From 54ee6ba0b406bd213165792336f498edaeab5c3c Mon Sep 17 00:00:00 2001
From: Alexey Potapenko <a.potapenko@vkteam.ru>
Date: Thu, 23 Oct 2025 15:42:06 +0300
Subject: [PATCH] hasher: implementation for sha1/sha256

This patch adds implementation of hasher types and interfaces
for sha1 and sha256 algorithms.

Closes #TNTP-4170
---
 .gitignore            |   2 +
 Makefile              |  12 +++++
 hasher/hasher.go      |  80 +++++++++++++++++++++++++++++++
 hasher/hasher_test.go | 107 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 201 insertions(+)
 create mode 100644 hasher/hasher.go
 create mode 100644 hasher/hasher_test.go

diff --git a/.gitignore b/.gitignore
index 2d83068..36e064c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 coverage.out
+/vendor/
+
diff --git a/Makefile b/Makefile
index 73bf4cf..f165ddb 100644
--- a/Makefile
+++ b/Makefile
@@ -34,3 +34,15 @@ coveralls-deps:
 	@echo "Installing coveralls"
 	@go get github.com/mattn/goveralls
 	@go install github.com/mattn/goveralls
+
+.PHONY: lint-deps
+lint-deps:
+	@echo "Installing lint deps"
+	@go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.5.0
+
+.PHONY: lint
+lint: lint-deps
+	@echo "Running go-linter"
+	@go mod tidy
+	@go mod vendor
+	@golangci-lint run --config=./.golangci.yml --modules-download-mode vendor --verbose
diff --git a/hasher/hasher.go b/hasher/hasher.go
new file mode 100644
index 0000000..30bbd2f
--- /dev/null
+++ b/hasher/hasher.go
@@ -0,0 +1,80 @@
+// Package hasher provides types and interfaces for hash calculating.
+package hasher
+
+import (
+	"crypto/sha1" //nolint:gosec
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"hash"
+)
+
+// ErrDataIsNil is returned if the passed data is nil.
+var ErrDataIsNil = errors.New("data is nil")
+
+// Hasher is the interface that storage hashers must implement.
+// It provides low-level operations for hash calculating.
+type Hasher interface {
+	Name() string
+	Hash(data []byte) ([]byte, error)
+}
+
+type sha256Hasher struct {
+	hash hash.Hash
+}
+
+// NewSHA256Hasher creates a new sha256Hasher instance.
+func NewSHA256Hasher() Hasher {
+	return &sha256Hasher{
+		hash: sha256.New(),
+	}
+}
+
+// Name implements Hasher interface.
+func (h *sha256Hasher) Name() string {
+	return "sha256"
+}
+
+// Hash implements Hasher interface.
+func (h *sha256Hasher) Hash(data []byte) ([]byte, error) {
+	if data == nil {
+		return nil, ErrDataIsNil
+	}
+
+	n, err := h.hash.Write(data)
+	if n < len(data) || err != nil {
+		return nil, fmt.Errorf("failed to write data: %w", err)
+	}
+
+	return h.hash.Sum(nil), nil
+}
+
+type sha1Hasher struct {
+	hash hash.Hash
+}
+
+// NewSHA1Hasher creates a new NewSHA1Hasher instance.
+func NewSHA1Hasher() Hasher {
+	return &sha1Hasher{
+		hash: sha1.New(), //nolint:gosec
+	}
+}
+
+// Name implements Hasher interface.
+func (h *sha1Hasher) Name() string {
+	return "sha1"
+}
+
+// Hash implements Hasher interface.
+func (h *sha1Hasher) Hash(data []byte) ([]byte, error) {
+	if data == nil {
+		return nil, ErrDataIsNil
+	}
+
+	n, err := h.hash.Write(data)
+	if n < len(data) || err != nil {
+		return nil, fmt.Errorf("failed to write data: %w", err)
+	}
+
+	return h.hash.Sum(nil), nil
+}
diff --git a/hasher/hasher_test.go b/hasher/hasher_test.go
new file mode 100644
index 0000000..a334dff
--- /dev/null
+++ b/hasher/hasher_test.go
@@ -0,0 +1,107 @@
+package hasher_test
+
+import (
+	"encoding/hex"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tarantool/go-storage/hasher"
+)
+
+func TestSHA1Hasher(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name string
+		in   []byte
+		out  string
+	}{
+		{"empty", []byte(""), "da39a3ee5e6b4b0d3255bfef95601890afd80709"},
+		{"abc", []byte("abc"), "a9993e364706816aba3e25717850c26c9cd0d89d"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			h := hasher.NewSHA1Hasher()
+
+			result, _ := h.Hash(test.in)
+
+			assert.Equal(t, test.out, hex.EncodeToString(result))
+		})
+	}
+}
+
+func TestSHA1Hasher_negative(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name              string
+		in                []byte
+		expectedErrorText string
+	}{
+		{"nil", nil, "data is nil"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			h := hasher.NewSHA1Hasher()
+
+			_, err := h.Hash(test.in)
+
+			assert.Contains(t, err.Error(), test.expectedErrorText)
+		})
+	}
+}
+
+func TestSHA256Hasher(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name string
+		in   []byte
+		out  string
+	}{
+		{"empty", []byte(""), "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"},
+		{"abc", []byte("abc"), "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			h := hasher.NewSHA256Hasher()
+
+			result, _ := h.Hash(test.in)
+
+			assert.Equal(t, test.out, hex.EncodeToString(result))
+		})
+	}
+}
+
+func TestSHA256Hasher_negative(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name              string
+		in                []byte
+		expectedErrorText string
+	}{
+		{"nil", nil, "data is nil"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			h := hasher.NewSHA256Hasher()
+
+			_, err := h.Hash(test.in)
+
+			assert.Contains(t, err.Error(), test.expectedErrorText)
+		})
+	}
+}