78 lines
1.9 KiB
Go
78 lines
1.9 KiB
Go
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package encoding
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import (
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"errors"
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"git.lumeweb.com/LumeWeb/libs5-go/types"
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"git.lumeweb.com/LumeWeb/libs5-go/utils"
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)
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type EncryptedCID struct {
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Multibase
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encryptedBlobHash Multihash
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originalCID CID
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encryptionAlgorithm byte
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padding uint32
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chunkSizeAsPowerOf2 int
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encryptionKey []byte
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}
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func NewEncryptedCID(encryptedBlobHash Multihash, originalCID CID, encryptionKey []byte, padding uint32, chunkSizeAsPowerOf2 int, encryptionAlgorithm byte) *EncryptedCID {
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e := &EncryptedCID{
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encryptedBlobHash: encryptedBlobHash,
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originalCID: originalCID,
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encryptionKey: encryptionKey,
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padding: padding,
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chunkSizeAsPowerOf2: chunkSizeAsPowerOf2,
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encryptionAlgorithm: encryptionAlgorithm,
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}
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m := NewMultibase(e)
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e.Multibase = m
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return e
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}
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func DecodeEncryptedCID(cid string) (*EncryptedCID, error) {
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data, err := MultibaseDecodeString(cid)
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if err != nil {
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return nil, err
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}
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return FromBytes(data)
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}
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func FromBytes(data []byte) (*EncryptedCID, error) {
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if types.CIDType(data[0]) != types.CIDTypeEncryptedStatic {
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return nil, errors.New("Invalid CID type")
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}
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cid, err := CIDFromBytes(data[72:])
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if err != nil {
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return nil, err
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}
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encryptedBlobHash := NewMultihash(data[3:36])
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encryptionKey := data[36:68]
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padding := utils.DecodeEndian(data[68:72])
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chunkSizeAsPowerOf2 := int(data[2])
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encryptionAlgorithm := data[1]
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return NewEncryptedCID(*encryptedBlobHash, *cid, encryptionKey, padding, chunkSizeAsPowerOf2, encryptionAlgorithm), nil
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}
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func (c *EncryptedCID) ChunkSize() int {
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return 1 << uint(c.chunkSizeAsPowerOf2)
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}
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func (c *EncryptedCID) ToBytes() []byte {
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data := []byte{
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byte(types.CIDTypeEncryptedStatic),
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c.encryptionAlgorithm,
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byte(c.chunkSizeAsPowerOf2),
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}
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data = append(data, c.encryptedBlobHash.FullBytes...)
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data = append(data, c.encryptionKey...)
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data = append(data, utils.EncodeEndian(c.padding, 4)...)
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data = append(data, c.originalCID.ToBytes()...)
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return data
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}
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