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rtc_dtls/handshake/
handshake_message_client_key_exchange.rs

1#[cfg(test)]
2mod handshake_message_client_key_exchange_test;
3
4use super::*;
5
6use byteorder::{BigEndian, WriteBytesExt};
7use std::io::{Read, Write};
8
9#[derive(Clone, Debug, PartialEq, Eq)]
10pub struct HandshakeMessageClientKeyExchange {
11    pub(crate) identity_hint: Vec<u8>,
12    pub(crate) public_key: Vec<u8>,
13}
14
15impl HandshakeMessageClientKeyExchange {
16    pub fn handshake_type(&self) -> HandshakeType {
17        HandshakeType::ClientKeyExchange
18    }
19
20    pub fn size(&self) -> usize {
21        if !self.public_key.is_empty() {
22            1 + self.public_key.len()
23        } else {
24            2 + self.identity_hint.len()
25        }
26    }
27
28    pub fn marshal<W: Write>(&self, writer: &mut W) -> Result<()> {
29        if (!self.identity_hint.is_empty() && !self.public_key.is_empty())
30            || (self.identity_hint.is_empty() && self.public_key.is_empty())
31        {
32            return Err(Error::ErrInvalidClientKeyExchange);
33        }
34
35        if !self.public_key.is_empty() {
36            writer.write_u8(self.public_key.len() as u8)?;
37            writer.write_all(&self.public_key)?;
38        } else {
39            writer.write_u16::<BigEndian>(self.identity_hint.len() as u16)?;
40            writer.write_all(&self.identity_hint)?;
41        }
42
43        Ok(writer.flush()?)
44    }
45
46    pub fn unmarshal<R: Read>(reader: &mut R) -> Result<Self> {
47        let mut data = vec![];
48        reader.read_to_end(&mut data)?;
49
50        // If parsed as PSK return early and only populate PSK Identity Hint
51        let psk_length = ((data[0] as u16) << 8) | data[1] as u16;
52        if data.len() == psk_length as usize + 2 {
53            return Ok(HandshakeMessageClientKeyExchange {
54                identity_hint: data[2..].to_vec(),
55                public_key: vec![],
56            });
57        }
58
59        let public_key_length = data[0] as usize;
60        if data.len() != public_key_length + 1 {
61            return Err(Error::ErrBufferTooSmall);
62        }
63
64        Ok(HandshakeMessageClientKeyExchange {
65            identity_hint: vec![],
66            public_key: data[1..].to_vec(),
67        })
68    }
69}