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Get ZKP public key for x2*s
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Get ZKP proof for x2*s
   psa_pake_output(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   

4. To provide the second round data received from the peer to the operation, call

   // Set B
   psa_pake_input(operation, #PSA_PAKE_STEP_KEY_SHARE, ...);
   // Set ZKP public key for x4*s
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PUBLIC, ...);
   // Set ZKP proof for x4*s
   psa_pake_input(operation, #PSA_PAKE_STEP_ZK_PROOF, ...);
   

5. To access the shared secret call

   // Get Ka=Kb=K
   psa_pake_get_implicit_key()
   

For more information consult the documentation of the individual PSA_PAKE_STEP_XXX constants.

At this point there is a cryptographic guarantee that only the authenticated party who used the same password is able to compute the key. But there is no guarantee that the peer is the party it claims to be and was able to do so.

That is, the authentication is only implicit (the peer is not authenticated at this point, and no action should be taken that assume that they are - like for example accessing restricted files).

To make the authentication explicit there are various methods, see Section 5 of RFC 8236 for two examples.

PSA_KEY_TYPE_NONE#

#define PSA_KEY_TYPE_NONE

((psa_key_type_t) 0x0000)

An invalid key type value.

Zero is not the encoding of any key type.

PSA_KEY_TYPE_VENDOR_FLAG#

#define PSA_KEY_TYPE_VENDOR_FLAG

((psa_key_type_t) 0x8000)

Vendor-defined key type flag.

Key types defined by this standard will never have the PSA_KEY_TYPE_VENDOR_FLAG bit set. Vendors who define additional key types must use an encoding with the PSA_KEY_TYPE_VENDOR_FLAG bit set and should respect the bitwise structure used by standard encodings whenever practical.

PSA_KEY_TYPE_CATEGORY_MASK#

#define PSA_KEY_TYPE_CATEGORY_MASK

((psa_key_type_t) 0x7000)

PSA_KEY_TYPE_CATEGORY_RAW#

#define PSA_KEY_TYPE_CATEGORY_RAW

((psa_key_type_t) 0x1000)

PSA_KEY_TYPE_CATEGORY_SYMMETRIC#

#define PSA_KEY_TYPE_CATEGORY_SYMMETRIC

((psa_key_type_t) 0x2000)

PSA_KEY_TYPE_CATEGORY_PUBLIC_KEY#

#define PSA_KEY_TYPE_CATEGORY_PUBLIC_KEY

((psa_key_type_t) 0x4000)

PSA_KEY_TYPE_CATEGORY_KEY_PAIR#

#define PSA_KEY_TYPE_CATEGORY_KEY_PAIR

((psa_key_type_t) 0x7000)

PSA_KEY_TYPE_CATEGORY_FLAG_PAIR#

#define PSA_KEY_TYPE_CATEGORY_FLAG_PAIR

((psa_key_type_t) 0x3000)

PSA_KEY_TYPE_IS_VENDOR_DEFINED#

#define PSA_KEY_TYPE_IS_VENDOR_DEFINED

(type)

Whether a key type is vendor-defined.

See also PSA_KEY_TYPE_VENDOR_FLAG.

PSA_KEY_TYPE_IS_UNSTRUCTURED#

#define PSA_KEY_TYPE_IS_UNSTRUCTURED

Whether a key type is an unstructured array of bytes.

This encompasses both symmetric keys and non-key data.

PSA_KEY_TYPE_IS_ASYMMETRIC#

#define PSA_KEY_TYPE_IS_ASYMMETRIC

Whether a key type is asymmetric: either a key pair or a public key.

PSA_KEY_TYPE_IS_PUBLIC_KEY#

#define PSA_KEY_TYPE_IS_PUBLIC_KEY

(type)

Whether a key type is the public part of a key pair.

PSA_KEY_TYPE_IS_KEY_PAIR#

#define PSA_KEY_TYPE_IS_KEY_PAIR

(type)

Whether a key type is a key pair containing a private part and a public part.

PSA_KEY_TYPE_KEY_PAIR_OF_PUBLIC_KEY#

#define PSA_KEY_TYPE_KEY_PAIR_OF_PUBLIC_KEY

(type)

The key pair type corresponding to a public key type.

You may also pass a key pair type as type, it will be left unchanged.

Returns

• The corresponding key pair type. If type is not a public key or a key pair, the return value is undefined.

PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR#

#define PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR

(type)

The public key type corresponding to a key pair type.

You may also pass a key pair type as type, it will be left unchanged.

Returns

• The corresponding public key type. If type is not a public key or a key pair, the return value is undefined.

PSA_KEY_TYPE_RAW_DATA#

#define PSA_KEY_TYPE_RAW_DATA

((psa_key_type_t) 0x1001)

Raw data.

A "key" of this type cannot be used for any cryptographic operation. Applications may use this type to store arbitrary data in the keystore.

PSA_KEY_TYPE_HMAC#

#define PSA_KEY_TYPE_HMAC

((psa_key_type_t) 0x1100)

HMAC key.

The key policy determines which underlying hash algorithm the key can be used for.

HMAC keys should generally have the same size as the underlying hash. This size can be calculated with #PSA_HASH_LENGTH(alg) where alg is the HMAC algorithm or the underlying hash algorithm.

PSA_KEY_TYPE_DERIVE#

#define PSA_KEY_TYPE_DERIVE

((psa_key_type_t) 0x1200)

A secret for key derivation.

This key type is for high-entropy secrets only. For low-entropy secrets, PSA_KEY_TYPE_PASSWORD should be used instead.

These keys can be used as the PSA_KEY_DERIVATION_INPUT_SECRET or PSA_KEY_DERIVATION_INPUT_PASSWORD input of key derivation algorithms.

The key policy determines which key derivation algorithm the key can be used for.

PSA_KEY_TYPE_PASSWORD#

#define PSA_KEY_TYPE_PASSWORD

((psa_key_type_t) 0x1203)

A low-entropy secret for password hashing or key derivation.

This key type is suitable for passwords and passphrases which are typically intended to be memorizable by humans, and have a low entropy relative to their size. It can be used for randomly generated or derived keys with maximum or near-maximum entropy, but PSA_KEY_TYPE_DERIVE is more suitable for such keys. It is not suitable for passwords with extremely low entropy, such as numerical PINs.

These keys can be used as the PSA_KEY_DERIVATION_INPUT_PASSWORD input of key derivation algorithms. Algorithms that accept such an input were designed to accept low-entropy secret and are known as password hashing or key stretching algorithms.

These keys cannot be used as the PSA_KEY_DERIVATION_INPUT_SECRET input of key derivation algorithms, as the algorithms that take such an input expect it to be high-entropy.

The key policy determines which key derivation algorithm the key can be used for, among the permissible subset defined above.

PSA_KEY_TYPE_PASSWORD_HASH#

#define PSA_KEY_TYPE_PASSWORD_HASH

((psa_key_type_t) 0x1205)

A secret value that can be used to verify a password hash.

The key policy determines which key derivation algorithm the key can be used for, among the same permissible subset as for PSA_KEY_TYPE_PASSWORD.

PSA_KEY_TYPE_PEPPER#

#define PSA_KEY_TYPE_PEPPER

((psa_key_type_t) 0x1206)

A secret value that can be used in when computing a password hash.

The key policy determines which key derivation algorithm the key can be used for, among the subset of algorithms that can use pepper.

PSA_KEY_TYPE_AES#

#define PSA_KEY_TYPE_AES

((psa_key_type_t) 0x2400)

Key for a cipher, AEAD or MAC algorithm based on the AES block cipher.

The size of the key can be 16 bytes (AES-128), 24 bytes (AES-192) or 32 bytes (AES-256).

PSA_KEY_TYPE_ARIA#

#define PSA_KEY_TYPE_ARIA

((psa_key_type_t) 0x2406)

Key for a cipher, AEAD or MAC algorithm based on the ARIA block cipher.

PSA_KEY_TYPE_DES#

#define PSA_KEY_TYPE_DES

((psa_key_type_t) 0x2301)

Key for a cipher or MAC algorithm based on DES or 3DES (Triple-DES).

The size of the key can be 64 bits (single DES), 128 bits (2-key 3DES) or 192 bits (3-key 3DES).

Note that single DES and 2-key 3DES are weak and strongly deprecated and should only be used to decrypt legacy data. 3-key 3DES is weak and deprecated and should only be used in legacy protocols.

PSA_KEY_TYPE_CAMELLIA#

#define PSA_KEY_TYPE_CAMELLIA

((psa_key_type_t) 0x2403)

Key for a cipher, AEAD or MAC algorithm based on the Camellia block cipher.

PSA_KEY_TYPE_CHACHA20#

#define PSA_KEY_TYPE_CHACHA20

((psa_key_type_t) 0x2004)

Key for the ChaCha20 stream cipher or the Chacha20-Poly1305 AEAD algorithm.

ChaCha20 and the ChaCha20_Poly1305 construction are defined in RFC 7539.

Note

• For ChaCha20 and ChaCha20_Poly1305, Mbed TLS only supports 12-byte nonces.

• For ChaCha20, the initial counter value is 0. To encrypt or decrypt with the initial counter value 1, you can process and discard a 64-byte block before the real data.

PSA_KEY_TYPE_RSA_PUBLIC_KEY#

#define PSA_KEY_TYPE_RSA_PUBLIC_KEY

((psa_key_type_t) 0x4001)

RSA public key.

The size of an RSA key is the bit size of the modulus.

PSA_KEY_TYPE_RSA_KEY_PAIR#

#define PSA_KEY_TYPE_RSA_KEY_PAIR

((psa_key_type_t) 0x7001)

RSA key pair (private and public key).

The size of an RSA key is the bit size of the modulus.

PSA_KEY_TYPE_IS_RSA#

#define PSA_KEY_TYPE_IS_RSA

(type)

Whether a key type is an RSA key (pair or public-only).

PSA_KEY_TYPE_ECC_PUBLIC_KEY_BASE#

#define PSA_KEY_TYPE_ECC_PUBLIC_KEY_BASE

((psa_key_type_t) 0x4100)

PSA_KEY_TYPE_ECC_KEY_PAIR_BASE#

#define PSA_KEY_TYPE_ECC_KEY_PAIR_BASE

((psa_key_type_t) 0x7100)

PSA_KEY_TYPE_ECC_CURVE_MASK#

#define PSA_KEY_TYPE_ECC_CURVE_MASK

((psa_key_type_t) 0x00ff)

PSA_KEY_TYPE_ECC_KEY_PAIR#

#define PSA_KEY_TYPE_ECC_KEY_PAIR

(curve)

Elliptic curve key pair.

The size of an elliptic curve key is the bit size associated with the curve, i.e. the bit size of q for a curve over a field *F_q*. See the documentation of PSA_ECC_FAMILY_xxx curve families for details.

PSA_KEY_TYPE_ECC_PUBLIC_KEY#

#define PSA_KEY_TYPE_ECC_PUBLIC_KEY

(curve)

Elliptic curve public key.

The size of an elliptic curve public key is the same as the corresponding private key (see PSA_KEY_TYPE_ECC_KEY_PAIR and the documentation of PSA_ECC_FAMILY_xxx curve families).

PSA_KEY_TYPE_IS_ECC#

#define PSA_KEY_TYPE_IS_ECC

Whether a key type is an elliptic curve key (pair or public-only).

PSA_KEY_TYPE_IS_ECC_KEY_PAIR#

#define PSA_KEY_TYPE_IS_ECC_KEY_PAIR

Whether a key type is an elliptic curve key pair.

PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY#

#define PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY

Whether a key type is an elliptic curve public key.

PSA_KEY_TYPE_ECC_GET_FAMILY#

#define PSA_KEY_TYPE_ECC_GET_FAMILY

Extract the curve from an elliptic curve key type.

PSA_ECC_FAMILY_IS_WEIERSTRASS#

#define PSA_ECC_FAMILY_IS_WEIERSTRASS

(family)

Check if the curve of given family is Weierstrass elliptic curve.

PSA_ECC_FAMILY_SECP_K1#

#define PSA_ECC_FAMILY_SECP_K1

((psa_ecc_family_t) 0x17)

SEC Koblitz curves over prime fields.

This family comprises the following curves: secp192k1, secp224k1, secp256k1. They are defined in Standards for Efficient Cryptography, SEC 2: Recommended Elliptic Curve Domain Parameters. https://www.secg.org/sec2-v2.pdf

PSA_ECC_FAMILY_SECP_R1#

#define PSA_ECC_FAMILY_SECP_R1

((psa_ecc_family_t) 0x12)

SEC random curves over prime fields.

This family comprises the following curves: secp192k1, secp224r1, secp256r1, secp384r1, secp521r1. They are defined in Standards for Efficient Cryptography, SEC 2: Recommended Elliptic Curve Domain Parameters. https://www.secg.org/sec2-v2.pdf

PSA_ECC_FAMILY_SECP_R2#

#define PSA_ECC_FAMILY_SECP_R2

((psa_ecc_family_t) 0x1b)

PSA_ECC_FAMILY_SECT_K1#

#define PSA_ECC_FAMILY_SECT_K1

((psa_ecc_family_t) 0x27)

SEC Koblitz curves over binary fields.

This family comprises the following curves: sect163k1, sect233k1, sect239k1, sect283k1, sect409k1, sect571k1. They are defined in Standards for Efficient Cryptography, SEC 2: Recommended Elliptic Curve Domain Parameters. https://www.secg.org/sec2-v2.pdf

PSA_ECC_FAMILY_SECT_R1#

#define PSA_ECC_FAMILY_SECT_R1

((psa_ecc_family_t) 0x22)

SEC random curves over binary fields.

This family comprises the following curves: sect163r1, sect233r1, sect283r1, sect409r1, sect571r1. They are defined in Standards for Efficient Cryptography, SEC 2: Recommended Elliptic Curve Domain Parameters. https://www.secg.org/sec2-v2.pdf

PSA_ECC_FAMILY_SECT_R2#

#define PSA_ECC_FAMILY_SECT_R2

((psa_ecc_family_t) 0x2b)

SEC additional random curves over binary fields.

This family comprises the following curve: sect163r2. It is defined in Standards for Efficient Cryptography, SEC 2: Recommended Elliptic Curve Domain Parameters. https://www.secg.org/sec2-v2.pdf

PSA_ECC_FAMILY_BRAINPOOL_P_R1#

#define PSA_ECC_FAMILY_BRAINPOOL_P_R1

((psa_ecc_family_t) 0x30)

Brainpool P random curves.

This family comprises the following curves: brainpoolP160r1, brainpoolP192r1, brainpoolP224r1, brainpoolP256r1, brainpoolP320r1, brainpoolP384r1, brainpoolP512r1. It is defined in RFC 5639.

PSA_ECC_FAMILY_MONTGOMERY#

#define PSA_ECC_FAMILY_MONTGOMERY

((psa_ecc_family_t) 0x41)

Curve25519 and Curve448.

This family comprises the following Montgomery curves:

• 255-bit: Bernstein et al., Curve25519: new Diffie-Hellman speed records, LNCS 3958, 2006. The algorithm PSA_ALG_ECDH performs X25519 when used with this curve.

• 448-bit: Hamburg, Ed448-Goldilocks, a new elliptic curve, NIST ECC Workshop, 2015. The algorithm PSA_ALG_ECDH performs X448 when used with this curve.

PSA_ECC_FAMILY_TWISTED_EDWARDS#

#define PSA_ECC_FAMILY_TWISTED_EDWARDS

((psa_ecc_family_t) 0x42)

The twisted Edwards curves Ed25519 and Ed448.

These curves are suitable for EdDSA (PSA_ALG_PURE_EDDSA for both curves, PSA_ALG_ED25519PH for the 255-bit curve, PSA_ALG_ED448PH for the 448-bit curve).

This family comprises the following twisted Edwards curves:

• 255-bit: Edwards25519, the twisted Edwards curve birationally equivalent to Curve25519. Bernstein et al., Twisted Edwards curves, Africacrypt 2008.

• 448-bit: Edwards448, the twisted Edwards curve birationally equivalent to Curve448. Hamburg, Ed448-Goldilocks, a new elliptic curve, NIST ECC Workshop, 2015.

PSA_KEY_TYPE_DH_PUBLIC_KEY_BASE#

#define PSA_KEY_TYPE_DH_PUBLIC_KEY_BASE

((psa_key_type_t) 0x4200)

PSA_KEY_TYPE_DH_KEY_PAIR_BASE#

#define PSA_KEY_TYPE_DH_KEY_PAIR_BASE

((psa_key_type_t) 0x7200)

PSA_KEY_TYPE_DH_GROUP_MASK#

#define PSA_KEY_TYPE_DH_GROUP_MASK

((psa_key_type_t) 0x00ff)

PSA_KEY_TYPE_DH_KEY_PAIR#

#define PSA_KEY_TYPE_DH_KEY_PAIR

(group)

Diffie-Hellman key pair.

PSA_KEY_TYPE_DH_PUBLIC_KEY#

#define PSA_KEY_TYPE_DH_PUBLIC_KEY

(group)

Diffie-Hellman public key.

PSA_KEY_TYPE_IS_DH#

#define PSA_KEY_TYPE_IS_DH

Whether a key type is a Diffie-Hellman key (pair or public-only).

PSA_KEY_TYPE_IS_DH_KEY_PAIR#

#define PSA_KEY_TYPE_IS_DH_KEY_PAIR

Whether a key type is a Diffie-Hellman key pair.

PSA_KEY_TYPE_IS_DH_PUBLIC_KEY#

#define PSA_KEY_TYPE_IS_DH_PUBLIC_KEY

Whether a key type is a Diffie-Hellman public key.

PSA_KEY_TYPE_DH_GET_FAMILY#

#define PSA_KEY_TYPE_DH_GET_FAMILY

Extract the group from a Diffie-Hellman key type.

PSA_DH_FAMILY_RFC7919#

#define PSA_DH_FAMILY_RFC7919

((psa_dh_family_t) 0x03)

Diffie-Hellman groups defined in RFC 7919 Appendix A.

This family includes groups with the following key sizes (in bits): 2048, 3072, 4096, 6144, 8192. A given implementation may support all of these sizes or only a subset.

PSA_GET_KEY_TYPE_BLOCK_SIZE_EXPONENT#

#define PSA_GET_KEY_TYPE_BLOCK_SIZE_EXPONENT

(type)

PSA_BLOCK_CIPHER_BLOCK_LENGTH#

#define PSA_BLOCK_CIPHER_BLOCK_LENGTH

The block size of a block cipher.

Returns

• The block size for a block cipher, or 1 for a stream cipher. The return value is undefined if type is not a supported cipher key type.

Note

• It is possible to build stream cipher algorithms on top of a block cipher, for example CTR mode (PSA_ALG_CTR). This macro only takes the key type into account, so it cannot be used to determine the size of the data that psa_cipher_update() might buffer for future processing in general.

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

Warnings

• This macro may evaluate its argument multiple times.

PSA_ALG_VENDOR_FLAG#

#define PSA_ALG_VENDOR_FLAG

((psa_algorithm_t) 0x80000000)

Vendor-defined algorithm flag.

Algorithms defined by this standard will never have the PSA_ALG_VENDOR_FLAG bit set. Vendors who define additional algorithms must use an encoding with the PSA_ALG_VENDOR_FLAG bit set and should respect the bitwise structure used by standard encodings whenever practical.

PSA_ALG_CATEGORY_MASK#

#define PSA_ALG_CATEGORY_MASK

((psa_algorithm_t) 0x7f000000)

PSA_ALG_CATEGORY_HASH#

#define PSA_ALG_CATEGORY_HASH

((psa_algorithm_t) 0x02000000)

PSA_ALG_CATEGORY_MAC#

#define PSA_ALG_CATEGORY_MAC

((psa_algorithm_t) 0x03000000)

PSA_ALG_CATEGORY_CIPHER#

#define PSA_ALG_CATEGORY_CIPHER

((psa_algorithm_t) 0x04000000)

PSA_ALG_CATEGORY_AEAD#

#define PSA_ALG_CATEGORY_AEAD

((psa_algorithm_t) 0x05000000)

PSA_ALG_CATEGORY_SIGN#

#define PSA_ALG_CATEGORY_SIGN

((psa_algorithm_t) 0x06000000)

PSA_ALG_CATEGORY_ASYMMETRIC_ENCRYPTION#

#define PSA_ALG_CATEGORY_ASYMMETRIC_ENCRYPTION

((psa_algorithm_t) 0x07000000)

PSA_ALG_CATEGORY_KEY_DERIVATION#

#define PSA_ALG_CATEGORY_KEY_DERIVATION

((psa_algorithm_t) 0x08000000)

PSA_ALG_CATEGORY_KEY_AGREEMENT#

#define PSA_ALG_CATEGORY_KEY_AGREEMENT

((psa_algorithm_t) 0x09000000)

PSA_ALG_IS_VENDOR_DEFINED#

#define PSA_ALG_IS_VENDOR_DEFINED

(alg)

Whether an algorithm is vendor-defined.

See also PSA_ALG_VENDOR_FLAG.

PSA_ALG_IS_HASH#

#define PSA_ALG_IS_HASH

(alg)

Whether the specified algorithm is a hash algorithm.

Returns

• 1 if alg is a hash algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_MAC#

#define PSA_ALG_IS_MAC

(alg)

Whether the specified algorithm is a MAC algorithm.

Returns

• 1 if alg is a MAC algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_CIPHER#

#define PSA_ALG_IS_CIPHER

(alg)

Whether the specified algorithm is a symmetric cipher algorithm.

Returns

• 1 if alg is a symmetric cipher algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_AEAD#

#define PSA_ALG_IS_AEAD

(alg)

Whether the specified algorithm is an authenticated encryption with associated data (AEAD) algorithm.

Returns

• 1 if alg is an AEAD algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_SIGN#

#define PSA_ALG_IS_SIGN

(alg)

Whether the specified algorithm is an asymmetric signature algorithm, also known as public-key signature algorithm.

Returns

• 1 if alg is an asymmetric signature algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_ASYMMETRIC_ENCRYPTION#

#define PSA_ALG_IS_ASYMMETRIC_ENCRYPTION

(alg)

Whether the specified algorithm is an asymmetric encryption algorithm, also known as public-key encryption algorithm.

Returns

• 1 if alg is an asymmetric encryption algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_KEY_AGREEMENT#

#define PSA_ALG_IS_KEY_AGREEMENT

(alg)

Whether the specified algorithm is a key agreement algorithm.

Returns

• 1 if alg is a key agreement algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_KEY_DERIVATION#

#define PSA_ALG_IS_KEY_DERIVATION

(alg)

Whether the specified algorithm is a key derivation algorithm.

Returns

• 1 if alg is a key derivation algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_KEY_DERIVATION_STRETCHING#

#define PSA_ALG_IS_KEY_DERIVATION_STRETCHING

Whether the specified algorithm is a key stretching / password hashing algorithm.

A key stretching / password hashing algorithm is a key derivation algorithm that is suitable for use with a low-entropy secret such as a password. Equivalently, it's a key derivation algorithm that uses a PSA_KEY_DERIVATION_INPUT_PASSWORD input step.

Returns

• 1 if alg is a key stretching / password hashing algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_NONE#

#define PSA_ALG_NONE

((psa_algorithm_t)0)

An invalid algorithm identifier value.

PSA_ALG_HASH_MASK#

#define PSA_ALG_HASH_MASK

((psa_algorithm_t) 0x000000ff)

PSA_ALG_MD5#

#define PSA_ALG_MD5

((psa_algorithm_t) 0x02000003)

MD5.

PSA_ALG_RIPEMD160#

#define PSA_ALG_RIPEMD160

((psa_algorithm_t) 0x02000004)

PSA_ALG_RIPEMD160.

PSA_ALG_SHA_1#

#define PSA_ALG_SHA_1

((psa_algorithm_t) 0x02000005)

SHA1.

PSA_ALG_SHA_224#

#define PSA_ALG_SHA_224

((psa_algorithm_t) 0x02000008)

SHA2-224.

PSA_ALG_SHA_256#

#define PSA_ALG_SHA_256

((psa_algorithm_t) 0x02000009)

SHA2-256.

PSA_ALG_SHA_384#

#define PSA_ALG_SHA_384

((psa_algorithm_t) 0x0200000a)

SHA2-384.

PSA_ALG_SHA_512#

#define PSA_ALG_SHA_512

((psa_algorithm_t) 0x0200000b)

SHA2-512.

PSA_ALG_SHA_512_224#

#define PSA_ALG_SHA_512_224

((psa_algorithm_t) 0x0200000c)

SHA2-512/224.

PSA_ALG_SHA_512_256#

#define PSA_ALG_SHA_512_256

((psa_algorithm_t) 0x0200000d)

SHA2-512/256.

PSA_ALG_SHA3_224#

#define PSA_ALG_SHA3_224

((psa_algorithm_t) 0x02000010)

SHA3-224.

PSA_ALG_SHA3_256#

#define PSA_ALG_SHA3_256

((psa_algorithm_t) 0x02000011)

SHA3-256.

PSA_ALG_SHA3_384#

#define PSA_ALG_SHA3_384

((psa_algorithm_t) 0x02000012)

SHA3-384.

PSA_ALG_SHA3_512#

#define PSA_ALG_SHA3_512

((psa_algorithm_t) 0x02000013)

SHA3-512.

PSA_ALG_SHAKE256_512#

#define PSA_ALG_SHAKE256_512

((psa_algorithm_t) 0x02000015)

The first 512 bits (64 bytes) of the SHAKE256 output.

This is the prehashing for Ed448ph (see PSA_ALG_ED448PH). For other scenarios where a hash function based on SHA3/SHAKE is desired, SHA3-512 has the same output size and a (theoretically) higher security strength.

PSA_ALG_ANY_HASH#

#define PSA_ALG_ANY_HASH

((psa_algorithm_t) 0x020000ff)

In a hash-and-sign algorithm policy, allow any hash algorithm.

This value may be used to form the algorithm usage field of a policy for a signature algorithm that is parametrized by a hash. The key may then be used to perform operations using the same signature algorithm parametrized with any supported hash.

That is, suppose that PSA_xxx_SIGNATURE is one of the following macros:

• PSA_ALG_RSA_PKCS1V15_SIGN, PSA_ALG_RSA_PSS, PSA_ALG_RSA_PSS_ANY_SALT,

• PSA_ALG_ECDSA, PSA_ALG_DETERMINISTIC_ECDSA. Then you may create and use a key as follows:

• Set the key usage field using PSA_ALG_ANY_HASH, for example:

  psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_SIGN_HASH); // or VERIFY
  psa_set_key_algorithm(&attributes, PSA_xxx_SIGNATURE(PSA_ALG_ANY_HASH));
  

• Import or generate key material.

• Call psa_sign_hash() or psa_verify_hash(), passing an algorithm built from PSA_xxx_SIGNATURE and a specific hash. Each call to sign or verify a message may use a different hash.

  psa_sign_hash(key, PSA_xxx_SIGNATURE(PSA_ALG_SHA_256), ...);
  psa_sign_hash(key, PSA_xxx_SIGNATURE(PSA_ALG_SHA_512), ...);
  psa_sign_hash(key, PSA_xxx_SIGNATURE(PSA_ALG_SHA3_256), ...);
  

This value may not be used to build other algorithms that are parametrized over a hash. For any valid use of this macro to build an algorithm alg, PSA_ALG_IS_HASH_AND_SIGN(alg) is true.

This value may not be used to build an algorithm specification to perform an operation. It is only valid to build policies.

PSA_ALG_MAC_SUBCATEGORY_MASK#

#define PSA_ALG_MAC_SUBCATEGORY_MASK

((psa_algorithm_t) 0x00c00000)

PSA_ALG_HMAC_BASE#

#define PSA_ALG_HMAC_BASE

((psa_algorithm_t) 0x03800000)

PSA_ALG_HMAC#

#define PSA_ALG_HMAC

(hash_alg)

Macro to build an HMAC algorithm.

For example, PSA_ALG_HMAC(PSA_ALG_SHA_256) is HMAC-SHA-256.

Returns

• The corresponding HMAC algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_HMAC_GET_HASH#

#define PSA_ALG_HMAC_GET_HASH

(hmac_alg)

PSA_ALG_IS_HMAC#

#define PSA_ALG_IS_HMAC

Whether the specified algorithm is an HMAC algorithm.

HMAC is a family of MAC algorithms that are based on a hash function.

Returns

• 1 if alg is an HMAC algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_MAC_TRUNCATION_MASK#

#define PSA_ALG_MAC_TRUNCATION_MASK

((psa_algorithm_t) 0x003f0000)

PSA_MAC_TRUNCATION_OFFSET#

#define PSA_MAC_TRUNCATION_OFFSET

16

PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG#

#define PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG

((psa_algorithm_t) 0x00008000)

PSA_ALG_TRUNCATED_MAC#

#define PSA_ALG_TRUNCATED_MAC

Macro to build a truncated MAC algorithm.

A truncated MAC algorithm is identical to the corresponding MAC algorithm except that the MAC value for the truncated algorithm consists of only the first mac_length bytes of the MAC value for the untruncated algorithm.

Note

• This macro may allow constructing algorithm identifiers that are not valid, either because the specified length is larger than the untruncated MAC or because the specified length is smaller than permitted by the implementation.

• It is implementation-defined whether a truncated MAC that is truncated to the same length as the MAC of the untruncated algorithm is considered identical to the untruncated algorithm for policy comparison purposes.

Returns

• The corresponding MAC algorithm with the specified length.

• Unspecified if mac_alg is not a supported MAC algorithm or if mac_length is too small or too large for the specified MAC algorithm.

PSA_ALG_FULL_LENGTH_MAC#

#define PSA_ALG_FULL_LENGTH_MAC

Macro to build the base MAC algorithm corresponding to a truncated MAC algorithm.

Returns

• The corresponding base MAC algorithm.

• Unspecified if mac_alg is not a supported MAC algorithm.

PSA_MAC_TRUNCATED_LENGTH#

#define PSA_MAC_TRUNCATED_LENGTH

(mac_alg)

Length to which a MAC algorithm is truncated.

Returns

• Length of the truncated MAC in bytes.

• 0 if mac_alg is a non-truncated MAC algorithm.

• Unspecified if mac_alg is not a supported MAC algorithm.

PSA_ALG_AT_LEAST_THIS_LENGTH_MAC#

#define PSA_ALG_AT_LEAST_THIS_LENGTH_MAC

Macro to build a MAC minimum-MAC-length wildcard algorithm.

A minimum-MAC-length MAC wildcard algorithm permits all MAC algorithms sharing the same base algorithm, and where the (potentially truncated) MAC length of the specific algorithm is equal to or larger then the wildcard algorithm's minimum MAC length.

Note

• When setting the minimum required MAC length to less than the smallest MAC length allowed by the base algorithm, this effectively becomes an 'any-MAC-length-allowed' policy for that base algorithm.

Returns

• The corresponding MAC wildcard algorithm with the specified minimum length.

• Unspecified if mac_alg is not a supported MAC algorithm or if min_mac_length is less than 1 or too large for the specified MAC algorithm.

PSA_ALG_CIPHER_MAC_BASE#

#define PSA_ALG_CIPHER_MAC_BASE

((psa_algorithm_t) 0x03c00000)

PSA_ALG_CBC_MAC#

#define PSA_ALG_CBC_MAC

((psa_algorithm_t) 0x03c00100)

The CBC-MAC construction over a block cipher.

Warnings

• CBC-MAC is insecure in many cases. A more secure mode, such as PSA_ALG_CMAC, is recommended.

PSA_ALG_CMAC#

#define PSA_ALG_CMAC

((psa_algorithm_t) 0x03c00200)

The CMAC construction over a block cipher.

PSA_ALG_IS_BLOCK_CIPHER_MAC#

#define PSA_ALG_IS_BLOCK_CIPHER_MAC

Whether the specified algorithm is a MAC algorithm based on a block cipher.

Returns

• 1 if alg is a MAC algorithm based on a block cipher, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_CIPHER_STREAM_FLAG#

#define PSA_ALG_CIPHER_STREAM_FLAG

((psa_algorithm_t) 0x00800000)

PSA_ALG_CIPHER_FROM_BLOCK_FLAG#

#define PSA_ALG_CIPHER_FROM_BLOCK_FLAG

((psa_algorithm_t) 0x00400000)

PSA_ALG_IS_STREAM_CIPHER#

#define PSA_ALG_IS_STREAM_CIPHER

Whether the specified algorithm is a stream cipher.

A stream cipher is a symmetric cipher that encrypts or decrypts messages by applying a bitwise-xor with a stream of bytes that is generated from a key.

Returns

• 1 if alg is a stream cipher algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier or if it is not a symmetric cipher algorithm.

PSA_ALG_STREAM_CIPHER#

#define PSA_ALG_STREAM_CIPHER

((psa_algorithm_t) 0x04800100)

The stream cipher mode of a stream cipher algorithm.

The underlying stream cipher is determined by the key type.

• To use ChaCha20, use a key type of PSA_KEY_TYPE_CHACHA20.

PSA_ALG_CTR#

#define PSA_ALG_CTR

((psa_algorithm_t) 0x04c01000)

The CTR stream cipher mode.

CTR is a stream cipher which is built from a block cipher. The underlying block cipher is determined by the key type. For example, to use AES-128-CTR, use this algorithm with a key of type PSA_KEY_TYPE_AES and a length of 128 bits (16 bytes).

PSA_ALG_CFB#

#define PSA_ALG_CFB

((psa_algorithm_t) 0x04c01100)

The CFB stream cipher mode.

The underlying block cipher is determined by the key type.

PSA_ALG_OFB#

#define PSA_ALG_OFB

((psa_algorithm_t) 0x04c01200)

The OFB stream cipher mode.

The underlying block cipher is determined by the key type.

PSA_ALG_XTS#

#define PSA_ALG_XTS

((psa_algorithm_t) 0x0440ff00)

The XTS cipher mode.

XTS is a cipher mode which is built from a block cipher. It requires at least one full block of input, but beyond this minimum the input does not need to be a whole number of blocks.

PSA_ALG_ECB_NO_PADDING#

#define PSA_ALG_ECB_NO_PADDING

((psa_algorithm_t) 0x04404400)

The Electronic Code Book (ECB) mode of a block cipher, with no padding.

Warnings

• ECB mode does not protect the confidentiality of the encrypted data except in extremely narrow circumstances. It is recommended that applications only use ECB if they need to construct an operating mode that the implementation does not provide. Implementations are encouraged to provide the modes that applications need in preference to supporting direct access to ECB.

The underlying block cipher is determined by the key type.

This symmetric cipher mode can only be used with messages whose lengths are a multiple of the block size of the chosen block cipher.

ECB mode does not accept an initialization vector (IV). When using a multi-part cipher operation with this algorithm, psa_cipher_generate_iv() and psa_cipher_set_iv() must not be called.

PSA_ALG_CBC_NO_PADDING#

#define PSA_ALG_CBC_NO_PADDING

((psa_algorithm_t) 0x04404000)

The CBC block cipher chaining mode, with no padding.

The underlying block cipher is determined by the key type.

This symmetric cipher mode can only be used with messages whose lengths are whole number of blocks for the chosen block cipher.

PSA_ALG_CBC_PKCS7#

#define PSA_ALG_CBC_PKCS7

((psa_algorithm_t) 0x04404100)

The CBC block cipher chaining mode with PKCS#7 padding.

The underlying block cipher is determined by the key type.

This is the padding method defined by PKCS#7 (RFC 2315) §10.3.

PSA_ALG_AEAD_FROM_BLOCK_FLAG#

#define PSA_ALG_AEAD_FROM_BLOCK_FLAG

((psa_algorithm_t) 0x00400000)

PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER#

#define PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER

Whether the specified algorithm is an AEAD mode on a block cipher.

Returns

• 1 if alg is an AEAD algorithm which is an AEAD mode based on a block cipher, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_CCM#

#define PSA_ALG_CCM

((psa_algorithm_t) 0x05500100)

The CCM authenticated encryption algorithm.

The underlying block cipher is determined by the key type.

PSA_ALG_CCM_STAR_NO_TAG#

#define PSA_ALG_CCM_STAR_NO_TAG

((psa_algorithm_t) 0x04c01300)

The CCM* cipher mode without authentication.

This is CCM* as specified in IEEE 802.15.4 §7, with a tag length of 0. For CCM* with a nonzero tag length, use the AEAD algorithm PSA_ALG_CCM.

The underlying block cipher is determined by the key type.

Currently only 13-byte long IV's are supported.

PSA_ALG_GCM#

#define PSA_ALG_GCM

((psa_algorithm_t) 0x05500200)

The GCM authenticated encryption algorithm.

The underlying block cipher is determined by the key type.

PSA_ALG_CHACHA20_POLY1305#

#define PSA_ALG_CHACHA20_POLY1305

((psa_algorithm_t) 0x05100500)

The Chacha20-Poly1305 AEAD algorithm.

The ChaCha20_Poly1305 construction is defined in RFC 7539.

Implementations must support 12-byte nonces, may support 8-byte nonces, and should reject other sizes.

Implementations must support 16-byte tags and should reject other sizes.

PSA_ALG_AEAD_TAG_LENGTH_MASK#

#define PSA_ALG_AEAD_TAG_LENGTH_MASK

((psa_algorithm_t) 0x003f0000)

PSA_AEAD_TAG_LENGTH_OFFSET#

#define PSA_AEAD_TAG_LENGTH_OFFSET

16

PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG#

#define PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG

((psa_algorithm_t) 0x00008000)

PSA_ALG_AEAD_WITH_SHORTENED_TAG#

#define PSA_ALG_AEAD_WITH_SHORTENED_TAG

Macro to build a shortened AEAD algorithm.

A shortened AEAD algorithm is similar to the corresponding AEAD algorithm, but has an authentication tag that consists of fewer bytes. Depending on the algorithm, the tag length may affect the calculation of the ciphertext.

Returns

• The corresponding AEAD algorithm with the specified length.

• Unspecified if aead_alg is not a supported AEAD algorithm or if tag_length is not valid for the specified AEAD algorithm.

PSA_ALG_AEAD_GET_TAG_LENGTH#

#define PSA_ALG_AEAD_GET_TAG_LENGTH

Retrieve the tag length of a specified AEAD algorithm.

Returns

• The tag length specified by the input algorithm.

• Unspecified if aead_alg is not a supported AEAD algorithm.

PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG#

#define PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG

Calculate the corresponding AEAD algorithm with the default tag length.

Returns

• The corresponding AEAD algorithm with the default tag length for that algorithm.

PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG_CASE#

#define PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG_CASE

PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG#

#define PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG

Macro to build an AEAD minimum-tag-length wildcard algorithm.

A minimum-tag-length AEAD wildcard algorithm permits all AEAD algorithms sharing the same base algorithm, and where the tag length of the specific algorithm is equal to or larger then the minimum tag length specified by the wildcard algorithm.

Note

• When setting the minimum required tag length to less than the smallest tag length allowed by the base algorithm, this effectively becomes an 'any-tag-length-allowed' policy for that base algorithm.

Returns

• The corresponding AEAD wildcard algorithm with the specified minimum length.

• Unspecified if aead_alg is not a supported AEAD algorithm or if min_tag_length is less than 1 or too large for the specified AEAD algorithm.

PSA_ALG_RSA_PKCS1V15_SIGN_BASE#

#define PSA_ALG_RSA_PKCS1V15_SIGN_BASE

((psa_algorithm_t) 0x06000200)

PSA_ALG_RSA_PKCS1V15_SIGN#

#define PSA_ALG_RSA_PKCS1V15_SIGN

(hash_alg)

RSA PKCS#1 v1.5 signature with hashing.

This is the signature scheme defined by RFC 8017 (PKCS#1: RSA Cryptography Specifications) under the name RSASSA-PKCS1-v1_5.

Returns

• The corresponding RSA PKCS#1 v1.5 signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_RSA_PKCS1V15_SIGN_RAW#

#define PSA_ALG_RSA_PKCS1V15_SIGN_RAW

PSA_ALG_RSA_PKCS1V15_SIGN_BASE

Raw PKCS#1 v1.5 signature.

The input to this algorithm is the DigestInfo structure used by RFC 8017 (PKCS#1: RSA Cryptography Specifications), §9.2 steps 3–6.

PSA_ALG_IS_RSA_PKCS1V15_SIGN#

#define PSA_ALG_IS_RSA_PKCS1V15_SIGN

(alg)

PSA_ALG_RSA_PSS_BASE#

#define PSA_ALG_RSA_PSS_BASE

((psa_algorithm_t) 0x06000300)

PSA_ALG_RSA_PSS_ANY_SALT_BASE#

#define PSA_ALG_RSA_PSS_ANY_SALT_BASE

((psa_algorithm_t) 0x06001300)

PSA_ALG_RSA_PSS#

#define PSA_ALG_RSA_PSS

(hash_alg)

RSA PSS signature with hashing.

This is the signature scheme defined by RFC 8017 (PKCS#1: RSA Cryptography Specifications) under the name RSASSA-PSS, with the message generation function MGF1, and with a salt length equal to the length of the hash, or the largest possible salt length for the algorithm and key size if that is smaller than the hash length. The specified hash algorithm is used to hash the input message, to create the salted hash, and for the mask generation.

Returns

• The corresponding RSA PSS signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_RSA_PSS_ANY_SALT#

#define PSA_ALG_RSA_PSS_ANY_SALT

(hash_alg)

RSA PSS signature with hashing with relaxed verification.

This algorithm has the same behavior as PSA_ALG_RSA_PSS when signing, but allows an arbitrary salt length (including 0) when verifying a signature.

Returns

• The corresponding RSA PSS signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_IS_RSA_PSS_STANDARD_SALT#

#define PSA_ALG_IS_RSA_PSS_STANDARD_SALT

(alg)

Whether the specified algorithm is RSA PSS with standard salt.

Returns

• 1 if alg is of the form PSA_ALG_RSA_PSS(hash_alg), where hash_alg is a hash algorithm or PSA_ALG_ANY_HASH. 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier or policy.

PSA_ALG_IS_RSA_PSS_ANY_SALT#

#define PSA_ALG_IS_RSA_PSS_ANY_SALT

(alg)

Whether the specified algorithm is RSA PSS with any salt.

Returns

• 1 if alg is of the form #PSA_ALG_RSA_PSS_ANY_SALT_BASE(hash_alg), where hash_alg is a hash algorithm or PSA_ALG_ANY_HASH. 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier or policy.

PSA_ALG_IS_RSA_PSS#

#define PSA_ALG_IS_RSA_PSS

Whether the specified algorithm is RSA PSS.

This includes any of the RSA PSS algorithm variants, regardless of the constraints on salt length.

Returns

• 1 if alg is of the form PSA_ALG_RSA_PSS(hash_alg) or #PSA_ALG_RSA_PSS_ANY_SALT_BASE(hash_alg), where hash_alg is a hash algorithm or PSA_ALG_ANY_HASH. 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier or policy.

PSA_ALG_ECDSA_BASE#

#define PSA_ALG_ECDSA_BASE

((psa_algorithm_t) 0x06000600)

PSA_ALG_ECDSA#

#define PSA_ALG_ECDSA

(hash_alg)

ECDSA signature with hashing.

This is the ECDSA signature scheme defined by ANSI X9.62, with a random per-message secret number (k).

The representation of the signature as a byte string consists of the concatenation of the signature values r and s. Each of r and s is encoded as an N-octet string, where N is the length of the base point of the curve in octets. Each value is represented in big-endian order (most significant octet first).

Returns

• The corresponding ECDSA signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_ECDSA_ANY#

#define PSA_ALG_ECDSA_ANY

PSA_ALG_ECDSA_BASE

ECDSA signature without hashing.

This is the same signature scheme as PSA_ALG_ECDSA(), but without specifying a hash algorithm. This algorithm may only be used to sign or verify a sequence of bytes that should be an already-calculated hash. Note that the input is padded with zeros on the left or truncated on the left as required to fit the curve size.

PSA_ALG_DETERMINISTIC_ECDSA_BASE#

#define PSA_ALG_DETERMINISTIC_ECDSA_BASE

((psa_algorithm_t) 0x06000700)

PSA_ALG_DETERMINISTIC_ECDSA#

#define PSA_ALG_DETERMINISTIC_ECDSA

(hash_alg)

Deterministic ECDSA signature with hashing.

This is the deterministic ECDSA signature scheme defined by RFC 6979.

The representation of a signature is the same as with PSA_ALG_ECDSA().

Note that when this algorithm is used for verification, signatures made with randomized ECDSA (PSA_ALG_ECDSA(hash_alg)) with the same private key are accepted. In other words, PSA_ALG_DETERMINISTIC_ECDSA(hash_alg) differs from PSA_ALG_ECDSA(hash_alg) only for signature, not for verification.

Returns

• The corresponding deterministic ECDSA signature algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_ECDSA_DETERMINISTIC_FLAG#

#define PSA_ALG_ECDSA_DETERMINISTIC_FLAG

((psa_algorithm_t) 0x00000100)

PSA_ALG_IS_ECDSA#

#define PSA_ALG_IS_ECDSA

PSA_ALG_ECDSA_IS_DETERMINISTIC#

#define PSA_ALG_ECDSA_IS_DETERMINISTIC

(alg)

PSA_ALG_IS_DETERMINISTIC_ECDSA#

#define PSA_ALG_IS_DETERMINISTIC_ECDSA

(alg)

PSA_ALG_IS_RANDOMIZED_ECDSA#

#define PSA_ALG_IS_RANDOMIZED_ECDSA

(alg)

PSA_ALG_PURE_EDDSA#

#define PSA_ALG_PURE_EDDSA

((psa_algorithm_t) 0x06000800)

Edwards-curve digital signature algorithm without prehashing (PureEdDSA), using standard parameters.

Contexts are not supported in the current version of this specification because there is no suitable signature interface that can take the context as a parameter. A future version of this specification may add suitable functions and extend this algorithm to support contexts.

PureEdDSA requires an elliptic curve key on a twisted Edwards curve. In this specification, the following curves are supported:

• PSA_ECC_FAMILY_TWISTED_EDWARDS, 255-bit: Ed25519 as specified in RFC 8032. The curve is Edwards25519. The hash function used internally is SHA-512.

• PSA_ECC_FAMILY_TWISTED_EDWARDS, 448-bit: Ed448 as specified in RFC 8032. The curve is Edwards448. The hash function used internally is the first 114 bytes of the SHAKE256 output.

This algorithm can be used with psa_sign_message() and psa_verify_message(). Since there is no prehashing, it cannot be used with psa_sign_hash() or psa_verify_hash().

The signature format is the concatenation of R and S as defined by RFC 8032 §5.1.6 and §5.2.6 (a 64-byte string for Ed25519, a 114-byte string for Ed448).

PSA_ALG_HASH_EDDSA_BASE#

#define PSA_ALG_HASH_EDDSA_BASE

((psa_algorithm_t) 0x06000900)

PSA_ALG_IS_HASH_EDDSA#

#define PSA_ALG_IS_HASH_EDDSA

(alg)

PSA_ALG_ED25519PH#

#define PSA_ALG_ED25519PH

    (PSA_ALG_HASH_EDDSA_BASE | (PSA_ALG_SHA_512 & PSA_ALG_HASH_MASK))

Edwards-curve digital signature algorithm with prehashing (HashEdDSA), using SHA-512 and the Edwards25519 curve.

See PSA_ALG_PURE_EDDSA regarding context support and the signature format.

This algorithm is Ed25519 as specified in RFC 8032. The curve is Edwards25519. The prehash is SHA-512. The hash function used internally is SHA-512.

This is a hash-and-sign algorithm: to calculate a signature, you can either:

• call psa_sign_message() on the message;

• or calculate the SHA-512 hash of the message with psa_hash_compute() or with a multi-part hash operation started with psa_hash_setup(), using the hash algorithm PSA_ALG_SHA_512, then sign the calculated hash with psa_sign_hash(). Verifying a signature is similar, using psa_verify_message() or psa_verify_hash() instead of the signature function.

PSA_ALG_ED448PH#

#define PSA_ALG_ED448PH

    (PSA_ALG_HASH_EDDSA_BASE | (PSA_ALG_SHAKE256_512 & PSA_ALG_HASH_MASK))

Edwards-curve digital signature algorithm with prehashing (HashEdDSA), using SHAKE256 and the Edwards448 curve.

See PSA_ALG_PURE_EDDSA regarding context support and the signature format.

This algorithm is Ed448 as specified in RFC 8032. The curve is Edwards448. The prehash is the first 64 bytes of the SHAKE256 output. The hash function used internally is the first 114 bytes of the SHAKE256 output.

This is a hash-and-sign algorithm: to calculate a signature, you can either:

• call psa_sign_message() on the message;

• or calculate the first 64 bytes of the SHAKE256 output of the message with psa_hash_compute() or with a multi-part hash operation started with psa_hash_setup(), using the hash algorithm PSA_ALG_SHAKE256_512, then sign the calculated hash with psa_sign_hash(). Verifying a signature is similar, using psa_verify_message() or psa_verify_hash() instead of the signature function.

PSA_ALG_IS_VENDOR_HASH_AND_SIGN#

#define PSA_ALG_IS_VENDOR_HASH_AND_SIGN

(alg)

PSA_ALG_IS_SIGN_HASH#

#define PSA_ALG_IS_SIGN_HASH

Whether the specified algorithm is a signature algorithm that can be used with psa_sign_hash() and psa_verify_hash().

This encompasses all strict hash-and-sign algorithms categorized by PSA_ALG_IS_HASH_AND_SIGN(), as well as algorithms that follow the paradigm more loosely:

• PSA_ALG_RSA_PKCS1V15_SIGN_RAW (expects its input to be an encoded hash)

• PSA_ALG_ECDSA_ANY (doesn't specify what kind of hash the input is)

Returns

• 1 if alg is a signature algorithm that can be used to sign a hash. 0 if alg is a signature algorithm that can only be used to sign a message. 0 if alg is not a signature algorithm. This macro can return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_SIGN_MESSAGE#

#define PSA_ALG_IS_SIGN_MESSAGE

(alg)

Whether the specified algorithm is a signature algorithm that can be used with psa_sign_message() and psa_verify_message().

Returns

• 1 if alg is a signature algorithm that can be used to sign a message. 0 if alg is a signature algorithm that can only be used to sign an already-calculated hash. 0 if alg is not a signature algorithm. This macro can return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_IS_HASH_AND_SIGN#

#define PSA_ALG_IS_HASH_AND_SIGN

Whether the specified algorithm is a hash-and-sign algorithm.

Hash-and-sign algorithms are asymmetric (public-key) signature algorithms structured in two parts: first the calculation of a hash in a way that does not depend on the key, then the calculation of a signature from the hash value and the key. Hash-and-sign algorithms encode the hash used for the hashing step, and you can call PSA_ALG_SIGN_GET_HASH to extract this algorithm.

Thus, for a hash-and-sign algorithm, psa_sign_message(key, alg, input, ...) is equivalent to

psa_hash_compute(PSA_ALG_SIGN_GET_HASH(alg), input, ..., hash, ...);
psa_sign_hash(key, alg, hash, ..., signature, ...);

Most usefully, separating the hash from the signature allows the hash to be calculated in multiple steps with psa_hash_setup(), psa_hash_update() and psa_hash_finish(). Likewise psa_verify_message() is equivalent to calculating the hash and then calling psa_verify_hash().

Returns

• 1 if alg is a hash-and-sign algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported algorithm identifier.

PSA_ALG_SIGN_GET_HASH#

#define PSA_ALG_SIGN_GET_HASH

Get the hash used by a hash-and-sign signature algorithm.

A hash-and-sign algorithm is a signature algorithm which is composed of two phases: first a hashing phase which does not use the key and produces a hash of the input message, then a signing phase which only uses the hash and the key and not the message itself.

Returns

• The underlying hash algorithm if alg is a hash-and-sign algorithm.

• 0 if alg is a signature algorithm that does not follow the hash-and-sign structure.

• Unspecified if alg is not a signature algorithm or if it is not supported by the implementation.

PSA_ALG_RSA_PKCS1V15_CRYPT#

#define PSA_ALG_RSA_PKCS1V15_CRYPT

((psa_algorithm_t) 0x07000200)

RSA PKCS#1 v1.5 encryption.

PSA_ALG_RSA_OAEP_BASE#

#define PSA_ALG_RSA_OAEP_BASE

((psa_algorithm_t) 0x07000300)

PSA_ALG_RSA_OAEP#

#define PSA_ALG_RSA_OAEP

(hash_alg)

RSA OAEP encryption.

This is the encryption scheme defined by RFC 8017 (PKCS#1: RSA Cryptography Specifications) under the name RSAES-OAEP, with the message generation function MGF1.

Returns

• The corresponding RSA OAEP encryption algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_IS_RSA_OAEP#

#define PSA_ALG_IS_RSA_OAEP

(alg)

PSA_ALG_RSA_OAEP_GET_HASH#

#define PSA_ALG_RSA_OAEP_GET_HASH

PSA_ALG_HKDF_BASE#

#define PSA_ALG_HKDF_BASE

((psa_algorithm_t) 0x08000100)

PSA_ALG_HKDF#

#define PSA_ALG_HKDF

(hash_alg)

Macro to build an HKDF algorithm.

For example, PSA_ALG_HKDF(PSA_ALG_SHA_256) is HKDF using HMAC-SHA-256.

This key derivation algorithm uses the following inputs:

• PSA_KEY_DERIVATION_INPUT_SALT is the salt used in the "extract" step. It is optional; if omitted, the derivation uses an empty salt.

• PSA_KEY_DERIVATION_INPUT_SECRET is the secret key used in the "extract" step.

• PSA_KEY_DERIVATION_INPUT_INFO is the info string used in the "expand" step. You must pass PSA_KEY_DERIVATION_INPUT_SALT before PSA_KEY_DERIVATION_INPUT_SECRET. You may pass PSA_KEY_DERIVATION_INPUT_INFO at any time after steup and before starting to generate output.

  Warnings

  • HKDF processes the salt as follows: first hash it with hash_alg if the salt is longer than the block size of the hash algorithm; then pad with null bytes up to the block size. As a result, it is possible for distinct salt inputs to result in the same outputs. To ensure unique outputs, it is recommended to use a fixed length for salt values.

  Returns

  • The corresponding HKDF algorithm.

  • Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_IS_HKDF#

#define PSA_ALG_IS_HKDF

(alg)

Whether the specified algorithm is an HKDF algorithm.

HKDF is a family of key derivation algorithms that are based on a hash function and the HMAC construction.

Returns

• 1 if alg is an HKDF algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported key derivation algorithm identifier.

PSA_ALG_HKDF_GET_HASH#

#define PSA_ALG_HKDF_GET_HASH

(hkdf_alg)

PSA_ALG_HKDF_EXTRACT_BASE#

#define PSA_ALG_HKDF_EXTRACT_BASE

((psa_algorithm_t) 0x08000400)

PSA_ALG_HKDF_EXTRACT#

#define PSA_ALG_HKDF_EXTRACT

(hash_alg)

Macro to build an HKDF-Extract algorithm.

For example, PSA_ALG_HKDF_EXTRACT(PSA_ALG_SHA_256) is HKDF-Extract using HMAC-SHA-256.

This key derivation algorithm uses the following inputs:

• PSA_KEY_DERIVATION_INPUT_SALT is the salt.

• PSA_KEY_DERIVATION_INPUT_SECRET is the input keying material used in the "extract" step. The inputs are mandatory and must be passed in the order above. Each input may only be passed once.

Warnings

• HKDF-Extract is not meant to be used on its own. PSA_ALG_HKDF should be used instead if possible. PSA_ALG_HKDF_EXTRACT is provided as a separate algorithm for the sake of protocols that use it as a building block. It may also be a slight performance optimization in applications that use HKDF with the same salt and key but many different info strings.

• HKDF processes the salt as follows: first hash it with hash_alg if the salt is longer than the block size of the hash algorithm; then pad with null bytes up to the block size. As a result, it is possible for distinct salt inputs to result in the same outputs. To ensure unique outputs, it is recommended to use a fixed length for salt values.

Returns

• The corresponding HKDF-Extract algorithm.

• Unspecified if hash_alg is not a supported hash algorithm.

PSA_ALG_IS_HKDF_EXTRACT#

#define PSA_ALG_IS_HKDF_EXTRACT

(alg)

Whether the specified algorithm is an HKDF-Extract algorithm.

HKDF-Extract is a family of key derivation algorithms that are based on a hash function and the HMAC construction.

Returns

• 1 if alg is an HKDF-Extract algorithm, 0 otherwise. This macro may return either 0 or 1 if alg is not a supported key derivation algorithm identifier.

PSA_ALG_HKDF_EXPAND_BASE#

#define PSA_ALG_HKDF_EXPAND_BASE

((psa_algorithm_t) 0x08000500)

PSA_ALG_HKDF_EXPAND#

#define PSA_ALG_HKDF_EXPAND

(hash_alg)

Macro to build an HKDF-Expand algorithm.

For example, PSA_ALG_HKDF_EXPAND(PSA_ALG_SHA_256) is HKDF-Expand using HMAC-SHA-256.

This key derivation algorithm uses the following inputs:

• PSA_KEY_DERIVATION_INPUT_SECRET is the pseudorandom key (PRK).

• PSA_KEY_DERIVATION_INPUT_INFO is the info string.

The inputs are mandatory and must be passed in the order above. Each input may only be passed once.

Warnings

• HKDF-Expand is not meant to be used on its own. PSA_ALG_HKDF should be used instead if possible. PSA_ALG_HKDF_EXPAND is provided as a separate algorithm for the sake of protocols that use it as a building block. It may also be a slight performance optimization in applications that use HKDF with the same salt and key but many different info strings.

Returns