systemprompt_files/services/upload/
service.rs

1//! [`FileUploadService`]: decode, validate, store, and record uploads.
2//!
3//! Decodes base64 payloads, enforces upload policy via [`FileValidator`],
4//! writes bytes to a traversal-checked storage path derived from the
5//! persistence mode, and records the file through [`FileRepository`], cleaning
6//! up the on-disk artefact if the database write fails.
7//!
8//! Copyright (c) systemprompt.io — Business Source License 1.1.
9//! See <https://systemprompt.io> for licensing details.
10
11use base64::Engine;
12use base64::engine::general_purpose::STANDARD;
13use sha2::{Digest, Sha256};
14use std::path::PathBuf;
15use systemprompt_database::DbPool;
16use systemprompt_identifiers::{ContextId, FileId, UserId};
17use tokio::fs;
18use tokio::io::AsyncWriteExt;
19use uuid::Uuid;
20
21use crate::config::{FilePersistenceMode, FilesConfig};
22use crate::models::{FileChecksums, FileMetadata};
23use crate::repository::{FileRepository, InsertFileRequest};
24
25use super::error::FileUploadError;
26use super::request::{FileUploadRequest, UploadedFile};
27use super::validator::{FileCategory, FileValidator};
28
29struct StoredArtifact<'a> {
30    file_id: &'a FileId,
31    storage_path: &'a std::path::Path,
32    public_url: &'a str,
33    size_bytes: u64,
34    sha256: String,
35}
36
37#[derive(Debug, Clone)]
38pub struct FileUploadService {
39    files_config: FilesConfig,
40    file_repository: FileRepository,
41    validator: FileValidator,
42}
43
44impl FileUploadService {
45    pub fn new(db_pool: &DbPool, files_config: FilesConfig) -> Result<Self, FileUploadError> {
46        let upload_config = *files_config.upload();
47        let file_repository =
48            FileRepository::new(db_pool).map_err(|e| FileUploadError::Database(e.to_string()))?;
49        let validator = FileValidator::new(upload_config);
50
51        Ok(Self {
52            files_config,
53            file_repository,
54            validator,
55        })
56    }
57
58    pub const fn validator(&self) -> &FileValidator {
59        &self.validator
60    }
61
62    pub fn is_enabled(&self) -> bool {
63        let cfg = self.files_config.upload();
64        cfg.enabled && cfg.persistence_mode != FilePersistenceMode::Disabled
65    }
66
67    pub async fn upload_file(
68        &self,
69        request: FileUploadRequest,
70    ) -> Result<UploadedFile, FileUploadError> {
71        let upload_config = self.files_config.upload();
72
73        if upload_config.persistence_mode == FilePersistenceMode::Disabled {
74            return Err(FileUploadError::PersistenceDisabled);
75        }
76
77        let max_encoded_size = (upload_config.max_file_size_bytes as f64 * 1.34) as usize + 100;
78        if request.bytes_base64.len() > max_encoded_size {
79            return Err(FileUploadError::Base64TooLarge {
80                encoded_size: request.bytes_base64.len(),
81            });
82        }
83
84        let bytes = STANDARD.decode(&request.bytes_base64)?;
85        let size_bytes = bytes.len() as u64;
86
87        let category = self.validator.validate(&request.mime_type, size_bytes)?;
88
89        let file_id = FileId::new(Uuid::new_v4().to_string());
90        let extension = FileValidator::get_extension(&request.mime_type, request.name.as_deref());
91        let filename = format!("{}.{}", file_id.as_str(), extension);
92
93        let (storage_path, relative_path) = self.determine_storage_path(
94            &category,
95            &filename,
96            &request.context_id,
97            request.user_id.as_ref(),
98        )?;
99
100        if let Some(parent) = storage_path.parent() {
101            fs::create_dir_all(parent).await?;
102        }
103
104        let mut file = fs::File::create(&storage_path).await?;
105        file.write_all(&bytes).await?;
106        file.flush().await?;
107
108        let sha256 = hex::encode(Sha256::digest(&bytes));
109
110        let public_url = self.files_config.upload_url(&relative_path);
111
112        self.record_file(
113            StoredArtifact {
114                file_id: &file_id,
115                storage_path: &storage_path,
116                public_url: &public_url,
117                size_bytes,
118                sha256,
119            },
120            &request,
121        )
122        .await?;
123
124        Ok(UploadedFile {
125            file_id,
126            path: relative_path,
127            public_url,
128            size_bytes: size_bytes as i64,
129        })
130    }
131
132    async fn record_file(
133        &self,
134        artifact: StoredArtifact<'_>,
135        request: &FileUploadRequest,
136    ) -> Result<(), FileUploadError> {
137        let StoredArtifact {
138            file_id,
139            storage_path,
140            public_url,
141            size_bytes,
142            sha256,
143        } = artifact;
144
145        let metadata = FileMetadata::new().with_checksums(FileChecksums::new().with_sha256(sha256));
146
147        let mut insert_request = InsertFileRequest::new(
148            file_id.clone(),
149            storage_path.to_string_lossy().to_string(),
150            public_url.to_owned(),
151            request.mime_type.clone(),
152        )
153        .with_size(size_bytes as i64)
154        .with_metadata(metadata)
155        .with_context_id(request.context_id.clone());
156
157        if let Some(user_id) = request.user_id.clone() {
158            insert_request = insert_request.with_user_id(user_id);
159        }
160
161        if let Some(session_id) = request.session_id.clone() {
162            insert_request = insert_request.with_session_id(session_id);
163        }
164
165        if let Some(trace_id) = request.trace_id.clone() {
166            insert_request = insert_request.with_trace_id(trace_id);
167        }
168
169        if let Err(e) = self.file_repository.insert(insert_request).await {
170            if let Err(cleanup_err) = fs::remove_file(storage_path).await {
171                tracing::warn!(
172                    path = %storage_path.display(),
173                    error = %cleanup_err,
174                    "Failed to clean up uploaded file after database error"
175                );
176            }
177            return Err(FileUploadError::Database(e.to_string()));
178        }
179
180        Ok(())
181    }
182
183    fn determine_storage_path(
184        &self,
185        category: &FileCategory,
186        filename: &str,
187        context_id: &ContextId,
188        user_id: Option<&UserId>,
189    ) -> Result<(PathBuf, String), FileUploadError> {
190        let base = self.files_config.uploads();
191        let upload_config = self.files_config.upload();
192
193        let context_str = context_id.as_str();
194        Self::validate_path_inputs(context_str, filename, user_id)?;
195
196        let (full_path, relative) = match upload_config.persistence_mode {
197            FilePersistenceMode::ContextScoped => {
198                let rel = format!(
199                    "contexts/{}/{}/{}",
200                    context_str,
201                    category.storage_subdir(),
202                    filename
203                );
204                (base.join(&rel), rel)
205            },
206            FilePersistenceMode::UserLibrary => {
207                let user_dir =
208                    user_id.map_or_else(|| "anonymous".to_owned(), |u| u.as_str().to_owned());
209                let rel = format!(
210                    "users/{}/{}/{}",
211                    user_dir,
212                    category.storage_subdir(),
213                    filename
214                );
215                (base.join(&rel), rel)
216            },
217            FilePersistenceMode::Disabled => {
218                return Err(FileUploadError::PersistenceDisabled);
219            },
220        };
221
222        for component in std::path::Path::new(&relative).components() {
223            use std::path::Component;
224            match component {
225                Component::Normal(_) | Component::CurDir => {},
226                Component::ParentDir | Component::RootDir | Component::Prefix(_) => {
227                    return Err(FileUploadError::PathValidation(
228                        "Resolved path contains traversal or absolute component".to_owned(),
229                    ));
230                },
231            }
232        }
233
234        if !full_path.starts_with(&base) {
235            return Err(FileUploadError::PathValidation(
236                "Resolved path escapes upload directory".to_owned(),
237            ));
238        }
239
240        Ok((full_path, relative))
241    }
242
243    fn validate_path_inputs(
244        context_str: &str,
245        filename: &str,
246        user_id: Option<&UserId>,
247    ) -> Result<(), FileUploadError> {
248        if context_str.contains("..") || context_str.contains('\0') {
249            return Err(FileUploadError::PathValidation(
250                "Invalid context_id: contains path traversal sequence".to_owned(),
251            ));
252        }
253
254        if let Some(uid) = user_id {
255            let user_str = uid.as_str();
256            if user_str.contains("..") || user_str.contains('\0') {
257                return Err(FileUploadError::PathValidation(
258                    "Invalid user_id: contains path traversal sequence".to_owned(),
259                ));
260            }
261        }
262
263        if filename.contains('\0')
264            || filename.contains('/')
265            || filename.contains('\\')
266            || filename == ".."
267            || filename == "."
268            || filename.is_empty()
269        {
270            return Err(FileUploadError::PathValidation(
271                "Invalid filename: must be a single path component".to_owned(),
272            ));
273        }
274
275        Ok(())
276    }
277}
systemprompt_files/services/upload/service.rs

systemprompt_files/services/upload/
service.rs
