crypto: add in secp256k1 support (#5500)

Secp256k1 was removed in the protobuf migration, this pr adds it back in order to provide this functionality for users (band)

Closes: #5495

.markdownlintignore

@@ -1,5 +1,6 @@
 docs/node_modules
 CHANGELOG.md
 docs/architecture/*
+crypto/secp256k1/**
 scripts/*
 .github

CHANGELOG.md

@@ -51,7 +51,6 @@ Friendly reminder, we have a [bug bounty program](https://hackerone.com/tendermi
     - [evidence] [\#5319](https://github.com/tendermint/tendermint/issues/5319) Remove Amnesia & potentialAmnesia evidence types and removed POLC. (@marbar3778)
     - [evidence] [\#5361](https://github.com/tendermint/tendermint/pull/5361) Add LightClientAttackEvidence and change evidence interface (@cmwaters)
     - [params] [\#5319](https://github.com/tendermint/tendermint/issues/5319) Remove `ProofofTrialPeriod` from evidence params (@marbar3778)
-    - [crypto/secp256k1] [\#5280](https://github.com/tendermint/tendermint/issues/5280) `secp256k1` has been removed from the Tendermint repo. (@marbar3778)
     - [light] [\#5347](https://github.com/tendermint/tendermint/issues/5347) `NewClient`, `NewHTTPClient`, `VerifyHeader` and `VerifyLightBlockAtHeight` now accept `context.Context` as 1st param (@melekes)
     - [state] [\#5348](https://github.com/tendermint/tendermint/issues/5348) Define an Interface for the state store. (@marbar3778)
 

UPGRADING.md

@@ -10,63 +10,63 @@ the encoding format (see "Protocol Buffers," below) and the block header (see "B
 
 ### ABCI Changes
 
-* New ABCI methods (`ListSnapshots`, `LoadSnapshotChunk`, `OfferSnapshot`, and `ApplySnapshotChunk`) 
-  were added to support the new State Sync feature. 
-  Previously, syncing a new node to a preexisting network could take days; but with State Sync, 
-  new nodes are able to join a network in a matter of seconds. 
-  Read [the spec](https://docs.tendermint.com/master/spec/abci/apps.html#state-sync) 
-  if you want to learn more about State Sync, or if you'd like your application to use it. 
-  (If you don't want to support State Sync in your application, you can just implement these new 
-  ABCI methods as no-ops, leaving them empty.) 
-
-* `KV.Pair` has been replaced with `abci.EventAttribute`. The `EventAttribute.Index` field 
+* New ABCI methods (`ListSnapshots`, `LoadSnapshotChunk`, `OfferSnapshot`, and `ApplySnapshotChunk`)
+  were added to support the new State Sync feature.
+  Previously, syncing a new node to a preexisting network could take days; but with State Sync,
+  new nodes are able to join a network in a matter of seconds.
+  Read [the spec](https://docs.tendermint.com/master/spec/abci/apps.html#state-sync)
+  if you want to learn more about State Sync, or if you'd like your application to use it.
+  (If you don't want to support State Sync in your application, you can just implement these new
+  ABCI methods as no-ops, leaving them empty.)
+
+* `KV.Pair` has been replaced with `abci.EventAttribute`. The `EventAttribute.Index` field
   allows ABCI applications to dictate which events should be indexed.
 
-* The blockchain can now start from an arbitrary initial height, 
+* The blockchain can now start from an arbitrary initial height,
   provided to the application via `RequestInitChain.InitialHeight`.
 
-* ABCI evidence type is now an enum with two recognized types of evidence: 
-  `DUPLICATE_VOTE` and `LIGHT_CLIENT_ATTACK`. 
-  Applications should be able to handle these evidence types 
+* ABCI evidence type is now an enum with two recognized types of evidence:
+  `DUPLICATE_VOTE` and `LIGHT_CLIENT_ATTACK`.
+  Applications should be able to handle these evidence types
   (i.e., through slashing or other accountability measures).
 
-* The [`PublicKey` type](https://github.com/tendermint/tendermint/blob/master/proto/tendermint/crypto/keys.proto#L13-L15) 
-  (used in ABCI as part of `ValidatorUpdate`) now uses a `oneof` protobuf type. 
-  Note that since Tendermint only supports ed25519 validator keys, there's only one 
+* The [`PublicKey` type](https://github.com/tendermint/tendermint/blob/master/proto/tendermint/crypto/keys.proto#L13-L15)
+  (used in ABCI as part of `ValidatorUpdate`) now uses a `oneof` protobuf type.
+  Note that since Tendermint only supports ed25519 validator keys, there's only one
   option in the `oneof`.  For more, see "Protocol Buffers," below.
 
-* The field `Proof`, on the ABCI type `ResponseQuery`, is now named `ProofOps`. 
-  For more, see "Crypto," below. 
+* The field `Proof`, on the ABCI type `ResponseQuery`, is now named `ProofOps`.
+  For more, see "Crypto," below.
 
 ### P2P Protocol
 
 The default codec is now proto3, not amino. The schema files can be found in the `/proto`
-directory. For more, see "Protobuf," below. 
+directory. For more, see "Protobuf," below.
 
 ### Blockchain Protocol
 
-* `Header#LastResultsHash` previously was the root hash of a Merkle tree built from `ResponseDeliverTx(Code, Data)` responses. 
+* `Header#LastResultsHash` previously was the root hash of a Merkle tree built from `ResponseDeliverTx(Code, Data)` responses.
   As of 0.34,`Header#LastResultsHash` is now the root hash of a Merkle tree built from:
     * `BeginBlock#Events`
     * Root hash of a Merkle tree built from `ResponseDeliverTx(Code, Data,
       GasWanted, GasUsed, Events)` responses
     * `BeginBlock#Events`
 
 * Merkle hashes of empty trees previously returned nothing, but now return the hash of an empty input,
-  to conform with [RFC-6962](https://tools.ietf.org/html/rfc6962). 
+  to conform with [RFC-6962](https://tools.ietf.org/html/rfc6962).
   This mainly affects `Header#DataHash`, `Header#LastResultsHash`, and
   `Header#EvidenceHash`, which are often empty. Non-empty hashes can also be affected, e.g. if their
   inputs depend on other (empty) Merkle hashes, giving different results.
 
 ### Transaction Indexing
 
-Tendermint now relies on the application to tell it which transactions to index. This means that 
-in the `config.toml`, generated by Tendermint, there is no longer a way to specify which 
+Tendermint now relies on the application to tell it which transactions to index. This means that
+in the `config.toml`, generated by Tendermint, there is no longer a way to specify which
 transactions to index. `tx.height` & `tx.hash` will always be indexed when using the `kv` indexer.
 
-Applications must now choose to either a) enable indexing for all transactions, or 
+Applications must now choose to either a) enable indexing for all transactions, or
 b) allow node operators to decide which transactions to index.
-Applications can notify Tendermint to index a specific transaction by setting 
+Applications can notify Tendermint to index a specific transaction by setting
 `Index: bool` to `true` in the Event Attribute:
 
 ```go
@@ -82,19 +82,19 @@ Applications can notify Tendermint to index a specific transaction by setting
 
 ### Protocol Buffers
 
-Tendermint 0.34 replaces Amino with Protocol Buffers for encoding. 
-This migration is extensive and results in a number of changes, however, 
+Tendermint 0.34 replaces Amino with Protocol Buffers for encoding.
+This migration is extensive and results in a number of changes, however,
 Tendermint only uses the types generated from Protocol Buffers for disk and
-wire serialization. 
+wire serialization.
 **This means that these changes should not affect you as a Tendermint user.**
 
 However, Tendermint users and contributors may note the following changes:
 
-* Directory layout changes: All proto files have been moved under one directory, `/proto`. 
-  This is in line with the recommended file layout by [Buf](https://buf.build).  
+* Directory layout changes: All proto files have been moved under one directory, `/proto`.
+  This is in line with the recommended file layout by [Buf](https://buf.build).
   For more, see the [Buf documentation](https://buf.build/docs/lint-checkers#file_layout).
-* ABCI Changes: As noted in the "ABCI Changes" section above, the `PublicKey` type now uses 
-  a `oneof` type. 
+* ABCI Changes: As noted in the "ABCI Changes" section above, the `PublicKey` type now uses
+  a `oneof` type.
 
 For more on the Protobuf changes, please see our [blog post on this migration](https://medium.com/tendermint/tendermint-0-34-protocol-buffers-and-you-8c40558939ae).
 
@@ -114,30 +114,27 @@ Tendermint 0.34 includes new and updated consensus parameters.
 
 #### Keys
 
-* Keys no longer include a type prefix. For example, ed25519 pubkeys have been renamed from 
-  `PubKeyEd25519` to `PubKey`. This reduces stutter (e.g., `ed25519.PubKey`). 
+* Keys no longer include a type prefix. For example, ed25519 pubkeys have been renamed from
+  `PubKeyEd25519` to `PubKey`. This reduces stutter (e.g., `ed25519.PubKey`).
 * Keys are now byte slices (`[]byte`) instead of byte arrays (`[<size>]byte`).
-* The multisig functionality that was previously in Tendermint now has 
-  a new home within the Cosmos SDK: 
+* The multisig functionality that was previously in Tendermint now has
+  a new home within the Cosmos SDK:
   [`cosmos/cosmos-sdk/types/multisig`](https://github.com/cosmos/cosmos-sdk/blob/master/crypto/types/multisig/multisignature.go).
-* Similarly, secp256k1 has been removed from the Tendermint repo. 
-  There is still [a secp256k1 implementation in the Cosmos SDK](https://github.com/cosmos/cosmos-sdk/tree/443e0c1f89bd3730a731aea30453bd732f7efa35/crypto/keys/secp256k1), 
-  and we recommend you use that package for all your secp256k1 needs.
 
 #### `merkle` Package
 
 * `SimpleHashFromMap()` and `SimpleProofsFromMap()` were removed.
-* The prefix `Simple` has been removed. (For example, `SimpleProof` is now called `Proof`.) 
-* All protobuf messages have been moved to the `/proto` directory. 
-* The protobuf message `Proof` that contained multiple ProofOp's has been renamed to `ProofOps`. 
-  As noted above, this affects the ABCI type `ResponseQuery`: 
+* The prefix `Simple` has been removed. (For example, `SimpleProof` is now called `Proof`.)
+* All protobuf messages have been moved to the `/proto` directory.
+* The protobuf message `Proof` that contained multiple ProofOp's has been renamed to `ProofOps`.
+  As noted above, this affects the ABCI type `ResponseQuery`:
   The field that was named Proof is now named `ProofOps`.
 * `HashFromByteSlices` and `ProofsFromByteSlices` now return a hash for empty inputs, to conform with
   [RFC-6962](https://tools.ietf.org/html/rfc6962).
 
 ### `libs` Package
 
-The `bech32` package has moved to the Cosmos SDK: 
+The `bech32` package has moved to the Cosmos SDK:
 [`cosmos/cosmos-sdk/types/bech32`](https://github.com/cosmos/cosmos-sdk/tree/4173ea5ebad906dd9b45325bed69b9c655504867/types/bech32).
 
 ### CLI
@@ -147,37 +144,37 @@ See [the docs](https://docs.tendermint.com/master/tendermint-core/light-client-p
 
 ### Light Client
 
-We have a new, rewritten light client! You can 
+We have a new, rewritten light client! You can
 [read more](https://medium.com/tendermint/everything-you-need-to-know-about-the-tendermint-light-client-f80d03856f98)
-about the justifications and details behind this change. 
+about the justifications and details behind this change.
 
 Other user-relevant changes include:
 
 * The old `lite` package was removed; the new light client uses the `light` package.
-* The `Verifier` was broken up into two pieces: 
-    * Core verification logic (pure `VerifyX` functions) 
+* The `Verifier` was broken up into two pieces:
+    * Core verification logic (pure `VerifyX` functions)
     * `Client` object, which represents the complete light client
-* The RPC client can be found in the `/rpc` directory. 
+* The RPC client can be found in the `/rpc` directory.
 * The HTTP(S) proxy is located in the `/proxy` directory.
 
 ### `state` Package
 
 * A new field `State.InitialHeight` has been added to record the initial chain height, which must be `1`
   (not `0`) if starting from height `1`. This can be configured via the genesis field `initial_height`.
-* The `state` package now has a `Store` interface. All functions in 
-  [state/store.go](https://github.com/tendermint/tendermint/blob/56911ee35298191c95ef1c7d3d5ec508237aaff4/state/store.go#L42-L42) 
+* The `state` package now has a `Store` interface. All functions in
+  [state/store.go](https://github.com/tendermint/tendermint/blob/56911ee35298191c95ef1c7d3d5ec508237aaff4/state/store.go#L42-L42)
   are now part of the interface. The interface returns errors on all methods and can be used by calling `state.NewStore(dbm.DB)`.
 
 ### `privval` Package
 
 All requests are now accompanied by the chain ID from the network.
-This is a optional field and can be ignored by key management systems. 
+This is a optional field and can be ignored by key management systems.
 It is recommended to check the chain ID if using the same key management system for multiple chains.
 
 ### RPC
 
 `/unsafe_start_cpu_profiler`, `/unsafe_stop_cpu_profiler` and
-`/unsafe_write_heap_profile` were removed. 
+`/unsafe_write_heap_profile` were removed.
 For profiling, please use the pprof server, which can
 be enabled through `--rpc.pprof_laddr=X` flag or `pprof_laddr=X` config setting
 in the rpc section.

abci/example/kvstore/persistent_kvstore.go

@@ -243,11 +243,11 @@ func (app *PersistentKVStoreApplication) execValidatorTx(tx []byte) types.Respon
 
 // add, update, or remove a validator
 func (app *PersistentKVStoreApplication) updateValidator(v types.ValidatorUpdate) types.ResponseDeliverTx {
-	key := []byte("val:" + string(v.PubKey.GetEd25519()))
 	pubkey, err := cryptoenc.PubKeyFromProto(v.PubKey)
 	if err != nil {
 		panic(fmt.Errorf("can't decode public key: %w", err))
 	}
+	key := []byte("val:" + string(pubkey.Bytes()))
 
 	if v.Power == 0 {
 		// remove validator

crypto/ed25519/ed25519.go

@@ -31,7 +31,7 @@ const (
 	// private key representations used by RFC 8032.
 	SeedSize = 32
 
-	keyType = "ed25519"
+	KeyType = "ed25519"
 )
 
 func init() {
@@ -93,7 +93,7 @@ func (privKey PrivKey) Equals(other crypto.PrivKey) bool {
 }
 
 func (privKey PrivKey) Type() string {
-	return keyType
+	return KeyType
 }
 
 // GenPrivKey generates a new ed25519 private key.
@@ -159,7 +159,7 @@ func (pubKey PubKey) String() string {
 }
 
 func (pubKey PubKey) Type() string {
-	return keyType
+	return KeyType
 }
 
 func (pubKey PubKey) Equals(other crypto.PubKey) bool {

crypto/encoding/codec.go

@@ -5,13 +5,15 @@ import (
 
 	"github.com/tendermint/tendermint/crypto"
 	"github.com/tendermint/tendermint/crypto/ed25519"
+	"github.com/tendermint/tendermint/crypto/secp256k1"
 	"github.com/tendermint/tendermint/libs/json"
 	pc "github.com/tendermint/tendermint/proto/tendermint/crypto"
 )
 
 func init() {
 	json.RegisterType((*pc.PublicKey)(nil), "tendermint.crypto.PublicKey")
 	json.RegisterType((*pc.PublicKey_Ed25519)(nil), "tendermint.crypto.PublicKey_Ed25519")
+	json.RegisterType((*pc.PublicKey_Secp256K1)(nil), "tendermint.crypto.PublicKey_Secp256K1")
 }
 
 // PubKeyToProto takes crypto.PubKey and transforms it to a protobuf Pubkey
@@ -24,6 +26,12 @@ func PubKeyToProto(k crypto.PubKey) (pc.PublicKey, error) {
 				Ed25519: k,
 			},
 		}
+	case secp256k1.PubKey:
+		kp = pc.PublicKey{
+			Sum: &pc.PublicKey_Secp256K1{
+				Secp256K1: k,
+			},
+		}
 	default:
 		return kp, fmt.Errorf("toproto: key type %v is not supported", k)
 	}
@@ -41,6 +49,14 @@ func PubKeyFromProto(k pc.PublicKey) (crypto.PubKey, error) {
 		pk := make(ed25519.PubKey, ed25519.PubKeySize)
 		copy(pk, k.Ed25519)
 		return pk, nil
+	case *pc.PublicKey_Secp256K1:
+		if len(k.Secp256K1) != secp256k1.PubKeySize {
+			return nil, fmt.Errorf("invalid size for PubKeyEd25519. Got %d, expected %d",
+				len(k.Secp256K1), secp256k1.PubKeySize)
+		}
+		pk := make(secp256k1.PubKey, secp256k1.PubKeySize)
+		copy(pk, k.Secp256K1)
+		return pk, nil
 	default:
 		return nil, fmt.Errorf("fromproto: key type %v is not supported", k)
 	}