~~NOTOC~~
{{wvds:title>Installation}}

===== Installation: 3-Step OEM Integration =====

<WRAP center round tip 80%>
The WvdS Crypto Service is a **ready-to-use black box**. You don't need to compile or configure anything. Simply follow these three steps.
</WRAP>

----

==== Step 1: Include Daemon in L4Re Image ====

Add the Crypto Service to your ''modules.list'':

<code lua>
-- modules.list
module wvds_crypto_service
module libcrypto.so.3
module libssl.so.3
</code>

----

==== Step 2: Start Daemon (Ned-Script) ====

Start the daemon in your Ned-Script:

<code lua>
local L4 = require("L4")

-- Create shared memory for communication
local crypto_ds = L4.Env.ram:create(64 * 1024, L4.Dataspace.ALL):m("rw")

-- Start Crypto Daemon
local crypto_daemon = L4.default_loader:start(
    { caps = { crypto_ep = crypto_ds:svr() } },
    "rom/wvds_crypto_service"
)

-- Your Gateway gets the client side
local gateway = L4.default_loader:start(
    { caps = { crypto_ep = crypto_ds } },
    "rom/iss_gateway"
)
</code>

**Explanation:**
  * ''crypto_ds'' - Shared Memory Dataspace (64 KB)
  * ''crypto_ep = crypto_ds:svr()'' - Server side for daemon
  * ''crypto_ep = crypto_ds'' - Client side for your Gateway

----

==== Step 3: Communicate from Your Code ====

Include the header and use the helper functions:

<code c>
#include "wvds_crypto.h"

void encrypt_sensor_data(const uint8_t* data, size_t len) {
    uint8_t request[1024];
    size_t request_len = sizeof(request);

    // Build request
    int rc = wvds_build_aes_encrypt_request(
        request, &request_len,
        1,                      // Key-ID
        "sensor", 6,            // AAD
        data, len               // Plaintext
    );

    if (rc == 0) {
        // Copy request to shared memory
        memcpy(shared_memory, request, request_len);

        // Signal daemon
        signal_crypto_daemon();

        // Wait for response
        wait_for_response();

        // Parse response
        uint8_t nonce[12], tag[16], ciphertext[1024];
        size_t ct_len;
        wvds_parse_aes_encrypt_response(
            shared_memory, response_len,
            nonce, tag, ciphertext, &ct_len
        );
    }
}
</code>

**That's all!**

----

==== Optional Configuration ====

If you want to change the default settings, you can provide a ''config.json'':

<code json>
{
    "version": "0.2.0",
    "key_storage": {
        "type": "file",
        "path": "/data/keys",
        "encryption": "aes-256-gcm"
    },
    "rate_limit": {
        "max_requests_per_second": 1000,
        "burst": 100
    },
    "logging": {
        "level": "info",
        "destination": "syslog"
    }
}
</code>

=== Key Storage Options ===

| Type | Description |
| ''file'' | Keys in filesystem (default) |
| ''tpm'' | Keys in TPM 2.0 |
| ''hsm'' | Keys in external HSM |

----

==== Verification ====

Check if the daemon is running correctly:

<code bash>
# L4Re Console
l4> ps
... wvds_crypto_service ...

# Send test request
l4> crypto_test encrypt "Hello World"
OK: Ciphertext = 0x...
</code>

----

==== Troubleshooting ====

| Problem | Solution |
| Daemon doesn't start | ''libcrypto.so.3'' in modules.list? |
| Shared memory error | Dataspace large enough (min 64 KB)? |
| Capability error | ''crypto_ep'' correctly mapped? |
| FIPS error | ''fipsmodule.cnf'' present? |

See also [[.:sicherheit#troubleshooting|Security > Troubleshooting]] for additional errors.

----

[[.:start|< Back to Overview]] | [[.:integration|Next: Code Examples >]]