Feat/support cosmos evm #1814

chiulam · 2025-08-27T08:33:46Z

Add Ethereum secp256k1 address support

Summary

This PR adds support for Ethereum-style secp256k1 addresses in CosmJS, enabling compatibility with Ethereum-derived address formats in Cosmos chains.

Changes

Added rawEthSecp256k1PubkeyToRawAddress() function to convert compressed Ethereum secp256k1 public keys to raw addresses
Updated pubkeyToRawAddress() to handle EthSecp256k1Pubkey type
Added support for keccak256 hashing for Ethereum address derivation
Imported necessary dependencies (keccak256, Secp256k1) from @cosmjs/crypto

Technical Details

Ethereum addresses are derived by taking the keccak256 hash of the uncompressed public key (without the 0x04 prefix) and using the last 20 bytes
The implementation follows Ethereum's address derivation standard while maintaining compatibility with existing Cosmos address formats
Added proper validation for compressed public key length (33 bytes)

Breaking Changes

None - this is a purely additive change that maintains backward compatibility.

- Implemented encoding for EthSecp256k1 public keys in amino format. - Added functions to encode and decode EthSecp256k1 signatures. - Updated pubkey type definitions to include EthSecp256k1. - Enhanced signing clients to handle EthSecp256k1 accounts. - Created DirectEthSecp256k1HdWallet for managing EthSecp256k1 keypairs. - Added tests for DirectEthSecp256k1HdWallet and DirectEthSecp256k1Wallet functionalities.

…y encoding

…key encoding

BigtoC · 2025-08-27T08:44:19Z

packages/cosmwasm-stargate/src/signingcosmwasmclient.ts

    }
-    const pubkey = encodePubkey(encodeSecp256k1Pubkey(accountFromSigner.pubkey));
+    let pubkey;
+    if (accountFromSigner.algo == "eth_secp256k1" || accountFromSigner.algo == "ethsecp256k1" ) {


It would be good to add a comment here to explain why you need eth_secp256k1 and ethsecp256k1.

packages/stargate/src/signingstargateclient.ts

…nd update pubkey encoding in clients

Cordtus · 2025-08-27T14:10:57Z

packages/amino/src/pubkeys.ts

+}
+
+export function isEthSecp256k1Pubkey(pubkey: Pubkey): pubkey is EthSecp256k1Pubkey {
+  return (pubkey as EthSecp256k1Pubkey).type === "os/PubKeyEthSecp256k1";


Is this a typo? os/PubKeyEthSecp256k1

It comes from https://github.com/cosmos/evm/blob/main/crypto/ethsecp256k1/ethsecp256k1.go#L36

Thanks.

What does "os/" mean in this context?

Maybe a legacy from evmOS?

Seems so. That is the earliest example of it I can see publicly within github.

dynst · 2025-08-30T19:04:31Z

packages/amino/src/signerutils.ts

+ * @param account The account data from a signer
+ * @returns The amino-encoded pubkey (EthSecp256k1Pubkey or Secp256k1Pubkey)
+ */
+export function getAminoPubkey(account: AccountData): any {


There's no good reason for the return type here to be any.

I have updated the code. Please have a look.

dynst

This function isn't updated:

cosmjs/packages/amino/src/pubkeys.ts

Lines 55 to 58 in 67234a8

    
           export function isSinglePubkey(pubkey: Pubkey): pubkey is SinglePubkey { 
        
             const singPubkeyTypes: string[] = [pubkeyType.ed25519, pubkeyType.secp256k1, pubkeyType.sr25519]; 
        
             return singPubkeyTypes.includes(pubkey.type); 
        
           }

…nction

…-usages Fix/add missing ethsecp256k1 pubkey usages

BigtoC · 2025-09-02T07:43:43Z

This function isn't updated:

cosmjs/packages/amino/src/pubkeys.ts

Lines 55 to 58 in 67234a8

export function isSinglePubkey(pubkey: Pubkey): pubkey is SinglePubkey {

const singPubkeyTypes: string[] = [pubkeyType.ed25519, pubkeyType.secp256k1, pubkeyType.sr25519];

return singPubkeyTypes.includes(pubkey.type);

}

I have updated the code. Please have a look.

webmaster128

Cool, looks pretty nice. Glad to see that the quality of evm signing imrpoved a lot on the chain side of things which makes it smooth to integrate.

webmaster128 · 2025-10-08T07:29:52Z

packages/amino/src/addresses.ts

  return ripemd160(sha256(pubkeyData));
 }

+export function rawEthSecp256k1PubkeyToRawAddress(pubkeyData: Uint8Array): Uint8Array {


An "raw Eth Secp256k1 Pubkey" is uncompressed by convention. All Ethereum ecosystem uses uncompressed pubkeys. So either the implementation is wrong but maybe it is a question of findung a better name for the function

I am wrong I guess and compressed pubkeys are used consostently in Cosmos, also evm code. Any thoughts on that matter?

I found the codes in cosmos/evmethsecp256k1.go, the PubKey() method returns a 33-byte compressed pubkey.

But when it derives an address, the Address() method first decompresses the pubkey, then uses the uncompressed pubkey to derive an address.

Thanks, that helps. Sounds like a reasonable approach for the Cosmos Stack

webmaster128 · 2025-10-08T07:33:34Z

packages/amino/src/encoding.ts

 // Prefixes listed here: https://github.com/tendermint/tendermint/blob/d419fffe18531317c28c29a292ad7d253f6cafdf/docs/spec/blockchain/encoding.md#public-key-cryptography
 // Last bytes is varint-encoded length prefix
 const pubkeyAminoPrefixSecp256k1 = fromHex("eb5ae987" + "21" /* fixed length */);
+const pubkeyAminoPrefixEthSecp256k1 = fromHex("5D7423DF" + "21" /* fixed length */);


Oh sweet, we now got a new Amino prefix for that? Could you add a reference to any documentation or source code where this is coming from?

This was a major blocker in earlier attempts to add EVM support to CosmJS

Prove pubkeyAminoPrefixEthSecp256k1 is correct

1. Reproduce the existing prefix to prove my method is correct

According to the Amino document, I compute the below result, which matches the existing pubkeyAminoPrefixSecp256k1.

2. Use the same method to compute pubkeyAminoPrefixEthSecp256k1

Wow this document you found there is amazing. I did not know that there was an algorithm for calculating those prefixes. Super nice, thanks!

webmaster128 · 2025-10-08T07:35:57Z

packages/amino/src/pubkeys.ts

+}
+
+export function isEthSecp256k1Pubkey(pubkey: Pubkey): pubkey is EthSecp256k1Pubkey {
+  return (pubkey as EthSecp256k1Pubkey).type === "os/PubKeyEthSecp256k1";


Thanks.

What does "os/" mean in this context?

webmaster128 · 2025-10-08T07:37:21Z

packages/amino/src/pubkeys.ts


+export interface EthSecp256k1Pubkey extends SinglePubkey {
+  readonly type: "os/PubKeyEthSecp256k1";
+  readonly value: string;


Question: is this a compressed or uncompressed encoding of the pubkey? In earlier versions of Ethermint this was uncompressed (but barely documented). Now looking at the code above it seems to be compressed.

webmaster128 · 2025-10-08T07:38:31Z

packages/amino/src/pubkeys.ts

-  secp256k1: "tendermint/PubKeySecp256k1" as const,
  /** @see https://github.com/tendermint/tendermint/blob/v0.33.0/crypto/secp256k1/secp256k1.go#L23 */
+  secp256k1: "tendermint/PubKeySecp256k1" as const,
+  /** @see https://github.com/cosmos/evm/blob/main/crypto/ethsecp256k1/ethsecp256k1.go#L36 */


Suggested change

/** @see https://github.com/cosmos/evm/blob/main/crypto/ethsecp256k1/ethsecp256k1.go#L36 */

/** @see https://github.com/cosmos/evm/blob/v1.0.0-rc2/crypto/ethsecp256k1/ethsecp256k1.go#L35-L36 */

packages/cosmwasm-stargate/src/signingcosmwasmclient.ts

webmaster128 · 2025-10-08T07:46:36Z

packages/proto-signing/src/directethsecp256k1hdwallet.ts

+      data: toBase64(encryptedData),
+    };
+    return JSON.stringify(out);
+  }


Could we please remove all references to kdf/serialize/deserialize from the newly added wallet? I know it is there for consistency but we will remove that functionality sooninsh and don't want new users to start with it. See #1796

I checked, and the serialize/deserialize functions are only referenced in test codes.

webmaster128 · 2025-10-08T07:47:40Z

packages/proto-signing/src/directethsecp256k1wallet.ts

+/**
+ * A wallet that holds a single secp256k1 keypair.
+ *
+ * If you want to work with BIP39 mnemonics and multiple accounts, use DirectSecp256k1HdWallet.


Suggested change

* If you want to work with BIP39 mnemonics and multiple accounts, use DirectSecp256k1HdWallet.

* If you want to work with BIP39 mnemonics and multiple accounts, use DirectEthSecp256k1HdWallet.

webmaster128 · 2025-10-08T07:54:31Z

packages/proto-signing/src/pubkey.ts

      value: Uint8Array.from(CosmosCryptoSecp256k1Pubkey.encode(pubkeyProto).finish()),
    });
+  } else if (isEthSecp256k1Pubkey(pubkey)) {
+    const pubkeyProto = CosmosCryptoSecp256k1Pubkey.fromPartial({


Suggested change

const pubkeyProto = CosmosCryptoSecp256k1Pubkey.fromPartial({

// Note: This code block is hacky because we should use the correct EVM proto type

// https://github.com/cosmos/evm/blob/v1.0.0-rc2/proto/cosmos/evm/crypto/v1/ethsecp256k1/keys.proto#L12-L17.

// However, we do not have that available here or in cosmjs-types yet and the classic secp256k1 pubkey has the same structure except for documentation and annotations:

// https://github.com/cosmos/cosmos-sdk/blob/v0.53.4/proto/cosmos/crypto/secp256k1/keys.proto#L14-L30

//

// Actually this type is so simple we should just have an Anybuf for TS instead of code generation (https://github.com/webmaster128/anybuf)

const pubkeyProto = CosmosCryptoSecp256k1Pubkey.fromPartial({

This just adds a comment, no code change

packages/proto-signing/src/signer.ts

… in tests

…asmclient.ts

…ation

…-update-from-comments

…om-comments Fix/add missing codes and update from comments

dynst · 2025-10-14T21:47:19Z

packages/amino/src/pubkeys.ts

+}
+
+export function isEthSecp256k1Pubkey(pubkey: Pubkey): pubkey is EthSecp256k1Pubkey {
+  return (pubkey as EthSecp256k1Pubkey).type === "os/PubKeyEthSecp256k1";


You should just use pubkey.type here, there's no reason to cast it before the check.

Should we also remove type casting in this line? https://github.com/cosmos/cosmjs/blob/main/packages/amino/src/pubkeys.ts#L24

return (pubkey as Secp256k1Pubkey).type === "tendermint/PubKeySecp256k1";

You're right! #1847

chiulam marked this pull request as draft August 27, 2025 08:34

allthatjazzleo and others added 6 commits August 27, 2025 16:37

feat: add DirectEthSecp256k1 wallet exports to index

36d2e10

feat: add EthSecp256k1Pubkey to pubkeyToRawAddress function

f811448

feat: support both eth_secp256k1 and ethsecp256k1 algorithms in pubke…

c640c39

…y encoding

feat: support ethsecp256k1 algorithm in SigningStargateClient for pub…

a489a7b

…key encoding

refactor: consolidate crypto imports in addresses.ts

ce7e8b9

chiulam force-pushed the feat/support-cosmos-evm branch from 6e044f9 to ce7e8b9 Compare August 27, 2025 08:39

chiulam marked this pull request as ready for review August 27, 2025 08:40

BigtoC reviewed Aug 27, 2025

View reviewed changes

feat: add utility functions for Ethereum secp256k1 account handling a…

2b9d6ac

…nd update pubkey encoding in clients

chiulam requested a review from BigtoC August 27, 2025 09:58

BigtoC approved these changes Aug 27, 2025

View reviewed changes

Cordtus reviewed Aug 27, 2025

View reviewed changes

dynst reviewed Aug 30, 2025

View reviewed changes

dynst suggested changes Aug 30, 2025

View reviewed changes

BigtoC and others added 4 commits September 1, 2025 16:20

feat: add ethsecp256k1 to supported pubkey types in isSinglePubkey fu…

b303742

…nction

feat: add support for ethsecp256k1 pubkey type in encoding

d15842c

chore: Specific getAminoPubkey return type instead of any

8ff0e05

Merge pull request #1 from BigtoC/fix/add-missing-ethsecp256k1-pubkey…

eaa0ebf

…-usages Fix/add missing ethsecp256k1 pubkey usages

webmaster128 reviewed Oct 8, 2025

View reviewed changes

BigtoC added 8 commits October 9, 2025 17:48

test: add encoding and decoding functions for EthSecp256k1 signatures…

54b103c

… in tests

refactor: remove eslint disable for naming convention in signingcosmw…

bbffd36

…asmclient.ts

fix: add missing 'ethsecp256k1' algorithm type in Algo definition

5b4a48a

fix: update ethsecp256k1 references and class name in wallet document…

fada481

…ation

doc: Add comments for the code block

03fa926

rollback .pnp.cjs

17ad7ba

chore: lint fix

5fee884

fix: update getAminoPubkey return type and import missing pubkey types

2949808

BigtoC and others added 3 commits October 9, 2025 18:39

Merge branch 'feat/support-cosmos-evm' into fix/add-missing-codes-and…

e77ae7a

…-update-from-comments

Merge pull request #2 from BigtoC/fix/add-missing-codes-and-update-fr…

5636a48

…om-comments Fix/add missing codes and update from comments

[autofix.ci] apply automated fixes

4a5fd80

dynst reviewed Oct 14, 2025

View reviewed changes

	export function isSinglePubkey(pubkey: Pubkey): pubkey is SinglePubkey {
	const singPubkeyTypes: string[] = [pubkeyType.ed25519, pubkeyType.secp256k1, pubkeyType.sr25519];
	return singPubkeyTypes.includes(pubkey.type);
	}

	/** @see https://github.com/cosmos/evm/blob/main/crypto/ethsecp256k1/ethsecp256k1.go#L36 */
	/** @see https://github.com/cosmos/evm/blob/v1.0.0-rc2/crypto/ethsecp256k1/ethsecp256k1.go#L35-L36 */

	* If you want to work with BIP39 mnemonics and multiple accounts, use DirectSecp256k1HdWallet.
	* If you want to work with BIP39 mnemonics and multiple accounts, use DirectEthSecp256k1HdWallet.

-    const pubkeyProto = CosmosCryptoSecp256k1Pubkey.fromPartial({
+    // Note: This code block is hacky because we should use the correct EVM proto type
+    // https://github.com/cosmos/evm/blob/v1.0.0-rc2/proto/cosmos/evm/crypto/v1/ethsecp256k1/keys.proto#L12-L17.
+    // However, we do not have that available here or in cosmjs-types yet and the classic secp256k1 pubkey has the same structure except for documentation and annotations:
+    // https://github.com/cosmos/cosmos-sdk/blob/v0.53.4/proto/cosmos/crypto/secp256k1/keys.proto#L14-L30
+    //
+    // Actually this type is so simple we should just have an Anybuf for TS instead of code generation (https://github.com/webmaster128/anybuf)
+    const pubkeyProto = CosmosCryptoSecp256k1Pubkey.fromPartial({

Feat/support cosmos evm #1814

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Feat/support cosmos evm #1814

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chiulam commented Aug 27, 2025

Add Ethereum secp256k1 address support

Summary

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Technical Details

Breaking Changes

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BigtoC commented Sep 2, 2025

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BigtoC Oct 9, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Prove pubkeyAminoPrefixEthSecp256k1 is correct

1. Reproduce the existing prefix to prove my method is correct

2. Use the same method to compute pubkeyAminoPrefixEthSecp256k1

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BigtoC Oct 9, 2025 •

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Prove `pubkeyAminoPrefixEthSecp256k1` is correct

2. Use the same method to compute `pubkeyAminoPrefixEthSecp256k1`