Calculate download checksums

crates/ely_app/Cargo.toml

@@ -12,6 +12,7 @@ ely_domain = { path = "../ely_domain" }
 gpui.workspace = true
 gpui-component.workspace = true
 gpui-component-assets.workspace = true
+sha2.workspace = true
 thiserror.workspace = true
 
 [lints]

crates/ely_app/src/services/download_checksums.rs

@@ -0,0 +1,117 @@
+use std::{
+    fs::{self, File},
+    io::{self, Read},
+    path::{Path, PathBuf},
+};
+
+use ely_domain::{DomainError, DownloadChecksum};
+use sha2::{Digest, Sha256};
+use thiserror::Error;
+
+const CHECKSUM_BUFFER_BYTES: usize = 64 * 1024;
+
+pub struct DownloadChecksumCalculator;
+
+#[derive(Debug, Error)]
+pub enum DownloadChecksumError {
+    #[error("download file is unavailable: {path}")]
+    FileUnavailable {
+        path: PathBuf,
+        #[source]
+        source: io::Error,
+    },
+
+    #[error("download path is not a file: {path}")]
+    NotAFile { path: PathBuf },
+
+    #[error(transparent)]
+    Domain(#[from] DomainError),
+}
+
+impl DownloadChecksumCalculator {
+    pub fn sha256(path: &Path) -> Result<DownloadChecksum, DownloadChecksumError> {
+        require_file(path)?;
+        let mut file = File::open(path).map_err(|source| {
+            DownloadChecksumError::FileUnavailable { path: path.to_path_buf(), source }
+        })?;
+        let mut hasher = Sha256::new();
+        let mut buffer = [0; CHECKSUM_BUFFER_BYTES];
+
+        loop {
+            let bytes_read = file.read(&mut buffer).map_err(|source| {
+                DownloadChecksumError::FileUnavailable { path: path.to_path_buf(), source }
+            })?;
+            if bytes_read == 0 {
+                break;
+            }
+            hasher.update(&buffer[..bytes_read]);
+        }
+
+        DownloadChecksum::sha256_hex(encode_lower_hex(&hasher.finalize())).map_err(Into::into)
+    }
+}
+
+fn require_file(path: &Path) -> Result<(), DownloadChecksumError> {
+    match fs::metadata(path) {
+        Ok(metadata) if metadata.is_file() => Ok(()),
+        Ok(_) => Err(DownloadChecksumError::NotAFile { path: path.to_path_buf() }),
+        Err(source) => {
+            Err(DownloadChecksumError::FileUnavailable { path: path.to_path_buf(), source })
+        }
+    }
+}
+
+fn encode_lower_hex(bytes: &[u8]) -> String {
+    const HEX: &[u8; 16] = b"0123456789abcdef";
+
+    let mut output = String::with_capacity(bytes.len() * 2);
+    for byte in bytes {
+        let byte = *byte;
+        output.push(HEX[(byte >> 4) as usize] as char);
+        output.push(HEX[(byte & 0x0f) as usize] as char);
+    }
+    output
+}
+
+#[cfg(test)]
+mod tests {
+    use std::{
+        error::Error,
+        fs,
+        path::PathBuf,
+        time::{SystemTime, UNIX_EPOCH},
+    };
+
+    use super::{DownloadChecksumCalculator, DownloadChecksumError};
+
+    #[test]
+    fn computes_sha256_for_download_file() -> Result<(), Box<dyn Error>> {
+        let path = temp_file_path("checksum")?;
+        fs::write(&path, [])?;
+
+        let checksum = DownloadChecksumCalculator::sha256(&path)?;
+        let value = checksum.value().to_string();
+        fs::remove_file(path)?;
+
+        assert_eq!(value, "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855");
+        Ok(())
+    }
+
+    #[test]
+    fn rejects_missing_download_file() -> Result<(), Box<dyn Error>> {
+        let path = temp_file_path("missing")?;
+
+        let error = match DownloadChecksumCalculator::sha256(&path) {
+            Ok(_) => return Err("missing download file should be rejected".into()),
+            Err(error) => error,
+        };
+
+        assert!(matches!(error, DownloadChecksumError::FileUnavailable { .. }));
+        Ok(())
+    }
+
+    fn temp_file_path(name: &str) -> Result<PathBuf, Box<dyn Error>> {
+        let nanos = SystemTime::now().duration_since(UNIX_EPOCH)?.as_nanos();
+        Ok(std::env::temp_dir().join(format!("ely-download-{name}-{nanos}.bin")))
+    }
+}

crates/ely_app/src/services/mod.rs

@@ -1 +1,2 @@
+pub mod download_checksums;
 pub mod download_files;

crates/ely_app/src/shell/internal_pages/download_actions.rs

@@ -16,7 +16,7 @@ impl ElyShell {
         cx: &mut Context<Self>,
     ) -> AnyElement {
         div()
-            .w(px(64.0))
+            .w(px(96.0))
             .flex()
             .items_center()
             .justify_end()
@@ -84,6 +84,7 @@ impl ElyShell {
                 |this| {
                     let open_id = entry.id().clone();
                     let reveal_id = entry.id().clone();
+                    let checksum_id = entry.id().clone();
 
                     this.child(
                         download_action_button("open", index, IconName::ExternalLink, "Open File")
@@ -104,6 +105,20 @@ impl ElyShell {
                         }))
                         .into_any_element(),
                     )
+                    .when(entry.checksum().is_none(), |this| {
+                        this.child(
+                            download_action_button(
+                                "checksum",
+                                index,
+                                IconName::CircleCheck,
+                                "Calculate SHA-256",
+                            )
+                            .on_click(cx.listener(move |shell, _, _, cx| {
+                                shell.calculate_download_checksum(&checksum_id, cx);
+                            }))
+                            .into_any_element(),
+                        )
+                    })
                 },
             )
             .into_any_element()

crates/ely_app/src/shell/internal_pages/downloads.rs

@@ -1,6 +1,6 @@
 use ely_browser_core::BrowserSnapshot;
 use ely_design_system::colors;
-use ely_domain::{DownloadEntry, DownloadSecurity};
+use ely_domain::{DownloadChecksum, DownloadEntry, DownloadSecurity};
 use gpui::prelude::FluentBuilder;
 use gpui::{
     AnyElement, Context, InteractiveElement, IntoElement, ParentElement, SharedString, Styled, div,
@@ -106,8 +106,8 @@ impl ElyShell {
                                 ),
                         ),
                 )
-                .when_some(self.download_file_error.clone(), |this, message| {
-                    this.child(render_download_file_error(message))
+                .when_some(self.download_action_error.clone(), |this, message| {
+                    this.child(render_download_action_error(message))
                 })
                 .when(
                     self.download_clear_confirmation && !snapshot.download_entries.is_empty(),
@@ -259,6 +259,9 @@ impl ElyShell {
                                     )
                                     .when(entry.security().requires_prompt(), |this| {
                                         this.child(render_security_prompt(entry.security()))
+                                    })
+                                    .when_some(entry.checksum(), |this, checksum| {
+                                        this.child(render_checksum_label(checksum))
                                     }),
                             ),
                     ),
@@ -296,7 +299,7 @@ impl ElyShell {
     }
 }
 
-fn render_download_file_error(message: String) -> AnyElement {
+fn render_download_action_error(message: String) -> AnyElement {
     div()
         .rounded_md()
         .border_1()
@@ -323,3 +326,18 @@ fn render_security_prompt(security: &DownloadSecurity) -> AnyElement {
         .child(download_security_label(security))
         .into_any_element()
 }
+
+fn render_checksum_label(checksum: &DownloadChecksum) -> AnyElement {
+    div()
+        .flex()
+        .items_center()
+        .gap_1()
+        .text_color(rgb(colors::SUCCESS))
+        .child(IconName::CircleCheck)
+        .child(format!("SHA-256 {}", short_checksum(checksum.value())))
+        .into_any_element()
+}
+
+fn short_checksum(value: &str) -> &str {
+    value.get(..12).unwrap_or(value)
+}

crates/ely_app/src/shell/mod.rs

@@ -9,7 +9,10 @@ use gpui_component::input::{InputEvent, InputState, SelectAll};
 use crate::{
     CloseCurrentTab, FocusAddressBar, FocusCommandMode, OpenDownloads, OpenHistory, OpenNewTab,
     OpenSettings, RestoreClosedTab, SelectNextTab, SelectPreviousTab, ToggleFavoriteTab,
-    TogglePinnedTab, services::download_files::DownloadFileAction,
+    TogglePinnedTab,
+    services::{
+        download_checksums::DownloadChecksumCalculator, download_files::DownloadFileAction,
+    },
 };
 
 enum ShellState {
@@ -22,7 +25,7 @@ pub struct ElyShell {
     focus_handle: FocusHandle,
     command_input: Entity<InputState>,
     last_intent: Option<CommandIntent>,
-    download_file_error: Option<String>,
+    download_action_error: Option<String>,
     download_clear_confirmation: bool,
     _command_subscription: Subscription,
 }
@@ -79,7 +82,7 @@ impl ElyShell {
             focus_handle: cx.focus_handle(),
             command_input,
             last_intent: None,
-            download_file_error: None,
+            download_action_error: None,
             download_clear_confirmation: false,
             _command_subscription: command_subscription,
         }
@@ -266,7 +269,26 @@ impl ElyShell {
             core.clear_downloads_for_active_profile();
         }
         self.download_clear_confirmation = false;
-        self.download_file_error = None;
+        self.download_action_error = None;
+        cx.notify();
+    }
+
+    fn calculate_download_checksum(&mut self, download_id: &DownloadId, cx: &mut Context<Self>) {
+        let result = match &mut self.state {
+            ShellState::Ready(core) => core
+                .download_target_file_path(download_id)
+                .map_err(|error| error.to_string())
+                .and_then(|path| {
+                    DownloadChecksumCalculator::sha256(&path).map_err(|error| error.to_string())
+                })
+                .and_then(|checksum| {
+                    core.record_download_checksum(download_id, checksum)
+                        .map_err(|error| error.to_string())
+                }),
+            ShellState::StartupError(message) => Err(message.clone()),
+        };
+
+        self.download_action_error = result.err();
         cx.notify();
     }
 
@@ -292,7 +314,7 @@ impl ElyShell {
             ShellState::StartupError(message) => Err(message.clone()),
         };
 
-        self.download_file_error = result.err();
+        self.download_action_error = result.err();
         cx.notify();
     }