feat: server sdk (#47)

* New webrtc build scripts (Still not integrated within the SDK)
* New livekit-api crate (Integrate the server sdk protocol of livekit)
* Moved livekit-utils to livekit-protocol

livekit-api/src/webhook_receiver.rs

@@ -0,0 +1,55 @@
+// Webhooks are not yet integrated into the Rust SDK.
+// Our webhooks protocol use protojson which isn't supported by Prost
+
+/*
+use crate::access_token::{AccessTokenError, TokenVerifier};
+use livekit_protocol as proto;
+use serde_json;
+use sha2::{Digest, Sha256};
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum WebhookError {
+    #[error("invalid signature")]
+    InvalidSignature,
+    #[error("failed to verify the authorization: {0}")]
+    InvalidAuth(#[from] AccessTokenError),
+    #[error("invalid body, failed to decode: {0}")]
+    InvalidData(#[from] serde_json::Error),
+}
+
+#[derive(Clone, Debug)]
+pub struct WebhookReceiver {
+    token_verifier: TokenVerifier,
+}
+
+impl WebhookReceiver {
+    pub fn new(token_verifier: TokenVerifier) -> Self {
+        Self { token_verifier }
+    }
+
+    pub fn receive(
+        &self,
+        body: &str,
+        auth_token: &str,
+    ) -> Result<proto::WebhookEvent, WebhookError> {
+        let claims = self.token_verifier.verify(auth_token)?;
+
+        let mut hasher = Sha256::new();
+        hasher.update(body);
+        let hash = hasher.finalize();
+
+        let hex: Result<Vec<u8>, std::num::ParseIntError> = (0..claims.sha256.len())
+            .step_by(2)
+            .map(|i| u8::from_str_radix(&claims.sha256[i..i + 2], 16))
+            .collect();
+
+        let hex = hex.map_err(|_| WebhookError::InvalidSignature)?; // Failed to parse
+
+        if &hex[..] != &hash[..] {
+            return Err(WebhookError::InvalidSignature);
+        }
+
+        Ok(serde_json::from_str(body)?)
+    }
+}*/