add more specific error handeling to certs

src/account/account.rs

@@ -15,6 +15,7 @@ use bytemuck::bytes_of;
 use chrono::{NaiveDate, NaiveDateTime, Utc};
 use openssl::bn::BigNum;
 use openssl::ecdsa::EcdsaSig;
+use openssl::error::ErrorStack;
 use rand::Rng;
 use rocket::http::Status;
 use rocket::request::{FromRequest, Outcome};
@@ -262,7 +263,7 @@ pub async fn link_certificate_to_pid(
     sqlx::query(
         "INSERT INTO certificate_pids (cert_hash, pid)
          VALUES ($1, $2)
-         ON CONFLICT DO NOTHING"
+         ON CONFLICT DO NOTHING",
     )
     .bind(&hash[..])
     .bind(pid)
@@ -330,14 +331,17 @@ impl<'r> FromRequest<'r> for DeviceCert {
         };
 
         let cert = match Certificate::new(cert_header) {
-            Some(c) => c,
-            None => return Outcome::Error((Status::BadGateway, INVALID_TOKEN_ERRORS)),
+            Ok(c) => c,
+            Err(e) => {
+                println!("error occurred whilest getting cert data: {}", e);
+                return Outcome::Error((Status::BadGateway, INVALID_TOKEN_ERRORS));
+            }
         };
 
         let hash = cert.hash();
 
         let existing = sqlx::query_as::<_, CertificateRecord>(
-            "SELECT hash, banned FROM certificates WHERE hash = $1"
+            "SELECT hash, banned FROM certificates WHERE hash = $1",
         )
         .bind(&hash[..])
         .fetch_optional(pool)
@@ -359,7 +363,7 @@ impl<'r> FromRequest<'r> for DeviceCert {
         } else {
             sqlx::query(
                 "INSERT INTO certificates (hash, banned)
-                 VALUES ($1, false)"
+                 VALUES ($1, false)",
             )
             .bind(&hash[..])
             .execute(pool)
@@ -396,19 +400,36 @@ MFIwEAYHKoZIzj0CAQYFK4EEABsDPgAEAP1WBBgs8XUJIQDDCK5IOZEbb5+h1TqV
 rwgzSUcrAAFxMWm1kf/TDL9z2nZkuo0N+VtNEQREZDXA7aQv
 -----END PUBLIC KEY-----"#;
 
+#[derive(thiserror::Error, Debug)]
+enum CertError {
+    #[error("unable to decode base64: {0}")]
+    Base64(#[from] base64::DecodeError),
+    #[error("unable to decode outer cert: {0}")]
+    OuterBinError(binrw::Error),
+    #[error("unable to decode inner cert: {0}")]
+    BinError(binrw::Error),
+    #[error("unable to create openssl ecdsa sig: {0}")]
+    EcdsaSig(ErrorStack),
+    #[error("error whilest validating signature: {0}")]
+    CryptoVerifError(ErrorStack),
+    #[error("certificate is not valid")]
+    ValidationError,
+}
+
 impl Certificate {
-    fn new(data: &str) -> Option<Self> {
-        let data = BASE64_STANDARD.decode(data).unwrap();
+    fn new(data: &str) -> Result<Self, CertError> {
+        let data = BASE64_STANDARD.decode(data)?;
 
-        let cert = OuterCertificate::read(&mut Cursor::new(&data)).ok()?;
+        let cert =
+            OuterCertificate::read(&mut Cursor::new(&data)).map_err(CertError::OuterBinError)?;
 
-        println!("key");
+        let key = openssl::ec::EcKey::public_key_from_pem(PUB_PEM).expect("invalid pem file");
 
-        let key = openssl::ec::EcKey::public_key_from_pem(PUB_PEM).ok()?;
+        let sig_components = read_p1363(&cert.signature)
+            .expect("unable to read signature despite fixed size signature");
 
-        let sig_components = read_p1363(&cert.signature)?;
-
-        let sig = EcdsaSig::from_private_components(sig_components.0, sig_components.1).unwrap();
+        let sig = EcdsaSig::from_private_components(sig_components.0, sig_components.1)
+            .map_err(CertError::EcdsaSig)?;
 
         let mut hasher = openssl::sha::Sha256::new();
 
@@ -416,11 +437,14 @@ impl Certificate {
 
         let hash = hasher.finish();
 
-        if !sig.verify(&hash[..], &key).ok()? {
-            return None;
+        if !sig
+            .verify(&hash[..], &key)
+            .map_err(CertError::CryptoVerifError)?
+        {
+            return Err(CertError::ValidationError);
         }
 
-        Certificate::read(&mut Cursor::new(cert.data)).ok()
+        Certificate::read(&mut Cursor::new(cert.data)).map_err(CertError::BinError)
     }
 
     pub fn hash(&self) -> [u8; 32] {
@@ -446,3 +470,15 @@ fn read_p1363(data: &[u8]) -> Option<(BigNum, BigNum)> {
         BigNum::from_slice(&data[half_len..]).ok()?,
     ))
 }
+
+#[cfg(test)]
+mod test {
+    use crate::account::account::Certificate;
+
+    #[test]
+    fn test() {
+        const CERT: &str = "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";
+
+        Certificate::new(CERT).unwrap();
+    }
+}