bugfix: ssz post-requests should check content type not accept (#13482)

* updating post requests that accept ssz to check content type instead of accept header * radek's review comments to make things more clear
2026-01-08 21:08:10 -05:00 · 2024-01-18 11:41:31 -06:00
parent fc05e306dd
commit 4d2067dbae
8 changed files with 106 additions and 70 deletions
--- a/beacon-chain/rpc/eth/beacon/handlers.go
+++ b/beacon-chain/rpc/eth/beacon/handlers.go
@@ -62,7 +62,7 @@ func (s *Server) GetBlock(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if httputil.SszRequested(r) {
+	if httputil.RespondWithSsz(r) {
 		s.getBlockSSZ(ctx, w, blk)
 	} else {
 		s.getBlock(ctx, w, blk)
@@ -105,7 +105,7 @@ func (s *Server) GetBlockV2(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if httputil.SszRequested(r) {
+	if httputil.RespondWithSsz(r) {
 		s.getBlockSSZV2(ctx, w, blk)
 	} else {
 		s.getBlockV2(ctx, w, blk)
@@ -205,7 +205,7 @@ func (s *Server) GetBlindedBlock(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if httputil.SszRequested(r) {
+	if httputil.RespondWithSsz(r) {
 		s.getBlindedBlockSSZ(ctx, w, blk)
 	} else {
 		s.getBlindedBlock(ctx, w, blk)
@@ -953,8 +953,7 @@ func (s *Server) PublishBlindedBlock(w http.ResponseWriter, r *http.Request) {
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
 		return
 	}
-	isSSZ := httputil.SszRequested(r)
-	if isSSZ {
+	if httputil.IsRequestSsz(r) {
 		s.publishBlindedBlockSSZ(ctx, w, r, false)
 	} else {
 		s.publishBlindedBlock(ctx, w, r, false)
@@ -978,8 +977,7 @@ func (s *Server) PublishBlindedBlockV2(w http.ResponseWriter, r *http.Request) {
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
 		return
 	}
-	isSSZ := httputil.SszRequested(r)
-	if isSSZ {
+	if httputil.IsRequestSsz(r) {
 		s.publishBlindedBlockSSZ(ctx, w, r, true)
 	} else {
 		s.publishBlindedBlock(ctx, w, r, true)
@@ -1250,8 +1248,7 @@ func (s *Server) PublishBlock(w http.ResponseWriter, r *http.Request) {
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
 		return
 	}
-	isSSZ := httputil.SszRequested(r)
-	if isSSZ {
+	if httputil.IsRequestSsz(r) {
 		s.publishBlockSSZ(ctx, w, r, false)
 	} else {
 		s.publishBlock(ctx, w, r, false)
@@ -1273,8 +1270,7 @@ func (s *Server) PublishBlockV2(w http.ResponseWriter, r *http.Request) {
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
 		return
 	}
-	isSSZ := httputil.SszRequested(r)
-	if isSSZ {
+	if httputil.IsRequestSsz(r) {
 		s.publishBlockSSZ(ctx, w, r, true)
 	} else {
 		s.publishBlock(ctx, w, r, true)
--- a/beacon-chain/rpc/eth/beacon/handlers_test.go
+++ b/beacon-chain/rpc/eth/beacon/handlers_test.go
@@ -1169,7 +1169,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetPhase0().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1199,7 +1199,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetAltair().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Altair))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1224,7 +1224,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1250,7 +1250,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetCapella().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1276,7 +1276,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetDeneb().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Deneb))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1296,7 +1296,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1317,7 +1317,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1335,7 +1335,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		}

 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte("foo")))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlock(writer, request)
@@ -1531,7 +1531,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetPhase0().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1561,7 +1561,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetAltair().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Altair))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1587,7 +1587,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1613,7 +1613,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedCapella().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1639,7 +1639,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedDeneb().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Deneb))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1672,7 +1672,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1690,7 +1690,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		}

 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte("foo")))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlindedBlock(writer, request)
@@ -1899,7 +1899,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetPhase0().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1929,7 +1929,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetAltair().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Altair))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1954,7 +1954,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1980,7 +1980,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetCapella().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2006,7 +2006,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetDeneb().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Deneb))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2026,7 +2026,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2047,7 +2047,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2061,7 +2061,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		}

 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.CapellaBlock)))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlockV2(writer, request)
@@ -2078,7 +2078,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		}

 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte("foo")))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlockV2(writer, request)
@@ -2286,7 +2286,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetPhase0().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2316,7 +2316,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetAltair().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Altair))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2342,7 +2342,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2368,7 +2368,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedCapella().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2394,7 +2394,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedDeneb().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Deneb))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2427,7 +2427,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2441,7 +2441,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		}

 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.BlindedCapellaBlock)))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlockV2(writer, request)
@@ -2458,7 +2458,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		}

 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte("foo")))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlindedBlockV2(writer, request)
--- a/beacon-chain/rpc/eth/blob/handlers.go
+++ b/beacon-chain/rpc/eth/blob/handlers.go
@@ -46,8 +46,7 @@ func (s *Server) Blobs(w http.ResponseWriter, r *http.Request) {
 	for i := range verifiedBlobs {
 		sidecars = append(sidecars, verifiedBlobs[i].BlobSidecar)
 	}
-	ssz := httputil.SszRequested(r)
-	if ssz {
+	if httputil.RespondWithSsz(r) {
 		sidecarResp := &eth.BlobSidecars{
 			Sidecars: sidecars,
 		}
--- a/beacon-chain/rpc/eth/debug/handlers.go
+++ b/beacon-chain/rpc/eth/debug/handlers.go
@@ -54,7 +54,7 @@ func (s *Server) GetBeaconStateV2(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if httputil.SszRequested(r) {
+	if httputil.RespondWithSsz(r) {
 		s.getBeaconStateSSZV2(ctx, w, []byte(stateId))
 	} else {
 		s.getBeaconStateV2(ctx, w, []byte(stateId))
--- a/beacon-chain/rpc/eth/validator/handlers_block.go
+++ b/beacon-chain/rpc/eth/validator/handlers_block.go
@@ -201,7 +201,7 @@ func (s *Server) ProduceBlockV3(w http.ResponseWriter, r *http.Request) {
 }

 func (s *Server) produceBlockV3(ctx context.Context, w http.ResponseWriter, r *http.Request, v1alpha1req *eth.BlockRequest, requiredType blockType) {
-	isSSZ := httputil.SszRequested(r)
+	isSSZ := httputil.RespondWithSsz(r)
 	v1alpha1resp, err := s.V1Alpha1Server.GetBeaconBlock(ctx, v1alpha1req)
 	if err != nil {
 		httputil.HandleError(w, err.Error(), http.StatusInternalServerError)
--- a/network/httputil/BUILD.bazel
+++ b/network/httputil/BUILD.bazel
@@ -22,5 +22,6 @@ go_test(
    deps = [
        "//api:go_default_library",
        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
    ],
 )
--- a/network/httputil/reader.go
+++ b/network/httputil/reader.go
@@ -12,8 +12,8 @@ import (
 // match a number with optional decimals
 var priorityRegex = regexp.MustCompile(`q=(\d+(?:\.\d+)?)`)

-// SszRequested takes a http request and checks to see if it should be requesting a ssz response.
-func SszRequested(req *http.Request) bool {
+// RespondWithSsz takes a http request and checks to see if it should be requesting a ssz response.
+func RespondWithSsz(req *http.Request) bool {
 	accept := req.Header.Values("Accept")
 	if len(accept) == 0 {
 		return false
@@ -51,3 +51,8 @@ func SszRequested(req *http.Request) bool {

 	return currentType == api.OctetStreamMediaType
 }
+
+// IsRequestSsz checks if the request object should be interpreted as ssz
+func IsRequestSsz(req *http.Request) bool {
+	return req.Header.Get("Content-Type") == api.OctetStreamMediaType
+}
--- a/network/httputil/reader_test.go
+++ b/network/httputil/reader_test.go
@@ -1,88 +1,123 @@
 package httputil

 import (
+	"bytes"
 	"fmt"
+	"net/http"
 	"net/http/httptest"
 	"testing"

 	"github.com/prysmaticlabs/prysm/v4/api"
 	"github.com/prysmaticlabs/prysm/v4/testing/assert"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
 )

-func TestSSZRequested(t *testing.T) {
+func TestRespondWithSsz(t *testing.T) {
 	t.Run("ssz_requested", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
 		request.Header["Accept"] = []string{api.OctetStreamMediaType}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, true, result)
 	})

 	t.Run("ssz_content_type_first", func(t *testing.T) {
 		request := httptest.NewRequest("GET", "http://foo.example", nil)
 		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s", api.OctetStreamMediaType, api.JsonMediaType)}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, true, result)
 	})

 	t.Run("ssz_content_type_preferred_1", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
 		request.Header["Accept"] = []string{fmt.Sprintf("%s;q=0.9,%s", api.JsonMediaType, api.OctetStreamMediaType)}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, true, result)
 	})

 	t.Run("ssz_content_type_preferred_2", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
 		request.Header["Accept"] = []string{fmt.Sprintf("%s;q=0.95,%s;q=0.9", api.OctetStreamMediaType, api.JsonMediaType)}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, true, result)
 	})

 	t.Run("other_content_type_preferred", func(t *testing.T) {
 		request := httptest.NewRequest("GET", "http://foo.example", nil)
 		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s;q=0.9", api.JsonMediaType, api.OctetStreamMediaType)}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, false, result)
 	})

 	t.Run("other_params", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
 		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s;q=0.9,otherparam=xyz", api.JsonMediaType, api.OctetStreamMediaType)}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, false, result)
 	})

 	t.Run("no_header", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
-		result := SszRequested(request)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
+		result := RespondWithSsz(request)
 		assert.Equal(t, false, result)
 	})

 	t.Run("empty_header", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
 		request.Header["Accept"] = []string{}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, false, result)
 	})

 	t.Run("empty_header_value", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
 		request.Header["Accept"] = []string{""}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, false, result)
 	})

 	t.Run("other_content_type", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
 		request.Header["Accept"] = []string{"application/other"}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
 		assert.Equal(t, false, result)
 	})

 	t.Run("garbage", func(t *testing.T) {
-		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request := httptest.NewRequest(http.MethodGet, "http://foo.example", nil)
 		request.Header["Accept"] = []string{"This is Sparta!!!"}
-		result := SszRequested(request)
+		result := RespondWithSsz(request)
+		assert.Equal(t, false, result)
+	})
+}
+
+func TestIsRequestSsz(t *testing.T) {
+	t.Run("ssz Post happy path", func(t *testing.T) {
+		var body bytes.Buffer
+		_, err := body.WriteString("something")
+		require.NoError(t, err)
+		request := httptest.NewRequest(http.MethodPost, "http://foo.example", &body)
+		request.Header["Content-Type"] = []string{api.OctetStreamMediaType}
+		result := IsRequestSsz(request)
+		assert.Equal(t, true, result)
+	})
+
+	t.Run("ssz Post missing header", func(t *testing.T) {
+		request := httptest.NewRequest(http.MethodPost, "http://foo.example", nil)
+		result := IsRequestSsz(request)
+		assert.Equal(t, false, result)
+	})
+
+	t.Run("ssz Post wrong content type", func(t *testing.T) {
+		request := httptest.NewRequest(http.MethodPost, "http://foo.example", nil)
+		request.Header["Content-Type"] = []string{"application/other"}
+		result := IsRequestSsz(request)
+		assert.Equal(t, false, result)
+	})
+
+	t.Run("ssz Post json content type", func(t *testing.T) {
+		request := httptest.NewRequest(http.MethodPost, "http://foo.example", nil)
+		request.Header["Content-Type"] = []string{api.JsonMediaType}
+		result := IsRequestSsz(request)
 		assert.Equal(t, false, result)
 	})
 }