dcrypt_algorithms/ec/p224/
constants.rs

1//! Shared constants and helper functions for P-224 operations
2
3/// Size of a P-224 scalar in bytes (28 bytes = 224 bits)
4pub const P224_SCALAR_SIZE: usize = 28;
5
6/// Size of a P-224 field element in bytes (28 bytes = 224 bits)
7pub const P224_FIELD_ELEMENT_SIZE: usize = 28;
8
9/// Size of an uncompressed P-224 point in bytes: format byte (0x04) + x-coordinate + y-coordinate
10pub const P224_POINT_UNCOMPRESSED_SIZE: usize = 1 + 2 * P224_FIELD_ELEMENT_SIZE; // 57 bytes: 0x04 || x || y
11
12/// Size of a compressed P-224 point in bytes: format byte (0x02/0x03) + x-coordinate
13pub const P224_POINT_COMPRESSED_SIZE: usize = 1 + P224_FIELD_ELEMENT_SIZE; // 29 bytes: 0x02/0x03 || x
14
15/// Size of the authentication tag for KEM ciphertext
16pub const P224_TAG_SIZE: usize = 16; // 16-byte truncated HMAC-SHA256
17
18/// Size of the complete KEM ciphertext: compressed point + authentication tag
19pub const P224_CIPHERTEXT_SIZE: usize = P224_POINT_COMPRESSED_SIZE + P224_TAG_SIZE; // 45 bytes total
20
21/// Size of the KDF output for P-224 ECDH-KEM shared secret derivation
22pub const P224_KEM_SHARED_SECRET_KDF_OUTPUT_SIZE: usize = 32;