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README.md

@@ -4,17 +4,17 @@ Manifest file generator and checker.
 
 # Problem Statement
 
-Given a plain URL, there is no standard way to safely and programmatically download everything "under" that URL path.  `wget -r` can traverse directory listings if they're enabled, but every server has a different format, and this does not verify cryptographic integrity of the files, or enable them to be fetched using a different protocol other than HTTP/s.
+Given a plain URL, there is no standard way to safely and programmatically download everything "under" that URL path. `wget -r` can traverse directory listings if they're enabled, but every server has a different format, and this does not verify cryptographic integrity of the files, or enable them to be fetched using a different protocol other than HTTP/s.
 
-Currently, the solution that people are using are sidecar files in the format of `SHASUMS` checksum files, as well as a `SHASUMS.asc` PGP detached signature.  This is not checksum-algorithm-agnostic and the sidecar file is not always consistently named.
+Currently, the solution that people are using are sidecar files in the format of `SHASUMS` checksum files, as well as a `SHASUMS.asc` PGP detached signature. This is not checksum-algorithm-agnostic and the sidecar file is not always consistently named.
 
 Real issues I face:
 
-* when I plug in an ExFAT hard drive, I don't know if any files on the filesystem are corrupted or missing
-    * current ad-hoc solution are `SHASUMS`/`SHASUMS.asc` files
-* when I want to mirror an HTTP archive, I have to use special tools like debmirror that understand the archive format
-    * the debian repository metadata structure is hot garbage
-* when I download a large file via HTTP, I have no way of knowing if the file content is what it's supposed to be
+- when I plug in an ExFAT hard drive, I don't know if any files on the filesystem are corrupted or missing
+  - current ad-hoc solution are `SHASUMS`/`SHASUMS.asc` files
+- when I want to mirror an HTTP archive, I have to use special tools like debmirror that understand the archive format
+  - the debian repository metadata structure is hot garbage
+- when I download a large file via HTTP, I have no way of knowing if the file content is what it's supposed to be
 
 # Proposed Solution
 
@@ -24,76 +24,78 @@ The manifest file would be called `index.mf`, and the tool for generating such w
 
 The manifest file would do several important things:
 
-* have a standard filename, so if given `https://example.com/downloadpackage/` one could fetch `https://example.com/downloadpackage/index.mf` to enumerate the full directory listing.
-* contain a version field for extensibility
-* contain structured data (protobuf, json, or cbor)
-* provide an inner signed container, so that the manifest file itself can embed a signature and a public key alongside in a single file
-* contain a list of files, each with a relative path to the manifest
-* contain manifest timestamp
-* contain ctime/mtime information for files so that file metadata can be preserved
-* contain cryptographic checksums in several different algorithms for each file
-    * probably encoded with multihash to indicate algo + hash
-    * sha256 at the minimum
-    * would be nice to include an IPFS/IPLD CIDv1 root hash for each file, which likely involves doing an ipfs file object chunking
-    * maybe even including the complete IPFS/IPLD directory tree objects and chunklists?
-        * this is because generating an `index.mf` does not imply publishing on ipfs at that time
-    * maybe a bittorrent chunklist for torrent client compatibility? perhaps a top-level infohash for the whole manifest?
+- have a standard filename, so if given `https://example.com/downloadpackage/` one could fetch `https://example.com/downloadpackage/index.mf` to enumerate the full directory listing.
+- contain a version field for extensibility
+- contain structured data (protobuf, json, or cbor)
+- provide an inner signed container, so that the manifest file itself can embed a signature and a public key alongside in a single file
+- contain a list of files, each with a relative path to the manifest
+- contain manifest timestamp
+- contain ctime/mtime information for files so that file metadata can be preserved
+- contain cryptographic checksums in several different algorithms for each file
+  - probably encoded with multihash to indicate algo + hash
+  - sha256 at the minimum
+  - would be nice to include an IPFS/IPLD CIDv1 root hash for each file, which likely involves doing an ipfs file object chunking
+  - maybe even including the complete IPFS/IPLD directory tree objects and chunklists?
+    - this is because generating an `index.mf` does not imply publishing on ipfs at that time
+  - maybe a bittorrent chunklist for torrent client compatibility? perhaps a top-level infohash for the whole manifest?
 
 # Design Goals
 
-* Replace SHASUMS/SHASUMS.asc files
-* be easy to download/resume a whole directory tree published via HTTP
-* be easy to use across protocols (given an HTTPS url, fetch manifest, then download file contents via bittorrent or ipfs)
-* not strongly coupled to HTTP use case, should not require special hosting, content types, or HTTP headers being sent
+- Replace SHASUMS/SHASUMS.asc files
+- be easy to download/resume a whole directory tree published via HTTP
+- be easy to use across protocols (given an HTTPS url, fetch manifest, then download file contents via bittorrent or ipfs)
+- not strongly coupled to HTTP use case, should not require special hosting, content types, or HTTP headers being sent
 
 # Non-Goals
-* Manifest generation speed
-    * likely involves IPFS chunking, bittorrent chunking, and several different cryptographic hash functions over the entirety of each and every file
-* Small manifest file size (within reason)
-    * 30MiB files are "small" these days, given modern storage/bandwidth
-    * metadata size should not be used as an excuse to sacrifice utility (such as providing checksums over each chunk of a large file)
+
+- Manifest generation speed
+  - likely involves IPFS chunking, bittorrent chunking, and several different cryptographic hash functions over the entirety of each and every file
+- Small manifest file size (within reason)
+  - 30MiB files are "small" these days, given modern storage/bandwidth
+  - metadata size should not be used as an excuse to sacrifice utility (such as providing checksums over each chunk of a large file)
 
 # Open Questions
 
-* Should the manifest file include checksums of individual file chunks, or just for the whole assembled file?
-    * If so, should the chunksize be fixed or dynamic?
+- Should the manifest file include checksums of individual file chunks, or just for the whole assembled file?
 
-* Should the manifest signature format be GnuPG signatures, or those from
+  - If so, should the chunksize be fixed or dynamic?
+
+- Should the manifest signature format be GnuPG signatures, or those from
   OpenBSD's signify (of which there is a good [golang
   implementation](https://github.com/frankbraun/gosignify)?
 
-* Should the on-disk serialization format be proto3 or json?
+- Should the on-disk serialization format be proto3 or json?
 
 # Tool Examples
 
-* `mfer gen` / `mfer gen .`
-    * recurses under current directory and writes out an `index.mf`
-* `mfer check` / `mfer check .`
-    * verifies checksums of all files in manifest, displaying error and exiting nonzero if any files are missing or corrupted
-* `mfer fetch https://example.com/stuff/`
-    * fetches `/stuff/index.mf` and downloads all files listed in manifest, optionally resuming any that already exist locally, and assures cryptographic integrity of downloaded files.
+- `mfer gen` / `mfer gen .`
+  - recurses under current directory and writes out an `index.mf`
+- `mfer check` / `mfer check .`
+  - verifies checksums of all files in manifest, displaying error and exiting nonzero if any files are missing or corrupted
+- `mfer fetch https://example.com/stuff/`
+  - fetches `/stuff/index.mf` and downloads all files listed in manifest, optionally resuming any that already exist locally, and assures cryptographic integrity of downloaded files.
 
 # Implementation Plan
 
 ## Phase One:
 
-* golang module for reusability/embedding
-* golang module client providing `mfer` CLI
+- golang module for reusability/embedding
+- golang module client providing `mfer` CLI
 
 ## Phase Two:
 
-* ES6 or TypeScript module for reusability/embedding
-* ES6/TypeScript module client providing `mfer.js` CLI
+- ES6 or TypeScript module for reusability/embedding
+- ES6/TypeScript module client providing `mfer.js` CLI
 
 # Hopes And Dreams
 
-* `aria2c https://example.com/manifestdirectory/`
-    * (fetches `https://example.com/manifestdirectory/index.mf`, downloads and checksums all files, resumes any that exist locally already)
-* `mfer fetch https://example.com/manifestdirectory/`
-* a command line option to zero/omit mtime/ctime, as well as manifest timestamp, and sort all directory listings so that manifest file generation is deterministic/reproducible
-* URL format `mfer fetch https://exmaple.com/manifestdirectory/?key=5539AD00DE4C42F3AFE11575052443F4DF2A55C2` to assert in the URL which PGP signing key should be used in the manifest, so that shared URLs have a cryptographic trust root
-* a "well-known" key in the manifest that maps well known keys (could reuse the http spec) to specific file paths in the manifest.
-    * example: a `berlin.sneak.app.slideshow` key that maps to a json slideshow config listing what image paths to show, and for how long, and in what order
+- `aria2c https://example.com/manifestdirectory/`
+  - (fetches `https://example.com/manifestdirectory/index.mf`, downloads and checksums all files, resumes any that exist locally already)
+- `mfer fetch https://example.com/manifestdirectory/`
+- a command line option to zero/omit mtime/ctime, as well as manifest timestamp, and sort all directory listings so that manifest file generation is deterministic/reproducible
+- URL format `mfer fetch https://exmaple.com/manifestdirectory/?key=5539AD00DE4C42F3AFE11575052443F4DF2A55C2` to assert in the URL which PGP signing key should be used in the manifest, so that shared URLs have a cryptographic trust root
+- a "well-known" key in the manifest that maps well known keys (could reuse the http spec) to specific file paths in the manifest.
+  - example: a `berlin.sneak.app.slideshow` key that maps to a json slideshow config listing what image paths to show, and for how long, and in what order
 
 # Use Cases
 
@@ -114,6 +116,7 @@ I use filesystems that don't include data checksums, and I would like a cryptogr
 I would like to be able to plug in a hard drive or flash drive and, if there is an `index.mf` in the root, automatically detect missing/corrupted files, regardless of filesystem format.
 
 # Collaboration
+
 Please email [`sneak@sneak.berlin`](mailto:sneak@sneak.berlin) with your desired username for an account on this Gitea instance.
 
 I am currently interested in hiring a contractor skilled with the Go standard library interfaces to specify this tool in full and develop a prototype implementation.