101 lines
3 KiB
Go
101 lines
3 KiB
Go
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package crypt
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import (
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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core "github.com/host-uk/core/pkg/framework/core"
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"golang.org/x/crypto/chacha20poly1305"
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)
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// ChaCha20Encrypt encrypts plaintext using ChaCha20-Poly1305.
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// The key must be 32 bytes. The nonce is randomly generated and prepended
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// to the ciphertext.
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func ChaCha20Encrypt(plaintext, key []byte) ([]byte, error) {
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aead, err := chacha20poly1305.NewX(key)
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if err != nil {
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return nil, core.E("crypt.ChaCha20Encrypt", "failed to create cipher", err)
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}
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nonce := make([]byte, aead.NonceSize())
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if _, err := rand.Read(nonce); err != nil {
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return nil, core.E("crypt.ChaCha20Encrypt", "failed to generate nonce", err)
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}
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ciphertext := aead.Seal(nonce, nonce, plaintext, nil)
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return ciphertext, nil
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}
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// ChaCha20Decrypt decrypts ciphertext encrypted with ChaCha20Encrypt.
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// The key must be 32 bytes. Expects the nonce prepended to the ciphertext.
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func ChaCha20Decrypt(ciphertext, key []byte) ([]byte, error) {
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aead, err := chacha20poly1305.NewX(key)
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if err != nil {
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return nil, core.E("crypt.ChaCha20Decrypt", "failed to create cipher", err)
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}
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nonceSize := aead.NonceSize()
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if len(ciphertext) < nonceSize {
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return nil, core.E("crypt.ChaCha20Decrypt", "ciphertext too short", nil)
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}
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nonce, encrypted := ciphertext[:nonceSize], ciphertext[nonceSize:]
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plaintext, err := aead.Open(nil, nonce, encrypted, nil)
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if err != nil {
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return nil, core.E("crypt.ChaCha20Decrypt", "failed to decrypt", err)
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}
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return plaintext, nil
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}
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// AESGCMEncrypt encrypts plaintext using AES-256-GCM.
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// The key must be 32 bytes. The nonce is randomly generated and prepended
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// to the ciphertext.
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func AESGCMEncrypt(plaintext, key []byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, core.E("crypt.AESGCMEncrypt", "failed to create cipher", err)
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}
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aead, err := cipher.NewGCM(block)
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if err != nil {
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return nil, core.E("crypt.AESGCMEncrypt", "failed to create GCM", err)
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}
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nonce := make([]byte, aead.NonceSize())
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if _, err := rand.Read(nonce); err != nil {
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return nil, core.E("crypt.AESGCMEncrypt", "failed to generate nonce", err)
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}
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ciphertext := aead.Seal(nonce, nonce, plaintext, nil)
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return ciphertext, nil
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}
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// AESGCMDecrypt decrypts ciphertext encrypted with AESGCMEncrypt.
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// The key must be 32 bytes. Expects the nonce prepended to the ciphertext.
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func AESGCMDecrypt(ciphertext, key []byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, core.E("crypt.AESGCMDecrypt", "failed to create cipher", err)
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}
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aead, err := cipher.NewGCM(block)
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if err != nil {
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return nil, core.E("crypt.AESGCMDecrypt", "failed to create GCM", err)
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}
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nonceSize := aead.NonceSize()
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if len(ciphertext) < nonceSize {
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return nil, core.E("crypt.AESGCMDecrypt", "ciphertext too short", nil)
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}
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nonce, encrypted := ciphertext[:nonceSize], ciphertext[nonceSize:]
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plaintext, err := aead.Open(nil, nonce, encrypted, nil)
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if err != nil {
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return nil, core.E("crypt.AESGCMDecrypt", "failed to decrypt", err)
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}
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return plaintext, nil
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}
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