package crypto import ( "crypto" "crypto/rand" "crypto/rsa" "crypto/sha256" "crypto/x509" "errors" "io" pb "github.com/libp2p/go-libp2p/core/crypto/pb" "github.com/libp2p/go-libp2p/core/internal/catch" ) // RsaPrivateKey is a rsa private key type RsaPrivateKey struct { sk rsa.PrivateKey } // RsaPublicKey is a rsa public key type RsaPublicKey struct { k rsa.PublicKey cached []byte } // GenerateRSAKeyPair generates a new rsa private and public key func GenerateRSAKeyPair(bits int, src io.Reader) (PrivKey, PubKey, error) { if bits < MinRsaKeyBits { return nil, nil, ErrRsaKeyTooSmall } if bits > maxRsaKeyBits { return nil, nil, ErrRsaKeyTooBig } priv, err := rsa.GenerateKey(src, bits) if err != nil { return nil, nil, err } pk := priv.PublicKey return &RsaPrivateKey{sk: *priv}, &RsaPublicKey{k: pk}, nil } // Verify compares a signature against input data func (pk *RsaPublicKey) Verify(data, sig []byte) (success bool, err error) { defer func() { catch.HandlePanic(recover(), &err, "RSA signature verification") // To be safe if err != nil { success = false } }() hashed := sha256.Sum256(data) err = rsa.VerifyPKCS1v15(&pk.k, crypto.SHA256, hashed[:], sig) if err != nil { return false, err } return true, nil } func (pk *RsaPublicKey) Type() pb.KeyType { return pb.KeyType_RSA } func (pk *RsaPublicKey) Raw() (res []byte, err error) { defer func() { catch.HandlePanic(recover(), &err, "RSA public-key marshaling") }() return x509.MarshalPKIXPublicKey(&pk.k) } // Equals checks whether this key is equal to another func (pk *RsaPublicKey) Equals(k Key) bool { // make sure this is a rsa public key other, ok := (k).(*RsaPublicKey) if !ok { return basicEquals(pk, k) } return pk.k.N.Cmp(other.k.N) == 0 && pk.k.E == other.k.E } // Sign returns a signature of the input data func (sk *RsaPrivateKey) Sign(message []byte) (sig []byte, err error) { defer func() { catch.HandlePanic(recover(), &err, "RSA signing") }() hashed := sha256.Sum256(message) return rsa.SignPKCS1v15(rand.Reader, &sk.sk, crypto.SHA256, hashed[:]) } // GetPublic returns a public key func (sk *RsaPrivateKey) GetPublic() PubKey { return &RsaPublicKey{k: sk.sk.PublicKey} } func (sk *RsaPrivateKey) Type() pb.KeyType { return pb.KeyType_RSA } func (sk *RsaPrivateKey) Raw() (res []byte, err error) { defer func() { catch.HandlePanic(recover(), &err, "RSA private-key marshaling") }() b := x509.MarshalPKCS1PrivateKey(&sk.sk) return b, nil } // Equals checks whether this key is equal to another func (sk *RsaPrivateKey) Equals(k Key) bool { // make sure this is a rsa public key other, ok := (k).(*RsaPrivateKey) if !ok { return basicEquals(sk, k) } a := sk.sk b := other.sk // Don't care about constant time. We're only comparing the public half. return a.PublicKey.N.Cmp(b.PublicKey.N) == 0 && a.PublicKey.E == b.PublicKey.E } // UnmarshalRsaPrivateKey returns a private key from the input x509 bytes func UnmarshalRsaPrivateKey(b []byte) (key PrivKey, err error) { defer func() { catch.HandlePanic(recover(), &err, "RSA private-key unmarshaling") }() sk, err := x509.ParsePKCS1PrivateKey(b) if err != nil { return nil, err } if sk.N.BitLen() < MinRsaKeyBits { return nil, ErrRsaKeyTooSmall } if sk.N.BitLen() > maxRsaKeyBits { return nil, ErrRsaKeyTooBig } return &RsaPrivateKey{sk: *sk}, nil } // UnmarshalRsaPublicKey returns a public key from the input x509 bytes func UnmarshalRsaPublicKey(b []byte) (key PubKey, err error) { defer func() { catch.HandlePanic(recover(), &err, "RSA public-key unmarshaling") }() pub, err := x509.ParsePKIXPublicKey(b) if err != nil { return nil, err } pk, ok := pub.(*rsa.PublicKey) if !ok { return nil, errors.New("not actually an rsa public key") } if pk.N.BitLen() < MinRsaKeyBits { return nil, ErrRsaKeyTooSmall } if pk.N.BitLen() > maxRsaKeyBits { return nil, ErrRsaKeyTooBig } return &RsaPublicKey{k: *pk}, nil }