Header Enrichment

This feature would allow operators to enable header enrichment for UE HTTP traffic. This way AGW could add subscriber information to HTTP requests. There could be privacy implication of this feature, so operator should check local laws before using this feature. Today AGW would add following parameters to HTTP request:

IMSI
MSISDN

Following are steps to configure Header enrichment

1. Enable header enrichment Feature for AGW

There are two option to enable header enrichment:

Enable it in pipelineD config file You would need to ssh on the AGW and add following line to pipelineD config file '/etc/magma/pipelined.yml'
```
he_enabled: true
```

Enable via '/LTE/{Network-id}/{Gateway-id}/' API You would need to define following parameters for Header enrichment under 'cellular' parameter.

"he_config": {
   "enable_header_enrichment": true,

   "enable_encryption": false,

     "he_hash_function": "MD5",
       "hmac_key": "Xs21Ncas87"

     "he_encryption_algorithm": "RC4",
        "encryption_key": "C14r0315v0x",

     "he_encoding_type": "BASE64",
 },

enable_header_enrichment: This would add plain text to HTTP requests
enable_encryption: This would encrypt the data passed in HTTP header. First the data is hashed then encrypted and encoded as per configuration.
he_hash_function: User Data would be hashed using specified algorithm and key from 'hmac_key'. Supported algorithms: MD5, HEX, SHA256
he_encryption_algorithm: Hashed data is encrypted using specified algorithm and key from 'encryption_key'. Supported algorithms: "RC4", "AES256_CBC_HMAC_MD5", "AES256_ECB_HMAC_MD5", "GZIPPED_AES256_ECB_SHA1"
he_encoding_type: Encode the UE data using specified algorithm. Supported algorithms: "BASE64", "HEX2BIN"

2. Define Policy Rule

You need to define policy that defines flow along with list of URL that needs header enrichment.

This can be done via NMS. Use 'traffic/policy' Page define egress policy. Following example show required parameters for Header enrichment rule.

{
  "flow_list": [
    {
      "action": "PERMIT",
      "match": {
        "direction": "UPLINK",
        "ip_dst": {
          "address": "192.168.0.0/16",
          "version": "IPv4"
        },
        "ip_proto": "IPPROTO_TCP",
        "ip_src": {
          "version": "IPv4"
        },
        "tcp_dst": 80
      }
    }
  ],
  "header_enrichment_targets": [
    "abc.com"
  ],
  "id": "test123",
  "priority": 1,
  "rating_group": 1000,
  "tracking_type": "NO_TRACKING"
}

Please note this rule needs to have single flow with following parameters

Mandatory field: action equals permit.
Mandatory field: Direction needs to be uplink.
Mandatory field: tcp_dst port needs to be 80 (http).
Mandatory field: ip_dst is IP address range of the HTTP servers.
Mandatory field: header_enrichment_targets which is list of URLs. Do not specify http protocol in URL name, for example http://abc.com is not supported, but abc.com is a valid target.
Define Policy tracking according to your requirements.

3. Apply the policy to subscribers

Now apply the rule to subscribers. This can be using by '/LTE/{network-ID}/Subscribers/{subscriber-id}/' API

"active_policies": [
    "test123"
],