Files
notarius/internal/core/source/digest.go

36 lines
948 B
Go

package source
import (
"crypto/sha256"
"encoding/hex"
"encoding/json"
"fmt"
)
// DigestDocument returns a deterministic digest of the canonical source
// document content. The existing Digest field is excluded from its own digest.
func DigestDocument(doc *SourceDocument) (string, error) {
if doc == nil {
return "", fmt.Errorf("source document must not be nil")
}
payload := struct {
ID string `json:"id"`
Kind string `json:"kind"`
Format string `json:"format"`
Units []SourceUnit `json:"units"`
Metadata map[string]any `json:"metadata,omitempty"`
}{
ID: doc.ID,
Kind: doc.Kind,
Format: doc.Format,
Units: doc.Units,
Metadata: doc.Metadata,
}
encoded, err := json.Marshal(payload)
if err != nil {
return "", fmt.Errorf("encode source document for digest: %w", err)
}
sum := sha256.Sum256(encoded)
return "sha256:" + hex.EncodeToString(sum[:]), nil
}