{ "openapi": "3.1.1", "info": { "title": "Local File Encryption Studio API", "version": "1.0.0", "summary": "Encrypt and decrypt files with AES-256-GCM and a password, locally in your browser.", "description": "Every endpoint performs the same calculation as the human page and returns inputs, result, units, assumptions, sources, warnings and computedAt. MCP endpoint: /mcp." }, "servers": [ { "url": "https://fileencryptionstudio.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "Encrypt and decrypt files with AES-256-GCM and a password, locally in your browser.", "description": "Encrypts any file up to 100 MB with AES-256-GCM, using a password (PBKDF2-SHA-256, at least 600,000 iterations) or a raw 256-bit key, and decrypts it again. The output is a small documented container. With JavaScript on, everything runs in your browser via WebCrypto and the file never leaves your device.\n\nMethodology:\n- Encryption: AES-256 in GCM mode (authenticated encryption) with a random 96-bit IV. The 16-byte authentication tag detects a wrong key and any modification of the file or its header.\n- Password mode: the key is PBKDF2-HMAC-SHA-256(password in Unicode NFC, UTF-8; random 16-byte salt; ≥ 600,000 iterations; 32 bytes). Raw-key mode uses your 32-byte key directly (or a random one generated for you).\n- Container \"UWFE\" v1, all integers big-endian: bytes 0–3 \"UWFE\"; 4 version (1); 5 KDF (1 = PBKDF2-SHA-256, 0 = raw key); 6–9 iterations (0 for raw key); 10 salt length S; then S salt bytes; then IV length (12) and the IV; then ciphertext followed by the 16-byte tag. The whole header is authenticated as GCM additional data.\n- With JavaScript on, the browser does everything with WebCrypto (crypto.subtle: PBKDF2, AES-GCM) and offers the result as a local download; the file and password never leave your device.\n- Without JavaScript or via the API/MCP, the server performs the same steps with Node.js crypto. It then receives the file and the password; the output is kept as a download for about 2 hours and then deleted.\n\nIf you forget the password or lose the key, the file cannot be recovered. Keep an unencrypted backup until you have tested decryption.", "tags": [ "crypto" ], "x-mcp-tool": "file_encryption_studio", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/FileEncryptionStudioInput" }, "examples": { "example1": { "summary": "Encrypt a text file with a password (demo seed)", "value": { "action": "encrypt", "file": { "filename": "notes.txt", "contentType": "text/plain", "contentBase64": "TWVldGluZyBub3RlczogdGhlIHNwYXJlIGtleSBpcyB1bmRlciB0aGUgYmx1ZSBmbG93ZXJwb3QuCg==" }, "keyMode": "password", "password": "correct horse battery staple", "seed": "demo" } }, "example2": { "summary": "Decrypt the demo file", "value": { "action": "decrypt", "file": { "filename": "notes.txt.uwenc", "contentType": "application/octet-stream", "contentBase64": "VVdGRQEBAAknwBDpZOKuJvfa5dh6b4uQWgxhDBz+qzPNLpyER5uJf0+lqHctv57Gg4dAu9etoo9XyTMcu4qngNaolW3xIPUsAFquU/AQK9yw1zMFh2AKPSCkQVO45yYcipxdJ/Geh65IpBMyFXIxSia1" }, "keyMode": "password", "password": "correct horse battery staple" } }, "example3": { "summary": "Encrypt with a raw AES-256 key", "value": { "action": "encrypt", "file": { "filename": "data.csv", "contentType": "text/csv", "contentBase64": "aWQsYW1vdW50CjEsNDIK" }, "keyMode": "rawkey", "rawKey": "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f", "seed": "raw-demo" } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/FileEncryptionStudioResult" } } } }, "400": { "description": "Malformed JSON body.", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "422": { "description": "Invalid input (see errors[]).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "429": { "description": "Rate limit exceeded (see Retry-After).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } } } } }, "/api/v1/tool": { "get": { "operationId": "getToolDefinition", "summary": "Inputs, output schema and examples for this tool", "responses": { "200": { "description": "Tool definition.", "content": { "application/json": { "schema": { "type": "object" } } } } } } } }, "components": { "schemas": { "Problem": { "type": "object", "description": "RFC 9457 problem details. 422 responses include per-field `errors`.", "required": [ "type", "title", "status", "detail" ], "properties": { "type": { "type": "string" }, "title": { "type": "string" }, "status": { "type": "integer" }, "detail": { "type": "string" }, "code": { "type": "string" }, "errors": { "type": "array", "items": { "type": "object", "required": [ "field", "message" ], "properties": { "field": { "type": "string" }, "message": { "type": "string" } } } } } }, "FileEncryptionStudioInput": { "type": "object", "additionalProperties": false, "properties": { "action": { "title": "Action", "type": "string", "enum": [ "encrypt", "decrypt" ], "default": "encrypt" }, "file": { "title": "File", "description": "Up to 100 MB. With JavaScript on, the file is processed in your browser and never uploaded. Upload as {filename, contentType?, contentBase64}. Max 102400 KiB. Accepts */*.", "type": "object", "additionalProperties": false, "required": [ "filename", "contentBase64" ], "properties": { "filename": { "type": "string" }, "contentType": { "type": "string" }, "contentBase64": { "type": "string" } } }, "keyMode": { "title": "Key", "type": "string", "enum": [ "password", "rawkey" ], "default": "password" }, "password": { "title": "Password", "description": "Use a long passphrase. It cannot be recovered: without it the file is lost.", "type": "string", "maxLength": 1024 }, "rawKey": { "title": "Raw key (64 hex or 44 Base64 characters)", "description": "Raw-key mode. Leave empty when encrypting to generate a random key (shown once).", "type": "string", "maxLength": 200 }, "iterations": { "title": "PBKDF2 iterations (encrypt)", "description": "At least 600,000 (OWASP 2023 recommendation for PBKDF2-HMAC-SHA-256). Decryption reads the value from the file.", "type": "integer", "minimum": 600000, "maximum": 10000000, "default": 600000 }, "seed": { "title": "Demo seed (optional; fixes salt and IV — never for real files)", "description": "Only for reproducible demos. Reusing a salt/IV with the same password breaks AES-GCM security.", "type": "string", "maxLength": 200 } }, "required": [ "file" ] }, "FileEncryptionStudioResult": { "type": "object", "additionalProperties": false, "required": [ "schemaVersion", "tool", "computedAt", "inputs", "summary", "result", "units", "assumptions", "sources", "warnings", "presentation", "links" ], "properties": { "schemaVersion": { "type": "string", "const": "1.0" }, "tool": { "type": "object", "additionalProperties": false, "required": [ "id", "name", "version" ], "properties": { "id": { "type": "string" }, "name": { "type": "string" }, "version": { "type": "string" } } }, "computedAt": { "type": "string", "format": "date-time" }, "inputs": { "type": "object", "description": "Normalised inputs actually used, including applied defaults." }, "summary": { "type": "string" }, "result": { "type": "object", "additionalProperties": false, "required": [ "action", "format", "kdf", "iterations", "saltHex", "ivHex", "headerBytes", "inputBytes", "outputBytes", "generatedKeyHex", "seeded", "artifact" ], "properties": { "action": { "type": "string", "enum": [ "encrypt", "decrypt" ] }, "format": { "type": "string", "description": "Container format id." }, "kdf": { "type": "string", "enum": [ "pbkdf2-sha256", "raw-key" ] }, "iterations": { "type": [ "integer", "null" ] }, "saltHex": { "type": [ "string", "null" ] }, "ivHex": { "type": "string" }, "headerBytes": { "type": "integer" }, "inputBytes": { "type": "integer" }, "outputBytes": { "type": "integer" }, "generatedKeyHex": { "type": [ "string", "null" ], "description": "Only when a random raw key was generated for you." }, "seeded": { "type": "boolean" }, "artifact": { "type": "object", "additionalProperties": false, "required": [ "artifactId", "filename", "mime", "bytes", "sha256", "path" ], "properties": { "artifactId": { "type": "string" }, "filename": { "type": "string" }, "mime": { "type": "string" }, "bytes": { "type": "integer" }, "sha256": { "type": "string" }, "path": { "type": "string" } } } } }, "units": { "type": "object", "additionalProperties": { "type": "string" } }, "assumptions": { "type": "array", "items": { "type": "string" } }, "sources": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "title" ], "properties": { "title": { "type": "string" }, "url": { "type": "string" }, "publisher": { "type": "string" }, "retrievedAt": { "type": "string" }, "note": { "type": "string" } } } }, "warnings": { "type": "array", "items": { "type": "string" } }, "presentation": { "type": "array", "items": { "type": "object" }, "description": "Display blocks used by the human page (same data)." }, "links": { "type": "object", "additionalProperties": false, "required": [ "human", "api", "openapi", "methodology" ], "properties": { "human": { "type": "string", "format": "uri" }, "api": { "type": "string", "format": "uri" }, "openapi": { "type": "string", "format": "uri" }, "methodology": { "type": "string", "format": "uri" } } } } } } } }