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1 | | // Copyright 2025 Google LLC |
2 | | // |
3 | | // Licensed under the Apache License, Version 2.0 (the "License"); |
4 | | // you may not use this file except in compliance with the License. |
5 | | // You may obtain a copy of the License at |
6 | | // |
7 | | // http://www.apache.org/licenses/LICENSE-2.0 |
8 | | // |
9 | | // Unless required by applicable law or agreed to in writing, software |
10 | | // distributed under the License is distributed on an "AS IS" BASIS, |
11 | | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | | // See the License for the specific language governing permissions and |
13 | | // limitations under the License. |
14 | | // |
15 | | //////////////////////////////////////////////////////////////////////////////// |
16 | | #include <stdint.h> |
17 | | #include <stddef.h> |
18 | | #include <unistd.h> |
19 | | #include <sys/types.h> |
20 | | |
21 | | #include <vector> |
22 | | #include <algorithm> |
23 | | |
24 | | #include "mhd_helper.h" |
25 | | |
26 | | static void request_ended_cb(void *cls, |
27 | | const struct MHD_RequestEndedData *data, |
28 | 0 | void *request_app_context) { |
29 | | // Do nothing |
30 | 0 | } |
31 | | |
32 | 1.43k | static enum MHD_HTTP_StatusCode pick_status_code(FuzzedDataProvider &fdp) { |
33 | | // Randomly pick a valid or invalid HTTP response status code |
34 | 1.43k | return fdp.ConsumeBool() |
35 | 1.43k | ? fdp.PickValueInArray({ |
36 | 1.06k | MHD_HTTP_STATUS_OK, MHD_HTTP_STATUS_CREATED, MHD_HTTP_STATUS_NO_CONTENT, |
37 | 1.06k | MHD_HTTP_STATUS_PARTIAL_CONTENT, MHD_HTTP_STATUS_BAD_REQUEST, |
38 | 1.06k | MHD_HTTP_STATUS_UNAUTHORIZED, MHD_HTTP_STATUS_FORBIDDEN, |
39 | 1.06k | MHD_HTTP_STATUS_NOT_FOUND, MHD_HTTP_STATUS_INTERNAL_SERVER_ERROR }) |
40 | 1.43k | : (enum MHD_HTTP_StatusCode)(fdp.ConsumeIntegralInRange<int>(0, 999)); |
41 | 1.43k | } |
42 | | |
43 | | static MHD_Response* create_response(FuzzedDataProvider &fdp, |
44 | 1.43k | enum MHD_HTTP_StatusCode sc) { |
45 | 1.43k | struct MHD_Response* r = nullptr; |
46 | | |
47 | | // Generate random response body |
48 | 1.43k | const size_t body_len = fdp.ConsumeIntegralInRange<size_t>( |
49 | 1.43k | 0, std::min<size_t>(fdp.remaining_bytes(), 8192)); |
50 | 1.43k | std::string body = fdp.ConsumeBytesAsString(body_len); |
51 | | |
52 | | |
53 | | // Randomly select which constructing function to use for respone object creation |
54 | 1.43k | enum CtorKind { |
55 | 1.43k | EMPTY, BUF_STATIC, BUF_COPY, IOVEC, FROM_FD, FROM_PIPE |
56 | 1.43k | }; |
57 | 1.43k | CtorKind ctor = fdp.PickValueInArray<CtorKind>( |
58 | 1.43k | {EMPTY, BUF_STATIC, BUF_COPY, IOVEC, FROM_FD, FROM_PIPE}); |
59 | | |
60 | 1.43k | switch (ctor) { |
61 | 0 | default: |
62 | 536 | case EMPTY: { |
63 | | // Create empty response |
64 | 536 | r = MHD_response_from_empty(sc); |
65 | 536 | break; |
66 | 0 | } |
67 | 218 | case BUF_STATIC: { |
68 | | // Create response with random body and static buffer status |
69 | 218 | r = MHD_response_from_buffer_static(sc, body.size(), body.c_str()); |
70 | 218 | break; |
71 | 0 | } |
72 | 144 | case BUF_COPY: { |
73 | | // Create response with random body and copy buffer in |
74 | 144 | r = MHD_response_from_buffer_copy(sc, body.size(), body.data()); |
75 | 144 | break; |
76 | 0 | } |
77 | 220 | case IOVEC: { |
78 | | // Create response from random IO vector |
79 | 220 | unsigned cnt = fdp.ConsumeIntegralInRange<unsigned>(0, 6); |
80 | 220 | std::vector<MHD_IoVec> iov(cnt); |
81 | 220 | std::vector<std::string> chunks; chunks.reserve(cnt); |
82 | 863 | for (unsigned i=0;i<cnt;i++) { |
83 | 643 | chunks.push_back(fdp.ConsumeBytesAsString( |
84 | 643 | fdp.ConsumeIntegralInRange<size_t>(0, 1024))); |
85 | 643 | iov[i].iov_base = chunks.back().data(); |
86 | 643 | iov[i].iov_len = chunks.back().size(); |
87 | 643 | } |
88 | 220 | r = MHD_response_from_iovec(sc, cnt ? cnt : 0, cnt ? iov.data() : nullptr, nullptr, nullptr); |
89 | 220 | break; |
90 | 0 | } |
91 | 186 | case FROM_FD: { |
92 | | // Create response from file with random data |
93 | 186 | char path[] = "/tmp/mhdrespXXXXXX"; |
94 | 186 | int fd = mkstemp(path); |
95 | 186 | if (fd >= 0) { |
96 | 186 | unlink(path); |
97 | 186 | if (!body.empty()) (void) ::write(fd, body.data(), body.size()); |
98 | 186 | uint64_t sz = (uint64_t)body.size(); |
99 | 186 | uint64_t off = 0; |
100 | 186 | if (fdp.ConsumeBool()) { |
101 | 87 | off = std::min<uint64_t>(sz, fdp.ConsumeIntegral<uint64_t>() % (sz + 1)); |
102 | 87 | } |
103 | 186 | uint64_t len = (sz > off) ? (fdp.ConsumeIntegral<uint64_t>() % (sz - off + 1)) : 0; |
104 | 186 | r = MHD_response_from_fd(sc, fd, off, len); |
105 | 186 | if (!r) { |
106 | 14 | close(fd); |
107 | 14 | } |
108 | 186 | } |
109 | 186 | break; |
110 | 0 | } |
111 | 132 | case FROM_PIPE: { |
112 | | // Create response by piping in random data |
113 | 132 | int pfd[2]; |
114 | 132 | if (0 == pipe(pfd)) { |
115 | 132 | std::string pbytes = fdp.ConsumeBytesAsString( |
116 | 132 | fdp.ConsumeIntegralInRange<size_t>(0, 2048)); |
117 | 132 | if (!pbytes.empty()) { |
118 | 83 | ::write(pfd[1], pbytes.data(), pbytes.size()); |
119 | 83 | } |
120 | 132 | close(pfd[1]); |
121 | 132 | r = MHD_response_from_pipe(sc, pfd[0]); |
122 | 132 | if (!r) { |
123 | 13 | close(pfd[0]); |
124 | 13 | } |
125 | 132 | } |
126 | 132 | break; |
127 | 0 | } |
128 | 1.43k | } |
129 | | |
130 | 1.43k | return r; |
131 | 1.43k | } |
132 | | |
133 | 1.35k | static void add_headers(FuzzedDataProvider &fdp, MHD_Response *r) { |
134 | 1.35k | const char* ct = fdp.ConsumeBool() ? "text/plain" : "application/octet-stream"; |
135 | 1.35k | MHD_response_add_header(r, "Content-Type", ct); |
136 | | |
137 | | // Add random standard headers |
138 | 1.35k | size_t num_headers = fdp.ConsumeIntegralInRange<size_t>(0, 10); |
139 | 3.82k | for (size_t i = 0; i < num_headers; i++) { |
140 | 2.47k | std::string name = safe_ascii(fdp.ConsumeRandomLengthString(20), false); |
141 | 2.47k | std::string val = safe_ascii(fdp.ConsumeRandomLengthString(60), true); |
142 | 2.47k | MHD_response_add_header(r, name.c_str(), val.c_str()); |
143 | 2.47k | } |
144 | | |
145 | | // Add random predefined header |
146 | 1.35k | enum MHD_PredefinedHeader which = |
147 | 1.35k | fdp.PickValueInArray<enum MHD_PredefinedHeader>( |
148 | 1.35k | { MHD_PREDEF_ACCEPT_CHARSET, MHD_PREDEF_ACCEPT_LANGUAGE }); |
149 | 1.35k | std::string value = safe_ascii(fdp.ConsumeRandomLengthString(32)); |
150 | 1.35k | MHD_response_add_predef_header(r, which, value.c_str()); |
151 | 1.35k | } |
152 | | |
153 | 1.35k | static void randomise_response_options(FuzzedDataProvider &fdp, MHD_Response *r) { |
154 | 1.35k | if (fdp.ConsumeBool()) { |
155 | 277 | auto o = MHD_R_OPTION_REUSABLE(ToMhdBool(fdp.ConsumeBool())); |
156 | 277 | MHD_response_set_option(r, &o); |
157 | 277 | } |
158 | 1.35k | if (fdp.ConsumeBool()) { |
159 | 231 | auto o = MHD_R_OPTION_HEAD_ONLY_RESPONSE(ToMhdBool(fdp.ConsumeBool())); |
160 | 231 | MHD_response_set_option(r, &o); |
161 | 231 | } |
162 | 1.35k | if (fdp.ConsumeBool()) { |
163 | 293 | auto o = MHD_R_OPTION_CHUNKED_ENC(ToMhdBool(fdp.ConsumeBool())); |
164 | 293 | MHD_response_set_option(r, &o); |
165 | 293 | } |
166 | 1.35k | if (fdp.ConsumeBool()) { |
167 | 207 | auto o = MHD_R_OPTION_CONN_CLOSE(ToMhdBool(fdp.ConsumeBool())); |
168 | 207 | MHD_response_set_option(r, &o); |
169 | 207 | } |
170 | 1.35k | if (fdp.ConsumeBool()) { |
171 | 248 | auto o = MHD_R_OPTION_HTTP_1_0_SERVER(ToMhdBool(fdp.ConsumeBool())); |
172 | 248 | MHD_response_set_option(r, &o); |
173 | 248 | } |
174 | 1.35k | if (fdp.ConsumeBool()) { |
175 | 190 | auto o = MHD_R_OPTION_HTTP_1_0_COMPATIBLE_STRICT(ToMhdBool(fdp.ConsumeBool())); |
176 | 190 | MHD_response_set_option(r, &o); |
177 | 190 | } |
178 | 1.35k | if (fdp.ConsumeBool()) { |
179 | 210 | auto o = MHD_R_OPTION_INSANITY_HEADER_CONTENT_LENGTH(ToMhdBool(fdp.ConsumeBool())); |
180 | 210 | MHD_response_set_option(r, &o); |
181 | 210 | } |
182 | 1.35k | if (fdp.ConsumeBool()) { |
183 | 343 | auto o = MHD_R_OPTION_TERMINATION_CALLBACK(&request_ended_cb, nullptr); |
184 | 343 | MHD_response_set_option(r, &o); |
185 | 343 | } |
186 | 1.35k | } |
187 | | |
188 | | static void add_auth(FuzzedDataProvider &fdp, MHD_Response *r, |
189 | 1.35k | enum MHD_HTTP_StatusCode sc) { |
190 | 1.35k | if (sc == MHD_HTTP_STATUS_UNAUTHORIZED) { |
191 | | // Randomly add different challenge under 401 status code |
192 | 366 | if (fdp.ConsumeBool()) { |
193 | | // Use digest challenge |
194 | 154 | std::string realm = safe_ascii(fdp.ConsumeRandomLengthString(24)); |
195 | 154 | MHD_response_add_auth_basic_challenge(r, realm.c_str(), ToMhdBool(fdp.ConsumeBool())); |
196 | 154 | if (fdp.ConsumeBool()) { |
197 | 110 | std::string drealm = safe_ascii(fdp.ConsumeRandomLengthString(24)); |
198 | 110 | const char* opaque = fdp.ConsumeBool() ? "opaque" : nullptr; |
199 | 110 | const char* domain = fdp.ConsumeBool() ? "/a /b" : nullptr; |
200 | 110 | enum MHD_DigestAuthMultiQOP mqop = |
201 | 110 | fdp.ConsumeBool()? MHD_DIGEST_AUTH_MULT_QOP_AUTH : MHD_DIGEST_AUTH_MULT_QOP_AUTH_INT; |
202 | 110 | enum MHD_DigestAuthMultiAlgo malgo = |
203 | 110 | fdp.ConsumeBool()? MHD_DIGEST_AUTH_MULT_ALGO_ANY : MHD_DIGEST_AUTH_MULT_ALGO_MD5; |
204 | 110 | MHD_response_add_auth_digest_challenge( |
205 | 110 | r, drealm.c_str(), opaque, domain, ToMhdBool(fdp.ConsumeBool()), |
206 | 110 | mqop, malgo, ToMhdBool(fdp.ConsumeBool()), ToMhdBool(fdp.ConsumeBool())); |
207 | 110 | } |
208 | 212 | } else { |
209 | | // Use basic challenge |
210 | 212 | std::string realm = safe_ascii(fdp.ConsumeRandomLengthString(24)); |
211 | 212 | const char* opaque = fdp.ConsumeBool() ? "opaque" : nullptr; |
212 | 212 | const char* domain = fdp.ConsumeBool() ? "/a /b" : nullptr; |
213 | 212 | enum MHD_DigestAuthMultiQOP mqop = |
214 | 212 | fdp.ConsumeBool()? MHD_DIGEST_AUTH_MULT_QOP_AUTH : MHD_DIGEST_AUTH_MULT_QOP_AUTH_INT; |
215 | 212 | enum MHD_DigestAuthMultiAlgo malgo = |
216 | 212 | fdp.ConsumeBool()? MHD_DIGEST_AUTH_MULT_ALGO_ANY : MHD_DIGEST_AUTH_MULT_ALGO_MD5; |
217 | 212 | MHD_response_add_auth_digest_challenge( |
218 | 212 | r, realm.c_str(), opaque, domain, ToMhdBool(fdp.ConsumeBool()), |
219 | 212 | mqop, malgo, ToMhdBool(fdp.ConsumeBool()), |
220 | 212 | ToMhdBool(fdp.ConsumeBool())); |
221 | 212 | if (fdp.ConsumeBool()) { |
222 | 36 | std::string brealm = safe_ascii(fdp.ConsumeRandomLengthString(24)); |
223 | 36 | MHD_response_add_auth_basic_challenge(r, brealm.c_str(), ToMhdBool(fdp.ConsumeBool())); |
224 | 36 | } |
225 | 212 | } |
226 | 985 | } else { |
227 | | // For all other status code, randomly determine if challenges are added |
228 | | |
229 | | // Randomly choose if basic challenge is used or not |
230 | 985 | if (fdp.ConsumeBool()) { |
231 | 226 | std::string realm = safe_ascii(fdp.ConsumeRandomLengthString(24)); |
232 | 226 | MHD_response_add_auth_basic_challenge(r, realm.c_str(), ToMhdBool(fdp.ConsumeBool())); |
233 | 226 | } |
234 | | |
235 | | // Randomly choose if disgest challenge is used or not |
236 | 985 | if (fdp.ConsumeBool()) { |
237 | 232 | std::string realm = safe_ascii(fdp.ConsumeRandomLengthString(24)); |
238 | 232 | const char* opaque = fdp.ConsumeBool() ? "opaque" : nullptr; |
239 | 232 | const char* domain = fdp.ConsumeBool() ? "/a /b" : nullptr; |
240 | 232 | enum MHD_DigestAuthMultiQOP mqop = |
241 | 232 | fdp.ConsumeBool()? MHD_DIGEST_AUTH_MULT_QOP_AUTH : MHD_DIGEST_AUTH_MULT_QOP_AUTH_INT; |
242 | 232 | enum MHD_DigestAuthMultiAlgo malgo = |
243 | 232 | fdp.ConsumeBool()? MHD_DIGEST_AUTH_MULT_ALGO_ANY : MHD_DIGEST_AUTH_MULT_ALGO_MD5; |
244 | 232 | MHD_response_add_auth_digest_challenge( |
245 | 232 | r, realm.c_str(), opaque, domain, ToMhdBool(fdp.ConsumeBool()), |
246 | 232 | mqop, malgo, ToMhdBool(fdp.ConsumeBool()), ToMhdBool(fdp.ConsumeBool())); |
247 | 232 | } |
248 | 985 | } |
249 | 1.35k | } |
250 | | |
251 | 1.43k | extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { |
252 | 1.43k | if (size == 0) { |
253 | 0 | return 0; |
254 | 0 | } |
255 | 1.43k | FuzzedDataProvider fdp(data, size); |
256 | | |
257 | | // Pick a random response status code |
258 | 1.43k | enum MHD_HTTP_StatusCode sc = pick_status_code(fdp); |
259 | | |
260 | | // Create a random response object |
261 | 1.43k | struct MHD_Response* r = create_response(fdp, sc); |
262 | 1.43k | if (!r) { |
263 | 85 | return 0; |
264 | 85 | } |
265 | | |
266 | | // Add random headers into the response object |
267 | 1.35k | add_headers(fdp, r); |
268 | | |
269 | | // Set random options for the response object |
270 | 1.35k | randomise_response_options(fdp, r); |
271 | | |
272 | | // Add authentication challenges to response |
273 | 1.35k | add_auth(fdp, r, sc); |
274 | | |
275 | | // Fuzz additional targets on response status |
276 | 1.35k | MHD_HTTP_status_code_to_string(sc); |
277 | 1.35k | MHD_status_code_to_string((enum MHD_StatusCode)sc); |
278 | | |
279 | | // Destory the response object |
280 | 1.35k | MHD_response_destroy(r); |
281 | 1.35k | return 0; |
282 | 1.43k | } |