Learn X By Example
Learn X By Example

    Go by Example: SHA256 Hashes

    Go by Example : SHA256 Hashes

    SHA256 hashes are frequently used to compute short identities for binary or text blobs. For example, TLS/SSL certificates use SHA256 to compute a certificate’s signature. Here’s how to compute SHA256 hashes in Go.

    package main

    Go implements several hash functions in various crypto/* packages.

    import (
    "crypto/sha256"
    "fmt"
)
    func main() {
    s := "sha256 this string"

    Here we start with a new hash.

        h := sha256.New()

    Write expects bytes. If you have a string s , use []byte(s) to coerce it to bytes.

        h.Write([]byte(s))

    This gets the finalized hash result as a byte slice. The argument to Sum can be used to append to an existing byte slice: it usually isn’t needed.

        bs := h.Sum(nil)
        fmt.Println(s)
    fmt.Printf("%x\n", bs)
}

    Running the program computes the hash and prints it in a human-readable hex format.

    $ go run sha256-hashes.go
sha256 this string
1af1dfa857bf1d8814fe1af8983c18080019922e557f15a8a...

    You can compute other hashes using a similar pattern to the one shown above. For example, to compute SHA512 hashes import crypto/sha512 and use sha512.New() .

    Note that if you need cryptographically secure hashes, you should carefully research hash strength !

    Next example: Base64 Encoding .

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