new marshalling for ciphertext raw #43
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pszal
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pszal
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I understand that json is slow but isn't it an issue for all tdh2 artifacts? (e.g., c.tdh2Ctxt.Marshal() is json too AFAIR). Wouldn't it be a better experiment to change encoding everywhere to something with acceptable performance? In general, I'm against writing custom parsers...
| c.Nonce, _, err = parseLengthPrefixed(data, offset) | ||
| if err != nil { | ||
| return fmt.Errorf("cannot decode nonce: %w", err) | ||
| } |
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You need to assert there is no data left after the last offset.
| func prefixWithLength(b []byte) []byte { | ||
| length := len(b) | ||
| buf := make([]byte, 4+length) | ||
| binary.BigEndian.PutUint32(buf[:4], uint32(length)) |
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length is 64bit on 64-bit machine so it can overflow here. You need to ensure it is <= MaxUint32 or increase the length prefix
| } | ||
| } | ||
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| func TestCiphertextRawMarshal(t *testing.T) { |
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A good start but I feel like tests for all the code are necessary.
| // where _TDH2Ctxt, _SymCtxt, and _Nonce are length-prefixed byte slices. | ||
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| func (c ciphertextRaw) Marshal() ([]byte, error) { | ||
| buf := make([]byte, 0, 4+len(c.TDH2Ctxt)+4+len(c.SymCtxt)+4+len(c.Nonce)) |
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len() is 64bit on 64bit architectures, so assuming 4 bytes for length is incorrect
| if offset+4 > len(data) { | ||
| return nil, 0, fmt.Errorf("unexpected EOF while reading length") | ||
| } | ||
| length := int(binary.BigEndian.Uint32(data[offset : offset+4])) |
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int can overflow on 32bit machine here
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tdh2easy.ciphertextRawis serialized as_TDH2Ctxt || _SymCtxt || _Noncewhere_TDH2Ctxt,_SymCtxt, and_Nonceare length-prefixed byte slices.