diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/ssh/mlkem.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/ssh/mlkem.go | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/vendor/golang.org/x/crypto/ssh/mlkem.go b/vendor/golang.org/x/crypto/ssh/mlkem.go deleted file mode 100644 index ddc0ed1fc..000000000 --- a/vendor/golang.org/x/crypto/ssh/mlkem.go +++ /dev/null @@ -1,168 +0,0 @@ -// Copyright 2024 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package ssh - -import ( - "crypto" - "crypto/mlkem" - "crypto/sha256" - "errors" - "fmt" - "io" - - "golang.org/x/crypto/curve25519" -) - -// mlkem768WithCurve25519sha256 implements the hybrid ML-KEM768 with -// curve25519-sha256 key exchange method, as described by -// draft-kampanakis-curdle-ssh-pq-ke-05 section 2.3.3. -type mlkem768WithCurve25519sha256 struct{} - -func (kex *mlkem768WithCurve25519sha256) Client(c packetConn, rand io.Reader, magics *handshakeMagics) (*kexResult, error) { - var c25519kp curve25519KeyPair - if err := c25519kp.generate(rand); err != nil { - return nil, err - } - - seed := make([]byte, mlkem.SeedSize) - if _, err := io.ReadFull(rand, seed); err != nil { - return nil, err - } - - mlkemDk, err := mlkem.NewDecapsulationKey768(seed) - if err != nil { - return nil, err - } - - hybridKey := append(mlkemDk.EncapsulationKey().Bytes(), c25519kp.pub[:]...) - if err := c.writePacket(Marshal(&kexECDHInitMsg{hybridKey})); err != nil { - return nil, err - } - - packet, err := c.readPacket() - if err != nil { - return nil, err - } - - var reply kexECDHReplyMsg - if err = Unmarshal(packet, &reply); err != nil { - return nil, err - } - - if len(reply.EphemeralPubKey) != mlkem.CiphertextSize768+32 { - return nil, errors.New("ssh: peer's mlkem768x25519 public value has wrong length") - } - - // Perform KEM decapsulate operation to obtain shared key from ML-KEM. - mlkem768Secret, err := mlkemDk.Decapsulate(reply.EphemeralPubKey[:mlkem.CiphertextSize768]) - if err != nil { - return nil, err - } - - // Complete Curve25519 ECDH to obtain its shared key. - c25519Secret, err := curve25519.X25519(c25519kp.priv[:], reply.EphemeralPubKey[mlkem.CiphertextSize768:]) - if err != nil { - return nil, fmt.Errorf("ssh: peer's mlkem768x25519 public value is not valid: %w", err) - } - // Compute actual shared key. - h := sha256.New() - h.Write(mlkem768Secret) - h.Write(c25519Secret) - secret := h.Sum(nil) - - h.Reset() - magics.write(h) - writeString(h, reply.HostKey) - writeString(h, hybridKey) - writeString(h, reply.EphemeralPubKey) - - K := make([]byte, stringLength(len(secret))) - marshalString(K, secret) - h.Write(K) - - return &kexResult{ - H: h.Sum(nil), - K: K, - HostKey: reply.HostKey, - Signature: reply.Signature, - Hash: crypto.SHA256, - }, nil -} - -func (kex *mlkem768WithCurve25519sha256) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (*kexResult, error) { - packet, err := c.readPacket() - if err != nil { - return nil, err - } - - var kexInit kexECDHInitMsg - if err = Unmarshal(packet, &kexInit); err != nil { - return nil, err - } - - if len(kexInit.ClientPubKey) != mlkem.EncapsulationKeySize768+32 { - return nil, errors.New("ssh: peer's ML-KEM768/curve25519 public value has wrong length") - } - - encapsulationKey, err := mlkem.NewEncapsulationKey768(kexInit.ClientPubKey[:mlkem.EncapsulationKeySize768]) - if err != nil { - return nil, fmt.Errorf("ssh: peer's ML-KEM768 encapsulation key is not valid: %w", err) - } - // Perform KEM encapsulate operation to obtain ciphertext and shared key. - mlkem768Secret, mlkem768Ciphertext := encapsulationKey.Encapsulate() - - // Perform server side of Curve25519 ECDH to obtain server public value and - // shared key. - var c25519kp curve25519KeyPair - if err := c25519kp.generate(rand); err != nil { - return nil, err - } - c25519Secret, err := curve25519.X25519(c25519kp.priv[:], kexInit.ClientPubKey[mlkem.EncapsulationKeySize768:]) - if err != nil { - return nil, fmt.Errorf("ssh: peer's ML-KEM768/curve25519 public value is not valid: %w", err) - } - hybridKey := append(mlkem768Ciphertext, c25519kp.pub[:]...) - - // Compute actual shared key. - h := sha256.New() - h.Write(mlkem768Secret) - h.Write(c25519Secret) - secret := h.Sum(nil) - - hostKeyBytes := priv.PublicKey().Marshal() - - h.Reset() - magics.write(h) - writeString(h, hostKeyBytes) - writeString(h, kexInit.ClientPubKey) - writeString(h, hybridKey) - - K := make([]byte, stringLength(len(secret))) - marshalString(K, secret) - h.Write(K) - - H := h.Sum(nil) - - sig, err := signAndMarshal(priv, rand, H, algo) - if err != nil { - return nil, err - } - - reply := kexECDHReplyMsg{ - EphemeralPubKey: hybridKey, - HostKey: hostKeyBytes, - Signature: sig, - } - if err := c.writePacket(Marshal(&reply)); err != nil { - return nil, err - } - return &kexResult{ - H: H, - K: K, - HostKey: hostKeyBytes, - Signature: sig, - Hash: crypto.SHA256, - }, nil -} |
