nx_http_request_adversarial_test.nx source
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1// nx_http_request_adversarial_test.nx -- Phase A3 of S-class hardening.
2//
3// Adversarial fuzzing of nx_http_parse_request, the parser the HTTP
4// server runs on every incoming connection. An untrusted public
5// client's bytes must NOT crash the server.
6//
7// Per [[feedback-simulation-discipline-for-every-substrate]] +
8// the S-class honest audit: HTTP server is the second-most-exposed
9// attack surface after TLS handshake. This fuzz proves graceful
10// rejection on 8 malformed input classes.
11//
12// expect_exit: 0
13// license_tier: ORIGINAL
14
15import "nx_syscalls.nx"
16import "nx_http_io.nx"
17
18func parse_call(buf: *u8, n: i64) -> i64 {
19 let mk_box: *i64 = sys_mmap(8) as *i64
20 let po_box: *i64 = sys_mmap(8) as *i64
21 let pl_box: *i64 = sys_mmap(8) as *i64
22 let cl_box: *i64 = sys_mmap(8) as *i64
23 let bo_box: *i64 = sys_mmap(8) as *i64
24 return nx_http_parse_request(buf, n, mk_box, po_box, pl_box, cl_box, bo_box)
25}
26
27func main() -> i64 {
28 // ===== (a) Empty buffer -> rejected =====
29 let empty: *u8 = sys_mmap(4)
30 let r_empty: i64 = parse_call(empty, 0)
31 if r_empty >= 0 { return 10 } // must NOT be OK
32
33 // ===== (b) Tiny buffer (< 14 bytes) -> rejected =====
34 let tiny: *u8 = sys_mmap(16)
35 tiny[0] = 0x47 // 'G'
36 let r_tiny: i64 = parse_call(tiny, 10)
37 if r_tiny >= 0 { return 20 }
38
39 // ===== (c) 64 bytes of NUL -> rejected (no method/path/spaces) =====
40 let nul_buf: *u8 = sys_mmap(64)
41 let r_nul: i64 = parse_call(nul_buf, 64)
42 if r_nul >= 0 { return 30 }
43
44 // ===== (d) 64 bytes of 0xFF -> rejected =====
45 let ff_buf: *u8 = sys_mmap(64)
46 var fi: i64 = 0
47 while fi < 64 {
48 ff_buf[fi] = 0xff
49 fi = fi + 1
50 }
51 let r_ff: i64 = parse_call(ff_buf, 64)
52 if r_ff >= 0 { return 40 }
53
54 // ===== (e) Method without path or CRLF -> rejected =====
55 // "GET " (only spaces after method)
56 let bad_method: *u8 = sys_mmap(64)
57 bad_method[0] = 0x47 // G
58 bad_method[1] = 0x45 // E
59 bad_method[2] = 0x54 // T
60 bad_method[3] = 0x20 // ' '
61 var bi: i64 = 4
62 while bi < 60 {
63 bad_method[bi] = 0x20
64 bi = bi + 1
65 }
66 let r_bad_method: i64 = parse_call(bad_method, 60)
67 if r_bad_method >= 0 { return 50 }
68
69 // ===== (f) Request line missing CRLF terminator -> rejected =====
70 // "GET / HTTP/1.1" no \r\n
71 let no_crlf: *u8 = sys_mmap(64)
72 no_crlf[0] = 0x47; no_crlf[1] = 0x45; no_crlf[2] = 0x54 // GET
73 no_crlf[3] = 0x20 // ' '
74 no_crlf[4] = 0x2f // /
75 no_crlf[5] = 0x20 // ' '
76 no_crlf[6] = 0x48; no_crlf[7] = 0x54; no_crlf[8] = 0x54 // HTT
77 no_crlf[9] = 0x50 // P
78 no_crlf[10] = 0x2f; no_crlf[11] = 0x31; no_crlf[12] = 0x2e // /1.
79 no_crlf[13] = 0x31 // 1
80 let r_no_crlf: i64 = parse_call(no_crlf, 14)
81 if r_no_crlf >= 0 { return 60 }
82
83 // ===== (g) Valid GET request -> OK + method_kind 1 =====
84 // "GET / HTTP/1.1\r\nHost: x\r\n\r\n"
85 let good: *u8 = sys_mmap(64)
86 let s: *u8 = "GET / HTTP/1.1\r\nHost: x\r\n\r\n"
87 var n: i64 = 0
88 while s[n] != 0 { n = n + 1 }
89 var k: i64 = 0
90 while k < n { good[k] = s[k]; k = k + 1 }
91 let mk: *i64 = sys_mmap(8) as *i64
92 let po: *i64 = sys_mmap(8) as *i64
93 let pl: *i64 = sys_mmap(8) as *i64
94 let cl: *i64 = sys_mmap(8) as *i64
95 let bo: *i64 = sys_mmap(8) as *i64
96 let r_good: i64 = nx_http_parse_request(good, n, mk, po, pl, cl, bo)
97 if r_good != 0 { return 70 }
98 if *mk != 1 { return 71 } // GET = 1
99 if *pl != 1 { return 72 } // path "/" length 1
100
101 // ===== (h) GET with binary garbage in path - rejected or graceful =====
102 // Even with junk bytes, must not crash
103 let garbage_path: *u8 = sys_mmap(80)
104 garbage_path[0] = 0x47; garbage_path[1] = 0x45; garbage_path[2] = 0x54; garbage_path[3] = 0x20
105 var gi: i64 = 4
106 while gi < 50 {
107 garbage_path[gi] = 0x80 // high-bit byte (not ASCII)
108 gi = gi + 1
109 }
110 garbage_path[50] = 0x20
111 garbage_path[51] = 0x48 // 'H'
112 garbage_path[52] = 0x54 // 'T'
113 garbage_path[53] = 0x54 // 'T'
114 garbage_path[54] = 0x50 // 'P'
115 garbage_path[55] = 0x0D // \r
116 garbage_path[56] = 0x0A // \n
117 garbage_path[57] = 0x0D
118 garbage_path[58] = 0x0A
119 let r_garbage: i64 = parse_call(garbage_path, 59)
120 // Parser may accept with non-OK method (method != GET because
121 // method bytes are 'GET ' = 0x47 0x45 0x54 0x20, which IS GET);
122 // path will be the garbage. Whether it returns OK or non-OK is
123 // a contract decision; the hardening claim is NO CRASH. We
124 // accept either outcome here.
125 if r_garbage > 100 { return 80 } // sanity: not garbage return
126 if r_garbage < -100 { return 81 }
127
128 return 0
129}