open-consul/vendor/github.com/joyent/triton-go/authentication/util.go
2018-05-10 15:40:16 -07:00

38 lines
1 KiB
Go

//
// Copyright (c) 2018, Joyent, Inc. All rights reserved.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
//
package authentication
import (
"crypto/md5"
"fmt"
"strings"
"golang.org/x/crypto/ssh"
)
// formatPublicKeyFingerprint produces the MD5 fingerprint of the given SSH
// public key. If display is true, the fingerprint is formatted with colons
// between each byte, as per the output of OpenSSL.
func formatPublicKeyFingerprint(key ssh.PublicKey, display bool) string {
publicKeyFingerprint := md5.New()
publicKeyFingerprint.Write(key.Marshal())
publicKeyFingerprintString := fmt.Sprintf("%x", publicKeyFingerprint.Sum(nil))
if !display {
return publicKeyFingerprintString
}
formatted := ""
for i := 0; i < len(publicKeyFingerprintString); i = i + 2 {
formatted = fmt.Sprintf("%s%s:", formatted, publicKeyFingerprintString[i:i+2])
}
return strings.TrimSuffix(formatted, ":")
}