link purb-db to libpurb

.github/workflows/go_lint.yml

@@ -2,7 +2,7 @@ name: Go lint
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
     types:
       - opened
@@ -14,14 +14,23 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-    - name: Set up Go ^1.19
-      uses: actions/setup-go@v3
+    - name: Set up Go 1.21
+      uses: actions/setup-go@v4
       with:
-        go-version: ^1.19
+        go-version: "=1.21"
 
-    - name: Check out code into the Go module directory
+    - name: Checkout
       uses: actions/checkout@v3
+      with:
+        fetch-depth: 0 # Shallow clones should be disabled for a better relevancy of Sonar analysis
 
+    - name: golangci-lint
+      uses: golangci/golangci-lint-action@v3
+      with:
+        # documentation: https://github.com/golangci/golangci-lint-action#readme
+        version: latest
+        install-mode: "binary"
+
     - name: Lint
       run: make lint
 

.github/workflows/go_test.yml

@@ -2,40 +2,36 @@ name: Go test
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
     types:
       - opened
       - synchronize
       - reopened
 
 jobs:
-
   test:
     strategy:
       matrix:
-        platform: [ubuntu-latest, macos-latest, windows-latest]
+        platform: [ubuntu-latest] #, macos-latest, windows-latest]
     runs-on: ${{matrix.platform}}
     env:
       LLVL: trace
     steps:
-    - name: Set up Go 1.19
-      uses: actions/setup-go@v3
+    - name: Checkout
+      uses: actions/checkout@v3
       with:
-        go-version: "=1.19"
+        fetch-depth: 0 # Shallow clones should be disabled for a better relevancy of Sonar analysis
+
+    - name: Set up Go 1.21
+      uses: actions/setup-go@v4
+      with:
+        go-version: "=1.21"
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v3
-
     - name: Test without coverage
-      env:
-        CRY_LVL: "warn"
-      if: matrix.platform == 'macos-latest' || matrix.platform == 'windows-latest'
       run: make test
 
     - name: Test with coverage
-      env:
-        CRY_LVL: "warn"
       if: matrix.platform == 'ubuntu-latest'
       run: make coverage
 
@@ -45,25 +41,9 @@ jobs:
       with:
         args: >
           -Dsonar.organization=dedis
-          -Dsonar.projectKey=dedis_dela
+          -Dsonar.projectKey=dedis_purb-db
           -Dsonar.go.tests.reportPaths=report.json
           -Dsonar.go.coverage.reportPaths=profile.cov
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
-
-    - name: Send coverage
-      if: matrix.platform == 'ubuntu-latest'
-      uses: shogo82148/actions-goveralls@v1
-      with:
-        path-to-profile: profile.cov
-        parallel: true
-
-  # notifies that all test jobs are finished.
-  finish:
-    needs: test
-    runs-on: ubuntu-latest
-    steps:
-      - uses: shogo82148/actions-goveralls@v1
-        with:
-          parallel-finished: true

Makefile

@@ -1,4 +1,4 @@
-.PHONY: all tidy generate lint vet test coverage pushdoc
+.PHONY: all tidy lint vet test coverage
 
 # Default "make" target to check locally that everything is ok, BEFORE pushing remotely
 all: lint vet test
@@ -9,19 +9,17 @@ tidy:
 
 # Some packages are excluded from staticcheck due to deprecated warnings: #208.
 lint: tidy
-	# Coding style static check.
-	@go install honnef.co/go/tools/cmd/staticcheck@latest
-	staticcheck `go list ./... | grep -Ev "(go\.dedis\.ch/dela/internal/testing|go\.dedis\.ch/dela/mino/minogrpc/ptypes)"`
+	golangci-lint run
 
 vet: tidy
-	@echo "⚠️ Warning: the following only works with go >= 1.14" && \
-	go install go.dedis.ch/dela/internal/mcheck && \
-	go vet -vettool=`go env GOPATH`/bin/mcheck -commentLen -ifInit ./...
+	go vet go.dedis.ch/purb-db/...
 
-# test runs all tests in DELA without coverage
 test: tidy
-	go test ./...
+	# Test without coverage
+	LLVL=""
+	go test go.dedis.ch/purb-db/...
 
-# test runs all tests in DELA and generate a coverage output (to be used by sonarcloud)
 coverage: tidy
-	go test -json -covermode=count -coverprofile=profile.cov ./... | tee report.json
+	# Test and generate a coverage output usable by sonarcloud
+	LLVL=""
+	go test -json -covermode=count -coverpkg=purb-db/... -coverprofile=profile.cov go.dedis.ch/purb-db/... | tee report.json

README.md

@@ -1,2 +1,2 @@
-# dela-purb
+# purb-db
 A {key,value} storage that is PURBified before saving it to disk.

go.mod

@@ -1,3 +1,38 @@
-module dela-purb
+module go.dedis.ch/purb-db
 
 go 1.21
+
+require (
+	github.com/stretchr/testify v1.8.4
+	go.dedis.ch/dela v0.0.0-20231011144949-4677467c030c
+	go.dedis.ch/kyber/v3 v3.1.1-0.20231024084410-31ea167adbbb
+	go.dedis.ch/libpurb v0.0.0-20231108133532-c70e1b84b632
+	golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa
+	golang.org/x/xerrors v0.0.0-20231012003039-104605ab7028
+)
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/cpuguy83/go-md2man/v2 v2.0.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.19 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_golang v1.5.1 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.10.0 // indirect
+	github.com/prometheus/procfs v0.7.3 // indirect
+	github.com/rs/zerolog v1.31.0 // indirect
+	github.com/russross/blackfriday/v2 v2.0.1 // indirect
+	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect
+	github.com/urfave/cli/v2 v2.2.0 // indirect
+	go.dedis.ch/fixbuf v1.0.3 // indirect
+	go.etcd.io/bbolt v1.3.5 // indirect
+	golang.org/x/crypto v0.14.0 // indirect
+	golang.org/x/sys v0.14.0 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -10,7 +10,7 @@ github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6r
 github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
 github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
-github.com/coreos/go-systemd/v22 v22.3.3-0.20220203105225-a9a7ef127534/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
+github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.0 h1:EoUDS0afbrsXAZ9YQ9jdu/mZ2sXgT1/2yyNng4PGlyM=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
@@ -33,8 +33,9 @@ github.com/golang/protobuf v1.5.2/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiu
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
+github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
@@ -45,10 +46,11 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/mattn/go-colorable v0.1.12 h1:jF+Du6AlPIjs2BiUiQlKOX0rt3SujHxPnksPKZbaA40=
-github.com/mattn/go-colorable v0.1.12/go.mod h1:u5H1YNBxpqRaxsYJYSkiCWKzEfiAb1Gb520KVy5xxl4=
-github.com/mattn/go-isatty v0.0.14 h1:yVuAays6BHfxijgZPzw+3Zlu5yQgKGP2/hcQbHb7S9Y=
-github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
+github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
+github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -82,9 +84,9 @@ github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsT
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
 github.com/prometheus/procfs v0.7.3 h1:4jVXhlkAyzOScmCkXBTOLRLTz8EeU+eyjrwB/EPq0VU=
 github.com/prometheus/procfs v0.7.3/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
-github.com/rs/xid v1.4.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
-github.com/rs/zerolog v1.28.0 h1:MirSo27VyNi7RJYP3078AA1+Cyzd2GB66qy3aUHvsWY=
-github.com/rs/zerolog v1.28.0/go.mod h1:NILgTygv/Uej1ra5XxGf82ZFSLk58MFGAUS2o6usyD0=
+github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
+github.com/rs/zerolog v1.31.0 h1:FcTR3NnLWW+NnTwwhFWiJSZr4ECLpqCm6QsEnyvbV4A=
+github.com/rs/zerolog v1.31.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
 github.com/russross/blackfriday/v2 v2.0.1 h1:lPqVAte+HuHNfhJ/0LC98ESWRz8afy9tM/0RK8m9o+Q=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/shurcooL/sanitized_anchor_name v1.0.0 h1:PdmoCO6wvbs+7yrJyMORt4/BmY5IYyJwS/kOiWx8mHo=
@@ -102,12 +104,20 @@ github.com/urfave/cli/v2 v2.2.0 h1:JTTnM6wKzdA0Jqodd966MVj4vWbbquZykeX1sKbe2C4=
 github.com/urfave/cli/v2 v2.2.0/go.mod h1:SE9GqnLQmjVa0iPEY0f1w3ygNIYcIJ0OKPMoW2caLfQ=
 go.dedis.ch/dela v0.0.0-20231011144949-4677467c030c h1:3qMO3ewks1QptS5GJyz59HYprgBEVUjk+9BWI6vEsRc=
 go.dedis.ch/dela v0.0.0-20231011144949-4677467c030c/go.mod h1:Oh/WK8JMO0POQg7nR3u436u+HwsZwPqPzDWAasgmFAU=
+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 v3.1.1-0.20231024084410-31ea167adbbb h1:G7GmitWgVMlkBaSzHJJo05bydYhLFCSPzKwCHTwf3NM=
+go.dedis.ch/kyber/v3 v3.1.1-0.20231024084410-31ea167adbbb/go.mod h1:nL0a5f3E//lnOCKumtzMmb8qzykxOVsihqp8C1Eb5rc=
+go.dedis.ch/libpurb v0.0.0-20231108133532-c70e1b84b632 h1:e3rOQfoyJm6ywIbuBcRwoKdWSUsPmcW9qdHO47dOmyc=
+go.dedis.ch/libpurb v0.0.0-20231108133532-c70e1b84b632/go.mod h1:XCi40g75txGSLusqJOanJytpkxiQLJzRb9RRV9UN2p4=
 go.etcd.io/bbolt v1.3.5 h1:XAzx9gjCb0Rxj7EoqcClPD1d5ZBxZJk0jbuoPHenBt0=
 go.etcd.io/bbolt v1.3.5/go.mod h1:G5EMThwa9y8QZGBClrRx5EY+Yw9kAhnjy3bSjsnlVTQ=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.1.0 h1:MDRAIl0xIo9Io2xV565hzXHw3zVseKrJKodhohM5CjU=
-golang.org/x/crypto v0.1.0/go.mod h1:RecgLatLF4+eUMCP1PoPZQb+cVrJcOPbHkTkbkB9sbw=
+golang.org/x/crypto v0.14.0 h1:wBqGXzWJW6m1XrIKlAH0Hs1JJ7+9KBwnIO8v66Q9cHc=
+golang.org/x/crypto v0.14.0/go.mod h1:MVFd36DqK4CsrnJYDkBA3VC4m2GkXAM0PvzMCn4JQf4=
+golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa h1:FRnLl4eNAQl8hwxVVC17teOw8kdjVDVAiFMtgUdTSRQ=
+golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa/go.mod h1:zk2irFbV9DP96SEBUUAy67IdHUaZuSnrz1n472HUCLE=
 golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190613194153-d28f0bde5980/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -121,12 +131,11 @@ golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200122134326-e047566fdf82/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
-golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.13.0 h1:Af8nKPmuFypiUBjVoU9V20FiaFXOcuZI21p0ycVYYGE=
-golang.org/x/sys v0.13.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
+golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20231012003039-104605ab7028 h1:+cNy6SZtPcJQH3LJVLOSmiC7MMxXNOb3PU/VUEz+EhU=

store/kv/blob.go

@@ -0,0 +1,90 @@
+// Blob is a wrapper around libpurb.Purb
+package kv
+
+import (
+	"go.dedis.ch/kyber/v3/group/curve25519"
+	"go.dedis.ch/kyber/v3/util/key"
+	"go.dedis.ch/libpurb/libpurb"
+	"golang.org/x/xerrors"
+
+	"go.dedis.ch/kyber/v3/util/random"
+)
+
+const numberOfRecipients = 1
+
+// NewBlob creates a new blob
+func NewBlob(keypair []key.Pair) *libpurb.Purb {
+	p := libpurb.NewPurb(
+		getSuiteInfo(),
+		false,
+		random.New(),
+	)
+	p.Recipients = createRecipients(keypair)
+
+	return p
+}
+
+// Encode encodes a slice of bytes into a blob
+func Encode(purb *libpurb.Purb, data []byte) ([]byte, error) {
+	err := purb.Encode(data)
+	blob := purb.ToBytes()
+
+	return blob, err
+}
+
+// Decode decodes a blob into a slice of bytes
+func Decode(purb *libpurb.Purb, blob []byte) ([]byte, error) {
+	success, decrypted, err := purb.Decode(blob)
+
+	if !success {
+		err = xerrors.Errorf("Failed to decrypt blob: %v", err)
+	}
+
+	return decrypted, err
+}
+
+// ---------------------------------------------------------------------------
+// helper functions
+
+// see example in libpurb
+func getSuiteInfo() libpurb.SuiteInfoMap {
+	info := make(libpurb.SuiteInfoMap)
+	cornerstoneLength := 32             // defined by Curve 25519
+	entryPointLength := 16 + 4 + 4 + 16 // 16-byte symmetric key + 2 * 4-byte offset positions + 16-byte authentication tag
+	info[curve25519.NewBlakeSHA256Curve25519(true).String()] = &libpurb.SuiteInfo{
+		AllowedPositions: []int{
+			12 + 0*cornerstoneLength,
+			12 + 1*cornerstoneLength,
+			12 + 3*cornerstoneLength,
+			12 + 4*cornerstoneLength,
+		},
+		CornerstoneLength: cornerstoneLength, EntryPointLength: entryPointLength,
+	}
+	return info
+}
+
+// see example in libpurb
+func createRecipients(keypair []key.Pair) []libpurb.Recipient {
+	r := make([]libpurb.Recipient, 0)
+	suites := []libpurb.Suite{curve25519.NewBlakeSHA256Curve25519(true)}
+
+	if len(keypair) < numberOfRecipients {
+		keypair = make([]key.Pair, 0)
+	}
+
+	for _, suite := range suites {
+		for i := 0; i < numberOfRecipients; i++ {
+			if len(keypair) < numberOfRecipients {
+				keypair = append(keypair, *key.NewKeyPair(suite))
+			}
+
+			r = append(r, libpurb.Recipient{
+				SuiteName:  suite.String(),
+				Suite:      suite,
+				PublicKey:  keypair[i].Public,
+				PrivateKey: keypair[i].Private,
+			})
+		}
+	}
+	return r
+}