NewDecoder creates a new http-mice stream decoder. It reads first few bytes from r to determine the record size, and fails if the record size exceeds maxRecordSize.
(r io.Reader, digestHeaderValue string, maxRecordSize uint64)
| 165 | // from r to determine the record size, and fails if the record size exceeds |
| 166 | // maxRecordSize. |
| 167 | func (enc Encoding) NewDecoder(r io.Reader, digestHeaderValue string, maxRecordSize uint64) (io.Reader, error) { |
| 168 | toplevelProof, err := enc.parseDigestHeader(digestHeaderValue) |
| 169 | if err != nil { |
| 170 | return nil, err |
| 171 | } |
| 172 | |
| 173 | var recordSize uint64 |
| 174 | err = binary.Read(r, binary.BigEndian, &recordSize) |
| 175 | if err == io.EOF && enc != Draft02Encoding { |
| 176 | // As a special case, the encoding of an empty payload is itself an |
| 177 | // empty message (i.e. it omits the initial record size), and its |
| 178 | // integrity proof is SHA-256("\0"). [spec text] |
| 179 | if !validateRecord(nil, toplevelProof, true) { |
| 180 | return nil, ErrValidationFailure |
| 181 | } |
| 182 | // Return an empty reader. |
| 183 | return &decoder{encoding: enc}, nil |
| 184 | } |
| 185 | if err != nil { |
| 186 | return nil, fmt.Errorf("mice: cannot read record size: %v", err) |
| 187 | } |
| 188 | if recordSize == 0 || recordSize > maxRecordSize { |
| 189 | return nil, fmt.Errorf("mice: invalid record size %v", recordSize) |
| 190 | } |
| 191 | return &decoder{ |
| 192 | encoding: enc, |
| 193 | recordSize: recordSize, |
| 194 | r: r, |
| 195 | nextProof: toplevelProof, |
| 196 | recordBuf: make([]byte, recordSize+sha256.Size), |
| 197 | }, nil |
| 198 | } |
| 199 | |
| 200 | func (d *decoder) Read(dst []byte) (int, error) { |
| 201 | if len(d.out) == 0 { |