WIP python client for the roughtime protocol.
All values in the protocol must be little endian. Take care when encoding and decoding integers, strings etc.
| Field/Section | Offset | Length (in bytes) | Type | Values | Description |
|---|---|---|---|---|---|
| tag_num | 0 | 4 | uint32 | [0, 2**32) | Lists the number of tags defined the packet |
| offset(s) | 4 | [0, 4*(tag_num-1)) | uint32 | [0, len(packet)) | Offset table indicating the start of every sub-section (denoted by a tag) in the body of the packet (i.e offsets from the end of the protocol header). In cases where the tag_num is 0 or 1, the offset section maybe entirely ommitted since the meaning is obvious. Implication: The first value in the offset table always indicates the start of the second tag. Valid Roughtime packets always have at least two sections. |
| tag(s) | 4*(tag_num) | [0, 4*(tag_num) | uint32 | Anything | Name/identifier for a particular subsection in the packet. The roughtime protocol specifies predefined sections for different types of interactions |
| body | 4 + 4*(2*tag_num - 1) | [0,1024 - len(header)) | * | Anything | Binary blob of data to be indexed in using offsets and tags. The interpretation of the data is based on the meaning assigned to sections (out of band) |
- Protocol Description: https://roughtime.googlesource.com/roughtime/+/master/PROTOCOL.md
- Roughtime Implementation by Google: https://roughtime.googlesource.com/roughtime/+/master/
- Cloudflare's Implementation: https://github.com/cloudflare/roughtime
- Signatures vs Decryption in cryptography I: https://crypto.stackexchange.com/a/9897/62507
- Signatures vs Decryption in cryptography II: https://www.cs.cornell.edu/courses/cs5430/2015sp/notes/rsa_sign_vs_dec.php
- How does a public key verify a signature? https://stackoverflow.com/q/18257185/1220089
- "how digital signature verification process works" (sic) https://security.stackexchange.com/a/8039/17500