sops/decrypt/decrypt.go

80 строки
2.4 KiB
Go

/*
Package decrypt is the external API other Go programs can use to decrypt SOPS files. It is the only package in SOPS with
a stable API.
*/
package decrypt // import "github.com/getsops/sops/v3/decrypt"
import (
"fmt"
"os"
"time"
"github.com/getsops/sops/v3/aes"
"github.com/getsops/sops/v3/cmd/sops/common"
. "github.com/getsops/sops/v3/cmd/sops/formats" // Re-export
)
// File is a wrapper around Data that reads a local encrypted
// file and returns its cleartext data in an []byte
func File(path, format string) (cleartext []byte, err error) {
// Read the file into an []byte
encryptedData, err := os.ReadFile(path)
if err != nil {
return nil, fmt.Errorf("Failed to read %q: %w", path, err)
}
// uses same logic as cli.
formatFmt := FormatForPathOrString(path, format)
return DataWithFormat(encryptedData, formatFmt)
}
// DataWithFormat is a helper that takes encrypted data, and a format enum value,
// decrypts the data and returns its cleartext in an []byte.
func DataWithFormat(data []byte, format Format) (cleartext []byte, err error) {
store := common.StoreForFormat(format)
// Load SOPS file and access the data key
tree, err := store.LoadEncryptedFile(data)
if err != nil {
return nil, err
}
key, err := tree.Metadata.GetDataKey()
if err != nil {
return nil, err
}
// Decrypt the tree
cipher := aes.NewCipher()
mac, err := tree.Decrypt(key, cipher)
if err != nil {
return nil, err
}
// Compute the hash of the cleartext tree and compare it with
// the one that was stored in the document. If they match,
// integrity was preserved
originalMac, err := cipher.Decrypt(
tree.Metadata.MessageAuthenticationCode,
key,
tree.Metadata.LastModified.Format(time.RFC3339),
)
if err != nil {
return nil, fmt.Errorf("Failed to decrypt original mac: %w", err)
}
if originalMac != mac {
return nil, fmt.Errorf("Failed to verify data integrity. expected mac %q, got %q", originalMac, mac)
}
return store.EmitPlainFile(tree.Branches)
}
// Data is a helper that takes encrypted data and a format string,
// decrypts the data and returns its cleartext in an []byte.
// The format string can be `json`, `yaml`, `ini`, `dotenv` or `binary`.
// If the format string is empty, binary format is assumed.
func Data(data []byte, format string) (cleartext []byte, err error) {
formatFmt := FormatFromString(format)
return DataWithFormat(data, formatFmt)
}