use an address length limit compatible with ibc-go

[dynst]

ibc-go 8.0 added length validation that an address is a 2048 byte string or smaller - before that there was no maximum length. Make the faucet's isValidAddress function match it.

https://github.com/cosmos/ibc-go/blob/904047fc783f43ab87e3121c2c0c47ef7a6b075e/modules/apps/transfer/types/msgs.go#L16

cosmos/ibc-go#4859 (comment)

[webmaster128]

Why do you want to do this change? 2048 is just a safety measure to avoid too much data.

We can set a limit in fromBech32 if that is needed.

As address lengths only 32 and 20 bytes is used in practice. So we need different data lengths for something?

[dynst]

As address lengths only 32 and 20 bytes is used in practice.

That hasn't been true for a while now; chains that use novel cryptographic algorithms use longer lengths, like Penumbra. There was a whole compatibility issue with Noble enforcing a maximum address string length of 90 bytes (because they used a BIP-172 compliant bech32 library).

circlefin/noble-fiattokenfactory#32

Penumbra has both Bech32m addresses and Bech32 ones for compatibility, and Bech32 addresses can be 150 characters long (e.g. penumbracompat11ld2kghffzgwq4597ejpgmnwxa7ju0cndytuxtsjh8qhjyfuwq0rwd5flnw4a3fgclw7m5puh50nskn2c88flhne2hzchnpxru609d5wgmqqvhdf0sy2tktqfcm2p2tmxeuc86n).

https://forum.penumbra.zone/t/usdc-transfers-temporarily-affected-by-noble-chain-upgrade/129

https://protocol.penumbra.zone/main/addresses_keys/addresses.html#address-encodings

[webmaster128]

I see. Then we can fix it like this:

diff --git a/packages/faucet/src/addresses.spec.ts b/packages/faucet/src/addresses.spec.ts
index 639f52970d..c5c2725425 100644
--- a/packages/faucet/src/addresses.spec.ts
+++ b/packages/faucet/src/addresses.spec.ts
@@ -11,6 +11,12 @@ describe("isValidAddress", () => {
     );
   });
 
+  it("accepts an Penumbra address", () => {
+    expect(isValidAddress("penumbracompat11ld2kghffzgwq4597ejpgmnwxa7ju0cndytuxtsjh8qhjyfuwq0rwd5flnw4a3fgclw7m5puh50nskn2c88flhne2hzchnpxru609d5wgmqqvhdf0sy2tktqfcm2p2tmxeuc86n", "penumbracompat1")).toBe(
+      true,
+    );
+  });
+
   it("rejects an invalid address", () => {
     expect(isValidAddress("cosmos1fail", "cosmos")).toBe(false);
   });
diff --git a/packages/faucet/src/addresses.ts b/packages/faucet/src/addresses.ts
index e336322689..36eeb986b7 100644
--- a/packages/faucet/src/addresses.ts
+++ b/packages/faucet/src/addresses.ts
@@ -1,12 +1,16 @@
 import { fromBech32 } from "@cosmjs/encoding";
 
+// Penumbra are up to 150 chars. ibg-go has a limit of 2048.
+// See https://github.com/cosmos/cosmjs/pull/1674
+const lengthLimit = 512;
+
 export function isValidAddress(input: string, requiredPrefix: string): boolean {
   try {
-    const { prefix, data } = fromBech32(input);
+    const { prefix, data } = fromBech32(input, lengthLimit);
     if (prefix !== requiredPrefix) {
       return false;
     }
-    return data.length >= 20 && data.length <= 32;
+    return data.length >= 20 && data.length <= 128;
   } catch {
     return false;
   }

[webmaster128]

Merged as part of #1683. Sorry, I missed the last commit now. But did not have rights to push to the PR for some reason.

Thanks!