mirror of https://github.com/v2ray/v2ray-core
74 lines
1.7 KiB
Go
74 lines
1.7 KiB
Go
package encoding
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import (
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"crypto/md5"
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"hash/fnv"
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"v2ray.com/core/common/serial"
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)
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// Authenticate authenticates a byte array using Fnv hash.
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func Authenticate(b []byte) uint32 {
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fnv1hash := fnv.New32a()
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fnv1hash.Write(b)
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return fnv1hash.Sum32()
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}
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type NoOpAuthenticator struct{}
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func (NoOpAuthenticator) NonceSize() int {
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return 0
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}
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func (NoOpAuthenticator) Overhead() int {
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return 0
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}
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// Seal implements AEAD.Seal().
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func (NoOpAuthenticator) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
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return append(dst[:0], plaintext...)
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}
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// Open implements AEAD.Open().
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func (NoOpAuthenticator) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
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return append(dst[:0], ciphertext...), nil
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}
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// FnvAuthenticator is an AEAD based on Fnv hash.
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type FnvAuthenticator struct {
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}
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// NonceSize implements AEAD.NonceSize().
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func (v *FnvAuthenticator) NonceSize() int {
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return 0
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}
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// Overhead impelements AEAD.Overhead().
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func (v *FnvAuthenticator) Overhead() int {
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return 4
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}
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// Seal implements AEAD.Seal().
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func (v *FnvAuthenticator) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
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dst = serial.Uint32ToBytes(Authenticate(plaintext), dst)
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return append(dst, plaintext...)
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}
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// Open implements AEAD.Open().
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func (v *FnvAuthenticator) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
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if serial.BytesToUint32(ciphertext[:4]) != Authenticate(ciphertext[4:]) {
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return dst, newError("invalid authentication")
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}
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return append(dst, ciphertext[4:]...), nil
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}
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// GenerateChacha20Poly1305Key generates a 32-byte key from a given 16-byte array.
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func GenerateChacha20Poly1305Key(b []byte) []byte {
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key := make([]byte, 32)
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t := md5.Sum(b)
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copy(key, t[:])
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t = md5.Sum(key[:16])
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copy(key[16:], t[:])
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return key
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}
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