api: rename /api/versions to versionsapi and /api/attestationcfig to attestationconfigapi (#1876)

* rename to attestationconfigapi + put client and fetcher inside pkg

* rename api/version to versionsapi and put fetcher + client inside pkg

* rename AttestationConfigAPIFetcher to Fetcher

internal/api/attestationconfigapi/fetcher_test.go

@@ -0,0 +1,108 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+package attestationconfigapi
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var testCfg = AzureSEVSNPVersionAPI{
+	AzureSEVSNPVersion: AzureSEVSNPVersion{
+		Microcode:  93,
+		TEE:        0,
+		SNP:        6,
+		Bootloader: 2,
+	},
+}
+
+func TestFetchLatestAzureSEVSNPVersion(t *testing.T) {
+	testcases := map[string]struct {
+		signature []byte
+		wantErr   bool
+		want      AzureSEVSNPVersionAPI
+	}{
+		"get version with valid signature": {
+			signature: []byte("MEQCIBPEbYg89MIQuaGStLhKGLGMKvKFoYCaAniDLwoIwulqAiB+rj7KMaMOMGxmUsjI7KheCXSNM8NzN+tuDw6AywI75A=="), // signed with release key
+			want:      testCfg,
+		},
+		"fail with invalid signature": {
+			signature: []byte("invalid"),
+			wantErr:   true,
+		},
+	}
+	for name, tc := range testcases {
+		t.Run(name, func(t *testing.T) {
+			client := &http.Client{
+				Transport: &fakeConfigAPIHandler{
+					signature: tc.signature,
+				},
+			}
+			fetcher := NewFetcherWithClient(client)
+			res, err := fetcher.FetchAzureSEVSNPVersionLatest(context.Background())
+
+			assert := assert.New(t)
+			if tc.wantErr {
+				assert.Error(err)
+			} else {
+				assert.NoError(err)
+				assert.Equal(testCfg, res)
+			}
+		})
+	}
+}
+
+type fakeConfigAPIHandler struct {
+	signature []byte
+}
+
+// RoundTrip resolves the request and returns a dummy response.
+func (f *fakeConfigAPIHandler) RoundTrip(req *http.Request) (*http.Response, error) {
+	if req.URL.Path == "/constellation/v1/attestation/azure-sev-snp/list" {
+		res := &http.Response{}
+		data := []string{"2021-01-01-01-01.json", "2019-01-01-01-02.json"} // return multiple versions to check that latest version is correctly selected
+		bt, err := json.Marshal(data)
+		if err != nil {
+			return nil, err
+		}
+		res.Body = io.NopCloser(bytes.NewReader(bt))
+		res.Header = http.Header{}
+		res.Header.Set("Content-Type", "application/json")
+		res.StatusCode = http.StatusOK
+		return res, nil
+	} else if req.URL.Path == "/constellation/v1/attestation/azure-sev-snp/2021-01-01-01-01.json" {
+		res := &http.Response{}
+		bt, err := json.Marshal(testCfg)
+		if err != nil {
+			return nil, err
+		}
+		res.Body = io.NopCloser(bytes.NewReader(bt))
+		res.StatusCode = http.StatusOK
+		return res, nil
+
+	} else if req.URL.Path == "/constellation/v1/attestation/azure-sev-snp/2021-01-01-01-01.json.sig" {
+		res := &http.Response{}
+		obj := AzureSEVSNPVersionSignature{
+			Signature: f.signature,
+		}
+		bt, err := json.Marshal(obj)
+		if err != nil {
+			return nil, err
+		}
+		res.Body = io.NopCloser(bytes.NewReader(bt))
+		res.StatusCode = http.StatusOK
+		return res, nil
+
+	}
+	return nil, errors.New("no endpoint found")
+}