Files
go-i2p/lib/common/keys_and_cert/keys_and_cert.go
2024-10-03 21:31:54 -04:00

145 lines
5.2 KiB
Go

// Package keys_and_cert implements the I2P KeysAndCert common data structure
package keys_and_cert
import (
"errors"
. "github.com/go-i2p/go-i2p/lib/common/certificate"
. "github.com/go-i2p/go-i2p/lib/common/key_certificate"
"github.com/go-i2p/go-i2p/lib/crypto"
log "github.com/sirupsen/logrus"
)
// Sizes of various KeysAndCert structures and requirements
const (
KEYS_AND_CERT_PUBKEY_SIZE = 256
KEYS_AND_CERT_SPK_SIZE = 128
KEYS_AND_CERT_MIN_SIZE = 387
KEYS_AND_CERT_DATA_SIZE = 384
)
/*
[KeysAndCert]
Accurate for version 0.9.49
Description
An encryption public key, a signing public key, and a certificate, used as either a RouterIdentity or a Destination.
Contents
A PublicKey followed by a SigningPublicKey and then a Certificate.
+----+----+----+----+----+----+----+----+
| public_key |
+ +
| |
~ ~
~ ~
| |
+----+----+----+----+----+----+----+----+
| padding (optional) |
~ ~
~ ~
| |
+----+----+----+----+----+----+----+----+
| signing_key |
+ +
| |
~ ~
~ ~
| |
+----+----+----+----+----+----+----+----+
| certificate |
+----+----+----+-//
public_key :: PublicKey (partial or full)
length -> 256 bytes or as specified in key certificate
padding :: random data
length -> 0 bytes or as specified in key certificate
padding length + signing_key length == 128 bytes
signing__key :: SigningPublicKey (partial or full)
length -> 128 bytes or as specified in key certificate
padding length + signing_key length == 128 bytes
certificate :: Certificate
length -> >= 3 bytes
total length: 387+ bytes
*/
// KeysAndCert is the represenation of an I2P KeysAndCert.
//
// https://geti2p.net/spec/common-structures#keysandcert
type KeysAndCert struct {
KeyCertificate *KeyCertificate
publicKey crypto.PublicKey
padding []byte
signingPublicKey crypto.SigningPublicKey
}
// Bytes returns the entire KeyCertificate in []byte form, trims payload to specified length.
func (keys_and_cert KeysAndCert) Bytes() []byte {
return keys_and_cert.KeyCertificate.Bytes()
}
// PublicKey returns the public key as a crypto.PublicKey.
func (keys_and_cert *KeysAndCert) PublicKey() (key crypto.PublicKey) {
return keys_and_cert.publicKey
}
// SigningPublicKey returns the signing public key.
func (keys_and_cert *KeysAndCert) SigningPublicKey() (signing_public_key crypto.SigningPublicKey) {
return keys_and_cert.signingPublicKey
}
// Certfificate returns the certificate.
func (keys_and_cert *KeysAndCert) Certificate() (cert Certificate) {
return keys_and_cert.KeyCertificate.Certificate
}
// ReadKeysAndCert creates a new *KeysAndCert from []byte using ReadKeysAndCert.
// Returns a pointer to KeysAndCert unlike ReadKeysAndCert.
func ReadKeysAndCert(data []byte) (keys_and_cert KeysAndCert, remainder []byte, err error) {
data_len := len(data)
// keys_and_cert = KeysAndCert{}
if data_len < KEYS_AND_CERT_MIN_SIZE && data_len > KEYS_AND_CERT_DATA_SIZE {
log.WithFields(log.Fields{
"at": "ReadKeysAndCert",
"data_len": data_len,
"required_len": KEYS_AND_CERT_MIN_SIZE,
"reason": "not enough data",
}).Error("error parsing keys and cert")
err = errors.New("error parsing KeysAndCert: data is smaller than minimum valid size")
keys_and_cert.KeyCertificate, remainder, _ = NewKeyCertificate(data[KEYS_AND_CERT_DATA_SIZE:])
return
} else if data_len < KEYS_AND_CERT_DATA_SIZE {
log.WithFields(log.Fields{
"at": "ReadKeysAndCert",
"data_len": data_len,
"required_len": KEYS_AND_CERT_MIN_SIZE,
"reason": "not enough data",
}).Error("error parsing keys and cert")
err = errors.New("error parsing KeysAndCert: data is smaller than minimum valid size")
return
}
keys_and_cert.KeyCertificate, remainder, err = NewKeyCertificate(data[KEYS_AND_CERT_DATA_SIZE:])
if err != nil {
return
}
// TODO: this only supports one key type right now and it's the old key type, but the layout is the same.
// a case-switch which sets the size of the SPK and the PK should be used to replace the referenced KEYS_AND_CERT_PUBKEY_SIZE
// and KEYS_AND_CERT_SPK_SIZE constants in the future.
keys_and_cert.publicKey, err = keys_and_cert.KeyCertificate.ConstructPublicKey(data[:keys_and_cert.KeyCertificate.CryptoSize()])
if err != nil {
return
}
keys_and_cert.signingPublicKey, err = keys_and_cert.KeyCertificate.ConstructSigningPublicKey(data[KEYS_AND_CERT_DATA_SIZE-keys_and_cert.KeyCertificate.SignatureSize() : KEYS_AND_CERT_DATA_SIZE])
if err != nil {
return
}
padding := data[KEYS_AND_CERT_PUBKEY_SIZE : KEYS_AND_CERT_DATA_SIZE-KEYS_AND_CERT_SPK_SIZE]
keys_and_cert.padding = padding
return
}