mirror of https://github.com/portainer/portainer
36 lines
762 B
Go
36 lines
762 B
Go
package libcrypto
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import (
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"crypto/aes"
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"crypto/cipher"
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"errors"
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)
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// Decrypt decrypts data using 256-bit AES-GCM. This both hides the content of
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// the data and provides a check that it hasn't been altered. Expects input
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// form nonce|ciphertext|tag where '|' indicates concatenation.
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// Creates a 32bit hash of the key before decrypting the data.
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func Decrypt(data []byte, key []byte) ([]byte, error) {
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hashKey := Hash32Bit(key)
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block, err := aes.NewCipher(hashKey)
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if err != nil {
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return nil, err
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}
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gcm, err := cipher.NewGCM(block)
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if err != nil {
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return nil, err
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}
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if len(data) < gcm.NonceSize() {
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return nil, errors.New("malformed ciphertext")
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}
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return gcm.Open(nil,
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data[:gcm.NonceSize()],
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data[gcm.NonceSize():],
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nil,
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)
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}
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