From 4e5b41f150c32e1f8ff1e0346bde44defd98dfc2 Mon Sep 17 00:00:00 2001
From: link2xt <link2xt@testrun.org>
Date: Mon, 25 Sep 2023 14:03:09 +0000
Subject: [PATCH] fix: require valid email addresses in
 dc_provider_new_from_email[_with_dns]()

---
 deltachat-ffi/src/lib.rs | 16 +++++++++++++---
 src/provider.rs          | 36 ++++++++++++++++++++++++++++--------
 2 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/deltachat-ffi/src/lib.rs b/deltachat-ffi/src/lib.rs
index ba33b9637..8025620ef 100644
--- a/deltachat-ffi/src/lib.rs
+++ b/deltachat-ffi/src/lib.rs
@@ -4531,7 +4531,14 @@ pub unsafe extern "C" fn dc_provider_new_from_email(
 
     let ctx = &*context;
 
-    match block_on(provider::get_provider_info(ctx, addr.as_str(), true)) {
+    match block_on(provider::get_provider_info_by_addr(
+        ctx,
+        addr.as_str(),
+        true,
+    ))
+    .log_err(ctx)
+    .unwrap_or_default()
+    {
         Some(provider) => provider,
         None => ptr::null_mut(),
     }
@@ -4558,11 +4565,14 @@ pub unsafe extern "C" fn dc_provider_new_from_email_with_dns(
 
     match socks5_enabled {
         Ok(socks5_enabled) => {
-            match block_on(provider::get_provider_info(
+            match block_on(provider::get_provider_info_by_addr(
                 ctx,
                 addr.as_str(),
                 socks5_enabled,
-            )) {
+            ))
+            .log_err(ctx)
+            .unwrap_or_default()
+            {
                 Some(provider) => provider,
                 None => ptr::null_mut(),
             }
diff --git a/src/provider.rs b/src/provider.rs
index 9a8a438ca..fe7073ebe 100644
--- a/src/provider.rs
+++ b/src/provider.rs
@@ -8,6 +8,7 @@ use trust_dns_resolver::{config, AsyncResolver, TokioAsyncResolver};
 use crate::config::Config;
 use crate::context::Context;
 use crate::provider::data::{PROVIDER_DATA, PROVIDER_IDS};
+use crate::tools::EmailAddress;
 
 /// Provider status according to manual testing.
 #[derive(Debug, Display, Copy, Clone, PartialEq, Eq, FromPrimitive, ToPrimitive)]
@@ -175,21 +176,30 @@ fn get_resolver() -> Result<TokioAsyncResolver> {
     Ok(resolver)
 }
 
+/// Returns provider for the given an e-mail address.
+///
+/// Returns an error if provided address is not valid.
+pub async fn get_provider_info_by_addr(
+    context: &Context,
+    addr: &str,
+    skip_mx: bool,
+) -> Result<Option<&'static Provider>> {
+    let addr = EmailAddress::new(addr)?;
+
+    let provider = get_provider_info(context, &addr.domain, skip_mx).await;
+    Ok(provider)
+}
+
 /// Returns provider for the given domain.
 ///
 /// This function looks up domain in offline database first. If not
 /// found, it queries MX record for the domain and looks up offline
 /// database for MX domains.
-///
-/// For compatibility, email address can be passed to this function
-/// instead of the domain.
 pub async fn get_provider_info(
     context: &Context,
     domain: &str,
     skip_mx: bool,
 ) -> Option<&'static Provider> {
-    let domain = domain.rsplit('@').next()?;
-
     if let Some(provider) = get_provider_by_domain(domain) {
         return Some(provider);
     }
@@ -314,15 +324,25 @@ mod tests {
         let t = TestContext::new().await;
         assert!(get_provider_info(&t, "", false).await.is_none());
         assert!(get_provider_info(&t, "google.com", false).await.unwrap().id == "gmail");
+        assert!(get_provider_info(&t, "example@google.com", false)
+            .await
+            .is_none());
+    }
 
-        // get_provider_info() accepts email addresses for backwards compatibility
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn test_get_provider_info_by_addr() -> Result<()> {
+        let t = TestContext::new().await;
+        assert!(get_provider_info_by_addr(&t, "google.com", false)
+            .await
+            .is_err());
         assert!(
-            get_provider_info(&t, "example@google.com", false)
-                .await
+            get_provider_info_by_addr(&t, "example@google.com", false)
+                .await?
                 .unwrap()
                 .id
                 == "gmail"
         );
+        Ok(())
     }
 
     #[test]