/
signatures.go
183 lines (151 loc) · 5.62 KB
/
signatures.go
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package funding
import (
"context"
"encoding/json"
"github.com/centrifuge/go-centrifuge/config"
"github.com/centrifuge/go-centrifuge/contextutil"
"github.com/centrifuge/go-centrifuge/documents"
"github.com/centrifuge/go-centrifuge/errors"
"github.com/centrifuge/go-centrifuge/extensions"
"github.com/centrifuge/go-centrifuge/identity"
"github.com/centrifuge/go-centrifuge/utils"
"github.com/ethereum/go-ethereum/common/hexutil"
)
// TODO: move to generic signed attributes
func (s service) createSignAttrs(model documents.Model, idxFunding string, selfDID identity.DID, account config.Account) ([]documents.Attribute, error) {
var attributes []documents.Attribute
data, err := s.deriveFundingData(model, idxFunding)
if err != nil {
return nil, err
}
signMsg, err := json.Marshal(data)
if err != nil {
return nil, extensions.ErrJSON
}
// example "funding_agreement[2].signatures"
sLabel := extensions.GenerateLabel(fundingFieldKey, idxFunding, fundingSignatures)
attrIdx, err := extensions.IncrementArrayAttrIDX(model, sLabel)
if err != nil {
return nil, err
}
attributes = append(attributes, attrIdx)
// example: "funding_agreement[2].signatures[4]"
sFieldLabel := extensions.GenerateLabel(extensions.GenerateLabel(fundingFieldKey, idxFunding, "")+fundingSignaturesFieldKey, attrIdx.Value.Int256.String(), "")
attrSign, err := documents.NewSignedAttribute(sFieldLabel, selfDID, account, model.ID(), model.NextVersion(), signMsg, documents.AttrBytes)
if err != nil {
return nil, err
}
attributes = append(attributes, attrSign)
return attributes, nil
}
// TODO: move to generic signed attributes
// Sign adds a signature to an existing document
func (s service) Sign(ctx context.Context, agreementID string, identifier []byte) (documents.Model, error) {
selfDID, err := contextutil.AccountDID(ctx)
if err != nil {
return nil, errors.NewTypedError(documents.ErrDocumentConfigAccountID, err)
}
account, err := contextutil.Account(ctx)
if err != nil {
return nil, errors.NewTypedError(documents.ErrDocumentConfigAccountID, err)
}
model, err := s.docSrv.GetCurrentVersion(ctx, identifier)
if err != nil {
return nil, documents.ErrDocumentNotFound
}
idxFunding, err := extensions.FindAttributeSetIDX(model, agreementID, AttrFundingLabel, agreementIDLabel, fundingFieldKey)
if err != nil {
return nil, extensions.ErrAttributeSetNotFound
}
attributes, err := s.createSignAttrs(model, idxFunding, selfDID, account)
if err != nil {
return nil, err
}
err = model.AddAttributes(documents.CollaboratorsAccess{}, true, attributes...)
if err != nil {
return nil, err
}
return model, nil
}
func (s service) validateValueOfSignAttr(funding Data, signAttr documents.Attribute) (bool, error) {
value, err := json.Marshal(funding)
if err != nil {
return false, extensions.ErrJSON
}
return utils.IsSameByteSlice(value, signAttr.Value.Signed.Value), nil
}
func (s service) validateSignedFundingVersion(ctx context.Context, identifier []byte, fundingID string, signAttr documents.Attribute) (sig Signature, err error) {
did := signAttr.Value.Signed.Identity
signedDocVersion, err := s.docSrv.GetVersion(ctx, identifier, signAttr.Value.Signed.DocumentVersion)
if err != nil {
return sig, documents.ErrDocumentNotFound
}
signedFunding, err := s.findFunding(signedDocVersion, fundingID)
if err != nil {
return sig, extensions.ErrAttributeSetNotFound
}
valid, err := s.validateValueOfSignAttr(signedFunding, signAttr)
if err != nil {
return sig, err
}
if valid {
// the value of the older funding version signature is correct
return Signature{Valid: "true", SignedVersion: hexutil.Encode(identifier), Identity: did.String(), OutdatedSignature: "true"}, nil
}
return Signature{Valid: "false", SignedVersion: hexutil.Encode(identifier), Identity: did.String(), OutdatedSignature: "true"}, nil
}
func (s service) signAttrToClientData(ctx context.Context, current documents.Model, funding Data, signAttr documents.Attribute) (sig Signature, err error) {
if signAttr.Value.Type != documents.AttrSigned {
return sig, extensions.ErrAttrSetSignature
}
did := signAttr.Value.Signed.Identity
valid, err := s.validateValueOfSignAttr(funding, signAttr)
if err != nil {
return sig, err
}
// value correct (funding data didn't change since signing)
if valid {
return Signature{Valid: "true", SignedVersion: hexutil.Encode(current.ID()), Identity: did.String(), OutdatedSignature: "false"}, nil
}
return s.validateSignedFundingVersion(ctx, current.ID(), funding.AgreementID, signAttr)
}
func (s service) deriveFundingSignatures(ctx context.Context, model documents.Model, funding Data, idxFunding string) ([]Signature, error) {
var signatures []Signature
sLabel := extensions.GenerateLabel(fundingFieldKey, idxFunding, fundingSignatures)
key, err := documents.AttrKeyFromLabel(sLabel)
if err != nil {
return nil, err
}
if !model.AttributeExists(key) {
return signatures, nil
}
lastIdx, err := extensions.GetArrayLatestIDX(model, sLabel)
if err != nil {
return nil, err
}
i, err := documents.NewInt256("0")
if err != nil {
return nil, err
}
for i.Cmp(lastIdx) != 1 {
sFieldLabel := extensions.GenerateLabel(extensions.GenerateLabel(fundingFieldKey, idxFunding, "")+fundingSignaturesFieldKey, i.String(), "")
key, err := documents.AttrKeyFromLabel(sFieldLabel)
if err != nil {
return nil, err
}
attrSign, err := model.GetAttribute(key)
if err != nil {
return nil, err
}
clientSign, err := s.signAttrToClientData(ctx, model, funding, attrSign)
if err != nil {
continue
}
signatures = append(signatures, clientSign)
i, err = i.Inc()
if err != nil {
return nil, err
}
}
return signatures, nil
}