[t][c] Add recover procedure

dfssc/cmd/recover.go

+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"dfss/dfssc/sign"
+	"github.com/spf13/cobra"
+)
+
+var recoverCmd = &cobra.Command{
+	Use:   "recover <f>",
+	Short: "try to recover signed contract from recover data file f",
+	Run:   recover,
+}
+
+func recover(cmd *cobra.Command, args []string) {
+	if len(args) != 1 {
+		_ = cmd.Usage()
+		return
+	}
+
+	var passphrase string
+	_ = readPassword(&passphrase, false)
+	filename := args[0]
+
+	err := sign.Recover(filename, passphrase)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+		return
+	}
+
+	fmt.Println("Successfully recovered signed contract.")
+	fmt.Println("Check .proof file.")
+}

dfssc/cmd/root.go

@@ -58,6 +58,5 @@ func init() {
 	_ = viper.BindPFlag("timeout", RootCmd.PersistentFlags().Lookup("timeout"))
 
 	// Bind subcommands to root
-	RootCmd.AddCommand(dfss.VersionCmd, registerCmd, authCmd, newCmd, showCmd, fetchCmd, importCmd, exportCmd, signCmd, unregisterCmd)
-
+	RootCmd.AddCommand(dfss.VersionCmd, registerCmd, authCmd, newCmd, showCmd, fetchCmd, importCmd, exportCmd, signCmd, unregisterCmd, recoverCmd)
 }

dfssc/cmd/sign.go

@@ -74,6 +74,13 @@ var signCmd = &cobra.Command{
 		// TODO Warning, integration tests are checking Stdout
 		fmt.Println("Everybody is ready, starting the signature", signatureUUID)
 
+		// Persisting the signatureUUID and ttp addrport in case of a crash, to be able to recover
+		filename, err = manager.PersistRecoverDataToFile()
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+
 		// Signature
 		manager.OnProgressUpdate = signProgressFn
 		err = manager.Sign()
@@ -83,6 +90,13 @@ var signCmd = &cobra.Command{
 		}
 
 		fmt.Println("Signature complete! See .proof file for evidences.")
+
+		// deleting the recover data file
+		err = os.Remove(filename)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
 	},
 }
 

dfssc/common/file.go

@@ -9,7 +9,6 @@ import (
 
 // UnmarshalDFSSFile decodes a json-encoded DFSS file
 func UnmarshalDFSSFile(data []byte) (*contract.JSON, error) {
-
 	c := &contract.JSON{}
 	err := json.Unmarshal(data, c)
 	if err != nil {
@@ -22,3 +21,25 @@ func UnmarshalDFSSFile(data []byte) (*contract.JSON, error) {
 
 	return c, nil
 }
+
+// RecoverDataJSON : contains all the necessary information to try and recover a previously signed contract from the ttp
+type RecoverDataJSON struct {
+	SignatureUUID string
+	TTPAddrport   string
+	TTPHash       []byte
+}
+
+// UnmarshalRecoverDataFile decodes a json-encoded Recover dara file
+func UnmarshalRecoverDataFile(data []byte) (*RecoverDataJSON, error) {
+	r := &RecoverDataJSON{}
+	err := json.Unmarshal(data, r)
+	if err != nil {
+		return nil, err
+	}
+
+	if r.SignatureUUID == "" || r.TTPAddrport == "" || r.TTPHash == nil {
+		return nil, errors.New("Invalid recover data file")
+	}
+
+	return r, nil
+}

dfssc/common/file_test.go

 package common
 
 import (
+	"crypto/sha512"
+	"encoding/json"
 	"io/ioutil"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"gopkg.in/mgo.v2/bson"
 )
 
 func TestUnmarshalDFSSFile(t *testing.T) {
@@ -16,3 +19,28 @@ func TestUnmarshalDFSSFile(t *testing.T) {
 	assert.Equal(t, "filename.pdf", c.File.Name)
 	// a tiny test, full unmarshal is tested in dfss/dfssp/contract package
 }
+
+func TestUnmarshalRecoverDataFile(t *testing.T) {
+	bsonUUID := bson.NewObjectId()
+	uuid := bsonUUID.Hex()
+	ttpAddrport := "127.0.0.1:0000"
+
+	h := sha512.Sum512([]byte{7})
+	ttpHash := h[:]
+
+	recData := RecoverDataJSON{
+		SignatureUUID: uuid,
+		TTPAddrport:   ttpAddrport,
+		TTPHash:       ttpHash,
+	}
+
+	file, err := json.MarshalIndent(recData, "", "  ")
+	assert.Nil(t, err)
+
+	unmarshal, err := UnmarshalRecoverDataFile(file)
+	assert.Nil(t, err)
+
+	assert.Equal(t, uuid, unmarshal.SignatureUUID)
+	assert.Equal(t, ttpAddrport, unmarshal.TTPAddrport)
+	assert.Equal(t, ttpHash, unmarshal.TTPHash)
+}

dfssc/sign/persist.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 
 	cAPI "dfss/dfssc/api"
+	"dfss/dfssc/common"
 	"dfss/dfssp/contract"
 )
 
@@ -45,5 +46,34 @@ func (m *SignatureManager) PersistSignaturesToFile() error {
 		return err
 	}
 
-	return ioutil.WriteFile(m.mail+"-"+m.contract.UUID+".proof", proof, 0600)
+	return ioutil.WriteFile(m.mail+"-"+m.uuid+".proof", proof, 0600)
+}
+
+// PersistRecoverDataToFile : save recover informations to disk.
+// returns the file name and an error if any occured
+func (m *SignatureManager) PersistRecoverDataToFile() (string, error) {
+	// Check content, don't write an empty file
+	if len(m.uuid) == 0 || len(m.ttpData.Addrport) == 0 || len(m.ttpData.Hash) == 0 {
+		return "", fmt.Errorf("Invalid recover data. Cannot persist file.")
+	}
+
+	// Fill JSON struct
+	recData := common.RecoverDataJSON{
+		SignatureUUID: m.uuid,
+		TTPAddrport:   m.ttpData.Addrport,
+		TTPHash:       m.ttpData.Hash,
+	}
+
+	file, err := json.MarshalIndent(recData, "", "  ")
+	if err != nil {
+		return "", err
+	}
+
+	filename := m.mail + "-" + m.uuid + ".run"
+	err = ioutil.WriteFile(filename, file, 0600)
+	if err != nil {
+		return "", err
+	}
+
+	return filename, nil
 }

dfssc/sign/protocol.go

@@ -261,7 +261,7 @@ func (m *SignatureManager) resolve() error {
 		return nil
 	}
 	dAPI.DLog("contacted TTP, received signed contract")
-	return ioutil.WriteFile(m.mail+"-"+m.contract.UUID+".proof", response.Contract, 0600)
+	return ioutil.WriteFile(m.mail+"-"+m.uuid+".proof", response.Contract, 0600)
 }
 
 // checkPromise : verifies that the promise is valid wrt the expected promises.

dfssc/sign/recover.go

+package sign
+
+import (
+	"errors"
+	"io/ioutil"
+	"time"
+
+	"dfss/dfssc/common"
+	"dfss/dfssc/security"
+	tAPI "dfss/dfsst/api"
+	"dfss/net"
+
+	"golang.org/x/net/context"
+)
+
+// Recover : performs a recover attempt using the provided recover file, and the user's passphrase to use secured connection
+func Recover(filename, passphrase string) error {
+	json, err := readRecoveryFile(filename)
+	if err != nil {
+		return err
+	}
+
+	auth := security.NewAuthContainer(passphrase)
+	_, _, _, err = auth.LoadFiles()
+	if err != nil {
+		return err
+	}
+
+	ttp, err := connectToTTP(json, auth)
+	if err != nil {
+		return err
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Minute)
+	defer cancel()
+
+	response, err := ttp.Recover(ctx, &tAPI.RecoverRequest{SignatureUUID: json.SignatureUUID})
+	if err != nil {
+		return err
+	}
+
+	return treatTTPResponse(response, auth, json.SignatureUUID)
+}
+
+// readRecoveryFile : reads the recovery file from disk
+func readRecoveryFile(filename string) (*common.RecoverDataJSON, error) {
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	json, err := common.UnmarshalRecoverDataFile(data)
+	if err != nil {
+		return nil, err
+	}
+
+	return json, nil
+}
+
+// connectToTTP : connects to the ttp, using the provided recover data and authentication information
+func connectToTTP(json *common.RecoverDataJSON, auth *security.AuthContainer) (tAPI.TTPClient, error) {
+	// TODO check that the connection spots missing TTP and returns an error quickly enough
+	conn, err := net.Connect(json.TTPAddrport, auth.Cert, auth.Key, auth.CA, json.TTPHash)
+	if err != nil {
+		return nil, err
+	}
+	return tAPI.NewTTPClient(conn), nil
+}
+
+// treatTTPResponse : handles the writing of the recoverd contract on the disk if it was recovered.
+func treatTTPResponse(response *tAPI.TTPResponse, auth *security.AuthContainer, signatureUUID string) error {
+	if len(response.Contract) == 0 {
+		return errors.New("Contract was not successfully signed. Impossible to recover.")
+	}
+
+	return ioutil.WriteFile(auth.Cert.Subject.CommonName+"-"+signatureUUID+".proof", response.Contract, 0600)
+}

dfsst/entities/check_request.go

@@ -29,13 +29,13 @@ func IsRequestValid(ctx context.Context, promises []*cAPI.Promise) (valid bool,
 		return
 	}
 
-	sender, err := GetSenderHashFromContext(ctx)
-	if err != nil {
+	sender := net.GetClientHash(&ctx)
+	if sender == nil {
 		valid = false
 		return
 	}
 
-	senderIndex, err = GetIndexOfSigner(promises[0], sender)
+	senderIndex, err := GetIndexOfSigner(promises[0], sender)
 	if err != nil {
 		valid = false
 		return
@@ -76,19 +76,6 @@ func IsPromiseSignedByPlatform(promise *cAPI.Promise) (bool, bson.ObjectId, []Si
 	return true, signatureUUID, signers
 }
 
-// GetSenderHashFromContext : creates the sender's certificate hash from the specified context.
-func GetSenderHashFromContext(ctx context.Context) ([]byte, error) {
-	state, _, ok := net.GetTLSState(&ctx)
-	if !ok || len(state.VerifiedChains) == 0 {
-		return nil, errors.New("Empty verified sender certificate")
-	}
-
-	cert := state.VerifiedChains[0][0]
-	hash := auth.GetCertificateHash(cert)
-
-	return hash, nil
-}
-
 // GetIndexOfSigner : determines the index of the specified signer's hash in the array of signers' hashes.
 func GetIndexOfSigner(promise *cAPI.Promise, hash []byte) (uint32, error) {
 	for i, h := range promise.Context.Signers {

dfsst/entities/signatureArchives.go

 package entities
 
 import (
+	"bytes"
+
 	"gopkg.in/mgo.v2/bson"
 )
 
@@ -105,3 +107,15 @@ func NewAbortedSigner(signerIndex, abortIndex uint32) *AbortedSigner {
 		AbortIndex:  abortIndex,
 	}
 }
+
+// ContainsSigner : determines whether or not the specified signer is one of the signers,
+// and also returns the sequence id of said signer.
+func (archives *SignatureArchives) ContainsSigner(hash []byte) (bool, uint32) {
+	for i, s := range archives.Signers {
+		if bytes.Equal(hash, s.Hash) {
+			return true, uint32(i)
+		}
+	}
+
+	return false, uint32(0)
+}

dfsst/entities/signatureArchives_test.go

@@ -25,3 +25,26 @@ func TestArePromisesEqual(t *testing.T) {
 	equal = promise0.Equal(promise1)
 	assert.Equal(t, equal, true)
 }
+
+func TestContainsSigner(t *testing.T) {
+	archives := NewSignatureArchives(signatureUUIDBson, sequence, signersEntities, contractDocumentHash, seal)
+	badHash := []byte{}
+	present, index := archives.ContainsSigner(badHash)
+	assert.False(t, present)
+	assert.Equal(t, uint32(0), index)
+
+	badHash = []byte{0, 0, 7}
+	present, index = archives.ContainsSigner(badHash)
+	assert.False(t, present)
+	assert.Equal(t, uint32(0), index)
+
+	goodHash := signersEntities[0].Hash
+	present, index = archives.ContainsSigner(goodHash)
+	assert.True(t, present)
+	assert.Equal(t, uint32(0), index)
+
+	goodHash = signersEntities[1].Hash
+	present, index = archives.ContainsSigner(goodHash)
+	assert.True(t, present)
+	assert.Equal(t, uint32(1), index)
+}

dfsst/resolve/resolve.go

@@ -182,8 +182,8 @@ func Solve(manager *entities.ArchivesManager) (bool, []byte) {
 func GenerateSignedContract(archives *entities.SignatureArchives) []byte {
 	var pseudoContract string
 	for _, p := range archives.ReceivedPromises {
-		signature := "SIGNATURE FROM SIGNER " + string(archives.Signers[p.SenderKeyIndex].Hash)
-		signature += " ON SIGNATURE n° " + string(archives.ID) + "\n"
+		signature := "SIGNATURE FROM SIGNER " + fmt.Sprintf("%x", archives.Signers[p.SenderKeyIndex].Hash)
+		signature += " ON SIGNATURE n° " + fmt.Sprint(archives.ID) + "\n"
 		pseudoContract += signature
 	}
 

dfsst/resolve/resolve_test.go

@@ -446,8 +446,8 @@ func TestGenerateSignedContract(t *testing.T) {
 
 	var pseudoContract string
 	for _, p := range promises {
-		signature := "SIGNATURE FROM SIGNER " + string(signersEntities[p.SenderKeyIndex].Hash)
-		signature += " ON SIGNATURE n° " + string(id) + "\n"
+		signature := "SIGNATURE FROM SIGNER " + fmt.Sprintf("%x", signersEntities[p.SenderKeyIndex].Hash)
+		signature += " ON SIGNATURE n° " + fmt.Sprint(id) + "\n"
 		pseudoContract += signature
 	}
 

dfsst/server/server.go

@@ -226,8 +226,44 @@ func (server *ttpServer) handleContractGenerationTry(manager *entities.ArchivesM
 
 // Recover route for the TTP.
 func (server *ttpServer) Recover(ctx context.Context, in *tAPI.RecoverRequest) (*tAPI.TTPResponse, error) {
-	// TODO
-	return nil, nil
+	if !bson.IsObjectIdHex(in.SignatureUUID) {
+		return nil, errors.New("Invalid signature uuid.")
+	}
+	bsonUUID := bson.ObjectIdHex(in.SignatureUUID)
+
+	manager := entities.NewArchivesManager(server.DB)
+	present, archives := manager.ContainsSignature(bsonUUID)
+	if !present {
+		return nil, errors.New("Unknown signature uuid.")
+	}
+	manager.Archives = archives
+
+	contract, err := handleRecover(ctx, manager)
+	if err != nil {
+		return nil, err
+	}
+
+	return &tAPI.TTPResponse{Contract: contract}, nil
+}
+
+func handleRecover(ctx context.Context, manager *entities.ArchivesManager) ([]byte, error) {
+	senderHash := net.GetClientHash(&ctx)
+	if senderHash == nil {
+		return []byte{}, errors.New("Bad authentication.")
+	}
+
+	present, senderID := manager.Archives.ContainsSigner(senderHash)
+	if !present {
+		return []byte{}, errors.New("Signer was not part of the signature.")
+	}
+
+	aborted := manager.HasReceivedAbortToken(senderID)
+	if aborted {
+		return []byte{}, errors.New("Signer was aborted.")
+	}
+
+	_, contract := manager.WasContractSigned()
+	return contract, nil
 }
 
 // GetServer returns the gRPC server.

dfsst/server/server_test.go

@@ -104,8 +104,3 @@ func TestMain(m *testing.M) {
 
 	os.Exit(code)
 }
-
-func TestAlert(t *testing.T) {
-	// TODO
-	// This requires the user of a real Alert message
-}

tests/sign_test.go

@@ -144,25 +144,30 @@ func checkProofFile(t *testing.T, nb int) {
 // TestSignContractFailure tests the signature with a faulty client, when contract can't be generated.
 // In this test, everything should not work fine, because client3 shutdowns way too early.
 func TestSignContractFailure(t *testing.T) {
-	signatureHelper(t, "1", 0)
+	signatureHelper(t, true)
 }
 
 // TestSignContractSuccess tests the signature with a faulty client, when contract can be generated.
 // In this test, everything should not work fine, because client3 shutdowns way too early.
 func TestSignContractSuccess(t *testing.T) {
-	signatureHelper(t, "2", 2)
+	signatureHelper(t, false)
 }
 
 // signatureHelper : launches a parametrized signature, with the number of rounds a client will accomplish before shutting down,
 // and the number of proof files expected to be generated.
-func signatureHelper(t *testing.T, round string, nbFiles int) {
+func signatureHelper(t *testing.T, failure bool) {
 	// Setup
 	stop, clients, contractPath, contractFilePath := setupSignature(t)
 	defer stop()
 
+	stopBefore, expectedProofFile1, expectedProofFile2 := "1", 0, 0
+	if !failure {
+		stopBefore, expectedProofFile1, expectedProofFile2 = "2", 2, 1
+	}
+
 	// Configure client3 to be faulty
 	setLastArg(clients[2], "--stopbefore", true)
-	setLastArg(clients[2], round, false)
+	setLastArg(clients[2], stopBefore, false)
 	setLastArg(clients[2], "sign", false)
 
 	// Sign!
@@ -183,6 +188,40 @@ func signatureHelper(t *testing.T, round string, nbFiles int) {
 		<-closeChannel
 	}
 
-	checkProofFile(t, nbFiles)
+	checkProofFile(t, expectedProofFile1)
+	filename := checkRecoverFile(t, "client3@example.com")
+	callRecover(newClient(clients[2]), filename)
+	_ = os.Remove(filename)
+	checkProofFile(t, expectedProofFile2)
+
 	time.Sleep(time.Second)
+	return
+}
+
+// checkProofFile counts the number of proof file contained in the current directory, and compares it to the nb parameter.
+func checkRecoverFile(t *testing.T, mail string) string {
+	// Ensure that all the files are present
+	recoverFile := regexp.MustCompile(mail + `.*\.run`)
+	files, _ := ioutil.ReadDir("./")
+
+	var filename string
+	matches := 0
+	for _, file := range files {
+		if recoverFile.Match([]byte(file.Name())) {
+			matches++
+			filename = file.Name()