diff --git a/src/constants.rs b/src/constants.rs new file mode 100644 index 0000000..26923e8 --- /dev/null +++ b/src/constants.rs @@ -0,0 +1,100 @@ +// DES Constants (from FIPS 46-3 spec) +/// Initial Permutation (IP) table. +pub const IP: [u8; 64] = [ + 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, + 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, + 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7, +]; + +/// Inverse Initial Permutation (FP) table. +pub const FP: [u8; 64] = [ + 40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, + 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, + 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25, +]; + +/// PC1 table (64 to 56 bits). +pub const PC1: [u8; 64] = [ + 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, + 52, 44, 36, 28, 20, 12, 4, 61, 53, 45, 37, 29, 21, 13, 5, 62, 54, 46, 38, 30, 22, 14, 6, 63, + 55, 47, 39, 31, 23, 15, 7, 0, 0, 0, 0, 0, 0, 0, 0, // Parity bits skipped +]; + +/// PC2 table (56 to 48 bits). +pub const PC2: [u8; 56] = [ + 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, + 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32, 0, 0, + 0, 0, 0, 0, 0, 0, // Parity bits skipped +]; + +/// Expansion permutation (32 to 48 bits). +pub const EXPANSION: [u8; 48] = [ + 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 16, 17, 18, + 19, 20, 21, 20, 21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1, +]; + +/// P-box permutation (32 bits). +pub const PERMUTATION: [u8; 32] = [ + 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, + 13, 30, 6, 22, 11, 4, 25, +]; + +/// S-boxes: 8 boxes, each 4x16 (row x col) -> 0-15. +pub const S_BOXES: [[[u8; 16]; 4]; 8] = [ + // S1 + [ + [14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7], + [0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8], + [4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0], + [15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13], + ], + // S2 + [ + [15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10], + [3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5], + [0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15], + [13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9], + ], + // S3 + [ + [10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8], + [13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1], + [13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7], + [1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12], + ], + // S4 + [ + [7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15], + [13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9], + [10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4], + [3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14], + ], + // S5 + [ + [2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9], + [14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6], + [4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14], + [11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3], + ], + // S6 + [ + [12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11], + [10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8], + [9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6], + [4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13], + ], + // S7 + [ + [4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1], + [13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6], + [1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2], + [6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12], + ], + // S8 + [ + [13, 2, 8, 4, 6, 15, 11, 1, 19, 9, 3, 14, 5, 0, 12, 7], + [1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2], + [7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8], + [2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11], + ], +]; diff --git a/src/lib.rs b/src/lib.rs index 97b192e..d6569e9 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -1,57 +1,83 @@ +mod constants; + +use crate::constants::PERMUTATION; + #[derive(Debug)] pub struct DES { pub subkeys: [u64; 16], - _s_boxes: Vec>>, } impl DES { + /// Create a new DES instance from a 64-bit key (8 bytes). #[must_use] pub fn new(key: u64) -> Self { - let mut des = Self { - subkeys: [0; 16], - _s_boxes: Vec::new(), - }; + let mut des = Self { subkeys: [0; 16] }; des.generate_subkeys(key); des } + /// Encrypt a 64-bit block. #[must_use] - pub fn encrypt(&self, _plaintext: u64) -> u64 { + pub fn encrypt(&self, block: u64) -> u64 { + self.des(block, true) + } + + /// Decrypt a 64-bit block. + #[must_use] + pub fn decrypt(&self, block: u64) -> u64 { + self.des(block, false) + } + + #[must_use] + fn expand(&self, right_half: u32) -> u64 { + todo!() + } + + /// Feistel function: Expand, XOR with subkey, S-box, permute. + #[must_use] + fn feistel(&self, right: u32, subkey: u64) -> u32 { + todo!() + } + + /// Core DES function: encrypt if forward=true, else decrypt. + #[must_use] + fn des(&self, mut block: u64, forward: bool) -> u64 { + todo!() + } + + /// Generate 16 subkeys from the 64-bit key. + fn generate_subkeys(&mut self, key: u64) { + todo!() + } + + /// Helper functions for permutations (bit manipulation) + #[must_use] + fn permutate(&self, input: u32, table: &[u8], n: usize) -> u32 { todo!() } #[must_use] - pub fn decrypt(&self, _plaintext: u64) -> u64 { + fn ip(&self, input: u64) -> u64 { todo!() } #[must_use] - pub fn ip(&self, _input: u64) -> u64 { + pub fn fp(&self, input: u64) -> u64 { todo!() } #[must_use] - pub fn pc1(&self, _key: u64) -> u64 { + pub fn pc1(&self, input: u64) -> u64 { todo!() } #[must_use] - pub fn expand(&self, _right_half: u32) -> u64 { + pub fn pc2(&self, input: u64) -> u64 { todo!() } - #[must_use] - pub fn permutate_output(&self, _input: u32) -> u32 { - todo!() - } - - #[must_use] - pub fn feistel(&self, _right: u32, _subkey: u64) -> u32 { - todo!() - } - - fn generate_subkeys(&mut self, _key: u64) { - todo!() + fn permutate_output(&self, input: u32) -> u32 { + self.permutate(input, &PERMUTATION, 32) } } @@ -69,7 +95,7 @@ impl DES { /// /// If data length is not multiple of 8 bytes #[must_use] -pub fn encrypt_ecb(_data: &[u8], _key: &[u8; 8]) -> Vec { +pub fn encrypt_ecb(data: &[u8], key: &[u8; 8]) -> Vec { todo!() } @@ -87,12 +113,14 @@ pub fn encrypt_ecb(_data: &[u8], _key: &[u8; 8]) -> Vec { /// /// If data length is not multiple of 8 bytes #[must_use] -pub fn decrypt_ecb(_data: &[u8], _key: &[u8; 8]) -> Vec { +pub fn decrypt_ecb(data: &[u8], key: &[u8; 8]) -> Vec { todo!() } #[cfg(test)] mod tests { + use crate::constants::S_BOXES; + use super::*; use claims::assert_le; use rand::random; @@ -104,7 +132,7 @@ mod tests { const TEST_CIPHERTEXT: u64 = 0x85E813540F0AB405; impl DES { - fn apply_sboxes(&self, _input: u64) -> u32 { + fn apply_sboxes(&self, input: u64) -> u32 { // Implementation for testing S-boxes in isolation // Return 32-bit result after 8 S-boxes todo!() @@ -230,7 +258,6 @@ mod tests { #[test] fn sbox_subsitution() { - let des = des_instance(); let sbox_tests = [ // (box_idx, 6-bit input, expected 4-bit output) (0, 0b000000, 14), // S1: 00 0000 -> row 0, col 0 -> 14 @@ -242,7 +269,7 @@ mod tests { for (box_idx, input, expected) in sbox_tests { let row = (input & 1) | ((input >> 4) & 0x2); let col = (input >> 1) & 0xF; - let val = des._s_boxes[box_idx][row as usize][col as usize]; + let val = S_BOXES[box_idx][row as usize][col as usize]; assert_eq!( val, @@ -326,7 +353,7 @@ mod tests { #[test] #[should_panic(expected = "Invalid key size")] fn invalid_key_size() { - DES::new(0); + let _ = DES::new(0); } #[test] @@ -336,7 +363,7 @@ mod tests { let start = Instant::now(); for _ in 0..10000 { - des.encrypt(plaintext); + let _ = des.encrypt(plaintext); } let duration = start.elapsed();