25 lines
624 B
Go
25 lines
624 B
Go
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package encryption
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import (
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"errors"
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"golang.org/x/crypto/chacha20poly1305"
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)
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func Decrypt(key, ciphertextMsg []byte) ([]byte, error) {
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aead, err := chacha20poly1305.New(key)
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if err != nil {
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return nil, err
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}
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nonceSize := aead.NonceSize()
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tagSize := aead.Overhead()
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if len(ciphertextMsg) < nonceSize+tagSize {
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return nil, errors.New("ciphertext too short")
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}
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// Split nonce and ciphertext.
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nonce, ciphertext, tag := ciphertextMsg[:nonceSize], ciphertextMsg[nonceSize:len(ciphertextMsg)-tagSize], ciphertextMsg[len(ciphertextMsg)-tagSize:]
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return aead.Open(nil, nonce, append(ciphertext, tag...), nil)
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}
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