providerutils.go

// Package providerutils provides utility functions for the storage provider & provider FSM
package providerutils

import (
	"context"

	"github.com/ipfs/go-cid"
	"golang.org/x/xerrors"

	"github.com/filecoin-project/go-address"
	cborutil "github.com/filecoin-project/go-cbor-util"
	"github.com/filecoin-project/go-state-types/crypto"
	"github.com/filecoin-project/specs-actors/v8/actors/builtin/market"

	"github.com/filecoin-project/go-fil-markets/filestore"
	"github.com/filecoin-project/go-fil-markets/piecestore"
	"github.com/filecoin-project/go-fil-markets/shared"
	"github.com/filecoin-project/go-fil-markets/storagemarket/impl/blockrecorder"
)

// VerifyFunc is a function that can validate a signature for a given address and bytes
type VerifyFunc func(context.Context, crypto.Signature, address.Address, []byte, shared.TipSetToken) (bool, error)

// VerifyProposal verifies the signature on the given signed proposal matches
// the client addres for the proposal, using the given signature verification function
func VerifyProposal(ctx context.Context, sdp market.ClientDealProposal, tok shared.TipSetToken, verifier VerifyFunc) error {
	b, err := cborutil.Dump(&sdp.Proposal)
	if err != nil {
		return err
	}

	return VerifySignature(ctx, sdp.ClientSignature, sdp.Proposal.Client, b, tok, verifier)
}

// VerifySignature verifies the signature over the given bytes
func VerifySignature(ctx context.Context, signature crypto.Signature, signer address.Address, buf []byte, tok shared.TipSetToken, verifier VerifyFunc) error {
	verified, err := verifier(ctx, signature, signer, buf, tok)
	if err != nil {
		return xerrors.Errorf("verifying: %w", err)
	}

	if !verified {
		return xerrors.New("could not verify signature")
	}

	return nil
}

// WorkerLookupFunc is a function that can lookup a miner worker address from a storage miner actor
type WorkerLookupFunc func(context.Context, address.Address, shared.TipSetToken) (address.Address, error)

// SignFunc is a function that can sign a set of bytes with a given address
type SignFunc func(context.Context, address.Address, []byte) (*crypto.Signature, error)

// SignMinerData signs the given data structure with a signature for the given address
func SignMinerData(ctx context.Context, data interface{}, address address.Address, tok shared.TipSetToken, workerLookup WorkerLookupFunc, sign SignFunc) (*crypto.Signature, error) {
	msg, err := cborutil.Dump(data)
	if err != nil {
		return nil, xerrors.Errorf("serializing: %w", err)
	}

	worker, err := workerLookup(ctx, address, tok)
	if err != nil {
		return nil, err
	}

	sig, err := sign(ctx, worker, msg)
	if err != nil {
		return nil, xerrors.Errorf("failed to sign: %w", err)
	}
	return sig, nil
}

// LoadBlockLocations loads a metadata file then converts it to a map of cid -> blockLocation
func LoadBlockLocations(fs filestore.FileStore, metadataPath filestore.Path) (map[cid.Cid]piecestore.BlockLocation, error) {
	metadataFile, err := fs.Open(metadataPath)
	if err != nil {
		return nil, err
	}
	metadata, err := blockrecorder.ReadBlockMetadata(metadataFile)
	_ = metadataFile.Close()
	if err != nil {
		return nil, err
	}
	blockLocations := make(map[cid.Cid]piecestore.BlockLocation, len(metadata))
	for _, metadatum := range metadata {
		blockLocations[metadatum.CID] = piecestore.BlockLocation{RelOffset: metadatum.Offset, BlockSize: metadatum.Size}
	}
	return blockLocations, nil
}