node/node_test: Add RSA to crypto benchmark

node/pkg/node/node_test.go

@@ -1061,6 +1061,44 @@ func BenchmarkCrypto(b *testing.B) {
 		})
 	})
 
+	/*
+		RSA is an option for libp2p.
+		In an optimized RSA implementation, signature verification in RSA can be faster than with elliptic curves, while signature generation is always slower.
+		Since libp2p is verification-heavy, this might overall still be a faster option.
+		This benchmarks show that the libp2p RSA sigverify seems to be unoptimized and is actually slower than ED25519, as of go-libp2p v0.29.2:
+			libp2p_(Ed25519)/sign-64		36178 ns/op
+			libp2p_(Ed25519)/verify-64		85326 ns/op
+			libp2p_(RSA)/sign-64		  2226550 ns/op
+			libp2p_(RSA)/verify-64		   327945 ns/op
+	*/
+	b.Run("libp2p (RSA)", func(b *testing.B) {
+
+		r := math_rand.New(math_rand.NewSource(0)) //#nosec G404 testnet / devnet keys are public knowledge
+		p2pKey, _, err := libp2p_crypto.GenerateKeyPairWithReader(libp2p_crypto.RSA, 2048, r)
+		if err != nil {
+			panic(err)
+		}
+
+		b.Run("sign", func(b *testing.B) {
+			msgs := signingMsgs(b.N)
+			b.ResetTimer()
+			signMsgsP2p(p2pKey, msgs)
+		})
+
+		b.Run("verify", func(b *testing.B) {
+			msgs := signingMsgs(b.N)
+			signatures := signMsgsP2p(p2pKey, msgs)
+			b.ResetTimer()
+
+			// RSA.Verify
+			for i := 0; i < b.N; i++ {
+				ok, err := p2pKey.GetPublic().Verify(msgs[i], signatures[i])
+				assert.NoError(b, err)
+				assert.True(b, ok)
+			}
+		})
+	})
+
 	b.Run("ethcrypto (secp256k1)", func(b *testing.B) {
 
 		gk := devnet.InsecureDeterministicEcdsaKeyByIndex(ethcrypto.S256(), 0)