Documentation
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Overview ¶
Package bbsnative is a cgo wrapper around zk-cred-bbs's plain C-ABI Go binding (src/go_ffi.rs / include/zk_cred_bbs_go.h in that crate). The static library is staged by the repository Makefile's `bbs-native-lib` target.
Unlike zk-cred-longfellow's verifier binding, this exposes the ISSUER side too: an issuer offering BBS credentials must verify the holder's commitment and blind-sign it, and there is no pure-Go implementation of either.
Memory ¶
The C ABI has no handles — BBS has no proving key to load and no circuit to compile, so every call is bytes in, bytes out. The only owned allocations crossing back are the signature buffer and the error string, each freed here immediately after being copied into Go memory.
Index ¶
- Constants
- func Describe(status int32, msg string) string
- type Backend
- func (Backend) BlindSign(suite uint32, secretKey, publicKey, commitment, header []byte, ...) ([]byte, int32, string)
- func (Backend) Issue(suite uint32, secretKey, publicKey, commitment []byte, vct string, ...) (string, int32, string)
- func (Backend) SkToPk(secretKey []byte) ([]byte, int32, string)
- func (Backend) VerifyPresentation(suite uint32, presentedJWP string, publicKey []byte) ([]byte, int32, string)
- func (Backend) VerifyProof(suite uint32, publicKey, proof, header, presentationHeader []byte, ...) (int32, string)
Constants ¶
const StatusOK int32 = C.ZK_CRED_BBS_OK
StatusOK is the ABI's success code.
const StatusPanic int32 = C.ZK_CRED_BBS_PANIC
StatusPanic is the ABI's "a panic was caught crossing the boundary" code. Exposed so the wrapping package can distinguish it from an ordinary verification failure without duplicating the constant.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Backend ¶
type Backend struct{}
Backend is the cgo-backed implementation. Stateless; safe to share.
func (Backend) BlindSign ¶
func (Backend) BlindSign(suite uint32, secretKey, publicKey, commitment, header []byte, messages [][]byte) ([]byte, int32, string)
BlindSign implements the issuer half. See bbs.BlindSigner.
func (Backend) Issue ¶
func (Backend) Issue(suite uint32, secretKey, publicKey, commitment []byte, vct string, issuerClaimsJSON, holderPointersJSON, extraHeaderJSON []byte, keybind uint32) (string, int32, string)
Issue verifies the holder's commitment and returns a finished credential in JWP Compact Serialization.
The claim-to-message mapping happens on the Rust side, not here. It has to be byte-identical in the issuer, the wallet and the verifier, and when it is not every proof fails with nothing pointing at the cause - so there is exactly one implementation of it.
func (Backend) SkToPk ¶
SkToPk derives the public key belonging to a secret key.
The one call here that is not about signing or verifying a credential. It exists so an issuer can check, once at startup, that the two halves of a configured key pair belong together - a mismatch otherwise surfaces as credentials that fail at every relying party reporting only "does not verify", with nothing in the failure pointing at the configuration.
func (Backend) VerifyPresentation ¶
func (Backend) VerifyPresentation(suite uint32, presentedJWP string, publicKey []byte) ([]byte, int32, string)
VerifyPresentation checks a presentation and returns the raw JSON describing what it disclosed. Decoding that is the caller's job, so this layer stays free of the package's own types.
Source Files