feat(admin): commands for purging media

Cargo.lock

@@ -503,6 +503,7 @@ dependencies = [
  "hickory-resolver",
  "hmac",
  "http 1.1.0",
+ "humantime",
  "hyper 1.3.1",
  "hyper-util",
  "image",
@@ -1195,6 +1196,12 @@ version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
 
+[[package]]
+name = "humantime"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b112acc8b3adf4b107a8ec20977da0273a8c386765a3ec0229bd500a1443f9f"
+
 [[package]]
 name = "hyper"
 version = "0.14.29"

Cargo.toml

@@ -131,6 +131,8 @@ clap = { version = "4.3.0", default-features = false, features = [
   "string",
   "usage",
 ] }
+humantime = "2"
+
 futures-util = { version = "0.3.28", default-features = false }
 # Used for reading the configuration from conduit.toml & environment variables
 figment = { version = "0.10.8", features = ["env", "toml"] }

src/database/key_value/media.rs

@@ -1,4 +1,6 @@
-use ruma::{api::client::error::ErrorKind, ServerName, UserId};
+use std::{collections::BTreeMap, ops::Range};
+
+use ruma::{api::client::error::ErrorKind, OwnedServerName, ServerName, UserId};
 use sha2::{digest::Output, Sha256};
 use tracing::error;
 
@@ -153,6 +155,403 @@ impl service::media::Data for KeyValueDatabase {
             .map(|_| metadata)
             .ok_or_else(|| Error::BadRequest(ErrorKind::NotFound, "Media not found."))
     }
+
+    fn purge_and_get_hashes(
+        &self,
+        media: &[(OwnedServerName, String)],
+        force_filehash: bool,
+    ) -> Vec<Result<String>> {
+        let mut files = Vec::new();
+
+        let purge = |mut value: Vec<u8>| {
+            value.truncate(32);
+            let sha256_digest = value;
+
+            let sha256_hex = hex::encode(&sha256_digest);
+
+            self.purge_filehash(sha256_digest, false)?;
+
+            Ok(sha256_hex)
+        };
+
+        for (server_name, media_id) in media {
+            if force_filehash {
+                let mut key = server_name.as_bytes().to_vec();
+                key.push(0xff);
+                key.extend_from_slice(media_id.as_bytes());
+
+                match self.servernamemediaid_metadata.get(&key) {
+                    Ok(Some(value)) => {
+                        files.push(purge(value));
+                    }
+                    Ok(None) => (),
+                    Err(e) => {
+                        files.push(Err(e));
+                    }
+                }
+
+                key.push(0xff);
+                for (_, value) in self.thumbnailid_metadata.scan_prefix(key) {
+                    files.push(purge(value));
+                }
+            } else {
+                match self.purge_mediaid(server_name, media_id, false) {
+                    Ok(f) => {
+                        files.append(&mut f.into_iter().map(Ok).collect());
+                    }
+                    Err(e) => files.push(Err(e)),
+                }
+            }
+        }
+
+        files
+    }
+
+    fn purge_and_get_hashes_from_user(
+        &self,
+        user_id: &UserId,
+        force_filehash: bool,
+        after: Option<u64>,
+    ) -> Vec<Result<String>> {
+        let mut files = Vec::new();
+        let mut prefix = user_id.server_name().as_bytes().to_vec();
+        prefix.push(0xff);
+        prefix.extend_from_slice(user_id.localpart().as_bytes());
+        prefix.push(0xff);
+
+        let purge_filehash = |sha256_digest: Vec<u8>| {
+            let sha256_hex = hex::encode(&sha256_digest);
+
+            self.purge_filehash(sha256_digest, false)?;
+
+            Ok(sha256_hex)
+        };
+
+        for (k, _) in self.servername_userlocalpart_mediaid.scan_prefix(prefix) {
+            let metadata = || {
+                let mut parts = k.rsplit(|&b| b == 0xff);
+                let media_id_bytes = parts.next().ok_or_else(|| {
+                    Error::bad_database(
+                        "Invalid format for key of servername_userlocalpart_mediaid",
+                    )
+                })?;
+
+                let media_id = utils::string_from_bytes(media_id_bytes).map_err(|_| {
+                    Error::bad_database(
+                        "Invalid media_id string in servername_userlocalpart_mediaid",
+                    )
+                })?;
+
+                let mut key = user_id.server_name().as_bytes().to_vec();
+                key.push(0xff);
+                key.extend_from_slice(media_id.as_bytes());
+
+                Ok((
+                    self.servernamemediaid_metadata.get(&key)?.ok_or_else(|| {
+                    error!(
+                        "Missing metadata for \"mxc://{}/{media_id}\", despite storing it's uploader",
+                        user_id.server_name()
+                    );
+                        Error::BadDatabase("Missing metadata for media id and server_name")
+                    })?,
+                    media_id,
+                ))
+            };
+
+            let (mut metadata, media_id) = match metadata() {
+                Ok(v) => v,
+                Err(e) => {
+                    files.push(Err(e));
+                    continue;
+                }
+            };
+
+            metadata.truncate(32);
+            let sha256_digest = metadata;
+
+            if let Some(after) = after {
+                let metadata = match self
+                    .filehash_metadata
+                    .get(&sha256_digest)
+                    .map(|opt| opt.map(FilehashMetadata::from_vec))
+                {
+                    Ok(Some(metadata)) => metadata,
+                    // If the media has already been deleted, we shouldn't treat that as an error
+                    Ok(None) => continue,
+                    Err(e) => {
+                        files.push(Err(e));
+                        continue;
+                    }
+                };
+
+                let creation = match metadata.creation(&sha256_digest) {
+                    Ok(c) => c,
+                    Err(e) => {
+                        files.push(Err(e));
+                        continue;
+                    }
+                };
+
+                if creation < after {
+                    continue;
+                }
+            }
+
+            if force_filehash {
+                files.push(purge_filehash(sha256_digest));
+
+                let mut prefix = user_id.server_name().as_bytes().to_vec();
+                prefix.push(0xff);
+                prefix.extend_from_slice(media_id.as_bytes());
+                prefix.push(0xff);
+                for (_, mut metadata) in self.thumbnailid_metadata.scan_prefix(prefix) {
+                    metadata.truncate(32);
+                    let sha256_digest = metadata;
+                    files.push(purge_filehash(sha256_digest));
+                }
+            } else {
+                match self.purge_mediaid(user_id.server_name(), &media_id, false) {
+                    Ok(f) => {
+                        files.append(&mut f.into_iter().map(Ok).collect());
+                    }
+                    Err(e) => files.push(Err(e)),
+                }
+            }
+        }
+
+        files
+    }
+
+    fn purge_and_get_hashes_from_server(
+        &self,
+        server_name: &ServerName,
+        force_filehash: bool,
+        after: Option<u64>,
+    ) -> Vec<Result<String>> {
+        let mut prefix = server_name.as_bytes().to_vec();
+        prefix.push(0xff);
+
+        let mut files = Vec::new();
+
+        // Purges all references to the given media in the database,
+        // returning a Vec of hex sha256 digests
+        let purge_sha256 = |files: &mut Vec<Result<String>>, mut metadata: Vec<u8>| {
+            metadata.truncate(32);
+            let sha256_digest = metadata;
+
+            if let Some(after) = after {
+                let Some(metadata) = self
+                    .filehash_metadata
+                    .get(&sha256_digest)?
+                    .map(FilehashMetadata::from_vec)
+                else {
+                    // If the media has already been deleted, we shouldn't treat that as an error
+                    return Ok(());
+                };
+
+                if metadata.creation(&sha256_digest)? < after {
+                    return Ok(());
+                }
+            }
+
+            let sha256_hex = hex::encode(&sha256_digest);
+
+            self.purge_filehash(sha256_digest, false)?;
+
+            files.push(Ok(sha256_hex));
+            Ok(())
+        };
+
+        let purge_mediaid = |files: &mut Vec<Result<String>>, key: Vec<u8>| {
+            let mut parts = key.split(|&b| b == 0xff);
+
+            let server_name = parts
+                .next()
+                .ok_or_else(|| Error::bad_database("Invalid format of metadata key"))
+                .map(utils::string_from_bytes)?
+                .map_err(|_| Error::bad_database("Invalid ServerName String in metadata key"))
+                .map(OwnedServerName::try_from)?
+                .map_err(|_| Error::bad_database("Invalid ServerName String in metadata key"))?;
+
+            let media_id = parts
+                .next()
+                .ok_or_else(|| Error::bad_database("Invalid format of metadata key"))
+                .map(utils::string_from_bytes)?
+                .map_err(|_| Error::bad_database("Invalid Media ID String in metadata key"))?;
+
+            files.append(
+                &mut self
+                    .purge_mediaid(&server_name, &media_id, false)?
+                    .into_iter()
+                    .map(Ok)
+                    .collect(),
+            );
+
+            Ok(())
+        };
+
+        for (key, value) in self
+            .servernamemediaid_metadata
+            .scan_prefix(prefix.clone())
+            .chain(self.thumbnailid_metadata.scan_prefix(prefix.clone()))
+        {
+            if let Err(e) = if force_filehash {
+                purge_sha256(&mut files, value)
+            } else {
+                purge_mediaid(&mut files, key)
+            } {
+                files.push(Err(e));
+            }
+        }
+
+        files
+    }
+}
+
+impl KeyValueDatabase {
+    fn purge_mediaid(
+        &self,
+        server_name: &ServerName,
+        media_id: &str,
+        only_filehash_metadata: bool,
+    ) -> Result<Vec<String>> {
+        let mut files = Vec::new();
+
+        let count_required_to_purge = if only_filehash_metadata { 1 } else { 0 };
+
+        let mut key = server_name.as_bytes().to_vec();
+        key.push(0xff);
+        key.extend_from_slice(media_id.as_bytes());
+
+        if let Some(sha256_digest) = self.servernamemediaid_metadata.get(&key)?.map(|mut value| {
+            value.truncate(32);
+            value
+        }) {
+            if !only_filehash_metadata {
+                if let Some(localpart) = self.servernamemediaid_userlocalpart.get(&key)? {
+                    self.servernamemediaid_userlocalpart.remove(&key)?;
+
+                    let mut key = server_name.as_bytes().to_vec();
+                    key.push(0xff);
+                    key.extend_from_slice(&localpart);
+                    key.push(0xff);
+                    key.extend_from_slice(media_id.as_bytes());
+
+                    self.servername_userlocalpart_mediaid.remove(&key)?;
+                };
+
+                self.servernamemediaid_metadata.remove(&key)?;
+
+                let mut key = sha256_digest.clone();
+                key.extend_from_slice(server_name.as_bytes());
+                key.push(0xff);
+                key.extend_from_slice(media_id.as_bytes());
+
+                self.filehash_servername_mediaid.remove(&key)?;
+            }
+
+            if self
+                .filehash_servername_mediaid
+                .scan_prefix(sha256_digest.clone())
+                .count()
+                <= count_required_to_purge
+                && self
+                    .filehash_thumbnailid
+                    .scan_prefix(sha256_digest.clone())
+                    .next()
+                    .is_none()
+            {
+                self.filehash_metadata.remove(&sha256_digest)?;
+                files.push(hex::encode(sha256_digest));
+            }
+        }
+
+        key.push(0xff);
+
+        let mut thumbnails = BTreeMap::new();
+
+        for (thumbnail_id, mut value) in self.thumbnailid_metadata.scan_prefix(key) {
+            value.truncate(32);
+            let sha256_digest = value;
+
+            let entry = thumbnails
+                .entry(sha256_digest.clone())
+                .and_modify(|v| *v += 1)
+                .or_insert(1);
+
+            if !only_filehash_metadata {
+                self.filehash_thumbnailid.remove(&sha256_digest)?;
+                self.thumbnailid_metadata.remove(&thumbnail_id)?;
+            }
+
+            // Basically, if this is the only media pointing to the filehash, get rid of it.
+            // It's a little complicated due to how blocking works.
+            if self
+                .filehash_servername_mediaid
+                .scan_prefix(sha256_digest.clone())
+                .count()
+                <= count_required_to_purge
+                && self
+                    .filehash_thumbnailid
+                    .scan_prefix(sha256_digest.clone())
+                    .count()
+                    <= if only_filehash_metadata { *entry } else { 0 }
+            {
+                self.filehash_metadata.remove(&sha256_digest)?;
+                files.push(hex::encode(sha256_digest));
+            }
+        }
+
+        Ok(files)
+    }
+
+    fn purge_filehash(&self, sha256_digest: Vec<u8>, only_filehash_metadata: bool) -> Result<()> {
+        let handle_error = || {
+            error!(
+                "Invalid format of key in filehash_servername_mediaid for media with sha256 content hash of {}",
+                hex::encode(&sha256_digest)
+            );
+            Error::BadDatabase("Invalid format of key in filehash_servername_mediaid")
+        };
+
+        if !only_filehash_metadata {
+            for (key, _) in self.filehash_thumbnailid.scan_prefix(sha256_digest.clone()) {
+                self.filehash_thumbnailid.remove(&key)?;
+                let (_, key) = key.split_at(32);
+                self.thumbnailid_metadata.remove(key)?;
+            }
+
+            for (k, _) in self
+                .filehash_servername_mediaid
+                .scan_prefix(sha256_digest.clone())
+            {
+                let (_, servername_mediaid) = k.split_at_checked(32).ok_or_else(handle_error)?;
+
+                self.servernamemediaid_metadata.remove(servername_mediaid)?;
+                self.filehash_servername_mediaid.remove(&k)?;
+
+                if let Some(localpart) = self
+                    .servernamemediaid_userlocalpart
+                    .get(servername_mediaid)?
+                {
+                    self.servernamemediaid_userlocalpart
+                        .remove(servername_mediaid)?;
+
+                    let mut parts = servername_mediaid.split(|b: &u8| *b == 0xff);
+
+                    let mut key = parts.next().ok_or_else(handle_error)?.to_vec();
+                    key.push(0xff);
+                    key.extend_from_slice(&localpart);
+                    key.push(0xff);
+                    key.extend_from_slice(parts.next().ok_or_else(handle_error)?);
+
+                    self.servername_userlocalpart_mediaid.remove(&key)?;
+                };
+            }
+        }
+
+        self.filehash_metadata.remove(&sha256_digest)
+    }
 }
 
 fn parse_metadata(value: &[u8]) -> Result<DbFileMeta> {
@@ -213,7 +612,47 @@ impl FilehashMetadata {
         Self { value }
     }
 
+    pub fn from_vec(vec: Vec<u8>) -> Self {
+        Self { value: vec }
+    }
+
     pub fn value(&self) -> &[u8] {
         &self.value
     }
+
+    fn get_u64_val(
+        &self,
+        range: Range<usize>,
+        name: &str,
+        sha256_digest: &[u8],
+        invalid_error: &'static str,
+    ) -> Result<u64> {
+        self.value
+            .get(range)
+            .ok_or_else(|| {
+                error!(
+                    "Invalid format of metadata for media with sha256 content hash of {}",
+                    hex::encode(sha256_digest)
+                );
+                Error::BadDatabase("Invalid format of metadata in filehash_metadata")
+            })?
+            .try_into()
+            .map(u64::from_be_bytes)
+            .map_err(|_| {
+                error!(
+                    "Invalid {name} for media with sha256 content hash of {}",
+                    hex::encode(sha256_digest)
+                );
+                Error::BadDatabase(invalid_error)
+            })
+    }
+
+    pub fn creation(&self, sha256_digest: &[u8]) -> Result<u64> {
+        self.get_u64_val(
+            8..16,
+            "creation time",
+            sha256_digest,
+            "Invalid creation time in filehash_metadata",
+        )
+    }
 }

src/service/admin/mod.rs

@@ -1,6 +1,11 @@
-use std::{collections::BTreeMap, convert::TryFrom, sync::Arc, time::Instant};
+use std::{
+    collections::BTreeMap,
+    convert::TryFrom,
+    sync::Arc,
+    time::{Duration, Instant, SystemTime, UNIX_EPOCH},
+};
 
-use clap::Parser;
+use clap::{Args, Parser};
 use regex::Regex;
 use ruma::{
     api::appservice::Registration,
@@ -19,8 +24,8 @@ use ruma::{
         },
         TimelineEventType,
     },
-    EventId, MilliSecondsSinceUnixEpoch, OwnedRoomAliasId, OwnedRoomId, RoomAliasId, RoomId,
-    RoomVersionId, ServerName, UserId,
+    EventId, MilliSecondsSinceUnixEpoch, MxcUri, OwnedRoomAliasId, OwnedRoomId, OwnedServerName,
+    RoomAliasId, RoomId, RoomVersionId, ServerName, UserId,
 };
 use serde_json::value::to_raw_value;
 use tokio::sync::{mpsc, Mutex, RwLock};
@@ -82,11 +87,13 @@ enum AdminCommand {
     /// Deactivate a user
     ///
     /// User will not be removed from all rooms by default.
-    /// Use --leave-rooms to force the user to leave all rooms
+    /// Use --leave-rooms to force the user to leave all rooms.
     DeactivateUser {
         #[arg(short, long)]
         leave_rooms: bool,
         user_id: Box<UserId>,
+        #[command(flatten)]
+        purge_media: DeactivatePurgeMediaArgs,
     },
 
     #[command(verbatim_doc_comment)]
@@ -94,6 +101,8 @@ enum AdminCommand {
     ///
     /// Recommended to use in conjunction with list-local-users.
     ///
+    /// Use either --purge-all-media or --purge-media-from-last to either delete all media uploaded
+    /// by them (in the last {specified timeframe}, if any)
     /// Users will not be removed from joined rooms by default.
     /// Can be overridden with --leave-rooms flag.
     /// Removing a mass amount of users from a room may cause a significant amount of leave events.
@@ -107,9 +116,68 @@ enum AdminCommand {
         #[arg(short, long)]
         /// Remove users from their joined rooms
         leave_rooms: bool,
-        #[arg(short, long)]
+        #[arg(short = 'F', long)]
         /// Also deactivate admin accounts
         force: bool,
+        #[command(flatten)]
+        purge_media: DeactivatePurgeMediaArgs,
+    },
+
+    /// Purge a list of media, formatted as MXC URIs
+    /// There should be one URI per line, all contained within a code-block
+    ///
+    /// Note: This will also delete media with the same sha256 hash, so
+    /// only use this when you are certain all the media is undesirable
+    PurgeMedia,
+
+    /// Purges all media uploaded by the local users listed in a code-block.
+    ///
+    /// Note: This will also delete identical media uploaded by other users, so
+    /// only use this when all the media they uploaded is undesirable
+    PurgeMediaFromUsers {
+        #[arg(
+            long, short = 't',
+            value_parser = humantime::parse_duration
+        )]
+        /// Only purge media uploaded in the last {timeframe}
+        ///
+        /// Should be in the form specified by humantime::parse_duration
+        /// (e.g. 48h, 60min, 10days etc.)
+        // --help is unformatted
+        #[allow(rustdoc::bare_urls)]
+        /// https://docs.rs/humantime/2.2.0/humantime/fn.parse_duration.html
+        from_last: Option<Duration>,
+
+        #[arg(long, short)]
+        /// Also deletes other media with the same SHA256 hash, ensuring that the file is removed from
+        /// the media backend, so only use this when all the media they uploaded is undesirable
+        force_filehash: bool,
+    },
+
+    /// Purges all media from the specified server
+    ///
+    /// Note: This will also delete identical media uploaded by local users, so
+    /// only use this when all the media from that server is undesirable (or if
+    /// you know that no media on the remote server is also uploaded locally)
+    PurgeMediaFromServer {
+        server_id: Box<ServerName>,
+        #[arg(
+            long, short = 't',
+            value_parser = humantime::parse_duration
+        )]
+        /// Only purge media uploaded in the last {timeframe}
+        ///
+        /// Should be in the form specified by humantime::parse_duration
+        /// (e.g. 48h, 60min, 10days etc.)
+        // --help is unformatted
+        #[allow(rustdoc::bare_urls)]
+        /// https://docs.rs/humantime/2.2.0/humantime/fn.parse_duration.html
+        from_last: Option<Duration>,
+
+        #[arg(long, short)]
+        /// Also deletes other media with the same SHA256 hash, ensuring that the file is removed from
+        /// the media backend, so only use this when all the media they uploaded is undesirable
+        force_filehash: bool,
     },
 
     /// Get the auth_chain of a PDU
@@ -181,6 +249,37 @@ enum AdminCommand {
     HashAndSignEvent { room_version_id: RoomVersionId },
 }
 
+#[derive(Args, Debug)]
+#[group(multiple = true, required = false)]
+pub struct DeactivatePurgeMediaArgs {
+    #[arg(long, short = 'm')]
+    /// Purges all media uploaded by the user(s) after deactivating their account
+    purge_media: bool,
+
+    #[arg(
+        long, short = 't',
+        value_parser = humantime::parse_duration,
+        requires = "purge_media"
+    )]
+    /// If the --purge-media is present, it only purges media uploaded in the last {time-period}
+    ///
+    /// Should be in the form specified by humantime::parse_duration
+    /// (e.g. 48h, 60min, 10days etc.)
+    // --help is unformatted
+    #[allow(rustdoc::bare_urls)]
+    /// https://docs.rs/humantime/2.2.0/humantime/fn.parse_duration.html
+    ///
+    /// Note: This will also delete identical media uploaded by other users, so
+    /// only use this when all the media they uploaded in this timeframe is undesirable
+    media_from_last: Option<Duration>,
+
+    #[arg(long, short = 'f', requires = "purge_media")]
+    /// If the --purge-media is present, it will also delete identical media uploaded by other
+    /// users, ensuring that the file is removed from the media backend, so only use this when all
+    /// the media they uploaded is undesirable
+    force_filehash: bool,
+}
+
 #[derive(Debug)]
 pub enum AdminRoomEvent {
     ProcessMessage(String),
@@ -690,6 +789,7 @@ impl Service {
             AdminCommand::DeactivateUser {
                 leave_rooms,
                 user_id,
+                purge_media,
             } => {
                 let user_id = Arc::<UserId>::from(user_id);
                 if !services().users.exists(&user_id)? {
@@ -711,78 +811,42 @@ impl Service {
                         leave_all_rooms(&user_id).await?;
                     }
 
-                    RoomMessageEventContent::text_plain(format!(
-                        "User {user_id} has been deactivated"
+                    let failed_purged_media = if purge_media.purge_media {
+                        let after = purge_media
+                            .media_from_last
+                            .map(unix_secs_from_duration)
+                            .transpose()?;
+
+                        services()
+                            .media
+                            .purge_from_user(&user_id, purge_media.force_filehash, after)
+                            .len()
+                    } else {
+                        0
+                    };
+
+                    if failed_purged_media == 0 {
+                        RoomMessageEventContent::text_plain(format!(
+                            "User {user_id} has been deactivated"
+                        ))
+                    } else {
+                        RoomMessageEventContent ::text_plain(format!(
+                        "User {user_id} has been deactivated, but {failed_purged_media} media failed to be purged, check the logs for more details"
                     ))
+                    }
                 }
             }
-            AdminCommand::DeactivateAll { leave_rooms, force } => {
+            AdminCommand::DeactivateAll {
+                leave_rooms,
+                force,
+                purge_media,
+            } => {
                 if body.len() > 2 && body[0].trim() == "```" && body.last().unwrap().trim() == "```"
                 {
-                    let users = body.clone().drain(1..body.len() - 1).collect::<Vec<_>>();
-
-                    let mut user_ids = Vec::new();
-                    let mut remote_ids = Vec::new();
-                    let mut non_existent_ids = Vec::new();
-                    let mut invalid_users = Vec::new();
-
-                    for &user in &users {
-                        match <&UserId>::try_from(user) {
-                            Ok(user_id) => {
-                                if user_id.server_name() != services().globals.server_name() {
-                                    remote_ids.push(user_id)
-                                } else if !services().users.exists(user_id)? {
-                                    non_existent_ids.push(user_id)
-                                } else {
-                                    user_ids.push(user_id)
-                                }
-                            }
-                            Err(_) => {
-                                invalid_users.push(user);
-                            }
-                        }
-                    }
-
-                    let mut markdown_message = String::new();
-                    let mut html_message = String::new();
-                    if !invalid_users.is_empty() {
-                        markdown_message.push_str("The following user ids are not valid:\n```\n");
-                        html_message.push_str("The following user ids are not valid:\n<pre>\n");
-                        for invalid_user in invalid_users {
-                            markdown_message.push_str(&format!("{invalid_user}\n"));
-                            html_message.push_str(&format!("{invalid_user}\n"));
-                        }
-                        markdown_message.push_str("```\n\n");
-                        html_message.push_str("</pre>\n\n");
-                    }
-                    if !remote_ids.is_empty() {
-                        markdown_message
-                            .push_str("The following users are not from this server:\n```\n");
-                        html_message
-                            .push_str("The following users are not from this server:\n<pre>\n");
-                        for remote_id in remote_ids {
-                            markdown_message.push_str(&format!("{remote_id}\n"));
-                            html_message.push_str(&format!("{remote_id}\n"));
-                        }
-                        markdown_message.push_str("```\n\n");
-                        html_message.push_str("</pre>\n\n");
-                    }
-                    if !non_existent_ids.is_empty() {
-                        markdown_message.push_str("The following users do not exist:\n```\n");
-                        html_message.push_str("The following users do not exist:\n<pre>\n");
-                        for non_existent_id in non_existent_ids {
-                            markdown_message.push_str(&format!("{non_existent_id}\n"));
-                            html_message.push_str(&format!("{non_existent_id}\n"));
-                        }
-                        markdown_message.push_str("```\n\n");
-                        html_message.push_str("</pre>\n\n");
-                    }
-                    if !markdown_message.is_empty() {
-                        return Ok(RoomMessageEventContent::text_html(
-                            markdown_message,
-                            html_message,
-                        ));
-                    }
+                    let mut user_ids = match userids_from_body(&body)? {
+                        Ok(v) => v,
+                        Err(message) => return Ok(message),
+                    };
 
                     let mut deactivation_count = 0;
                     let mut admins = Vec::new();
@@ -812,12 +876,81 @@ impl Service {
                         }
                     }
 
-                    if admins.is_empty() {
+                    let mut failed_count = 0;
+
+                    if purge_media.purge_media {
+                        let after = purge_media
+                            .media_from_last
+                            .map(unix_secs_from_duration)
+                            .transpose()?;
+
+                        for user_id in user_ids {
+                            failed_count += services()
+                                .media
+                                .purge_from_user(user_id, purge_media.force_filehash, after)
+                                .len();
+                        }
+                    }
+
+                    let mut message = format!("Deactivated {deactivation_count} accounts.");
+                    if !admins.is_empty() {
+                        message.push_str(&format!("\nSkipped admin accounts: {:?}. Use --force to deactivate admin accounts",admins.join(", ")));
+                    }
+                    if failed_count != 0 {
+                        message.push_str(&format!(
+                            "\nFailed to delete {failed_count} media, check logs for more details"
+                        ))
+                    }
+
+                    RoomMessageEventContent::text_plain(message)
+                } else {
+                    RoomMessageEventContent::text_plain(
+                        "Expected code block in command body. Add --help for details.",
+                    )
+                }
+            }
+            AdminCommand::PurgeMedia => media_from_body(body).map_or_else(
+                |message| message,
+                |media| {
+                    let failed_count = services().media.purge(&media, true).len();
+
+                    if failed_count == 0 {
+                        RoomMessageEventContent::text_plain("Successfully purged media")
+                    } else {
                         RoomMessageEventContent::text_plain(format!(
-                            "Deactivated {deactivation_count} accounts."
+                            "Failed to delete {failed_count} media, check logs for more details"
                         ))
+                    }
+                },
+            ),
+            AdminCommand::PurgeMediaFromUsers {
+                from_last,
+                force_filehash,
+            } => {
+                let after = from_last.map(unix_secs_from_duration).transpose()?;
+
+                if body.len() > 2 && body[0].trim() == "```" && body.last().unwrap().trim() == "```"
+                {
+                    let user_ids = match userids_from_body(&body)? {
+                        Ok(v) => v,
+                        Err(message) => return Ok(message),
+                    };
+
+                    let mut failed_count = 0;
+
+                    for user_id in user_ids {
+                        failed_count += services()
+                            .media
+                            .purge_from_user(user_id, force_filehash, after)
+                            .len();
+                    }
+
+                    if failed_count == 0 {
+                        RoomMessageEventContent::text_plain("Successfully purged media")
                     } else {
-                        RoomMessageEventContent::text_plain(format!("Deactivated {} accounts.\nSkipped admin accounts: {:?}. Use --force to deactivate admin accounts", deactivation_count, admins.join(", ")))
+                        RoomMessageEventContent::text_plain(format!(
+                            "Failed to purge {failed_count} media, check logs for more details"
+                        ))
                     }
                 } else {
                     RoomMessageEventContent::text_plain(
@@ -825,6 +958,34 @@ impl Service {
                     )
                 }
             }
+            AdminCommand::PurgeMediaFromServer {
+                server_id: server_name,
+                from_last,
+                force_filehash,
+            } => {
+                if server_name == services().globals.server_name() {
+                    return Err(Error::AdminCommand(
+                        "Cannot purge all media from your own homeserver",
+                    ));
+                }
+
+                let after = from_last.map(unix_secs_from_duration).transpose()?;
+
+                let failed_count = services()
+                    .media
+                    .purge_from_server(&server_name, force_filehash, after)
+                    .len();
+
+                if failed_count == 0 {
+                    RoomMessageEventContent::text_plain(format!(
+                        "Media from {server_name} has successfully been purged"
+                    ))
+                } else {
+                    RoomMessageEventContent::text_plain(format!(
+                        "Failed to purge {failed_count} media, check logs for more details"
+                    ))
+                }
+            }
             AdminCommand::SignJson => {
                 if body.len() > 2 && body[0].trim() == "```" && body.last().unwrap().trim() == "```"
                 {
@@ -1456,6 +1617,105 @@ impl Service {
     }
 }
 
+fn userids_from_body<'a>(
+    body: &'a [&'a str],
+) -> Result<Result<Vec<&'a UserId>, RoomMessageEventContent>, Error> {
+    let users = body.to_owned().drain(1..body.len() - 1).collect::<Vec<_>>();
+
+    let mut user_ids = Vec::new();
+    let mut remote_ids = Vec::new();
+    let mut non_existent_ids = Vec::new();
+    let mut invalid_users = Vec::new();
+
+    for &user in &users {
+        match <&UserId>::try_from(user) {
+            Ok(user_id) => {
+                if user_id.server_name() != services().globals.server_name() {
+                    remote_ids.push(user_id)
+                } else if !services().users.exists(user_id)? {
+                    non_existent_ids.push(user_id)
+                } else {
+                    user_ids.push(user_id)
+                }
+            }
+            Err(_) => {
+                invalid_users.push(user);
+            }
+        }
+    }
+
+    let mut markdown_message = String::new();
+    let mut html_message = String::new();
+    if !invalid_users.is_empty() {
+        markdown_message.push_str("The following user ids are not valid:\n```\n");
+        html_message.push_str("The following user ids are not valid:\n<pre>\n");
+        for invalid_user in invalid_users {
+            markdown_message.push_str(&format!("{invalid_user}\n"));
+            html_message.push_str(&format!("{invalid_user}\n"));
+        }
+        markdown_message.push_str("```\n\n");
+        html_message.push_str("</pre>\n\n");
+    }
+    if !remote_ids.is_empty() {
+        markdown_message.push_str("The following users are not from this server:\n```\n");
+        html_message.push_str("The following users are not from this server:\n<pre>\n");
+        for remote_id in remote_ids {
+            markdown_message.push_str(&format!("{remote_id}\n"));
+            html_message.push_str(&format!("{remote_id}\n"));
+        }
+        markdown_message.push_str("```\n\n");
+        html_message.push_str("</pre>\n\n");
+    }
+    if !non_existent_ids.is_empty() {
+        markdown_message.push_str("The following users do not exist:\n```\n");
+        html_message.push_str("The following users do not exist:\n<pre>\n");
+        for non_existent_id in non_existent_ids {
+            markdown_message.push_str(&format!("{non_existent_id}\n"));
+            html_message.push_str(&format!("{non_existent_id}\n"));
+        }
+        markdown_message.push_str("```\n\n");
+        html_message.push_str("</pre>\n\n");
+    }
+    if !markdown_message.is_empty() {
+        return Ok(Err(RoomMessageEventContent::text_html(
+            markdown_message,
+            html_message,
+        )));
+    }
+
+    Ok(Ok(user_ids))
+}
+
+fn media_from_body(
+    body: Vec<&str>,
+) -> Result<Vec<(OwnedServerName, String)>, RoomMessageEventContent> {
+    if body.len() > 2 && body[0].trim() == "```" && body.last().unwrap().trim() == "```" {
+        Ok(body
+            .clone()
+            .drain(1..body.len() - 1)
+            .map(<Box<MxcUri>>::from)
+            .filter_map(|mxc| {
+                mxc.parts()
+                    .map(|(server_name, media_id)| (server_name.to_owned(), media_id.to_owned()))
+                    .ok()
+            })
+            .collect::<Vec<_>>())
+    } else {
+        Err(RoomMessageEventContent::text_plain(
+            "Expected code block in command body. Add --help for details.",
+        ))
+    }
+}
+
+fn unix_secs_from_duration(duration: Duration) -> Result<u64> {
+    SystemTime::now()
+        .checked_sub(duration).ok_or_else(||Error::AdminCommand("Given timeframe cannot be represented as system time, please try again with a shorter time-frame"))
+        .map(|time| time
+                .duration_since(UNIX_EPOCH)
+                .expect("Time is after unix epoch")
+                .as_secs())
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

src/service/media/data.rs

@@ -1,4 +1,4 @@
-use ruma::{ServerName, UserId};
+use ruma::{OwnedServerName, ServerName, UserId};
 use sha2::{digest::Output, Sha256};
 
 use crate::Result;
@@ -42,4 +42,24 @@ pub trait Data: Send + Sync {
         width: u32,
         height: u32,
     ) -> Result<DbFileMeta>;
+
+    fn purge_and_get_hashes(
+        &self,
+        media: &[(OwnedServerName, String)],
+        force_filehash: bool,
+    ) -> Vec<Result<String>>;
+
+    fn purge_and_get_hashes_from_user(
+        &self,
+        user_id: &UserId,
+        force_filehash: bool,
+        after: Option<u64>,
+    ) -> Vec<Result<String>>;
+
+    fn purge_and_get_hashes_from_server(
+        &self,
+        server_name: &ServerName,
+        force_filehash: bool,
+        after: Option<u64>,
+    ) -> Vec<Result<String>>;
 }

src/service/media/mod.rs

@@ -1,15 +1,19 @@
 mod data;
-use std::io::Cursor;
+use std::{fs, io::Cursor};
 
 pub use data::Data;
 use ruma::{
     api::client::{error::ErrorKind, media::is_safe_inline_content_type},
     http_headers::{ContentDisposition, ContentDispositionType},
-    ServerName, UserId,
+    OwnedServerName, ServerName, UserId,
 };
 use sha2::{digest::Output, Digest, Sha256};
+use tracing::error;
 
-use crate::{config::MediaConfig, services, Error, Result};
+use crate::{
+    config::{DirectoryStructure, MediaConfig},
+    services, Error, Result,
+};
 use image::imageops::FilterType;
 
 pub struct DbFileMeta {
@@ -293,6 +297,67 @@ impl Service {
             }))
         }
     }
+
+    /// Purges all of the specified media.
+    ///
+    /// If `force_filehash` is true, all media and/or thumbnails which share sha256 content hashes
+    /// with the purged media will also be purged, meaning that the media is guaranteed to be deleted
+    /// from the media backend. Otherwise, it will be deleted if only the media IDs requested to be
+    /// purged have that sha256 hash.
+    ///
+    /// Returns errors for all the files that were failed to be deleted, if any.
+    pub fn purge(&self, media: &[(OwnedServerName, String)], force_filehash: bool) -> Vec<Error> {
+        let hashes = self.db.purge_and_get_hashes(media, force_filehash);
+
+        purge_files(hashes)
+    }
+
+    /// Purges all (past a certain time in unix seconds, if specified) media
+    /// sent by a user.
+    ///
+    /// If `force_filehash` is true, all media and/or thumbnails which share sha256 content hashes
+    /// with the purged media will also be purged, meaning that the media is guaranteed to be deleted
+    /// from the media backend. Otherwise, it will be deleted if only the media IDs requested to be
+    /// purged have that sha256 hash.
+    ///
+    /// Returns errors for all the files that were failed to be deleted, if any.
+    ///
+    /// Note: it only currently works for local users, as we cannot determine who
+    /// exactly uploaded the file when it comes to remove users.
+    pub fn purge_from_user(
+        &self,
+        user_id: &UserId,
+        force_filehash: bool,
+        after: Option<u64>,
+    ) -> Vec<Error> {
+        let hashes = self
+            .db
+            .purge_and_get_hashes_from_user(user_id, force_filehash, after);
+
+        purge_files(hashes)
+    }
+
+    /// Purges all (past a certain time in unix seconds, if specified) media
+    /// obtained from the specified server (due to the MXC URI).
+    ///
+    /// If `force_filehash` is true, all media and/or thumbnails which share sha256 content hashes
+    /// with the purged media will also be purged, meaning that the media is guaranteed to be deleted
+    /// from the media backend. Otherwise, it will be deleted if only the media IDs requested to be
+    /// purged have that sha256 hash.
+    ///
+    /// Returns errors for all the files that were failed to be deleted, if any.
+    pub fn purge_from_server(
+        &self,
+        server_name: &ServerName,
+        force_filehash: bool,
+        after: Option<u64>,
+    ) -> Vec<Error> {
+        let hashes = self
+            .db
+            .purge_and_get_hashes_from_server(server_name, force_filehash, after);
+
+        purge_files(hashes)
+    }
 }
 
 /// Creates the media file, using the configured media backend
@@ -335,6 +400,68 @@ async fn get_file(sha256_hex: &str) -> Result<Vec<u8>> {
     })
 }
 
+/// Purges the given files from the media backend
+/// Returns a `Vec` of errors that occurred when attempting to delete the files
+///
+/// Note: this does NOT remove the related metadata from the database
+fn purge_files(hashes: Vec<Result<String>>) -> Vec<Error> {
+    hashes
+        .into_iter()
+        .map(|hash| match hash {
+            Ok(v) => delete_file(&v),
+            Err(e) => Err(e),
+        })
+        .filter_map(|r| if let Err(e) = r { Some(e) } else { None })
+        .collect()
+}
+
+/// Deletes the given file from the media backend
+///
+/// Note: this does NOT remove the related metadata from the database
+fn delete_file(sha256_hex: &str) -> Result<()> {
+    match &services().globals.config.media {
+        MediaConfig::FileSystem {
+            path,
+            directory_structure,
+        } => {
+            let mut path =
+                services()
+                    .globals
+                    .get_media_path(path, directory_structure, sha256_hex)?;
+
+            if let Err(e) = fs::remove_file(&path) {
+                // Multiple files with the same filehash might be requseted to be deleted
+                if e.kind() != std::io::ErrorKind::NotFound {
+                    error!("Error removing media from filesystem: {e}");
+                    Err(e)?;
+                }
+            }
+
+            if let DirectoryStructure::Deep { length: _, depth } = directory_structure {
+                let mut depth = depth.get();
+
+                while depth > 0 {
+                    // Here at the start so that the first time, the file gets removed from the path
+                    path.pop();
+
+                    if let Err(e) = fs::remove_dir(&path) {
+                        if e.kind() == std::io::ErrorKind::DirectoryNotEmpty {
+                            break;
+                        } else {
+                            error!("Error removing empty media directories: {e}");
+                            Err(e)?;
+                        }
+                    }
+
+                    depth -= 1;
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
 /// Creates a content disposition with the given `filename`, using the `content_type` to determine whether
 /// the disposition should be `inline` or `attachment`
 fn content_disposition(