Seth: namehash

dapptools/src/seth.rs

@@ -57,6 +57,9 @@ async fn main() -> eyre::Result<()> {
             let provider = Provider::try_from(rpc_url)?;
             println!("{}", Seth::new(provider).chain_id().await?);
         }
+        Subcommands::Namehash { name } => {
+            println!("{}", SimpleSeth::namehash(&name));
+        }
         Subcommands::SendTx { eth, to, sig, args } => {
             let provider = Provider::try_from(eth.rpc_url.as_str())?;
             if let Some(signer) = eth.signer()? {

dapptools/src/seth_opts.rs

@@ -63,6 +63,9 @@ pub enum Subcommands {
         #[structopt(long, env = "ETH_RPC_URL")]
         rpc_url: String,
     },
+    #[structopt(name = "namehash")]
+    #[structopt(about = "returns ENS namehash of provided name")]
+    Namehash { name: String },
     #[structopt(name = "send")]
     #[structopt(about = "Publish a transaction signed by <from> to call <to> with <data>")]
     SendTx {

seth/src/lib.rs

@@ -1,7 +1,7 @@
 //! Seth
 //!
 //! TODO
-use ethers_core::{types::*, utils};
+use ethers_core::{types::*, utils::{self, keccak256}};
 use ethers_providers::{Middleware, PendingTransaction};
 use eyre::Result;
 use rustc_hex::ToHex;
@@ -343,6 +343,39 @@ impl SimpleSeth {
         // need to use the Debug implementation
         Ok(format!("{:?}", H256::from_str(&padded)?))
     }
+
+    /// Converts ENS names to their namehash representation
+    /// [Namehash reference](https://docs.ens.domains/contract-api-reference/name-processing#hashing-names)
+    /// [namehash-rust reference](https://github.com/InstateDev/namehash-rust/blob/master/src/lib.rs)
+    ///
+    /// ```
+    /// use seth::SimpleSeth as Seth;
+    ///
+    /// assert_eq!(Seth::namehash(""), "0x0000000000000000000000000000000000000000000000000000000000000000");
+    /// assert_eq!(Seth::namehash("eth"), "0x93cdeb708b7545dc668eb9280176169d1c33cfd8ed6f04690a0bcc88a93fc4ae");
+    /// assert_eq!(Seth::namehash("foo.eth"), "0xde9b09fd7c5f901e23a3f19fecc54828e9c848539801e86591bd9801b019f84f");
+    /// assert_eq!(Seth::namehash("sub.foo.eth"), "0x500d86f9e663479e5aaa6e99276e55fc139c597211ee47d17e1e92da16a83402");
+    /// ```
+    pub fn namehash(ens: &str) -> String {
+        let mut node = vec![0u8; 32];
+
+        if !ens.is_empty() {
+            let ens_lower = ens.to_lowercase();
+            let mut labels: Vec<&str> = ens_lower.split(".").collect();
+            labels.reverse();
+
+            for label in labels {
+                let mut label_hash = keccak256(label.as_bytes());
+                node.append(&mut label_hash.to_vec());
+
+                label_hash = keccak256(node.as_slice());
+                node = label_hash.to_vec();
+            }
+        }
+
+        let namehash: String = node.to_hex();
+        format!("0x{}", namehash)
+    }
 }
 
 fn strip_0x(s: &str) -> &str {