Signer is a simple package that makes signing URLs painless. It uses github.com/tsawler/itsdangerous to sign URLs.
This is useful for things like sending an email with a link that can be verified, and which is tamper-proof.
go get github.com/tsawler/signer@latest
package main
import (
"fmt"
"github.com/tsawler/signer"
)
const secret = "somelongsecuresecret"
func main() {
// Create a variable of type Signature, and pass it a secret, <= 64 characters.
sign := signer.Signature{Secret: secret}
// Call the SignURL to get a signed version. Note that only the part after
// https://somesite.com or http://somesite.com is actually signed, but you
// must pass the full url. This way, we can use the package in development
// without worrying about the domain name of a particular site.
signed, _ := sign.SignURL("https://example.com/test?id=1")
fmt.Println("Signed url:", signed)
// Output is something like:
// https://example.com/test?id=1&hash=.3w4TgJ.pAJWBPAO5k1cimZJ-nrRKnlvosOY1Krrp3ALf1rOAds
// Verify that a signed URL is valid, and was issued by this application. Here,
// valid is true if the URL has a valid signature, and false if it is not.
valid, _ := sign.VerifyURL(signed)
fmt.Println("Valid url:", valid)
// You can also check for expiry. Here, the signed url expires after 30 minutes.
expired := sign.Expired(signed, 30)
fmt.Println("Expired:", expired)
}