forked from quic-go/quic-go
49 lines
1.1 KiB
Go
49 lines
1.1 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 retryAEAD cipher.AEAD
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func init() {
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var key = [16]byte{0xf5, 0xed, 0x46, 0x42, 0xe0, 0xe4, 0xc8, 0xd8, 0x78, 0xbb, 0xbc, 0x8a, 0x82, 0x88, 0x21, 0xc9}
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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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retryAEAD = aead
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}
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var retryBuf bytes.Buffer
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var retryMutex sync.Mutex
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var retryNonce [12]byte
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// GetRetryIntegrityTag calculates the integrity tag on a Retry packet
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func GetRetryIntegrityTag(retry []byte, origDestConnID protocol.ConnectionID) *[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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sealed := retryAEAD.Seal(tag[:0], retryNonce[:], nil, retryBuf.Bytes())
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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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