| /** |
| * \file psa/crypto_sizes.h |
| * |
| * \brief PSA cryptography module: Mbed TLS buffer size macros |
| * |
| * \note This file may not be included directly. Applications must |
| * include psa/crypto.h. |
| * |
| * This file contains the definitions of macros that are useful to |
| * compute buffer sizes. The signatures and semantics of these macros |
| * are standardized, but the definitions are not, because they depend on |
| * the available algorithms and, in some cases, on permitted tolerances |
| * on buffer sizes. |
| * |
| * In implementations with isolation between the application and the |
| * cryptography module, implementers should take care to ensure that |
| * the definitions that are exposed to applications match what the |
| * module implements. |
| * |
| * Macros that compute sizes whose values do not depend on the |
| * implementation are in crypto.h. |
| */ |
| /* |
| * Copyright The Mbed TLS Contributors |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef PSA_CRYPTO_SIZES_H |
| #define PSA_CRYPTO_SIZES_H |
| |
| /* Include the Mbed TLS configuration file, the way Mbed TLS does it |
| * in each of its header files. */ |
| #if !defined(MBEDTLS_CONFIG_FILE) |
| #include "mbedtls/config.h" |
| #else |
| #include MBEDTLS_CONFIG_FILE |
| #endif |
| |
| #define PSA_BITS_TO_BYTES(bits) (((bits) + 7) / 8) |
| #define PSA_BYTES_TO_BITS(bytes) ((bytes) * 8) |
| |
| #define PSA_ROUND_UP_TO_MULTIPLE(block_size, length) \ |
| (((length) + (block_size) - 1) / (block_size) * (block_size)) |
| |
| /** The size of the output of psa_hash_finish(), in bytes. |
| * |
| * This is also the hash size that psa_hash_verify() expects. |
| * |
| * \param alg A hash algorithm (\c PSA_ALG_XXX value such that |
| * #PSA_ALG_IS_HASH(\p alg) is true), or an HMAC algorithm |
| * (#PSA_ALG_HMAC(\c hash_alg) where \c hash_alg is a |
| * hash algorithm). |
| * |
| * \return The hash size for the specified hash algorithm. |
| * If the hash algorithm is not recognized, return 0. |
| * An implementation may return either 0 or the correct size |
| * for a hash algorithm that it recognizes, but does not support. |
| */ |
| #define PSA_HASH_LENGTH(alg) \ |
| ( \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD2 ? 16 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD4 ? 16 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_MD5 ? 16 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_RIPEMD160 ? 20 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_1 ? 20 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_224 ? 28 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_256 ? 32 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_384 ? 48 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512 ? 64 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_224 ? 28 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA_512_256 ? 32 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_224 ? 28 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_256 ? 32 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_384 ? 48 : \ |
| PSA_ALG_HMAC_GET_HASH(alg) == PSA_ALG_SHA3_512 ? 64 : \ |
| 0) |
| |
| /** \def PSA_HASH_MAX_SIZE |
| * |
| * Maximum size of a hash. |
| * |
| * This macro must expand to a compile-time constant integer. This value |
| * should be the maximum size of a hash supported by the implementation, |
| * in bytes, and must be no smaller than this maximum. |
| */ |
| /* Note: for HMAC-SHA-3, the block size is 144 bytes for HMAC-SHA3-226, |
| * 136 bytes for HMAC-SHA3-256, 104 bytes for SHA3-384, 72 bytes for |
| * HMAC-SHA3-512. */ |
| #if defined(MBEDTLS_SHA512_C) |
| #define PSA_HASH_MAX_SIZE 64 |
| #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128 |
| #else |
| #define PSA_HASH_MAX_SIZE 32 |
| #define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64 |
| #endif |
| |
| /** \def PSA_MAC_MAX_SIZE |
| * |
| * Maximum size of a MAC. |
| * |
| * This macro must expand to a compile-time constant integer. This value |
| * should be the maximum size of a MAC supported by the implementation, |
| * in bytes, and must be no smaller than this maximum. |
| */ |
| /* All non-HMAC MACs have a maximum size that's smaller than the |
| * minimum possible value of PSA_HASH_MAX_SIZE in this implementation. */ |
| /* Note that the encoding of truncated MAC algorithms limits this value |
| * to 64 bytes. |
| */ |
| #define PSA_MAC_MAX_SIZE PSA_HASH_MAX_SIZE |
| |
| /** The tag size for an AEAD algorithm, in bytes. |
| * |
| * \param alg An AEAD algorithm |
| * (\c PSA_ALG_XXX value such that |
| * #PSA_ALG_IS_AEAD(\p alg) is true). |
| * |
| * \return The tag size for the specified algorithm. |
| * If the AEAD algorithm does not have an identified |
| * tag that can be distinguished from the rest of |
| * the ciphertext, return 0. |
| * If the AEAD algorithm is not recognized, return 0. |
| * An implementation may return either 0 or a |
| * correct size for an AEAD algorithm that it |
| * recognizes, but does not support. |
| */ |
| #define PSA_AEAD_TAG_LENGTH(alg) \ |
| (PSA_ALG_IS_AEAD(alg) ? \ |
| (((alg) & PSA_ALG_AEAD_TAG_LENGTH_MASK) >> PSA_AEAD_TAG_LENGTH_OFFSET) : \ |
| 0) |
| |
| /* The maximum size of an RSA key on this implementation, in bits. |
| * This is a vendor-specific macro. |
| * |
| * Mbed TLS does not set a hard limit on the size of RSA keys: any key |
| * whose parameters fit in a bignum is accepted. However large keys can |
| * induce a large memory usage and long computation times. Unlike other |
| * auxiliary macros in this file and in crypto.h, which reflect how the |
| * library is configured, this macro defines how the library is |
| * configured. This implementation refuses to import or generate an |
| * RSA key whose size is larger than the value defined here. |
| * |
| * Note that an implementation may set different size limits for different |
| * operations, and does not need to accept all key sizes up to the limit. */ |
| #define PSA_VENDOR_RSA_MAX_KEY_BITS 4096 |
| |
| /* The maximum size of an ECC key on this implementation, in bits. |
| * This is a vendor-specific macro. */ |
| #if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 521 |
| #elif defined(MBEDTLS_ECP_DP_BP512R1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 512 |
| #elif defined(MBEDTLS_ECP_DP_CURVE448_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 448 |
| #elif defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384 |
| #elif defined(MBEDTLS_ECP_DP_BP384R1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 384 |
| #elif defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 |
| #elif defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 |
| #elif defined(MBEDTLS_ECP_DP_BP256R1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 256 |
| #elif defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 255 |
| #elif defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224 |
| #elif defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 224 |
| #elif defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192 |
| #elif defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED) |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 192 |
| #else |
| #define PSA_VENDOR_ECC_MAX_CURVE_BITS 0 |
| #endif |
| |
| /** This macro returns the maximum supported length of the PSK for the |
| * TLS-1.2 PSK-to-MS key derivation |
| * (#PSA_ALG_TLS12_PSK_TO_MS(\p hash_alg)). |
| * |
| * The maximum supported length does not depend on the chosen hash algorithm. |
| * |
| * Quoting RFC 4279, Sect 5.3: |
| * TLS implementations supporting these ciphersuites MUST support |
| * arbitrary PSK identities up to 128 octets in length, and arbitrary |
| * PSKs up to 64 octets in length. Supporting longer identities and |
| * keys is RECOMMENDED. |
| * |
| * Therefore, no implementation should define a value smaller than 64 |
| * for #PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE. |
| */ |
| #define PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE 128 |
| |
| /** The maximum size of a block cipher supported by the implementation. */ |
| #define PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE 16 |
| |
| /** The size of the output of psa_mac_sign_finish(), in bytes. |
| * |
| * This is also the MAC size that psa_mac_verify_finish() expects. |
| * |
| * \warning This macro may evaluate its arguments multiple times or |
| * zero times, so you should not pass arguments that contain |
| * side effects. |
| * |
| * \param key_type The type of the MAC key. |
| * \param key_bits The size of the MAC key in bits. |
| * \param alg A MAC algorithm (\c PSA_ALG_XXX value such that |
| * #PSA_ALG_IS_MAC(\p alg) is true). |
| * |
| * \return The MAC size for the specified algorithm with |
| * the specified key parameters. |
| * \return 0 if the MAC algorithm is not recognized. |
| * \return Either 0 or the correct size for a MAC algorithm that |
| * the implementation recognizes, but does not support. |
| * \return Unspecified if the key parameters are not consistent |
| * with the algorithm. |
| */ |
| #define PSA_MAC_LENGTH(key_type, key_bits, alg) \ |
| ((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \ |
| PSA_ALG_IS_HMAC(alg) ? PSA_HASH_LENGTH(PSA_ALG_HMAC_GET_HASH(alg)) : \ |
| PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ |
| ((void)(key_type), (void)(key_bits), 0)) |
| |
| /** The maximum size of the output of psa_aead_encrypt(), in bytes. |
| * |
| * If the size of the ciphertext buffer is at least this large, it is |
| * guaranteed that psa_aead_encrypt() will not fail due to an |
| * insufficient buffer size. Depending on the algorithm, the actual size of |
| * the ciphertext may be smaller. |
| * |
| * \param alg An AEAD algorithm |
| * (\c PSA_ALG_XXX value such that |
| * #PSA_ALG_IS_AEAD(\p alg) is true). |
| * \param plaintext_length Size of the plaintext in bytes. |
| * |
| * \return The AEAD ciphertext size for the specified |
| * algorithm. |
| * If the AEAD algorithm is not recognized, return 0. |
| * An implementation may return either 0 or a |
| * correct size for an AEAD algorithm that it |
| * recognizes, but does not support. |
| */ |
| #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(alg, plaintext_length) \ |
| (PSA_AEAD_TAG_LENGTH(alg) != 0 ? \ |
| (plaintext_length) + PSA_AEAD_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. |
| * |
| * \param alg An AEAD algorithm |
| * (\c PSA_ALG_XXX value such that |
| * #PSA_ALG_IS_AEAD(\p alg) is true). |
| * \param ciphertext_length Size of the plaintext in bytes. |
| * |
| * \return The AEAD ciphertext size for the specified |
| * algorithm. |
| * If the AEAD algorithm is not recognized, return 0. |
| * An implementation may return either 0 or a |
| * correct size for an AEAD algorithm that it |
| * recognizes, but does not support. |
| */ |
| #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(alg, ciphertext_length) \ |
| (PSA_AEAD_TAG_LENGTH(alg) != 0 ? \ |
| (ciphertext_length) - PSA_AEAD_TAG_LENGTH(alg) : \ |
| 0) |
| |
| /** A sufficient output buffer size for psa_aead_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. |
| * |
| * \param alg An AEAD algorithm |
| * (\c PSA_ALG_XXX value such that |
| * #PSA_ALG_IS_AEAD(\p alg) is true). |
| * \param input_length Size of the input in bytes. |
| * |
| * \return A sufficient output buffer size for the specified |
| * algorithm. |
| * If the AEAD algorithm is not recognized, return 0. |
| * An implementation may return either 0 or a |
| * correct size for an AEAD algorithm that it |
| * recognizes, but does not support. |
| */ |
| /* For all the AEAD modes defined in this specification, it is possible |
| * to emit output without delay. However, hardware may not always be |
| * capable of this. So for modes based on a block cipher, allow the |
| * implementation to delay the output until it has a full block. */ |
| #define PSA_AEAD_UPDATE_OUTPUT_SIZE(alg, input_length) \ |
| (PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ |
| PSA_ROUND_UP_TO_MULTIPLE(PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE, (input_length)) : \ |
| (input_length)) |
| |
| /** A sufficient ciphertext buffer size for psa_aead_finish(). |
| * |
| * If the size of the ciphertext buffer is at least this large, it is |
| * guaranteed that psa_aead_finish() will not fail due to an |
| * insufficient ciphertext buffer size. The actual size of the output may |
| * be smaller in any given call. |
| * |
| * \param alg An AEAD algorithm |
| * (\c PSA_ALG_XXX value such that |
| * #PSA_ALG_IS_AEAD(\p alg) is true). |
| * |
| * \return A sufficient ciphertext buffer size for the |
| * specified algorithm. |
| * If the AEAD algorithm is not recognized, return 0. |
| * An implementation may return either 0 or a |
| * correct size for an AEAD algorithm that it |
| * recognizes, but does not support. |
| */ |
| #define PSA_AEAD_FINISH_OUTPUT_SIZE(alg) \ |
| (PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ |
| PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE : \ |
| 0) |
| |
| /** A sufficient plaintext buffer size for psa_aead_verify(). |
| * |
| * If the size of the plaintext buffer is at least this large, it is |
| * guaranteed that psa_aead_verify() will not fail due to an |
| * insufficient plaintext buffer size. The actual size of the output may |
| * be smaller in any given call. |
| * |
| * \param alg An AEAD algorithm |
| * (\c PSA_ALG_XXX value such that |
| * #PSA_ALG_IS_AEAD(\p alg) is true). |
| * |
| * \return A sufficient plaintext buffer size for the |
| * specified algorithm. |
| * If the AEAD algorithm is not recognized, return 0. |
| * An implementation may return either 0 or a |
| * correct size for an AEAD algorithm that it |
| * recognizes, but does not support. |
| */ |
| #define PSA_AEAD_VERIFY_OUTPUT_SIZE(alg) \ |
| (PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) ? \ |
| PSA_BLOCK_CIPHER_BLOCK_MAX_SIZE : \ |
| 0) |
| |
| #define PSA_RSA_MINIMUM_PADDING_SIZE(alg) \ |
| (PSA_ALG_IS_RSA_OAEP(alg) ? \ |
| 2 * PSA_HASH_LENGTH(PSA_ALG_RSA_OAEP_GET_HASH(alg)) + 1 : \ |
| 11 /*PKCS#1v1.5*/) |
| |
| /** |
| * \brief ECDSA signature size for a given curve bit size |
| * |
| * \param curve_bits Curve size in bits. |
| * \return Signature size in bytes. |
| * |
| * \note This macro returns a compile-time constant if its argument is one. |
| */ |
| #define PSA_ECDSA_SIGNATURE_SIZE(curve_bits) \ |
| (PSA_BITS_TO_BYTES(curve_bits) * 2) |
| |
| /** Sufficient signature buffer size for psa_sign_hash(). |
| * |
| * This macro returns a sufficient buffer size for a signature using a key |
| * of the specified type and size, with the specified algorithm. |
| * Note that the actual size of the signature may be smaller |
| * (some algorithms produce a variable-size signature). |
| * |
| * \warning This function may call its arguments multiple times or |
| * zero times, so you should not pass arguments that contain |
| * side effects. |
| * |
| * \param key_type An asymmetric key type (this may indifferently be a |
| * key pair type or a public key type). |
| * \param key_bits The size of the key in bits. |
| * \param alg The signature algorithm. |
| * |
| * \return If the parameters are valid and supported, return |
| * a buffer size in bytes that guarantees that |
| * psa_sign_hash() will not fail with |
| * #PSA_ERROR_BUFFER_TOO_SMALL. |
| * If the parameters are a valid combination that is not supported |
| * by the implementation, this macro shall return either a |
| * sensible size or 0. |
| * If the parameters are not valid, the |
| * return value is unspecified. |
| */ |
| #define PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \ |
| (PSA_KEY_TYPE_IS_RSA(key_type) ? ((void)alg, PSA_BITS_TO_BYTES(key_bits)) : \ |
| PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \ |
| ((void)alg, 0)) |
| |
| #define PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE \ |
| PSA_ECDSA_SIGNATURE_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS) |
| |
| /** \def PSA_SIGNATURE_MAX_SIZE |
| * |
| * Maximum size of an asymmetric signature. |
| * |
| * This macro must expand to a compile-time constant integer. This value |
| * should be the maximum size of a signature supported by the implementation, |
| * in bytes, and must be no smaller than this maximum. |
| */ |
| #define PSA_SIGNATURE_MAX_SIZE \ |
| (PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) > PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE ? \ |
| PSA_BITS_TO_BYTES(PSA_VENDOR_RSA_MAX_KEY_BITS) : \ |
| PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE) |
| |
| /** Sufficient output buffer size for psa_asymmetric_encrypt(). |
| * |
| * This macro returns a sufficient buffer size for a ciphertext produced using |
| * a key of the specified type and size, with the specified algorithm. |
| * Note that the actual size of the ciphertext may be smaller, depending |
| * on the algorithm. |
| * |
| * \warning This function may call its arguments multiple times or |
| * zero times, so you should not pass arguments that contain |
| * side effects. |
| * |
| * \param key_type An asymmetric key type (this may indifferently be a |
| * key pair type or a public key type). |
| * \param key_bits The size of the key in bits. |
| * \param alg The asymmetric encryption algorithm. |
| * |
| * \return If the parameters are valid and supported, return |
| * a buffer size in bytes that guarantees that |
| * psa_asymmetric_encrypt() will not fail with |
| * #PSA_ERROR_BUFFER_TOO_SMALL. |
| * If the parameters are a valid combination that is not supported |
| * by the implementation, this macro shall return either a |
| * sensible size or 0. |
| * If the parameters are not valid, the |
| * return value is unspecified. |
| */ |
| #define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ |
| (PSA_KEY_TYPE_IS_RSA(key_type) ? \ |
| ((void)alg, PSA_BITS_TO_BYTES(key_bits)) : \ |
| 0) |
| |
| /** Sufficient output buffer size for psa_asymmetric_decrypt(). |
| * |
| * This macro returns a sufficient buffer size for a plaintext produced using |
| * a key of the specified type and size, with the specified algorithm. |
| * Note that the actual size of the plaintext may be smaller, depending |
| * on the algorithm. |
| * |
| * \warning This function may call its arguments multiple times or |
| * zero times, so you should not pass arguments that contain |
| * side effects. |
| * |
| * \param key_type An asymmetric key type (this may indifferently be a |
| * key pair type or a public key type). |
| * \param key_bits The size of the key in bits. |
| * \param alg The asymmetric encryption algorithm. |
| * |
| * \return If the parameters are valid and supported, return |
| * a buffer size in bytes that guarantees that |
| * psa_asymmetric_decrypt() will not fail with |
| * #PSA_ERROR_BUFFER_TOO_SMALL. |
| * If the parameters are a valid combination that is not supported |
| * by the implementation, this macro shall return either a |
| * sensible size or 0. |
| * If the parameters are not valid, the |
| * return value is unspecified. |
| */ |
| #define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \ |
| (PSA_KEY_TYPE_IS_RSA(key_type) ? \ |
| PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \ |
| 0) |
| |
| /* Maximum size of the ASN.1 encoding of an INTEGER with the specified |
| * number of bits. |
| * |
| * This definition assumes that bits <= 2^19 - 9 so that the length field |
| * is at most 3 bytes. The length of the encoding is the length of the |
| * bit string padded to a whole number of bytes plus: |
| * - 1 type byte; |
| * - 1 to 3 length bytes; |
| * - 0 to 1 bytes of leading 0 due to the sign bit. |
| */ |
| #define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \ |
| ((bits) / 8 + 5) |
| |
| /* Maximum size of the export encoding of an RSA public key. |
| * Assumes that the public exponent is less than 2^32. |
| * |
| * RSAPublicKey ::= SEQUENCE { |
| * modulus INTEGER, -- n |
| * publicExponent INTEGER } -- e |
| * |
| * - 4 bytes of SEQUENCE overhead; |
| * - n : INTEGER; |
| * - 7 bytes for the public exponent. |
| */ |
| #define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ |
| (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 11) |
| |
| /* Maximum size of the export encoding of an RSA key pair. |
| * Assumes thatthe public exponent is less than 2^32 and that the size |
| * difference between the two primes is at most 1 bit. |
| * |
| * RSAPrivateKey ::= SEQUENCE { |
| * version Version, -- 0 |
| * modulus INTEGER, -- N-bit |
| * publicExponent INTEGER, -- 32-bit |
| * privateExponent INTEGER, -- N-bit |
| * prime1 INTEGER, -- N/2-bit |
| * prime2 INTEGER, -- N/2-bit |
| * exponent1 INTEGER, -- N/2-bit |
| * exponent2 INTEGER, -- N/2-bit |
| * coefficient INTEGER, -- N/2-bit |
| * } |
| * |
| * - 4 bytes of SEQUENCE overhead; |
| * - 3 bytes of version; |
| * - 7 half-size INTEGERs plus 2 full-size INTEGERs, |
| * overapproximated as 9 half-size INTEGERS; |
| * - 7 bytes for the public exponent. |
| */ |
| #define PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) \ |
| (9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14) |
| |
| /* Maximum size of the export encoding of a DSA public key. |
| * |
| * SubjectPublicKeyInfo ::= SEQUENCE { |
| * algorithm AlgorithmIdentifier, |
| * subjectPublicKey BIT STRING } -- contains DSAPublicKey |
| * AlgorithmIdentifier ::= SEQUENCE { |
| * algorithm OBJECT IDENTIFIER, |
| * parameters Dss-Parms } -- SEQUENCE of 3 INTEGERs |
| * DSAPublicKey ::= INTEGER -- public key, Y |
| * |
| * - 3 * 4 bytes of SEQUENCE overhead; |
| * - 1 + 1 + 7 bytes of algorithm (DSA OID); |
| * - 4 bytes of BIT STRING overhead; |
| * - 3 full-size INTEGERs (p, g, y); |
| * - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits). |
| */ |
| #define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \ |
| (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 59) |
| |
| /* Maximum size of the export encoding of a DSA key pair. |
| * |
| * DSAPrivateKey ::= SEQUENCE { |
| * version Version, -- 0 |
| * prime INTEGER, -- p |
| * subprime INTEGER, -- q |
| * generator INTEGER, -- g |
| * public INTEGER, -- y |
| * private INTEGER, -- x |
| * } |
| * |
| * - 4 bytes of SEQUENCE overhead; |
| * - 3 bytes of version; |
| * - 3 full-size INTEGERs (p, g, y); |
| * - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits). |
| */ |
| #define PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) \ |
| (PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 75) |
| |
| /* Maximum size of the export encoding of an ECC public key. |
| * |
| * The representation of an ECC public key is: |
| * - The byte 0x04; |
| * - `x_P` as a `ceiling(m/8)`-byte string, big-endian; |
| * - `y_P` as a `ceiling(m/8)`-byte string, big-endian; |
| * - where m is the bit size associated with the curve. |
| * |
| * - 1 byte + 2 * point size. |
| */ |
| #define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \ |
| (2 * PSA_BITS_TO_BYTES(key_bits) + 1) |
| |
| /* Maximum size of the export encoding of an ECC key pair. |
| * |
| * An ECC key pair is represented by the secret value. |
| */ |
| #define PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) \ |
| (PSA_BITS_TO_BYTES(key_bits)) |
| |
| /** Sufficient output buffer size for psa_export_key() or |
| * psa_export_public_key(). |
| * |
| * This macro returns a compile-time constant if its arguments are |
| * compile-time constants. |
| * |
| * \warning This macro may evaluate its arguments multiple times or |
| * zero times, so you should not pass arguments that contain |
| * side effects. |
| * |
| * The following code illustrates how to allocate enough memory to export |
| * a key by querying the key type and size at runtime. |
| * \code{c} |
| * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; |
| * psa_status_t status; |
| * status = psa_get_key_attributes(key, &attributes); |
| * if (status != PSA_SUCCESS) handle_error(...); |
| * psa_key_type_t key_type = psa_get_key_type(&attributes); |
| * size_t key_bits = psa_get_key_bits(&attributes); |
| * size_t buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits); |
| * psa_reset_key_attributes(&attributes); |
| * uint8_t *buffer = malloc(buffer_size); |
| * if (buffer == NULL) handle_error(...); |
| * size_t buffer_length; |
| * status = psa_export_key(key, buffer, buffer_size, &buffer_length); |
| * if (status != PSA_SUCCESS) handle_error(...); |
| * \endcode |
| * |
| * \param key_type A supported key type. |
| * \param key_bits The size of the key in bits. |
| * |
| * \return If the parameters are valid and supported, return |
| * a buffer size in bytes that guarantees that |
| * psa_export_key() or psa_export_public_key() will not fail with |
| * #PSA_ERROR_BUFFER_TOO_SMALL. |
| * If the parameters are a valid combination that is not supported |
| * by the implementation, this macro shall return either a |
| * sensible size or 0. |
| * If the parameters are not valid, the |
| * return value is unspecified. |
| */ |
| #define PSA_EXPORT_KEY_OUTPUT_SIZE(key_type, key_bits) \ |
| (PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \ |
| (key_type) == PSA_KEY_TYPE_RSA_KEY_PAIR ? PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE(key_bits) : \ |
| (key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ |
| (key_type) == PSA_KEY_TYPE_DSA_KEY_PAIR ? PSA_KEY_EXPORT_DSA_KEY_PAIR_MAX_SIZE(key_bits) : \ |
| (key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \ |
| PSA_KEY_TYPE_IS_ECC_KEY_PAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(key_bits) : \ |
| PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \ |
| 0) |
| |
| /** The default nonce size for an AEAD algorithm, in bytes. |
| * |
| * This macro can be used to allocate a buffer of sufficient size to |
| * store the nonce output from #psa_aead_generate_nonce(). |
| * |
| * See also #PSA_AEAD_NONCE_MAX_SIZE. |
| * |
| * \note This is not the maximum size of nonce supported as input to #psa_aead_set_nonce(), |
| * #psa_aead_encrypt() or #psa_aead_decrypt(), just the default size that is generated by |
| * #psa_aead_generate_nonce(). |
| * |
| * \warning This macro may evaluate its arguments multiple times or |
| * zero times, so you should not pass arguments that contain |
| * side effects. |
| * |
| * \param key_type A symmetric key type that is compatible with algorithm \p alg. |
| * |
| * \param alg An AEAD algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_AEAD(\p alg) is true). |
| * |
| * \return The default nonce size for the specified key type and algorithm. |
| * If the key type or AEAD algorithm is not recognized, |
| * or the parameters are incompatible, return 0. |
| * An implementation can return either 0 or a correct size for a key type |
| * and AEAD algorithm that it recognizes, but does not support. |
| */ |
| #define PSA_AEAD_NONCE_LENGTH(key_type, alg) \ |
| (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 && \ |
| (PSA_ALG_AEAD_WITH_DEFAULT_TAG_LENGTH(alg) == PSA_ALG_CCM || \ |
| PSA_ALG_AEAD_WITH_DEFAULT_TAG_LENGTH(alg) == PSA_ALG_GCM) ? 12 : \ |
| (key_type) == PSA_KEY_TYPE_CHACHA20 && \ |
| PSA_ALG_AEAD_WITH_DEFAULT_TAG_LENGTH(alg) == PSA_ALG_CHACHA20_POLY1305 ? 12 : \ |
| 0) |
| |
| /** The maximum default nonce size among all supported pairs of key types and AEAD algorithms, in bytes. |
| * |
| * This is equal to or greater than any value that #PSA_AEAD_NONCE_LENGTH() may return. |
| * |
| * \note This is not the maximum size of nonce supported as input to #psa_aead_set_nonce(), |
| * #psa_aead_encrypt() or #psa_aead_decrypt(), just the largest size that may be generated by |
| * #psa_aead_generate_nonce(). |
| */ |
| #define PSA_AEAD_NONCE_MAX_SIZE 12 |
| |
| /** The default IV size for a cipher algorithm, in bytes. |
| * |
| * The IV that is generated as part of a call to #psa_cipher_encrypt() is always |
| * the default IV length for the algorithm. |
| * |
| * This macro can be used to allocate a buffer of sufficient size to |
| * store the IV output from #psa_cipher_generate_iv() when using |
| * a multi-part cipher operation. |
| * |
| * See also #PSA_CIPHER_IV_MAX_SIZE. |
| * |
| * \warning This macro may evaluate its arguments multiple times or |
| * zero times, so you should not pass arguments that contain |
| * side effects. |
| * |
| * \param key_type A symmetric key type that is compatible with algorithm \p alg. |
| * |
| * \param alg A cipher algorithm (\c PSA_ALG_XXX value such that #PSA_ALG_IS_CIPHER(\p alg) is true). |
| * |
| * \return The default IV size for the specified key type and algorithm. |
| * If the algorithm does not use an IV, return 0. |
| * If the key type or cipher algorithm is not recognized, |
| * or the parameters are incompatible, return 0. |
| * An implementation can return either 0 or a correct size for a key type |
| * and cipher algorithm that it recognizes, but does not support. |
| */ |
| #define PSA_CIPHER_IV_LENGTH(key_type, alg) \ |
| (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1 && \ |
| ((alg) == PSA_ALG_CTR || \ |
| (alg) == PSA_ALG_CFB || \ |
| (alg) == PSA_ALG_OFB || \ |
| (alg) == PSA_ALG_XTS || \ |
| (alg) == PSA_ALG_CBC_NO_PADDING || \ |
| (alg) == PSA_ALG_CBC_PKCS7) ? PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) : \ |
| (key_type) == PSA_KEY_TYPE_CHACHA20 && \ |
| (alg) == PSA_ALG_STREAM_CIPHER ? 12 : \ |
| 0) |
| |
| /** The maximum IV size for all supported cipher algorithms, in bytes. |
| * |
| * See also #PSA_CIPHER_IV_LENGTH(). |
| */ |
| #define PSA_CIPHER_IV_MAX_SIZE 16 |
| |
| #endif /* PSA_CRYPTO_SIZES_H */ |
