63 lines
1.7 KiB
Go
63 lines
1.7 KiB
Go
package handshake
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import (
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"bytes"
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"crypto/aes"
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"crypto/cipher"
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"fmt"
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"sync"
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"github.com/lucas-clemente/quic-go/internal/protocol"
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)
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var (
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oldRetryAEAD cipher.AEAD // used for QUIC draft versions up to 34
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retryAEAD cipher.AEAD // used for QUIC draft-34
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)
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func init() {
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oldRetryAEAD = initAEAD([16]byte{0xcc, 0xce, 0x18, 0x7e, 0xd0, 0x9a, 0x09, 0xd0, 0x57, 0x28, 0x15, 0x5a, 0x6c, 0xb9, 0x6b, 0xe1})
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retryAEAD = initAEAD([16]byte{0xbe, 0x0c, 0x69, 0x0b, 0x9f, 0x66, 0x57, 0x5a, 0x1d, 0x76, 0x6b, 0x54, 0xe3, 0x68, 0xc8, 0x4e})
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}
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func initAEAD(key [16]byte) cipher.AEAD {
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aes, err := aes.NewCipher(key[:])
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if err != nil {
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panic(err)
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}
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aead, err := cipher.NewGCM(aes)
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if err != nil {
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panic(err)
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}
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return aead
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}
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var (
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retryBuf bytes.Buffer
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retryMutex sync.Mutex
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oldRetryNonce = [12]byte{0xe5, 0x49, 0x30, 0xf9, 0x7f, 0x21, 0x36, 0xf0, 0x53, 0x0a, 0x8c, 0x1c}
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retryNonce = [12]byte{0x46, 0x15, 0x99, 0xd3, 0x5d, 0x63, 0x2b, 0xf2, 0x23, 0x98, 0x25, 0xbb}
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)
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// GetRetryIntegrityTag calculates the integrity tag on a Retry packet
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func GetRetryIntegrityTag(retry []byte, origDestConnID protocol.ConnectionID, version protocol.VersionNumber) *[16]byte {
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retryMutex.Lock()
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retryBuf.WriteByte(uint8(origDestConnID.Len()))
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retryBuf.Write(origDestConnID.Bytes())
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retryBuf.Write(retry)
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var tag [16]byte
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var sealed []byte
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if version != protocol.VersionDraft34 {
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sealed = oldRetryAEAD.Seal(tag[:0], oldRetryNonce[:], nil, retryBuf.Bytes())
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} else {
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sealed = retryAEAD.Seal(tag[:0], retryNonce[:], nil, retryBuf.Bytes())
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}
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if len(sealed) != 16 {
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panic(fmt.Sprintf("unexpected Retry integrity tag length: %d", len(sealed)))
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}
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retryBuf.Reset()
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retryMutex.Unlock()
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return &tag
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}
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