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+Fuzzing The Library
+============================
+
+Botan comes with a set of fuzzing endpoints which can be used to test
+the library.
+
+.. highlight:: shell
+
+Fuzzing with libFuzzer
+------------------------
+
+To fuzz with libFuzzer (https://llvm.org/docs/LibFuzzer.html), you'll first
+need to compile libFuzzer::
+
+  $ svn co https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer libFuzzer
+  $ cd libFuzzer && clang -c -g -O2 -std=c++11 *.cpp
+  $ ar cr libFuzzer.a libFuzzer/*.o
+
+Then build the fuzzers::
+
+  $ ./configure.py --cc=clang --build-fuzzer=libfuzzer --unsafe-fuzzer-mode \
+        --enable-sanitizers=coverage,address,undefined
+  $ make fuzzers
+
+Enabling 'coverage' sanitizer flags is required for libFuzzer to work.
+Address sanitizer and undefined sanitizer are optional.
+
+The fuzzer binaries will be in `build/fuzzer`. Simply pick one and run it, optionally
+also passing a directory containing corpus inputs.
+
+Using `libfuzzer` build mode implicitly assumes the fuzzers need to
+link with `libFuzzer`; if another library is needed (for example in
+OSS-Fuzz, which uses `libFuzzingEngine`), use the flag
+`--with-fuzzer-lib` to specify the desired name.
+
+Fuzzing with AFL
+--------------------
+
+To fuzz with AFL (http://lcamtuf.coredump.cx/afl/)::
+
+  $ ./configure.py --with-sanitizers --build-fuzzer=afl --unsafe-fuzzer-mode --cc-bin=afl-g++
+  $ make fuzzers
+
+For AFL sanitizers are optional. You can also use `afl-clang-fast++`
+or `afl-clang++`, be sure to set `--cc=clang` also.
+
+The fuzzer binaries will be in `build/fuzzer`. To run them you need to
+run under `afl-fuzz`::
+
+  $ afl-fuzz -i corpus_path -o output_path ./build/fuzzer/binary
+
+Fuzzing with TLS-Attacker
+--------------------------
+
+TLS-Attacker (https://github.com/RUB-NDS/TLS-Attacker) includes a mode for fuzzing
+TLS servers. A prebuilt copy of TLS-Attacker is available in a git repository::
+
+  $ git clone --depth 1 https://github.com/randombit/botan-ci-tools.git
+
+To run it against Botan's server::
+
+  $ ./configure.py --with-sanitizers
+  $ make botan
+  $ ./src/scripts/run_tls_attacker.py ./botan ./botan-ci-tools
+
+Output and logs from the fuzzer are placed into `/tmp`. See the
+TLS-Attacker documentation for more information about how to use this
+tool.
+
+Input Corpus
+-----------------------
+
+AFL requires an input corpus, and libFuzzer can certainly make good
+use of it.
+
+Some crypto corpus repositories include
+
+* https://github.com/randombit/crypto-corpus
+* https://github.com/mozilla/nss-fuzzing-corpus
+* https://github.com/google/boringssl/tree/master/fuzz
+* https://github.com/openssl/openssl/tree/master/fuzz/corpora
+
+Adding new fuzzers
+---------------------
+
+New fuzzers are created by adding a source file to `src/fuzzers` which
+have the signature:
+
+``void fuzz(const uint8_t in[], size_t len)``
+
+After adding your fuzzer, rerun ``./configure.py`` and build.