Sachy's crypto scheme lmao #13

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Cargo.lock

Cargo.toml

sachy-crypto

Cargo.toml

README.md

src

lib.rs

Cargo.lock

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Cargo.toml

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sachy-crypto/Cargo.toml

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sachy-crypto/README.md

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sachy-crypto/src/lib.rs

··· 1 1 #![no_std] 2 2 3 - use core::ops::AddAssign; 3 + use core::ops::{AddAssign, BitXor}; 4 4 5 5 use chacha20poly1305::{ 6 6 AeadInOut, ChaCha20Poly1305, KeyInit, ··· 47 47 Server, 48 48 } 49 49 50 + impl From<Role> for u8 { 51 + fn from(value: Role) -> Self { 52 + match value { 53 + Role::Client => 0, 54 + Role::Server => 1, 55 + } 56 + } 57 + } 58 + 59 + impl BitXor for Role { 60 + type Output = u8; 61 + 62 + fn bitxor(self, rhs: Self) -> u8 { 63 + u8::from(self) ^ u8::from(rhs) 64 + } 65 + } 66 + 50 67 impl EncapsulatedPublicKey { 51 68 pub fn serialize(&self) -> Sec1Point { 52 69 self.0.to_sec1_point(true) ··· 140 157 let counter = self.counter.to_be_bytes(); 141 158 142 159 self.transport.encrypt_in_place( 143 - &self.transport.mix_nonce(&counter, true), 160 + &self.transport.mix_nonce(&counter, Role::Client), 144 161 &counter, 145 162 msg, 146 163 )?; ··· 167 184 let counter = self.counter.to_be_bytes(); 168 185 169 186 self.transport.decrypt_in_place( 170 - &self.transport.mix_nonce(&counter, false), 187 + &self.transport.mix_nonce(&counter, Role::Server), 171 188 &counter, 172 189 msg, 173 190 )?; ··· 263 280 ) 264 281 } 265 282 266 - fn mix_nonce(&self, position: &[u8; 8], send: bool) -> aead::Nonce<ChaCha20Poly1305> { 283 + fn mix_nonce(&self, position: &[u8; 8], send: Role) -> aead::Nonce<ChaCha20Poly1305> { 267 284 let mut trump = aead::Nonce::<ChaCha20Poly1305>::default(); 268 285 269 - let epstein = match (self.role, send) { 270 - (Role::Client, true) | (Role::Server, false) => &self.client, 271 - (Role::Server, true) | (Role::Client, false) => &self.server, 286 + let switch = self.role ^ send; 287 + 288 + // Role switch allows toggling which nonce to use for encrypting/decrypting 289 + // Callee ROLE XOR Transport ROLE selects either same or other nonce context, 290 + // SAME (0) for sending, OTHER (1) for receiving 291 + let epstein = if switch.ct_eq(&0).into() { 292 + &self.client 293 + } else { 294 + &self.server 272 295 }; 273 296 274 297 let (head, tail) = trump.split_at_mut(position.len());

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Sachy's crypto scheme lmao

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