add endpoint to return document nullifier from hash

docs/spec/components/schemas/DocumentNullifier.yaml

@@ -0,0 +1,13 @@
+allOf:
+  - $ref: '#/components/schemas/DocumentNullifierKey'
+  - type: object
+    required:
+      - attributes
+    properties:
+      attributes:
+        type: object
+        required:
+          - document_nullifier_hash
+        properties:
+          document_nullifier_hash:
+            type: string

docs/spec/components/schemas/DocumentNullifierKey.yaml

@@ -0,0 +1,11 @@
+type: object
+required:
+  - id
+  - type
+properties:
+  id:
+    type: string
+  type:
+    type: string
+    enum:
+      - nullifiers

docs/spec/paths/intergrations@identity-provider-service@v1@document-nullifier.yaml

@@ -0,0 +1,34 @@
+get:
+  tags:
+    - Document Nullifier
+  summary: Document Nullifier retrieving
+  operationId: document-nullifier
+  parameters:
+    - in: query
+      name: dg2_hash
+      required: true
+      schema:
+        type: string
+  responses:
+    '200':
+      description: Success
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              data:
+                type: object
+                $ref: '#/components/schemas/DocumentNullifier'
+    '500':
+      description: Internal Error
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Errors'
+    '400':
+      description: Bad Request Error
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Errors'

internal/service/api/handlers/get_document_nullifier.go

@@ -0,0 +1,57 @@
+package handlers
+
+import (
+	"encoding/hex"
+	"github.com/iden3/go-iden3-crypto/poseidon"
+	"github.com/rarimo/passport-identity-provider/internal/service/api/requests"
+	"github.com/rarimo/passport-identity-provider/resources"
+	"gitlab.com/distributed_lab/ape"
+	"gitlab.com/distributed_lab/ape/problems"
+	"math/big"
+	"net/http"
+)
+
+func GetDocumentNullifier(w http.ResponseWriter, r *http.Request) {
+	req, err := requests.NewGetDocumentNullifierRequest(r)
+	if err != nil {
+		ape.RenderErr(w, problems.BadRequest(err)...)
+		return
+	}
+
+	dg2HashBytes, err := hex.DecodeString(req.DG2Hash)
+	if err != nil {
+		ape.RenderErr(w, problems.BadRequest(err)...)
+		return
+	}
+
+	nullifierHashInput := make([]*big.Int, 0)
+	if len(dg2HashBytes) >= 32 {
+		// break data in a half
+		nullifierHashInput = append(nullifierHashInput, new(big.Int).SetBytes(dg2HashBytes[:len(dg2HashBytes)/2]))
+		nullifierHashInput = append(nullifierHashInput, new(big.Int).SetBytes(dg2HashBytes[len(dg2HashBytes)/2:]))
+	} else {
+		nullifierHashInput = append(nullifierHashInput, new(big.Int).SetBytes(dg2HashBytes))
+	}
+
+	nullifierHashInput = append(nullifierHashInput, VerifierConfig(r).Blinder)
+
+	nullifierHash, err := poseidon.Hash(nullifierHashInput)
+	if err != nil {
+		Log(r).WithError(err).Error("failed to hash via Poseidon")
+		ape.RenderErr(w, problems.InternalError())
+		return
+	}
+
+	response := resources.DocumentNullifierResponse{
+		Data: resources.DocumentNullifier{
+			Key: resources.Key{
+				Type: resources.NULLIFIERS,
+			},
+			Attributes: resources.DocumentNullifierAttributes{
+				DocumentNullifierHash: nullifierHash.String(),
+			},
+		},
+	}
+
+	ape.Render(w, response)
+}

internal/service/api/requests/get_document_nullifier.go

@@ -0,0 +1,29 @@
+package requests
+
+import (
+	validation "github.com/go-ozzo/ozzo-validation/v4"
+	"gitlab.com/distributed_lab/logan/v3/errors"
+	"gitlab.com/distributed_lab/urlval"
+	"net/http"
+)
+
+type GetDocumentNullifierRequest struct {
+	DG2Hash string `url:"dg2_hash"`
+}
+
+func NewGetDocumentNullifierRequest(r *http.Request) (GetDocumentNullifierRequest, error) {
+	var req GetDocumentNullifierRequest
+
+	err := urlval.Decode(r.URL.Query(), &req)
+	if err != nil {
+		return GetDocumentNullifierRequest{}, errors.Wrap(err, "failed to decode url")
+	}
+
+	return req, validateGetDocumentNullifierRequest(req)
+}
+
+func validateGetDocumentNullifierRequest(r GetDocumentNullifierRequest) error {
+	return validation.Errors{
+		"/dg2_hash": validation.Validate(r.DG2Hash, validation.Required),
+	}.Filter()
+}

internal/service/router.go

@@ -44,6 +44,7 @@ func (s *service) router() chi.Router {
 		r.Route("/v1", func(r chi.Router) {
 			r.Post("/create-identity", handlers.CreateIdentity)
 			r.Get("/gist-data", handlers.GetGistData)
+			r.Get("/document-nullifier", handlers.GetDocumentNullifier)
 		})
 	})
 

resources/model_document_nullifier.go

@@ -0,0 +1,31 @@
+/*
+ * GENERATED. Do not modify. Your changes might be overwritten!
+ */
+
+package resources
+
+type DocumentNullifier struct {
+	Key
+	Attributes DocumentNullifierAttributes `json:"attributes"`
+}
+type DocumentNullifierResponse struct {
+	Data     DocumentNullifier `json:"data"`
+	Included Included          `json:"included"`
+}
+
+type DocumentNullifierListResponse struct {
+	Data     []DocumentNullifier `json:"data"`
+	Included Included            `json:"included"`
+	Links    *Links              `json:"links"`
+}
+
+// MustDocumentNullifier - returns DocumentNullifier from include collection.
+// if entry with specified key does not exist - returns nil
+// if entry with specified key exists but type or ID mismatches - panics
+func (c *Included) MustDocumentNullifier(key Key) *DocumentNullifier {
+	var documentNullifier DocumentNullifier
+	if c.tryFindEntry(key, &documentNullifier) {
+		return &documentNullifier
+	}
+	return nil
+}

resources/model_document_nullifier_attributes.go

@@ -0,0 +1,9 @@
+/*
+ * GENERATED. Do not modify. Your changes might be overwritten!
+ */
+
+package resources
+
+type DocumentNullifierAttributes struct {
+	DocumentNullifierHash string `json:"document_nullifier_hash"`
+}

resources/model_resource_type.go

@@ -9,5 +9,6 @@ type ResourceType string
 // List of ResourceType
 const (
 	CLAIMS     ResourceType = "claims"
+	NULLIFIERS ResourceType = "nullifiers"
 	GIST_DATAS ResourceType = "gist_datas"
 )