zat.dev
atproto utils for zig
zat.dev
atproto
sdk
zig
fix: NSID rejects TLD starting with digit, AT-URI validates components
NSID parser now enforces that the first domain segment (TLD) must start
with a letter, per the spec regex. Previously accepted strings like
"1.0.0.127.record".
AT-URI parser now validates all components: authority must be a valid DID
or handle, collection must be a valid NSID, rkey must be a valid record
key. Also rejects forbidden characters (space, #, ?).
Found by running official atproto-interop-tests fixtures.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
zzstoatzz.io
+26
-6
src/internal/at_uri.zig
+26
-6
src/internal/at_uri.zig
···
13
13
//! see: https://atproto.com/specs/at-uri-scheme
14
14
15
15
const std = @import("std");
16
+
const Did = @import("did.zig").Did;
17
+
const Handle = @import("handle.zig").Handle;
18
+
const Nsid = @import("nsid.zig").Nsid;
19
+
const Rkey = @import("rkey.zig").Rkey;
16
20
17
21
pub const AtUri = struct {
18
22
/// the full uri string (borrowed, not owned)
···
35
39
// must start with "at://"
36
40
if (!std.mem.startsWith(u8, s, prefix)) return null;
37
41
42
+
// reject forbidden characters anywhere after prefix
43
+
for (s) |c| {
44
+
if (c == ' ' or c == '#' or c == '?') return null;
45
+
}
46
+
38
47
// no trailing slash
39
48
if (s[s.len - 1] == '/') return null;
40
49
···
44
53
// find first slash (end of authority)
45
54
const authority_end_rel = std.mem.indexOfScalar(u8, after_prefix, '/');
46
55
47
-
if (authority_end_rel) |ae| {
48
-
if (ae == 0) return null; // empty authority
56
+
const auth_str = after_prefix[0 .. authority_end_rel orelse after_prefix.len];
57
+
if (auth_str.len == 0) return null;
58
+
59
+
// authority must be a valid DID or handle
60
+
if (Did.parse(auth_str) == null and Handle.parse(auth_str) == null) return null;
49
61
62
+
if (authority_end_rel) |ae| {
50
63
const after_authority = after_prefix[ae + 1 ..];
51
64
if (after_authority.len == 0) return null; // trailing slash after authority
52
65
53
66
// find second slash (end of collection)
54
67
const collection_end_rel = std.mem.indexOfScalar(u8, after_authority, '/');
55
68
69
+
const coll_str = after_authority[0 .. collection_end_rel orelse after_authority.len];
70
+
if (coll_str.len == 0) return null; // empty collection
71
+
72
+
// collection must be a valid NSID
73
+
if (Nsid.parse(coll_str) == null) return null;
74
+
56
75
if (collection_end_rel) |ce| {
57
-
if (ce == 0) return null; // empty collection
58
-
const after_collection = after_authority[ce + 1 ..];
59
-
if (after_collection.len == 0) return null; // trailing slash after collection
76
+
const rkey_str = after_authority[ce + 1 ..];
77
+
if (rkey_str.len == 0) return null; // trailing slash after collection
60
78
61
-
// full uri: authority + collection + rkey
79
+
// rkey must be a valid record key
80
+
if (Rkey.parse(rkey_str) == null) return null;
81
+
62
82
return .{
63
83
.raw = s,
64
84
.authority_end = prefix.len + ae,
+5
-2
src/internal/nsid.zig
+5
-2
src/internal/nsid.zig
···
41
41
if (c == '.') {
42
42
const segment = s[segment_start..i];
43
43
// all segments except last must be valid domain segments
44
-
if (!isValidDomainSegment(segment)) return null;
44
+
if (!isValidDomainSegment(segment, segment_count == 0)) return null;
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45
segment_count += 1;
46
46
last_dot = i;
47
47
segment_start = i + 1;
···
77
77
return self.raw[self.name_start..];
78
78
}
79
79
80
-
fn isValidDomainSegment(seg: []const u8) bool {
80
+
fn isValidDomainSegment(seg: []const u8, is_first: bool) bool {
81
81
// 1-63 characters
82
82
if (seg.len == 0 or seg.len > max_segment_length) return false;
83
83
84
84
// cannot start or end with hyphen
85
85
if (seg[0] == '-' or seg[seg.len - 1] == '-') return false;
86
+
87
+
// first segment (TLD) must start with a letter
88
+
if (is_first and !(seg[0] >= 'a' and seg[0] <= 'z')) return false;
86
89
87
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// lowercase letters, digits, and hyphens only
88
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for (seg) |c| {