75 lines
1.6 KiB
Go
75 lines
1.6 KiB
Go
package rfc6979
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import (
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"crypto/dsa"
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"crypto/ecdsa"
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"crypto/elliptic"
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"crypto/rand"
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"crypto/sha1"
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"crypto/sha512"
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"fmt"
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)
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// Generates a 521-bit ECDSA key, uses SHA-512 to sign a message, then verifies
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// it.
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func ExampleSignECDSA() {
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// Generate a key pair.
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// You need a high-quality PRNG for this.
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k, err := ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
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if err != nil {
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fmt.Println(err)
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return
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}
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// Hash a message.
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alg := sha512.New()
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alg.Write([]byte("I am a potato."))
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hash := alg.Sum(nil)
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// Sign the message. You don't need a PRNG for this.
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r, s := SignECDSA(k, hash, sha512.New)
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if !ecdsa.Verify(&k.PublicKey, hash, r, s) {
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fmt.Println("Invalid signature!")
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}
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// Output:
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}
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// Generates a 1024-bit DSA key, uses SHA-1 to sign a message, then verifies it.
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func ExampleSignDSA() {
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// Here I'm generating some DSA params, but you should really pre-generate
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// these and re-use them, since this takes a long time and isn't necessary.
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k := new(dsa.PrivateKey)
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if err := dsa.GenerateParameters(&k.Parameters, rand.Reader, dsa.L1024N160); err != nil {
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fmt.Println(err)
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return
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}
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// Generate a key pair.
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// You need a high-quality PRNG for this.
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err := dsa.GenerateKey(k, rand.Reader)
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if err != nil {
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fmt.Println(err)
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return
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}
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// Hash a message.
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alg := sha1.New()
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alg.Write([]byte("I am a potato."))
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hash := alg.Sum(nil)
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// Sign the message. You don't need a PRNG for this.
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r, s, err := SignDSA(k, hash, sha1.New)
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if err != nil {
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fmt.Println(err)
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return
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}
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if !dsa.Verify(&k.PublicKey, hash, r, s) {
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fmt.Println("Invalid signature!")
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}
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// Output:
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}
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