orchestrator-agent
dcd35e78ec
CI / ci (push) Successful in 8m31s
Co-authored-by: orchestrator-agent <20+orchestrator-agent@code.cubecraftcreations.com>
88 lines
2.5 KiB
Go
88 lines
2.5 KiB
Go
// Package vapid generates and validates the VAPID key pair Web Push signs
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// with (RFC 8292): a P-256 (ES256) key pair in the encoding webpush-go
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// reads. Both keys are unpadded base64url: the public key is the 65-byte
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// uncompressed point and the private key the 32-byte scalar.
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package vapid
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import (
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"crypto/ecdh"
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"crypto/rand"
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"encoding/base64"
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"errors"
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"fmt"
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)
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// encoding is unpadded base64url. Strict refuses non-zero trailing bits, so
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// every key has exactly one accepted spelling.
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var encoding = base64.RawURLEncoding.Strict()
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const (
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publicKeySize = 65 // 0x04 || X || Y
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privateKeySize = 32
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)
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// KeyPair is a VAPID key pair in its stored encoding.
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type KeyPair struct {
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PublicKey string
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PrivateKey string
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}
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// Generate returns a new random key pair.
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func Generate() (KeyPair, error) {
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k, err := ecdh.P256().GenerateKey(rand.Reader)
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if err != nil {
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return KeyPair{}, fmt.Errorf("vapid: generate key: %w", err)
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}
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return KeyPair{
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PublicKey: encoding.EncodeToString(k.PublicKey().Bytes()),
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PrivateKey: encoding.EncodeToString(k.Bytes()),
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}, nil
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}
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// ParsePublicKey parses an encoded public key, which must be a point on
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// P-256.
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func ParsePublicKey(s string) (*ecdh.PublicKey, error) {
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b, err := encoding.DecodeString(s)
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if err != nil {
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return nil, errors.New("not unpadded base64url")
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}
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if len(b) != publicKeySize || b[0] != 0x04 {
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return nil, fmt.Errorf("want the %d-byte uncompressed P-256 point, got %d bytes", publicKeySize, len(b))
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}
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k, err := ecdh.P256().NewPublicKey(b)
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if err != nil {
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return nil, errors.New("not a point on P-256")
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}
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return k, nil
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}
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// ParsePrivateKey parses an encoded private key. Its errors never quote the
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// key.
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func ParsePrivateKey(s string) (*ecdh.PrivateKey, error) {
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b, err := encoding.DecodeString(s)
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if err != nil {
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return nil, errors.New("not unpadded base64url")
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}
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if len(b) != privateKeySize {
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return nil, fmt.Errorf("want a %d-byte P-256 scalar, got %d bytes", privateKeySize, len(b))
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}
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k, err := ecdh.P256().NewPrivateKey(b)
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if err != nil {
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return nil, errors.New("not a valid P-256 scalar")
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}
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return k, nil
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}
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// ErrMismatch is returned by CheckPair when the private key's public key is
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// not the given public key.
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var ErrMismatch = errors.New("private key does not belong to the public key")
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// CheckPair reports whether private is the private key of public, by
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// deriving the public point from private and comparing.
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func CheckPair(public *ecdh.PublicKey, private *ecdh.PrivateKey) error {
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if !private.PublicKey().Equal(public) {
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return ErrMismatch
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}
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return nil
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}
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