QUIC SRTM: Add fuzzer for SRTM

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22612)

2 files changed, 129 insertions, 2 deletions

diff --git a/fuzz/build.info b/fuzz/build.info
index de7cadc79e..bbbc7c9654 100644
--- a/fuzz/build.info
+++ b/fuzz/build.info
@@ -30,7 +30,7 @@ IF[{- !$disabled{"fuzz-afl"} || !$disabled{"fuzz-libfuzzer"} -}]
   ENDIF
 
   IF[{- !$disabled{"quic"} -}]
-    PROGRAMS{noinst}=quic-client
+    PROGRAMS{noinst}=quic-client quic-srtm
   ENDIF
 
   SOURCE[asn1]=asn1.c driver.c fuzz_rand.c
@@ -97,6 +97,10 @@ IF[{- !$disabled{"fuzz-afl"} || !$disabled{"fuzz-libfuzzer"} -}]
   INCLUDE[quic-client]=../include {- $ex_inc -}
   DEPEND[quic-client]=../libcrypto.a ../libssl.a {- $ex_lib -}
 
+  SOURCE[quic-srtm]=quic-srtm.c driver.c fuzz_rand.c
+  INCLUDE[quic-srtm]=../include {- $ex_inc -}
+  DEPEND[quic-srtm]=../libcrypto.a ../libssl.a {- $ex_lib -}
+
   SOURCE[server]=server.c driver.c fuzz_rand.c
   INCLUDE[server]=../include {- $ex_inc -}
   DEPEND[server]=../libcrypto ../libssl {- $ex_lib -}
@@ -128,7 +132,7 @@ IF[{- !$disabled{tests} -}]
   ENDIF
 
   IF[{- !$disabled{"quic"} -}]
-    PROGRAMS{noinst}=quic-client-test
+    PROGRAMS{noinst}=quic-client-test quic-srtm-test
   ENDIF
 
   SOURCE[asn1-test]=asn1.c test-corpus.c fuzz_rand.c
@@ -196,6 +200,10 @@ IF[{- !$disabled{tests} -}]
   INCLUDE[quic-client-test]=../include
   DEPEND[quic-client-test]=../libcrypto.a ../libssl.a
 
+  SOURCE[quic-srtm-test]=quic-srtm.c test-corpus.c fuzz_rand.c
+  INCLUDE[quic-srtm-test]=../include
+  DEPEND[quic-srtm-test]=../libcrypto.a ../libssl.a
+
   SOURCE[server-test]=server.c test-corpus.c fuzz_rand.c
   INCLUDE[server-test]=../include
   DEPEND[server-test]=../libcrypto ../libssl
diff --git a/fuzz/quic-srtm.c b/fuzz/quic-srtm.c
new file mode 100644
index 0000000000..eb676c2279
--- /dev/null
+++ b/fuzz/quic-srtm.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * https://www.openssl.org/source/license.html
+ * or in the file LICENSE in the source distribution.
+ */
+
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <openssl/bio.h>
+#include "fuzzer.h"
+#include "internal/quic_srtm.h"
+
+int FuzzerInitialize(int *argc, char ***argv)
+{
+    FuzzerSetRand();
+    OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CRYPTO_STRINGS | OPENSSL_INIT_ASYNC, NULL);
+    OPENSSL_init_ssl(OPENSSL_INIT_LOAD_SSL_STRINGS, NULL);
+    ERR_clear_error();
+    return 1;
+}
+
+/*
+ * Fuzzer input "protocol":
+ *   Big endian
+ *   Zero or more of:
+ *     ADD    - u8(0x00) u64(opaque) u64(seq_num) u128(token)
+ *     REMOVE - u8(0x01) u64(opaque) u64(seq_num)
+ *     CULL   - u8(0x02) u64(opaque)
+ *     LOOKUP - u8(0x03) u128(token) u64(idx)
+ */
+enum {
+    CMD_ADD,
+    CMD_REMOVE,
+    CMD_CULL,
+    CMD_LOOKUP
+};
+
+int FuzzerTestOneInput(const uint8_t *buf, size_t len)
+{
+    int rc = 0;
+    QUIC_SRTM *srtm = NULL;
+    PACKET pkt;
+    unsigned int cmd;
+    uint64_t arg_opaque, arg_seq_num, arg_idx;
+    QUIC_STATELESS_RESET_TOKEN arg_token;
+
+    if ((srtm = ossl_quic_srtm_new(NULL, NULL)) == NULL) {
+        rc = -1;
+        goto err;
+    }
+
+    if (!PACKET_buf_init(&pkt, buf, len))
+        goto err;
+
+    while (PACKET_remaining(&pkt) > 0) {
+        if (!PACKET_get_1(&pkt, &cmd))
+            goto err;
+
+        switch (cmd) {
+        case CMD_ADD:
+            if (!PACKET_get_net_8(&pkt, &arg_opaque)
+                || !PACKET_get_net_8(&pkt, &arg_seq_num)
+                || !PACKET_copy_bytes(&pkt, arg_token.token,
+                                      sizeof(arg_token.token)))
+                continue; /* just stop */
+
+            ossl_quic_srtm_add(srtm, (void *)(uintptr_t)arg_opaque,
+                               arg_seq_num, &arg_token);
+            ossl_quic_srtm_check(srtm);
+            break;
+
+        case CMD_REMOVE:
+            if (!PACKET_get_net_8(&pkt, &arg_opaque)
+                || !PACKET_get_net_8(&pkt, &arg_seq_num))
+                continue; /* just stop */
+
+            ossl_quic_srtm_remove(srtm, (void *)(uintptr_t)arg_opaque,
+                                  arg_seq_num);
+            ossl_quic_srtm_check(srtm);
+            break;
+
+        case CMD_CULL:
+            if (!PACKET_get_net_8(&pkt, &arg_opaque))
+                continue; /* just stop */
+
+            ossl_quic_srtm_cull(srtm, (void *)(uintptr_t)arg_opaque);
+            ossl_quic_srtm_check(srtm);
+            break;
+
+        case CMD_LOOKUP:
+            if (!PACKET_copy_bytes(&pkt, arg_token.token,
+                                   sizeof(arg_token.token))
+                || !PACKET_get_net_8(&pkt, &arg_idx))
+                continue; /* just stop */
+
+            ossl_quic_srtm_lookup(srtm, &arg_token, (size_t)arg_idx,
+                                  NULL, NULL);
+            ossl_quic_srtm_check(srtm);
+            break;
+
+        default:
+            /* Other bytes are treated as no-ops */
+            continue;
+        }
+    }
+
+err:
+    ossl_quic_srtm_free(srtm);
+    return rc;
+}
+
+void FuzzerCleanup(void)
+{
+    FuzzerClearRand();
+}