Changes crypto provider configuration build failure to return an error instead of panic

Author: SirCipher

client/swimos_client/src/lib.rs

@@ -140,7 +140,7 @@ impl SwimClientTlsBuilder {
             RustlsClientNetworking::build(
                 Arc::new(Resolver::new().await),
                 tls_config,
-                crypto_provider.build(),
+                crypto_provider.try_build()?,
             )?,
         )
         .await)

runtime/swimos_remote/src/tls/errors.rs

@@ -32,4 +32,6 @@ pub enum TlsError {
     /// Performing the TLS handshake failed.
     #[error("TLS handshake failed: {0}")]
     HandshakeFailed(std::io::Error),
+    #[error("Invalid cryptographic provider configured: {0}")]
+    InvalidCryptoProvider(String),
 }

runtime/swimos_remote/src/tls/mod.rs

@@ -35,11 +35,15 @@ pub enum CryptoProviderConfig {
 }
 
 impl CryptoProviderConfig {
-    pub fn build(self) -> Arc<CryptoProvider> {
+    pub fn try_build(self) -> Result<Arc<CryptoProvider>, TlsError> {
         match self {
             CryptoProviderConfig::ProcessDefault => CryptoProvider::get_default()
-                .expect("No default cryptographic provider specified")
-                .clone(),
+                .ok_or_else(|| {
+                    TlsError::InvalidCryptoProvider(
+                        "No default cryptographic provider specified".to_string(),
+                    )
+                })
+                .cloned(),
             CryptoProviderConfig::FromFeatureFlags => {
                 #[cfg(all(feature = "ring_provider", not(feature = "aws_lc_rs_provider")))]
                 {
@@ -53,10 +57,10 @@ impl CryptoProviderConfig {
 
                 #[allow(unreachable_code)]
                 {
-                    panic!("Ambiguous cryptographic provider feature flags specified. Only \"ring_provider\" or \"aws_lc_rs_provider\" may be specified")
+                    Err(TlsError::InvalidCryptoProvider("Ambiguous cryptographic provider feature flags specified. Only \"ring_provider\" or \"aws_lc_rs_provider\" may be specified".to_string()))
                 }
             }
-            CryptoProviderConfig::Provided(provider) => provider,
+            CryptoProviderConfig::Provided(provider) => Ok(provider),
         }
     }
 }

server/swimos_server_app/src/server/builder/mod.rs

@@ -200,7 +200,7 @@ impl ServerBuilder {
             deflate,
             introspection,
         };
-        let crypto_provider = crypto_provider.build();
+        let crypto_provider = crypto_provider.try_build()?;
 
         if let Some(tls_conf) = tls_config {
             let client =