Adds special Darc attributes on read contract

calypso/contracts.go

@@ -3,8 +3,10 @@ package calypso
 import (
 	"errors"
 	"fmt"
+	"net/url"
 	"strings"
 
+	"github.com/dedis/odyssey/projectc"
 	"go.dedis.ch/cothority/v3"
 	"go.dedis.ch/cothority/v3/byzcoin"
 	"go.dedis.ch/cothority/v3/darc"
@@ -215,3 +217,82 @@ func intersectRosters(r1, r2 *onet.Roster) int {
 	}
 	return res
 }
+
+// VerifyInstruction uses a specific verification based on attr in the case its
+// a read spawn
+func (c ContractWrite) VerifyInstruction(rst byzcoin.ReadOnlyStateTrie, inst byzcoin.Instruction, ctxHash []byte) error {
+	log.Info("Hello from the verify instruction")
+	if inst.GetType() == byzcoin.SpawnType && inst.Spawn.ContractID == ContractReadID {
+		log.Info("Hello 2 from the verify instruction")
+		return inst.VerifyWithOption(rst, ctxHash, &byzcoin.VerificationOptions{EvalAttr: c.MakeAttrInterpreters(rst, inst)})
+	}
+	return inst.VerifyWithOption(rst, ctxHash, nil)
+}
+
+// MakeAttrInterpreters provides the attribute verification which check
+// the purposes and uses
+func (c ContractWrite) MakeAttrInterpreters(rst byzcoin.ReadOnlyStateTrie, inst byzcoin.Instruction) darc.AttrInterpreters {
+	log.Info("Hello from the MakeAttrInterpreters")
+	cb := func(attr string) error {
+		log.Info("Hello from the inside MakeAttrInterpreters")
+		// Expecting an 'attr' of form:
+		// purposes=purpose1,purpose2&uses=use1,use2,use4
+		// which, once parsed, gives map[purposes:[purpose1,purpose2] uses:[use1,use2]]
+		vals, err := url.ParseQuery(attr)
+		if err != nil {
+			return err
+		}
+		purposesStr := vals.Get("purposes")
+		usesStr := vals.Get("uses")
+
+		projectInstID := inst.Spawn.Args.Search("projectInstID")
+		if projectInstID == nil {
+			return errors.New("argument 'projectInstID' not found")
+		}
+
+		projectC := projectc.ProjectData{}
+		projectBuf, _, _, _, err := rst.GetValues(projectInstID)
+		if err != nil {
+			return fmt.Errorf("failed to get the given project instance '%x': %s", projectInstID, err.Error())
+		}
+		err = protobuf.DecodeWithConstructors(projectBuf, &projectC, network.DefaultConstructors(cothority.Suite))
+		if err != nil {
+			return errors.New("failed to decode project instance: " + err.Error())
+		}
+
+		purposes := strings.Split(purposesStr, ",")
+		log.Info("here are the Darc purposes: ", purposes)
+		uses := strings.Split(usesStr, ",")
+
+		errorMessages := make([]string, 0)
+		for _, purpose := range projectC.Purposes {
+			if !stringInSlice(purpose, purposes) {
+				errorMessages = append(errorMessages,
+					fmt.Sprintf("the purpose '%s' is not allowed", purpose))
+			}
+		}
+		for _, use := range projectC.Uses {
+			if !stringInSlice(use, uses) {
+				errorMessages = append(errorMessages,
+					fmt.Sprintf("the use '%s' is not allowed", use))
+			}
+		}
+
+		if len(errorMessages) != 0 {
+			return fmt.Errorf("validation of attributes failed: %s", strings.Join(errorMessages, ", "))
+		}
+
+		return nil
+
+	}
+	return darc.AttrInterpreters{"allowed": cb}
+}
+
+func stringInSlice(a string, list []string) bool {
+	for _, b := range list {
+		if b == a {
+			return true
+		}
+	}
+	return false
+}

calypso/csadmin/clicontracts/read.go

@@ -112,6 +112,12 @@ func ReadSpawn(c *cli.Context) error {
 		return errors.New("failed to encode read struct: " + err.Error())
 	}
 
+	projectInstID := c.String("projectInstID")
+	projectInstIDBuff, err := hex.DecodeString(projectInstID)
+	if err != nil {
+		return errors.New("failed to decode the projectInstID string")
+	}
+
 	counters, err := cl.GetSignerCounters(signer.Identity().String())
 	if err != nil {
 		return errors.New("failed to get the signer counters: " + err.Error())
@@ -122,7 +128,10 @@ func ReadSpawn(c *cli.Context) error {
 			InstanceID: byzcoin.NewInstanceID(proof.InclusionProof.Key()),
 			Spawn: &byzcoin.Spawn{
 				ContractID: calypso.ContractReadID,
-				Args:       byzcoin.Arguments{{Name: "read", Value: readBuf}},
+				Args: byzcoin.Arguments{
+					{Name: "read", Value: readBuf},
+					{Name: "projectInstID", Value: projectInstIDBuff},
+				},
 			},
 			SignerCounter: []uint64{counters.Counters[0] + 1},
 		}},

calypso/csadmin/commands.go

@@ -225,6 +225,10 @@ var cmds = cli.Commands{
 								Name:  "export, x",
 								Usage: "export the instance id to STDOUT",
 							},
+							cli.StringFlag{
+								Name:  "projectInstID, pid",
+								Usage: "The project instance ID, which contains the metadata for verification (optional)",
+							},
 						},
 					},
 				},

go.sum

@@ -63,16 +63,26 @@ github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UV
 go.dedis.ch/cothority/v3 v3.1.3/go.mod h1:9l9ftJQG/LJakHDm3RdrStrTsyMuHNr5h2A6IWrjAgY=
 go.dedis.ch/fixbuf v1.0.3 h1:hGcV9Cd/znUxlusJ64eAlExS+5cJDIyTyEG+otu5wQs=
 go.dedis.ch/fixbuf v1.0.3/go.mod h1:yzJMt34Wa5xD37V5RTdmp38cz3QhMagdGoem9anUalw=
+go.dedis.ch/kyber/v3 v3.0.0-pre2/go.mod h1:OzvaEnPvKlyrWyp3kGXlFdp7ap1VC6RkZDTaPikqhsQ=
+go.dedis.ch/kyber/v3 v3.0.3/go.mod h1:OzvaEnPvKlyrWyp3kGXlFdp7ap1VC6RkZDTaPikqhsQ=
 go.dedis.ch/kyber/v3 v3.0.4 h1:FDuC/S3STkvwxZ0ooo3gcp56QkUKsN7Jy7cpzBxL+vQ=
 go.dedis.ch/kyber/v3 v3.0.4/go.mod h1:OzvaEnPvKlyrWyp3kGXlFdp7ap1VC6RkZDTaPikqhsQ=
+go.dedis.ch/kyber/v3 v3.0.5 h1:BpjX6vY1R3b7TnJ0mUnCFRVXEJThSAj1zQzmNh4v+70=
+go.dedis.ch/kyber/v3 v3.0.5/go.mod h1:V1z0JihG9+dUEUCKLI9j9tjnlIflBw3wx8UOg0g3Pnk=
 go.dedis.ch/onet/v3 v3.0.20/go.mod h1:ImNGuFERh9xpFGfXH9nYBzkSk1TKTx6DPaeaeqvvQzc=
 go.dedis.ch/onet/v3 v3.0.21 h1:+sSu6fQnYy7ZQM5P9jDhI8pOc6Xu8Zr+RjU+urcp3LA=
 go.dedis.ch/onet/v3 v3.0.21/go.mod h1:ImNGuFERh9xpFGfXH9nYBzkSk1TKTx6DPaeaeqvvQzc=
+go.dedis.ch/onet/v3 v3.0.23 h1:jTqiI//xzzXuVrulMSSV+2qypDF0V1zcAMfY+N6lols=
+go.dedis.ch/onet/v3 v3.0.23/go.mod h1:OsEui5KY4+z0hc6od4JOjqZjqgKNTqiGSOMfBcR+Nks=
 go.dedis.ch/protobuf v1.0.5/go.mod h1:eIV4wicvi6JK0q/QnfIEGeSFNG0ZeB24kzut5+HaRLo=
 go.dedis.ch/protobuf v1.0.6 h1:E61p2XjYbYrTf3WeXE8M8Ui5WA3hX/NgbHHi5D0FLxI=
 go.dedis.ch/protobuf v1.0.6/go.mod h1:YHYXW6dQ9p2iJ3f+2fxKnOpjGx0MvL4cwpg1RVNXaV8=
+go.dedis.ch/protobuf v1.0.7 h1:wRUEiq3u0/vBhLjcw9CmAVrol+BnDyq2M0XLukdphyI=
+go.dedis.ch/protobuf v1.0.7/go.mod h1:pv5ysfkDX/EawiPqcW3ikOxsL5t+BqnV6xHSmE79KI4=
 go.etcd.io/bbolt v1.3.2 h1:Z/90sZLPOeCy2PwprqkFa25PdkusRzaj9P8zm/KNyvk=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
+go.etcd.io/bbolt v1.3.3 h1:MUGmc65QhB3pIlaQ5bB4LwqSj6GIonVJXpZiaKNyaKk=
+go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 golang.org/x/crypto v0.0.0-20190103213133-ff983b9c42bc/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190123085648-057139ce5d2b h1:Elez2XeF2p9uyVj0yEUDqQ56NFcDtcBNkYP7yv8YbUE=
 golang.org/x/crypto v0.0.0-20190123085648-057139ce5d2b/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
@@ -104,6 +114,8 @@ golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2 h1:z99zHgr7hKfrUcX/KsoJk5FJfjTceCKIp96+biqP4To=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 google.golang.org/appengine v1.4.0 h1:/wp5JvzpHIxhs/dumFmF7BXTf3Z+dd4uXta4kVyO508=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=