TLS origination from sidecar proxy failing with error [TLS error: 268436576:SSL routines:OPENSSL_internal:]

Question

I am trying to initiate a mTLS connection directly from the sidecar proxy container to the external service without any egress gateway.
My current config looks something like below. As you can see, I'm trying to upgrade the http requests to https with the client certs before reaching out to the external service.
Not sure if the config I have is correct though.

apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: somedomain-mtls
spec:
  hosts:
  - somedomain.com
  ports:
  - number: 443
    name: http
    protocol: HTTP
  resolution: DNS
  location: MESH_EXTERNAL
---

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: somedomain-mtls
spec:
  hosts:
  - somedomain.com
  http:
  - match:
    - port: 80
    route:
    - destination:
        host: somedomain.com
        port:
          number: 443
      weight: 100
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: somedomain-mtls
spec:
  host: somedomain.com
  trafficPolicy:
    loadBalancer:
      simple: ROUND_ROBIN
    portLevelSettings:
    - port:
        number: 443
      tls:
          mode: MUTUAL
          clientCertificate: /etc/istio/client-certs/client.pem
          privateKey: /etc/istio/client-certs/client.key
          caCertificates: /etc/istio/client-certs/ca.pem
          sni: somedomain.com
---

From the container, I am trying to reach the service using http but getting 503. On further checking the sidecar proxy logs, I see OpenSSL internal error but without any reason. Wondering what is wrong or being missed here.

2020-12-09T22:29:13.832279Z debug   envoy pool  [external/envoy/source/common/http/conn_pool_base.cc:337] queueing request due to no available connections
2020-12-09T22:29:13.832283Z debug   envoy pool  [external/envoy/source/common/http/conn_pool_base.cc:47] creating a new connection
2020-12-09T22:29:13.832310Z debug   envoy client    [external/envoy/source/common/http/codec_client.cc:34] [C1272] connecting
2020-12-09T22:29:13.832315Z debug   envoy connection    [external/envoy/source/common/network/connection_impl.cc:727] [C1272] connecting to x.x.x.x:443
2020-12-09T22:29:13.832357Z debug   envoy connection    [external/envoy/source/common/network/connection_impl.cc:736] [C1272] connection in progress
2020-12-09T22:29:13.857767Z debug   envoy connection    [external/envoy/source/common/network/connection_impl.cc:592] [C1272] connected
2020-12-09T22:29:13.857823Z debug   envoy connection    [external/envoy/source/extensions/transport_sockets/tls/ssl_socket.cc:191] [C1272] handshake expecting read
2020-12-09T22:29:13.881971Z debug   envoy connection    [external/envoy/source/extensions/transport_sockets/tls/ssl_socket.cc:198] [C1272] handshake error: 1
2020-12-09T22:29:13.881983Z debug   envoy connection    [external/envoy/source/extensions/transport_sockets/tls/ssl_socket.cc:226] [C1272] TLS error: 268436576:SSL routines:OPENSSL_internal:
2020-12-09T22:29:13.881989Z debug   envoy connection    [external/envoy/source/common/network/connection_impl.cc:200] [C1272] closing socket: 0
2020-12-09T22:29:13.882004Z debug   envoy client    [external/envoy/source/common/http/codec_client.cc:91] [C1272] disconnect. resetting 0 pending requests
2020-12-09T22:29:13.882010Z debug   envoy pool  [external/envoy/source/common/http/conn_pool_base.cc:265] [C1272] client disconnected, failure reason: TLS error: 268436576:SSL routines:OPENSSL_internal:
2020-12-09T22:29:13.882022Z debug   envoy router    [external/envoy/source/common/router/router.cc:1018] [C1271][S2062324833167670924] upstream reset: reset reason connection failure

Any pointers would be really helpful.

Thanks