Add makefile with lint support (#4)

.golangci.yml

@@ -0,0 +1,74 @@
+run:
+  concurrency: 4
+  deadline: 1m
+  issues-exit-code: 1
+  tests: true
+  # build-tags:
+  #   - mytag
+  skip-dirs:
+    - static
+  skip-files:
+    - .*_mock.go
+    - jail/doc.go
+
+output:
+  format: colored-line-number
+  print-issued-lines: true
+  print-linter-name: true
+
+linters-settings:
+  errcheck:
+    check-type-assertions: false
+    check-blank: false
+  govet:
+    check-shadowing: false
+  golint:
+    min-confidence: 0.8
+  gofmt:
+    simplify: true
+  gocyclo:
+    min-complexity: 16
+  maligned:
+    suggest-new: true
+  dupl:
+    threshold: 50
+  goconst:
+    min-len: 3
+    min-occurrences: 2
+  # depguard:
+  #   list-type: blacklist
+  #   include-go-root: false
+  #   packages:
+  #     - github.com/davecgh/go-spew/spew
+
+linters:
+  disable-all: true
+  enable:
+    - deadcode
+    #- depguard
+    - errcheck
+    - gas
+    - goconst
+    - gocyclo
+    - gofmt
+    - golint
+    - govet
+    - ineffassign
+    - interfacer
+    - megacheck
+    - misspell
+    - structcheck
+    - typecheck
+    - unconvert
+    - varcheck
+  fast: false
+
+issues:
+  exclude:
+    - "composite literal uses unkeyed fields" # govet
+#   exclude-use-default: true
+#   max-per-linter: 0
+#   max-same: 0
+#   new: false
+#   new-from-rev: ""
+#   new-from-patch: ""

Makefile

@@ -0,0 +1,59 @@
+.PHONY: help
+
+help: ##@other Show this help
+	@perl -e '$(HELP_FUN)' $(MAKEFILE_LIST)
+
+ifndef GOPATH
+	$(error GOPATH not set. Please set GOPATH and make sure status-go is located at $$GOPATH/src/github.com/status-im/status-go. \
+	For more information about the GOPATH environment variable, see https://golang.org/doc/code.html#GOPATH)
+endif
+
+
+EXPECTED_PATH=$(shell go env GOPATH)/src/github.com/status-im/doubleratchet
+ifneq ($(CURDIR),$(EXPECTED_PATH))
+define NOT_IN_GOPATH_ERROR
+
+Current dir is $(CURDIR), which seems to be different from your GOPATH.
+Please, build status-go from GOPATH for proper build.
+  GOPATH       = $(shell go env GOPATH)
+  Current dir  = $(CURDIR)
+  Expected dir = $(EXPECTED_PATH))
+See https://golang.org/doc/code.html#GOPATH for more info
+
+endef
+$(error $(NOT_IN_GOPATH_ERROR))
+endif
+
+GOBIN=$(dir $(realpath $(firstword $(MAKEFILE_LIST))))build/bin
+GIT_COMMIT := $(shell git rev-parse --short HEAD)
+
+# This is a code for automatic help generator.
+# It supports ANSI colors and categories.
+# To add new item into help output, simply add comments
+# starting with '##'. To add category, use @category.
+GREEN  := $(shell echo "\e[32m")
+WHITE  := $(shell echo "\e[37m")
+YELLOW := $(shell echo "\e[33m")
+RESET  := $(shell echo "\e[0m")
+HELP_FUN = \
+		   %help; \
+		   while(<>) { push @{$$help{$$2 // 'options'}}, [$$1, $$3] if /^([a-zA-Z0-9\-]+)\s*:.*\#\#(?:@([a-zA-Z\-]+))?\s(.*)$$/ }; \
+		   print "Usage: make [target]\n\n"; \
+		   for (sort keys %help) { \
+			   print "${WHITE}$$_:${RESET}\n"; \
+			   for (@{$$help{$$_}}) { \
+				   $$sep = " " x (32 - length $$_->[0]); \
+				   print "  ${YELLOW}$$_->[0]${RESET}$$sep${GREEN}$$_->[1]${RESET}\n"; \
+			   }; \
+			   print "\n"; \
+		   }
+
+setup: lint-install ##@other Prepare project for first build
+
+lint-install:
+	@# The following installs a specific version of golangci-lint, which is appropriate for a CI server to avoid different results from build to build
+	curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | bash -s -- -b $(GOPATH)/bin v1.9.1
+
+lint: ##@other Run linter
+	@echo "lint"
+	@golangci-lint run ./...

chains_test.go

@@ -1,8 +1,9 @@
 package doubleratchet
 
 import (
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 var chainKey = Key{0xeb, 0x8, 0x10, 0x7c, 0x33, 0x54, 0x0, 0x20, 0xe9, 0x4f, 0x6c, 0x84, 0xe4, 0x39, 0x50, 0x5a, 0x2f, 0x60, 0xbe, 0x81, 0xa, 0x78, 0x8b, 0xeb, 0x1e, 0x2c, 0x9, 0x8d, 0x4b, 0x4d, 0xc1, 0x40}

crypto.go

@@ -27,7 +27,7 @@ type DHPair interface {
 	PublicKey() Key
 }
 
-// Keys is any 32-byte key. It's created for the possibility of pretty hex output.
+// Key is any 32-byte key. It's created for the possibility of pretty hex output.
 type Key [32]byte
 
 // Stringer interface compliance.

crypto_test.go

@@ -1,8 +1,9 @@
 package doubleratchet
 
 import (
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestKey_String(t *testing.T) {

default_crypto.go

@@ -19,7 +19,7 @@ import (
 // see function comments for details.
 type DefaultCrypto struct{}
 
-// See the Crypto interface.
+// GenerateDH creates a new Diffie-Hellman key pair.
 func (c DefaultCrypto) GenerateDH() (DHPair, error) {
 	var privKey [32]byte
 	if _, err := io.ReadFull(rand.Reader, privKey[:]); err != nil {
@@ -37,7 +37,8 @@ func (c DefaultCrypto) GenerateDH() (DHPair, error) {
 	}, nil
 }
 
-// See the Crypto interface.
+// DH returns the output from the Diffie-Hellman calculation between
+// the private key from the DH key pair dhPair and the DH public key dbPub.
 func (c DefaultCrypto) DH(dhPair DHPair, dhPub Key) Key {
 	var (
 		dhOut   [32]byte
@@ -48,7 +49,8 @@ func (c DefaultCrypto) DH(dhPair DHPair, dhPub Key) Key {
 	return dhOut
 }
 
-// See the Crypto interface.
+// KdfRK returns a pair (32-byte root key, 32-byte chain key) as the output of applying
+// a KDF keyed by a 32-byte root key rk to a Diffie-Hellman output dhOut.
 func (c DefaultCrypto) KdfRK(rk, dhOut Key) (rootKey, chainKey, headerKey Key) {
 	var (
 		r   = hkdf.New(sha256.New, dhOut[:], rk[:], []byte("rsZUpEuXUqqwXBvSy3EcievAh4cMj6QL"))
@@ -64,7 +66,8 @@ func (c DefaultCrypto) KdfRK(rk, dhOut Key) (rootKey, chainKey, headerKey Key) {
 	return
 }
 
-// See the Crypto interface.
+// KdfCK returns a pair (32-byte chain key, 32-byte message key) as the output of applying
+// a KDF keyed by a 32-byte chain key ck to some constant.
 func (c DefaultCrypto) KdfCK(ck Key) (chainKey Key, msgKey Key) {
 	const (
 		ckInput = 15
@@ -73,11 +76,11 @@ func (c DefaultCrypto) KdfCK(ck Key) (chainKey Key, msgKey Key) {
 
 	h := hmac.New(sha256.New, ck[:])
 
-	h.Write([]byte{ckInput})
+	_, _ = h.Write([]byte{ckInput})
 	copy(chainKey[:], h.Sum(nil))
 	h.Reset()
 
-	h.Write([]byte{mkInput})
+	_, _ = h.Write([]byte{mkInput})
 	copy(msgKey[:], h.Sum(nil))
 
 	return chainKey, msgKey
@@ -101,7 +104,7 @@ func (c DefaultCrypto) Encrypt(mk Key, plaintext, ad []byte) []byte {
 	return append(ciphertext, c.computeSignature(authKey[:], ciphertext, ad)...)
 }
 
-// See the Crypto interface.
+// Decrypt returns the AEAD decryption of ciphertext with message key mk.
 func (c DefaultCrypto) Decrypt(mk Key, authCiphertext, ad []byte) ([]byte, error) {
 	var (
 		l          = len(authCiphertext)
@@ -147,8 +150,8 @@ func (c DefaultCrypto) deriveEncKeys(mk Key) (encKey Key, authKey Key, iv [16]by
 
 func (c DefaultCrypto) computeSignature(authKey, ciphertext, associatedData []byte) []byte {
 	h := hmac.New(sha256.New, authKey)
-	h.Write(associatedData)
-	h.Write(ciphertext)
+	_, _ = h.Write(associatedData)
+	_, _ = h.Write(ciphertext)
 	return h.Sum(nil)
 }
 

default_crypto_test.go

@@ -2,8 +2,9 @@ package doubleratchet
 
 import (
 	"fmt"
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestDhPair(t *testing.T) {

keys_storage_test.go

@@ -1,8 +1,9 @@
 package doubleratchet
 
 import (
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 var (
@@ -28,7 +29,8 @@ func TestKeysStorageInMemory_Put(t *testing.T) {
 	ks := &KeysStorageInMemory{}
 
 	// Act and assert.
-	ks.Put(pubKey1, 0, mk)
+	err := ks.Put(pubKey1, 0, mk)
+	require.NoError(t, err)
 }
 
 func TestKeysStorageInMemory_Count(t *testing.T) {
@@ -58,12 +60,15 @@ func TestKeysStorageInMemory_Flow(t *testing.T) {
 
 	t.Run("delete non-existent pubkey", func(t *testing.T) {
 		// Act and assert.
-		ks.DeletePk(pubKey1)
+		err := ks.DeletePk(pubKey1)
+		require.NoError(t, err)
 	})
 
 	t.Run("put and get existing", func(t *testing.T) {
 		// Act.
-		ks.Put(pubKey1, 0, mk)
+		err := ks.Put(pubKey1, 0, mk)
+		require.NoError(t, err)
+
 		k, ok, err := ks.Get(pubKey1, 0)
 
 		// Assert.
@@ -124,7 +129,9 @@ func TestKeysStorageInMemory_Flow(t *testing.T) {
 
 	t.Run("delete existing message key", func(t *testing.T) {
 		// Act.
-		ks.DeleteMk(pubKey1, 0)
+		err := ks.DeleteMk(pubKey1, 0)
+		require.NoError(t, err)
+
 		cnt, err := ks.Count(pubKey1)
 
 		// Assert.

message_test.go

@@ -1,8 +1,9 @@
 package doubleratchet
 
 import (
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestMessageHeader_EncodeAndDecode(t *testing.T) {

options.go

@@ -6,6 +6,7 @@ import "fmt"
 type option func(*State) error
 
 // WithMaxSkip specifies the maximum number of skipped message in a single chain.
+// nolint: golint
 func WithMaxSkip(n int) option {
 	return func(s *State) error {
 		if n < 0 {
@@ -17,6 +18,7 @@ func WithMaxSkip(n int) option {
 }
 
 // WithMaxKeep specifies the maximum number of ratchet steps before a message is deleted.
+// nolint: golint
 func WithMaxKeep(n int) option {
 	return func(s *State) error {
 		if n < 0 {
@@ -28,6 +30,7 @@ func WithMaxKeep(n int) option {
 }
 
 // WithKeysStorage replaces the default keys storage with the specified.
+// nolint: golint
 func WithKeysStorage(ks KeysStorage) option {
 	return func(s *State) error {
 		if ks == nil {
@@ -39,6 +42,7 @@ func WithKeysStorage(ks KeysStorage) option {
 }
 
 // WithCrypto replaces the default cryptographic supplement with the specified.
+// nolint: golint
 func WithCrypto(c Crypto) option {
 	return func(s *State) error {
 		if c == nil {

options_test.go

@@ -1,8 +1,9 @@
 package doubleratchet
 
 import (
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestWithMaxSkip_OK(t *testing.T) {

session.go

@@ -114,7 +114,7 @@ func (s *sessionState) RatchetDecrypt(m Message, ad []byte) ([]byte, error) {
 		if err != nil {
 			return nil, fmt.Errorf("can't decrypt skipped message: %s", err)
 		}
-		s.MkSkipped.DeleteMk(m.Header.DH, uint(m.Header.N))
+		_ = s.MkSkipped.DeleteMk(m.Header.DH, uint(m.Header.N))
 		return plaintext, nil
 	}
 

session_he.go

@@ -79,7 +79,7 @@ func (s *sessionHE) RatchetDecrypt(m MessageHE, ad []byte) ([]byte, error) {
 
 	var (
 		// All changes must be applied on a different session object, so that this session won't be modified nor left in a dirty session.
-		sc State = s.State
+		sc = s.State
 
 		skippedKeys1 []skippedKey
 		skippedKeys2 []skippedKey
@@ -103,9 +103,11 @@ func (s *sessionHE) RatchetDecrypt(m MessageHE, ad []byte) ([]byte, error) {
 		return nil, fmt.Errorf("can't decrypt: %s", err)
 	}
 
-	s.applyChanges(sc, append(skippedKeys1, skippedKeys2...))
+	if err = s.applyChanges(sc, append(skippedKeys1, skippedKeys2...)); err != nil {
+		return nil, fmt.Errorf("failed to apply changes: %s", err)
+	}
 	if step {
-		s.deleteSkippedKeys(s.HKr)
+		_ = s.deleteSkippedKeys(s.HKr)
 	}
 
 	return plaintext, nil
@@ -146,7 +148,7 @@ func (s *sessionHE) trySkippedMessages(m MessageHE, ad []byte) ([]byte, error) {
 			if err != nil {
 				return nil, fmt.Errorf("can't decrypt skipped message: %s", err)
 			}
-			s.MkSkipped.DeleteMk(hk, n)
+			_ = s.MkSkipped.DeleteMk(hk, n)
 			return plaintext, nil
 		}
 	}

session_he_test.go

@@ -2,14 +2,14 @@ package doubleratchet
 
 import (
 	"fmt"
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 var (
 	sharedHka  = Key{0xbd, 0x29, 0x18, 0xcb, 0x18, 0x6c, 0x26, 0x32, 0xd5, 0x82, 0x41, 0x2d, 0x11, 0xa4, 0x55, 0x87, 0x1e, 0x5b, 0xa3, 0xb5, 0x5a, 0x6d, 0xe1, 0x97, 0xde, 0xf7, 0x5e, 0xc3, 0xf2, 0xec, 0x1d, 0xd}
 	sharedNhkb = Key{0x32, 0x89, 0x3a, 0xed, 0x4b, 0xf0, 0xbf, 0xc1, 0xa5, 0xa9, 0x53, 0x73, 0x5b, 0xf9, 0x76, 0xce, 0x70, 0x8e, 0xe1, 0xa, 0xed, 0x98, 0x1d, 0xe3, 0xb4, 0xe9, 0xa9, 0x88, 0x54, 0x94, 0xaf, 0x23}
-	k          = Key{0x4b, 0x22, 0x7f, 0x60, 0x7b, 0x1e, 0x76, 0xb6, 0xf5, 0xf2, 0x72, 0x22, 0xf3, 0x14, 0xaf, 0x69, 0x60, 0xca, 0xd4, 0x26, 0x51, 0x88, 0xc9, 0xd, 0xbf, 0x23, 0x42, 0xfd, 0x1a, 0x30, 0xad, 0x4b}
 )
 
 func TestNewHE(t *testing.T) {

session_test.go

@@ -2,8 +2,9 @@ package doubleratchet
 
 import (
 	"fmt"
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestNew(t *testing.T) {

state_test.go

@@ -1,8 +1,9 @@
 package doubleratchet
 
 import (
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 var (