src: cjdns

src/centrifuge/cjdns.rs

@@ -0,0 +1,48 @@
+use crate::structs::{cjdns, CentrifugeError};
+use nom::number::complete::be_u16;
+use nom::bytes::complete::{tag, take};
+
+const BEACON_PASSWORD_LEN: usize = 20;
+const BEACON_PUBKEY_LEN: usize = 32;
+
+
+fn cjdns_eth_header(input: &[u8]) -> nom::IResult<&[u8], cjdns::CjdnsEthPkt> {
+    let (input, (
+        _version,
+        _zero,
+        _length,
+        _fc00,
+        _padding,
+        version,
+        password,
+        pubkey,
+    )) = nom::sequence::tuple((
+        tag(b"\x00"),
+        tag(b"\x00"),
+        be_u16,
+        tag(b"\xfc\x00"),
+        take(2usize),
+
+        be_u16,
+        take(BEACON_PASSWORD_LEN),
+        take(BEACON_PUBKEY_LEN),
+    ))(input)?;
+
+    Ok((input, cjdns::CjdnsEthPkt {
+        version,
+        password: password.to_vec(),
+        pubkey: pubkey.to_vec(),
+    }))
+}
+
+pub fn parse(remaining: &[u8]) -> Result<cjdns::CjdnsEthPkt, CentrifugeError> {
+    if let Ok((remaining, cjdns_eth_hdr)) = cjdns_eth_header(remaining) {
+        if remaining.is_empty() {
+            Ok(cjdns_eth_hdr)
+        } else {
+            Err(CentrifugeError::InvalidPacket)
+        }
+    } else {
+        Err(CentrifugeError::InvalidPacket)
+    }
+}