Hash
To create a hash utility program in Go that supports all major hash algorithms, follow these steps:
Step 1: Initialize the Go Module
First, create a new directory for your project and initialize the Go module.
mkdir hash_utility
cd hash_utility
mkdir lib
go mod init github.com/username/hash
Step 2: Create the hash.go File
Create a lib/hash.go file to handle the hashing functionality.
// hash.go
package lib
import (
"crypto/md5"
"crypto/sha1"
"crypto/sha256"
"crypto/sha512"
"encoding/hex"
"fmt"
"hash"
"io"
"os"
)
// HashData hashes the input data using the specified hash algorithm.
func HashData(data string, algorithm string) (string, error) {
var hasher hash.Hash
switch algorithm {
case "md5":
hasher = md5.New()
case "sha1":
hasher = sha1.New()
case "sha256":
hasher = sha256.New()
case "sha512":
hasher = sha512.New()
default:
return "", fmt.Errorf("unsupported hash algorithm: %s", algorithm)
}
_, err := hasher.Write([]byte(data))
if err != nil {
return "", err
}
return hex.EncodeToString(hasher.Sum(nil)), nil
}
// HashFile hashes the content of the specified file using the specified hash algorithm.
func HashFile(filePath string, algorithm string) (string, error) {
file, err := os.Open(filePath)
if err != nil {
return "", err
}
defer file.Close()
var hasher hash.Hash
switch algorithm {
case "md5":
hasher = md5.New()
case "sha1":
hasher = sha1.New()
case "sha256":
hasher = sha256.New()
case "sha512":
hasher = sha512.New()
default:
return "", fmt.Errorf("unsupported hash algorithm: %s", algorithm)
}
if _, err := io.Copy(hasher, file); err != nil {
return "", err
}
return hex.EncodeToString(hasher.Sum(nil)), nil
}
Step 3: Create the main.go File
Create a main.go file to use the hashing functionality.
package main
import (
"bufio"
"flag"
"fmt"
"io"
"os"
"github.com/username/hash/lib"
)
func main() {
algorithm := flag.String("algorithm", "sha256", "Hash algorithm: md5, sha1, sha256, sha512")
input := flag.String("input", "", "Input string")
filePath := flag.String("file", "", "Path to input file")
flag.Parse()
var data string
if *filePath != "" {
// Read from file
result, err := lib.HashFile(*filePath, *algorithm)
if err != nil {
fmt.Printf("Error hashing file: %v\n", err)
os.Exit(1)
}
fmt.Println(result)
return
} else if *input == "" {
// Check if input is coming from a pipe
fi, err := os.Stdin.Stat()
if err != nil {
fmt.Printf("Error: %v\n", err)
os.Exit(1)
}
if fi.Mode()&os.ModeNamedPipe != 0 {
// Read from stdin
reader := bufio.NewReader(os.Stdin)
inputBytes, err := io.ReadAll(reader)
if err != nil {
fmt.Printf("Error reading from stdin: %v\n", err)
os.Exit(1)
}
data = string(inputBytes)
} else {
fmt.Println("Enter input string:")
scanner := bufio.NewScanner(os.Stdin)
if scanner.Scan() {
data = scanner.Text()
}
}
} else {
data = *input
}
result, err := lib.HashData(data, *algorithm)
if err != nil {
fmt.Printf("Error hashing data: %v\n", err)
os.Exit(1)
}
fmt.Println(result)
}
Step 4: Run the Program
Run the program using the go run command.
To hash a string using SHA-256:
go run main.go --algorithm sha256 --input "Hello, World!"
To hash a file using SHA-256:
go run main.go --algorithm sha256 --file path/to/input.txt
To hash data piped from another command using SHA-256:
echo "Hello, World!" | go run main.go --algorithm sha256
This will hash the input data based on the specified algorithm.
Last modified: 08 January 2025