Merge 9e4f0a2b41 into 27dc67fadd

As users are migrating from LastPass, I am seeing more and more people hitting the max length of 10,000 on the "Notes" field, which applies to both CipherType.Login and CipherType.SecureNote.

This default is too low, and by being significantly lower than competing products, needlessly complicates the transition.

This is not helped by how unhelpful the import process is on web (showing errors in console only, silently dropping items), which is a PR for another day. By merging this, we can ensure that one of
the most common drop-offs is fixed.

45,000 matches LastPass. As we know that the encrypted length can be longer than the raw text, I have increased this to 50,000 so there is a healthy buffer to account for this inflation.

Mirrors PR at https://github.com/bitwarden/server/pull/2625

Cargo.lock

@@ -2819,7 +2819,6 @@ dependencies = [
  "futures-core",
  "futures-util",
  "h2 0.4.4",
- "hickory-resolver",
  "http 1.1.0",
  "http-body 1.0.0",
  "http-body-util",
@@ -3187,9 +3186,9 @@ checksum = "92d43fe69e652f3df9bdc2b85b2854a0825b86e4fb76bc44d945137d053639ca"
 
 [[package]]
 name = "serde"
-version = "1.0.198"
+version = "1.0.199"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9846a40c979031340571da2545a4e5b7c4163bdae79b301d5f86d03979451fcc"
+checksum = "0c9f6e76df036c77cd94996771fb40db98187f096dd0b9af39c6c6e452ba966a"
 dependencies = [
  "serde_derive",
 ]
@@ -3206,9 +3205,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.198"
+version = "1.0.199"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e88edab869b01783ba905e7d0153f9fc1a6505a96e4ad3018011eedb838566d9"
+checksum = "11bd257a6541e141e42ca6d24ae26f7714887b47e89aa739099104c7e4d3b7fc"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3970,6 +3969,7 @@ dependencies = [
  "futures",
  "governor",
  "handlebars",
+ "hickory-resolver",
  "html5gum",
  "job_scheduler_ng",
  "jsonwebtoken",

Cargo.toml

@@ -67,7 +67,7 @@ dashmap = "5.5.3"
 
 # Async futures
 futures = "0.3.30"
-tokio = { version = "1.37.0", features = ["rt-multi-thread", "fs", "io-util", "parking_lot", "time", "signal"] }
+tokio = { version = "1.37.0", features = ["rt-multi-thread", "fs", "io-util", "parking_lot", "time", "signal", "net"] }
 
 # A generic serialization/deserialization framework
 serde = { version = "1.0.198", features = ["derive"] }
@@ -123,7 +123,8 @@ email_address = "0.2.4"
 handlebars = { version = "5.1.2", features = ["dir_source"] }
 
 # HTTP client (Used for favicons, version check, DUO and HIBP API)
-reqwest = { version = "0.12.4", features = ["native-tls-alpn", "stream", "json", "gzip", "brotli", "socks", "cookies", "hickory-dns"] }
+reqwest = { version = "0.12.4", features = ["native-tls-alpn", "stream", "json", "gzip", "brotli", "socks", "cookies"] }
+hickory-resolver = "0.24.1"
 
 # Favicon extraction libraries
 html5gum = "0.5.7"

src/api/core/ciphers.rs

@@ -379,8 +379,8 @@ pub async fn update_cipher_from_data(
     }
 
     if let Some(note) = &data.Notes {
-        if note.len() > 10_000 {
-            err!("The field Notes exceeds the maximum encrypted value length of 10000 characters.")
+        if note.len() > 50_000 {
+            err!("The field Notes exceeds the maximum encrypted value length of 50000 characters.")
         }
     }
 

src/api/icons.rs

@@ -1,6 +1,6 @@
 use std::{
     net::IpAddr,
-    sync::Arc,
+    sync::{Arc, Mutex},
     time::{Duration, SystemTime},
 };
 
@@ -16,14 +16,13 @@ use rocket::{http::ContentType, response::Redirect, Route};
 use tokio::{
     fs::{create_dir_all, remove_file, symlink_metadata, File},
     io::{AsyncReadExt, AsyncWriteExt},
-    net::lookup_host,
 };
 
 use html5gum::{Emitter, HtmlString, InfallibleTokenizer, Readable, StringReader, Tokenizer};
 
 use crate::{
     error::Error,
-    util::{get_reqwest_client_builder, Cached},
+    util::{get_reqwest_client_builder, Cached, CustomDnsResolver, CustomResolverError},
     CONFIG,
 };
 
@@ -49,48 +48,32 @@ static CLIENT: Lazy<Client> = Lazy::new(|| {
     let icon_download_timeout = Duration::from_secs(CONFIG.icon_download_timeout());
     let pool_idle_timeout = Duration::from_secs(10);
     // Reuse the client between requests
-    let client = get_reqwest_client_builder()
+    get_reqwest_client_builder()
         .cookie_provider(Arc::clone(&cookie_store))
         .timeout(icon_download_timeout)
         .pool_max_idle_per_host(5) // Configure the Hyper Pool to only have max 5 idle connections
         .pool_idle_timeout(pool_idle_timeout) // Configure the Hyper Pool to timeout after 10 seconds
-        .hickory_dns(true)
-        .default_headers(default_headers.clone());
-
-    match client.build() {
-        Ok(client) => client,
-        Err(e) => {
-            error!("Possible trust-dns error, trying with trust-dns disabled: '{e}'");
-            get_reqwest_client_builder()
-                .cookie_provider(cookie_store)
-                .timeout(icon_download_timeout)
-                .pool_max_idle_per_host(5) // Configure the Hyper Pool to only have max 5 idle connections
-                .pool_idle_timeout(pool_idle_timeout) // Configure the Hyper Pool to timeout after 10 seconds
-                .hickory_dns(false)
-                .default_headers(default_headers)
-                .build()
-                .expect("Failed to build client")
-        }
-    }
+        .dns_resolver(CustomDnsResolver::instance())
+        .default_headers(default_headers.clone())
+        .build()
+        .expect("Failed to build client")
 });
 
 // Build Regex only once since this takes a lot of time.
 static ICON_SIZE_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"(?x)(\d+)\D*(\d+)").unwrap());
 
-// Special HashMap which holds the user defined Regex to speedup matching the regex.
-static ICON_BLACKLIST_REGEX: Lazy<dashmap::DashMap<String, Regex>> = Lazy::new(dashmap::DashMap::new);
-
-async fn icon_redirect(domain: &str, template: &str) -> Option<Redirect> {
+#[get("/<domain>/icon.png")]
+fn icon_external(domain: &str) -> Option<Redirect> {
     if !is_valid_domain(domain) {
         warn!("Invalid domain: {}", domain);
         return None;
     }
 
-    if check_domain_blacklist_reason(domain).await.is_some() {
+    if is_domain_blacklisted(domain) {
         return None;
     }
 
-    let url = template.replace("{}", domain);
+    let url = CONFIG._icon_service_url().replace("{}", domain);
     match CONFIG.icon_redirect_code() {
         301 => Some(Redirect::moved(url)), // legacy permanent redirect
         302 => Some(Redirect::found(url)), // legacy temporary redirect
@@ -103,11 +86,6 @@ async fn icon_redirect(domain: &str, template: &str) -> Option<Redirect> {
     }
 }
 
-#[get("/<domain>/icon.png")]
-async fn icon_external(domain: &str) -> Option<Redirect> {
-    icon_redirect(domain, &CONFIG._icon_service_url()).await
-}
-
 #[get("/<domain>/icon.png")]
 async fn icon_internal(domain: &str) -> Cached<(ContentType, Vec<u8>)> {
     const FALLBACK_ICON: &[u8] = include_bytes!("../static/images/fallback-icon.png");
@@ -166,153 +144,28 @@ fn is_valid_domain(domain: &str) -> bool {
     true
 }
 
-/// TODO: This is extracted from IpAddr::is_global, which is unstable:
-/// https://doc.rust-lang.org/nightly/std/net/enum.IpAddr.html#method.is_global
-/// Remove once https://github.com/rust-lang/rust/issues/27709 is merged
-#[allow(clippy::nonminimal_bool)]
-#[cfg(not(feature = "unstable"))]
-fn is_global(ip: IpAddr) -> bool {
-    match ip {
-        IpAddr::V4(ip) => {
-            // check if this address is 192.0.0.9 or 192.0.0.10. These addresses are the only two
-            // globally routable addresses in the 192.0.0.0/24 range.
-            if u32::from(ip) == 0xc0000009 || u32::from(ip) == 0xc000000a {
-                return true;
-            }
-            !ip.is_private()
-            && !ip.is_loopback()
-            && !ip.is_link_local()
-            && !ip.is_broadcast()
-            && !ip.is_documentation()
-            && !(ip.octets()[0] == 100 && (ip.octets()[1] & 0b1100_0000 == 0b0100_0000))
-            && !(ip.octets()[0] == 192 && ip.octets()[1] == 0 && ip.octets()[2] == 0)
-            && !(ip.octets()[0] & 240 == 240 && !ip.is_broadcast())
-            && !(ip.octets()[0] == 198 && (ip.octets()[1] & 0xfe) == 18)
-            // Make sure the address is not in 0.0.0.0/8
-            && ip.octets()[0] != 0
-        }
-        IpAddr::V6(ip) => {
-            if ip.is_multicast() && ip.segments()[0] & 0x000f == 14 {
-                true
-            } else {
-                !ip.is_multicast()
-                    && !ip.is_loopback()
-                    && !((ip.segments()[0] & 0xffc0) == 0xfe80)
-                    && !((ip.segments()[0] & 0xfe00) == 0xfc00)
-                    && !ip.is_unspecified()
-                    && !((ip.segments()[0] == 0x2001) && (ip.segments()[1] == 0xdb8))
-            }
-        }
-    }
-}
+pub fn is_domain_blacklisted(domain: &str) -> bool {
+    let Some(config_blacklist) = CONFIG.icon_blacklist_regex() else {
+        return false;
+    };
 
-#[cfg(feature = "unstable")]
-fn is_global(ip: IpAddr) -> bool {
-    ip.is_global()
-}
+    // Compiled domain blacklist
+    static COMPILED_BLACKLIST: Mutex<Option<(String, Regex)>> = Mutex::new(None);
+    let mut guard = COMPILED_BLACKLIST.lock().unwrap();
 
-/// These are some tests to check that the implementations match
-/// The IPv4 can be all checked in 5 mins or so and they are correct as of nightly 2020-07-11
-/// The IPV6 can't be checked in a reasonable time, so we check  about ten billion random ones, so far correct
-/// Note that the is_global implementation is subject to change as new IP RFCs are created
-///
-/// To run while showing progress output:
-/// cargo test --features sqlite,unstable -- --nocapture --ignored
-#[cfg(test)]
-#[cfg(feature = "unstable")]
-mod tests {
-    use super::*;
-
-    #[test]
-    #[ignore]
-    fn test_ipv4_global() {
-        for a in 0..u8::MAX {
-            println!("Iter: {}/255", a);
-            for b in 0..u8::MAX {
-                for c in 0..u8::MAX {
-                    for d in 0..u8::MAX {
-                        let ip = IpAddr::V4(std::net::Ipv4Addr::new(a, b, c, d));
-                        assert_eq!(ip.is_global(), is_global(ip))
-                    }
-                }
-            }
+    // If the stored regex is up to date, use it
+    if let Some((value, regex)) = &*guard {
+        if value == &config_blacklist {
+            return regex.is_match(domain);
         }
     }
 
-    #[test]
-    #[ignore]
-    fn test_ipv6_global() {
-        use ring::rand::{SecureRandom, SystemRandom};
-        let mut v = [0u8; 16];
-        let rand = SystemRandom::new();
-        for i in 0..1_000 {
-            println!("Iter: {}/1_000", i);
-            for _ in 0..10_000_000 {
-                rand.fill(&mut v).expect("Error generating random values");
-                let ip = IpAddr::V6(std::net::Ipv6Addr::new(
-                    (v[14] as u16) << 8 | v[15] as u16,
-                    (v[12] as u16) << 8 | v[13] as u16,
-                    (v[10] as u16) << 8 | v[11] as u16,
-                    (v[8] as u16) << 8 | v[9] as u16,
-                    (v[6] as u16) << 8 | v[7] as u16,
-                    (v[4] as u16) << 8 | v[5] as u16,
-                    (v[2] as u16) << 8 | v[3] as u16,
-                    (v[0] as u16) << 8 | v[1] as u16,
-                ));
-                assert_eq!(ip.is_global(), is_global(ip))
-            }
-        }
-    }
-}
+    // If we don't have a regex stored, or it's not up to date, recreate it
+    let regex = Regex::new(&config_blacklist).unwrap();
+    let is_match = regex.is_match(domain);
+    *guard = Some((config_blacklist, regex));
 
-#[derive(Clone)]
-enum DomainBlacklistReason {
-    Regex,
-    IP,
-}
-
-use cached::proc_macro::cached;
-#[cached(key = "String", convert = r#"{ domain.to_string() }"#, size = 16, time = 60)]
-async fn check_domain_blacklist_reason(domain: &str) -> Option<DomainBlacklistReason> {
-    // First check the blacklist regex if there is a match.
-    // This prevents the blocked domain(s) from being leaked via a DNS lookup.
-    if let Some(blacklist) = CONFIG.icon_blacklist_regex() {
-        // Use the pre-generate Regex stored in a Lazy HashMap if there's one, else generate it.
-        let is_match = if let Some(regex) = ICON_BLACKLIST_REGEX.get(&blacklist) {
-            regex.is_match(domain)
-        } else {
-            // Clear the current list if the previous key doesn't exists.
-            // To prevent growing of the HashMap after someone has changed it via the admin interface.
-            if ICON_BLACKLIST_REGEX.len() >= 1 {
-                ICON_BLACKLIST_REGEX.clear();
-            }
-
-            // Generate the regex to store in too the Lazy Static HashMap.
-            let blacklist_regex = Regex::new(&blacklist).unwrap();
-            let is_match = blacklist_regex.is_match(domain);
-            ICON_BLACKLIST_REGEX.insert(blacklist.clone(), blacklist_regex);
-
-            is_match
-        };
-
-        if is_match {
-            debug!("Blacklisted domain: {} matched ICON_BLACKLIST_REGEX", domain);
-            return Some(DomainBlacklistReason::Regex);
-        }
-    }
-
-    if CONFIG.icon_blacklist_non_global_ips() {
-        if let Ok(s) = lookup_host((domain, 0)).await {
-            for addr in s {
-                if !is_global(addr.ip()) {
-                    debug!("IP {} for domain '{}' is not a global IP!", addr.ip(), domain);
-                    return Some(DomainBlacklistReason::IP);
-                }
-            }
-        }
-    }
-
-    None
+    is_match
 }
 
 async fn get_icon(domain: &str) -> Option<(Vec<u8>, String)> {
@@ -342,6 +195,13 @@ async fn get_icon(domain: &str) -> Option<(Vec<u8>, String)> {
             Some((icon.to_vec(), icon_type.unwrap_or("x-icon").to_string()))
         }
         Err(e) => {
+            // If this error comes from the custom resolver, this means this is a blacklisted domain
+            // or non global IP, don't save the miss file in this case to avoid leaking it
+            if let Some(error) = CustomResolverError::downcast_ref(&e) {
+                warn!("{error}");
+                return None;
+            }
+
             warn!("Unable to download icon: {:?}", e);
             let miss_indicator = path + ".miss";
             save_icon(&miss_indicator, &[]).await;
@@ -491,42 +351,48 @@ async fn get_icon_url(domain: &str) -> Result<IconUrlResult, Error> {
     let ssldomain = format!("https://{domain}");
     let httpdomain = format!("http://{domain}");
 
-    // First check the domain as given during the request for both HTTPS and HTTP.
-    let resp = match get_page(&ssldomain).or_else(|_| get_page(&httpdomain)).await {
-        Ok(c) => Ok(c),
-        Err(e) => {
-            let mut sub_resp = Err(e);
+    // First check the domain as given during the request for HTTPS.
+    let resp = match get_page(&ssldomain).await {
+        Err(e) if CustomResolverError::downcast_ref(&e).is_none() => {
+            // If we get an error that is not caused by the blacklist, we retry with HTTP
+            match get_page(&httpdomain).await {
+                mut sub_resp @ Err(_) => {
+                    // When the domain is not an IP, and has more then one dot, remove all subdomains.
+                    let is_ip = domain.parse::<IpAddr>();
+                    if is_ip.is_err() && domain.matches('.').count() > 1 {
+                        let mut domain_parts = domain.split('.');
+                        let base_domain = format!(
+                            "{base}.{tld}",
+                            tld = domain_parts.next_back().unwrap(),
+                            base = domain_parts.next_back().unwrap()
+                        );
+                        if is_valid_domain(&base_domain) {
+                            let sslbase = format!("https://{base_domain}");
+                            let httpbase = format!("http://{base_domain}");
+                            debug!("[get_icon_url]: Trying without subdomains '{base_domain}'");
 
-            // When the domain is not an IP, and has more then one dot, remove all subdomains.
-            let is_ip = domain.parse::<IpAddr>();
-            if is_ip.is_err() && domain.matches('.').count() > 1 {
-                let mut domain_parts = domain.split('.');
-                let base_domain = format!(
-                    "{base}.{tld}",
-                    tld = domain_parts.next_back().unwrap(),
-                    base = domain_parts.next_back().unwrap()
-                );
-                if is_valid_domain(&base_domain) {
-                    let sslbase = format!("https://{base_domain}");
-                    let httpbase = format!("http://{base_domain}");
-                    debug!("[get_icon_url]: Trying without subdomains '{base_domain}'");
+                            sub_resp = get_page(&sslbase).or_else(|_| get_page(&httpbase)).await;
+                        }
 
-                    sub_resp = get_page(&sslbase).or_else(|_| get_page(&httpbase)).await;
-                }
-
-            // When the domain is not an IP, and has less then 2 dots, try to add www. infront of it.
-            } else if is_ip.is_err() && domain.matches('.').count() < 2 {
-                let www_domain = format!("www.{domain}");
-                if is_valid_domain(&www_domain) {
-                    let sslwww = format!("https://{www_domain}");
-                    let httpwww = format!("http://{www_domain}");
-                    debug!("[get_icon_url]: Trying with www. prefix '{www_domain}'");
-
-                    sub_resp = get_page(&sslwww).or_else(|_| get_page(&httpwww)).await;
+                    // When the domain is not an IP, and has less then 2 dots, try to add www. infront of it.
+                    } else if is_ip.is_err() && domain.matches('.').count() < 2 {
+                        let www_domain = format!("www.{domain}");
+                        if is_valid_domain(&www_domain) {
+                            let sslwww = format!("https://{www_domain}");
+                            let httpwww = format!("http://{www_domain}");
+                            debug!("[get_icon_url]: Trying with www. prefix '{www_domain}'");
+
+                            sub_resp = get_page(&sslwww).or_else(|_| get_page(&httpwww)).await;
+                        }
+                    }
+                    sub_resp
                 }
+                res => res,
             }
-            sub_resp
         }
+
+        // If we get a result or a blacklist error, just continue
+        res => res,
     };
 
     // Create the iconlist
@@ -573,21 +439,12 @@ async fn get_page(url: &str) -> Result<Response, Error> {
 }
 
 async fn get_page_with_referer(url: &str, referer: &str) -> Result<Response, Error> {
-    match check_domain_blacklist_reason(url::Url::parse(url).unwrap().host_str().unwrap_or_default()).await {
-        Some(DomainBlacklistReason::Regex) => warn!("Favicon '{}' is from a blacklisted domain!", url),
-        Some(DomainBlacklistReason::IP) => warn!("Favicon '{}' is hosted on a non-global IP!", url),
-        None => (),
-    }
-
     let mut client = CLIENT.get(url);
     if !referer.is_empty() {
         client = client.header("Referer", referer)
     }
 
-    match client.send().await {
-        Ok(c) => c.error_for_status().map_err(Into::into),
-        Err(e) => err_silent!(format!("{e}")),
-    }
+    Ok(client.send().await?.error_for_status()?)
 }
 
 /// Returns a Integer with the priority of the type of the icon which to prefer.
@@ -670,12 +527,6 @@ fn parse_sizes(sizes: &str) -> (u16, u16) {
 }
 
 async fn download_icon(domain: &str) -> Result<(Bytes, Option<&str>), Error> {
-    match check_domain_blacklist_reason(domain).await {
-        Some(DomainBlacklistReason::Regex) => err_silent!("Domain is blacklisted", domain),
-        Some(DomainBlacklistReason::IP) => err_silent!("Host resolves to a non-global IP", domain),
-        None => (),
-    }
-
     let icon_result = get_icon_url(domain).await?;
 
     let mut buffer = Bytes::new();
@@ -711,22 +562,19 @@ async fn download_icon(domain: &str) -> Result<(Bytes, Option<&str>), Error> {
                 _ => debug!("Extracted icon from data:image uri is invalid"),
             };
         } else {
-            match get_page_with_referer(&icon.href, &icon_result.referer).await {
-                Ok(res) => {
-                    buffer = stream_to_bytes_limit(res, 5120 * 1024).await?; // 5120KB/5MB for each icon max (Same as icons.bitwarden.net)
+            let res = get_page_with_referer(&icon.href, &icon_result.referer).await?;
 
-                    // Check if the icon type is allowed, else try an icon from the list.
-                    icon_type = get_icon_type(&buffer);
-                    if icon_type.is_none() {
-                        buffer.clear();
-                        debug!("Icon from {}, is not a valid image type", icon.href);
-                        continue;
-                    }
-                    info!("Downloaded icon from {}", icon.href);
-                    break;
-                }
-                Err(e) => debug!("{:?}", e),
-            };
+            buffer = stream_to_bytes_limit(res, 5120 * 1024).await?; // 5120KB/5MB for each icon max (Same as icons.bitwarden.net)
+
+            // Check if the icon type is allowed, else try an icon from the list.
+            icon_type = get_icon_type(&buffer);
+            if icon_type.is_none() {
+                buffer.clear();
+                debug!("Icon from {}, is not a valid image type", icon.href);
+                continue;
+            }
+            info!("Downloaded icon from {}", icon.href);
+            break;
         }
     }
 

src/api/mod.rs

@@ -20,7 +20,7 @@ pub use crate::api::{
     core::two_factor::send_incomplete_2fa_notifications,
     core::{emergency_notification_reminder_job, emergency_request_timeout_job},
     core::{event_cleanup_job, events_routes as core_events_routes},
-    icons::routes as icons_routes,
+    icons::{is_domain_blacklisted, routes as icons_routes},
     identity::routes as identity_routes,
     notifications::routes as notifications_routes,
     notifications::{AnonymousNotify, Notify, UpdateType, WS_ANONYMOUS_SUBSCRIPTIONS, WS_USERS},

src/db/models/cipher.rs

@@ -82,11 +82,11 @@ impl Cipher {
         let mut validation_errors = serde_json::Map::new();
         for (index, cipher) in cipher_data.iter().enumerate() {
             if let Some(note) = &cipher.Notes {
-                if note.len() > 10_000 {
+                if note.len() > 50_000 {
                     validation_errors.insert(
                         format!("Ciphers[{index}].Notes"),
                         serde_json::to_value([
-                            "The field Notes exceeds the maximum encrypted value length of 10000 characters.",
+                            "The field Notes exceeds the maximum encrypted value length of 50000 characters.",
                         ])
                         .unwrap(),
                     );

src/main.rs

@@ -211,8 +211,8 @@ fn launch_info() {
 }
 
 fn init_logging(level: log::LevelFilter) -> Result<(), fern::InitError> {
-    // Depending on the main log level we either want to disable or enable logging for trust-dns.
-    // Else if there are timeouts it will clutter the logs since trust-dns uses warn for this.
+    // Depending on the main log level we either want to disable or enable logging for hickory.
+    // Else if there are timeouts it will clutter the logs since hickory uses warn for this.
     let hickory_level = if level >= log::LevelFilter::Debug {
         level
     } else {
@@ -266,7 +266,7 @@ fn init_logging(level: log::LevelFilter) -> Result<(), fern::InitError> {
         .level_for("handlebars::render", handlebars_level)
         // Prevent cookie_store logs
         .level_for("cookie_store", log::LevelFilter::Off)
-        // Variable level for trust-dns used by reqwest
+        // Variable level for hickory used by reqwest
         .level_for("hickory_resolver::name_server::name_server", hickory_level)
         .level_for("hickory_proto::xfer", hickory_level)
         .level_for("diesel_logger", diesel_logger_level)

src/util.rs

@@ -4,6 +4,7 @@
 use std::{collections::HashMap, io::Cursor, ops::Deref, path::Path};
 
 use num_traits::ToPrimitive;
+use once_cell::sync::Lazy;
 use rocket::{
     fairing::{Fairing, Info, Kind},
     http::{ContentType, Header, HeaderMap, Method, Status},
@@ -701,14 +702,9 @@ where
 
 use reqwest::{header, Client, ClientBuilder};
 
-pub fn get_reqwest_client() -> Client {
-    match get_reqwest_client_builder().build() {
-        Ok(client) => client,
-        Err(e) => {
-            error!("Possible trust-dns error, trying with trust-dns disabled: '{e}'");
-            get_reqwest_client_builder().hickory_dns(false).build().expect("Failed to build client")
-        }
-    }
+pub fn get_reqwest_client() -> &'static Client {
+    static INSTANCE: Lazy<Client> = Lazy::new(|| get_reqwest_client_builder().build().expect("Failed to build client"));
+    &INSTANCE
 }
 
 pub fn get_reqwest_client_builder() -> ClientBuilder {
@@ -767,3 +763,248 @@ pub fn parse_experimental_client_feature_flags(experimental_client_feature_flags
 
     feature_states
 }
+
+mod dns_resolver {
+    use std::{
+        fmt,
+        net::{IpAddr, SocketAddr},
+        sync::Arc,
+    };
+
+    use hickory_resolver::{system_conf::read_system_conf, TokioAsyncResolver};
+    use once_cell::sync::Lazy;
+    use reqwest::dns::{Name, Resolve, Resolving};
+
+    use crate::{util::is_global, CONFIG};
+
+    #[derive(Debug, Clone)]
+    pub enum CustomResolverError {
+        Blacklist {
+            domain: String,
+        },
+        NonGlobalIp {
+            domain: String,
+            ip: IpAddr,
+        },
+    }
+
+    impl CustomResolverError {
+        pub fn downcast_ref(e: &dyn std::error::Error) -> Option<&Self> {
+            let mut source = e.source();
+
+            while let Some(err) = source {
+                source = err.source();
+                if let Some(err) = err.downcast_ref::<CustomResolverError>() {
+                    return Some(err);
+                }
+            }
+            None
+        }
+    }
+
+    impl fmt::Display for CustomResolverError {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            match self {
+                Self::Blacklist {
+                    domain,
+                } => write!(f, "Blacklisted domain: {domain} matched ICON_BLACKLIST_REGEX"),
+                Self::NonGlobalIp {
+                    domain,
+                    ip,
+                } => write!(f, "IP {ip} for domain '{domain}' is not a global IP!"),
+            }
+        }
+    }
+
+    impl std::error::Error for CustomResolverError {}
+
+    #[derive(Debug, Clone)]
+    pub enum CustomDnsResolver {
+        Default(),
+        Hickory(Arc<TokioAsyncResolver>),
+    }
+    type BoxError = Box<dyn std::error::Error + Send + Sync>;
+
+    impl CustomDnsResolver {
+        pub fn instance() -> Arc<Self> {
+            static INSTANCE: Lazy<Arc<CustomDnsResolver>> = Lazy::new(CustomDnsResolver::new);
+            Arc::clone(&*INSTANCE)
+        }
+
+        fn new() -> Arc<Self> {
+            match read_system_conf() {
+                Ok((config, opts)) => {
+                    let resolver = TokioAsyncResolver::tokio(config.clone(), opts.clone());
+                    Arc::new(Self::Hickory(Arc::new(resolver)))
+                }
+                Err(e) => {
+                    warn!("Error creating Hickory resolver, falling back to default: {e:?}");
+                    Arc::new(Self::Default())
+                }
+            }
+        }
+
+        // Note that we get an iterator of addresses, but we only grab the first one for convenience
+        async fn resolve_domain(&self, name: &str) -> Result<Option<SocketAddr>, BoxError> {
+            pre_resolve(name)?;
+
+            let result = match self {
+                Self::Default() => tokio::net::lookup_host(name).await?.next(),
+                Self::Hickory(r) => r.lookup_ip(name).await?.iter().next().map(|a| SocketAddr::new(a, 0)),
+            };
+
+            if let Some(addr) = &result {
+                post_resolve(name, addr.ip())?;
+            }
+
+            Ok(result)
+        }
+    }
+
+    fn pre_resolve(name: &str) -> Result<(), CustomResolverError> {
+        if crate::api::is_domain_blacklisted(name) {
+            return Err(CustomResolverError::Blacklist {
+                domain: name.to_string(),
+            });
+        }
+
+        Ok(())
+    }
+
+    fn post_resolve(name: &str, ip: IpAddr) -> Result<(), CustomResolverError> {
+        if CONFIG.icon_blacklist_non_global_ips() && !is_global(ip) {
+            Err(CustomResolverError::NonGlobalIp {
+                domain: name.to_string(),
+                ip,
+            })
+        } else {
+            Ok(())
+        }
+    }
+
+    impl Resolve for CustomDnsResolver {
+        fn resolve(&self, name: Name) -> Resolving {
+            let this = self.clone();
+            Box::pin(async move {
+                let name = name.as_str();
+                let result = this.resolve_domain(name).await?;
+                Ok::<reqwest::dns::Addrs, _>(Box::new(result.into_iter()))
+            })
+        }
+    }
+}
+
+pub use dns_resolver::{CustomDnsResolver, CustomResolverError};
+
+/// TODO: This is extracted from IpAddr::is_global, which is unstable:
+/// https://doc.rust-lang.org/nightly/std/net/enum.IpAddr.html#method.is_global
+/// Remove once https://github.com/rust-lang/rust/issues/27709 is merged
+#[allow(clippy::nonminimal_bool)]
+#[cfg(any(not(feature = "unstable"), test))]
+pub fn is_global_hardcoded(ip: std::net::IpAddr) -> bool {
+    match ip {
+        std::net::IpAddr::V4(ip) => {
+            !(ip.octets()[0] == 0 // "This network"
+            || ip.is_private()
+            || (ip.octets()[0] == 100 && (ip.octets()[1] & 0b1100_0000 == 0b0100_0000)) //ip.is_shared()
+            || ip.is_loopback()
+            || ip.is_link_local()
+            // addresses reserved for future protocols (`192.0.0.0/24`)
+            ||(ip.octets()[0] == 192 && ip.octets()[1] == 0 && ip.octets()[2] == 0)
+            || ip.is_documentation()
+            || (ip.octets()[0] == 198 && (ip.octets()[1] & 0xfe) == 18) // ip.is_benchmarking()
+            || (ip.octets()[0] & 240 == 240 && !ip.is_broadcast()) //ip.is_reserved()
+            || ip.is_broadcast())
+        }
+        std::net::IpAddr::V6(ip) => {
+            !(ip.is_unspecified()
+            || ip.is_loopback()
+            // IPv4-mapped Address (`::ffff:0:0/96`)
+            || matches!(ip.segments(), [0, 0, 0, 0, 0, 0xffff, _, _])
+            // IPv4-IPv6 Translat. (`64:ff9b:1::/48`)
+            || matches!(ip.segments(), [0x64, 0xff9b, 1, _, _, _, _, _])
+            // Discard-Only Address Block (`100::/64`)
+            || matches!(ip.segments(), [0x100, 0, 0, 0, _, _, _, _])
+            // IETF Protocol Assignments (`2001::/23`)
+            || (matches!(ip.segments(), [0x2001, b, _, _, _, _, _, _] if b < 0x200)
+                && !(
+                    // Port Control Protocol Anycast (`2001:1::1`)
+                    u128::from_be_bytes(ip.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0001
+                    // Traversal Using Relays around NAT Anycast (`2001:1::2`)
+                    || u128::from_be_bytes(ip.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0002
+                    // AMT (`2001:3::/32`)
+                    || matches!(ip.segments(), [0x2001, 3, _, _, _, _, _, _])
+                    // AS112-v6 (`2001:4:112::/48`)
+                    || matches!(ip.segments(), [0x2001, 4, 0x112, _, _, _, _, _])
+                    // ORCHIDv2 (`2001:20::/28`)
+                    || matches!(ip.segments(), [0x2001, b, _, _, _, _, _, _] if (0x20..=0x2F).contains(&b))
+                ))
+            || ((ip.segments()[0] == 0x2001) && (ip.segments()[1] == 0xdb8)) // ip.is_documentation()
+            || ((ip.segments()[0] & 0xfe00) == 0xfc00) //ip.is_unique_local()
+            || ((ip.segments()[0] & 0xffc0) == 0xfe80)) //ip.is_unicast_link_local()
+        }
+    }
+}
+
+#[cfg(not(feature = "unstable"))]
+pub use is_global_hardcoded as is_global;
+
+#[cfg(feature = "unstable")]
+#[inline(always)]
+pub fn is_global(ip: std::net::IpAddr) -> bool {
+    ip.is_global()
+}
+
+/// These are some tests to check that the implementations match
+/// The IPv4 can be all checked in 30 seconds or so and they are correct as of nightly 2023-07-17
+/// The IPV6 can't be checked in a reasonable time, so we check over a hundred billion random ones, so far correct
+/// Note that the is_global implementation is subject to change as new IP RFCs are created
+///
+/// To run while showing progress output:
+/// cargo +nightly test --release --features sqlite,unstable -- --nocapture --ignored
+#[cfg(test)]
+#[cfg(feature = "unstable")]
+mod tests {
+    use super::*;
+    use std::net::IpAddr;
+
+    #[test]
+    #[ignore]
+    fn test_ipv4_global() {
+        for a in 0..u8::MAX {
+            println!("Iter: {}/255", a);
+            for b in 0..u8::MAX {
+                for c in 0..u8::MAX {
+                    for d in 0..u8::MAX {
+                        let ip = IpAddr::V4(std::net::Ipv4Addr::new(a, b, c, d));
+                        assert_eq!(ip.is_global(), is_global_hardcoded(ip), "IP mismatch: {}", ip)
+                    }
+                }
+            }
+        }
+    }
+
+    #[test]
+    #[ignore]
+    fn test_ipv6_global() {
+        use rand::Rng;
+
+        std::thread::scope(|s| {
+            for t in 0..16 {
+                let handle = s.spawn(move || {
+                    let mut v = [0u8; 16];
+                    let mut rng = rand::thread_rng();
+
+                    for i in 0..20 {
+                        println!("Thread {t} Iter: {i}/50");
+                        for _ in 0..500_000_000 {
+                            rng.fill(&mut v);
+                            let ip = IpAddr::V6(std::net::Ipv6Addr::from(v));
+                            assert_eq!(ip.is_global(), is_global_hardcoded(ip), "IP mismatch: {ip}");
+                        }
+                    }
+                });
+            }
+        });
+    }
+}