oprf/protocol/
configuration.rs

1//! ## 3.1. Configuration
2
3use hacspec_lib::i2osp;
4
5///  Each of the three protocol variants are identified with a one-byte
6///    value (in hexadecimal):
7///
8/// | Mode      | Value |
9/// |-----------|-------|
10/// | modeOPRF  | 0x00  |
11/// | modeVOPRF | 0x01  |
12/// | modePOPRF | 0x02  |
13/// |           |       |
14/// | modecoPRF | 0x03  |
15///
16/// **Note:** `modecoPRF` is not part of the original draft document, but belongs to our Convertible OPRF extension.
17#[allow(non_camel_case_types)]
18pub enum ModeID {
19    modeOPRF = 0x00,
20    modeVOPRF = 0x01,
21    modePOPRF = 0x02,
22    modecoPRF = 0x03,
23}
24
25impl From<u32> for ModeID {
26    fn from(value: u32) -> Self {
27        match value {
28            0 => ModeID::modeOPRF,
29            1 => ModeID::modeVOPRF,
30            2 => ModeID::modePOPRF,
31            3 => ModeID::modecoPRF,
32            _ => panic!("Invalid ModeID."),
33        }
34    }
35}
36
37/// Additionally, each protocol variant is instantiated with a
38/// ciphersuite, or suite.  Each ciphersuite is identified with an ASCII
39/// string identifier, referred to as identifier; see Section 4 for the
40/// set of initial ciphersuite values.
41///
42/// The mode and ciphersuite identifier values are combined to create a
43/// "context string" used throughout the protocol with the following
44/// function:
45///
46/// ```text
47///    def CreateContextString(mode, identifier):
48///      return "OPRFV1-" || I2OSP(mode, 1) || "-" || identifier
49/// ```
50pub fn create_context_string(mode: ModeID, identifier: &[u8]) -> Vec<u8> {
51    let mut res = b"OPRFV1-".to_vec(); // "OPRVV1-"
52    res.extend_from_slice(&i2osp(mode as usize, 1)); //    || I2OSP(mode, 1)
53    res.extend_from_slice(b"-"); //    || "-"
54    res.extend_from_slice(identifier); //    || identifier
55
56    res
57}
oprf/protocol/configuration.rs

oprf/protocol/
configuration.rs
