Add fuzzers to exercise specific pipeline classes

.gitignore

@@ -25,5 +25,4 @@ manual/html.xsl
 manual/print.xsl
 qpdf/build/
 zlib-flate/build/
-fuzz/qpdf_fuzzer_seed_corpus/
 distribution/

fuzz/ascii85_fuzzer.cc

@@ -0,0 +1,52 @@
+#include <qpdf/Pl_Discard.hh>
+#include <qpdf/Pl_ASCII85Decoder.hh>
+#include <iostream>
+#include <stdexcept>
+
+class FuzzHelper
+{
+  public:
+    FuzzHelper(unsigned char const* data, size_t size);
+    void run();
+
+  private:
+    void doChecks();
+
+    unsigned char const* data;
+    size_t size;
+};
+
+FuzzHelper::FuzzHelper(unsigned char const* data, size_t size) :
+    data(data),
+    size(size)
+{
+}
+
+void
+FuzzHelper::doChecks()
+{
+    Pl_Discard discard;
+    Pl_ASCII85Decoder p("decode", &discard);
+    p.write(const_cast<unsigned char*>(data), size);
+    p.finish();
+}
+
+void
+FuzzHelper::run()
+{
+    try
+    {
+        doChecks();
+    }
+    catch (std::runtime_error const& e)
+    {
+        std::cerr << "runtime_error: " << e.what() << std::endl;
+    }
+}
+
+extern "C" int LLVMFuzzerTestOneInput(unsigned char const* data, size_t size)
+{
+    FuzzHelper f(data, size);
+    f.run();
+    return 0;
+}

fuzz/ascii85_fuzzer_seed_corpus/a0113b6bc9b18c0d120bdf79f10a4928dc6fc908

@@ -0,0 +1,43 @@
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fuzz/build.mk

@@ -1,15 +1,25 @@
 # This directory contains support for Google's oss-fuzz project. See
 # https://github.com/google/oss-fuzz/tree/master/projects/qpdf
 
-FUZZERS = qpdf_fuzzer
+FUZZERS = \
+    qpdf_fuzzer \
+    ascii85_fuzzer \
+    dct_fuzzer \
+    flate_fuzzer \
+    hex_fuzzer \
+    lzw_fuzzer \
+    pngpredictor_fuzzer \
+    runlength_fuzzer \
+    tiffpredictor_fuzzer
 
 DEFAULT_FUZZ_RUNNER := standalone_fuzz_target_runner
 OBJ_DEFAULT_FUZZ := fuzz/$(OUTPUT_DIR)/$(DEFAULT_FUZZ_RUNNER).$(OBJ)
 
 BINS_fuzz = $(foreach B,$(FUZZERS),fuzz/$(OUTPUT_DIR)/$(call binname,$(B)))
 TARGETS_fuzz = $(OBJ_DEFAULT_FUZZ) $(BINS_fuzz) fuzz_corpus
 
-INCLUDES_fuzz = include
+# Fuzzers test private classes too, so we need libqpdf in the include path
+INCLUDES_fuzz = include libqpdf
 
 # LIB_FUZZING_ENGINE is overridden by oss-fuzz
 LIB_FUZZING_ENGINE ?= $(OBJ_DEFAULT_FUZZ)
@@ -129,6 +139,8 @@ install_fuzz: $(STATIC_BINS_fuzz)
 	  fi; \
 	  if test -d fuzz/$(OUTPUT_DIR)/$${B}_seed_corpus; then \
 	    (cd fuzz/$(OUTPUT_DIR)/$${B}_seed_corpus; zip -q -r $(OUT)/$${B}_seed_corpus.zip .); \
+	  elif test -d fuzz/$${B}_seed_corpus; then \
+	    (cd fuzz/$${B}_seed_corpus; zip -q -r $(OUT)/$${B}_seed_corpus.zip .); \
 	  fi; \
 	done
 

fuzz/dct_fuzzer.cc

@@ -0,0 +1,52 @@
+#include <qpdf/Pl_Discard.hh>
+#include <qpdf/Pl_DCT.hh>
+#include <iostream>
+#include <stdexcept>
+
+class FuzzHelper
+{
+  public:
+    FuzzHelper(unsigned char const* data, size_t size);
+    void run();
+
+  private:
+    void doChecks();
+
+    unsigned char const* data;
+    size_t size;
+};
+
+FuzzHelper::FuzzHelper(unsigned char const* data, size_t size) :
+    data(data),
+    size(size)
+{
+}
+
+void
+FuzzHelper::doChecks()
+{
+    Pl_Discard discard;
+    Pl_DCT p("decode", &discard);
+    p.write(const_cast<unsigned char*>(data), size);
+    p.finish();
+}
+
+void
+FuzzHelper::run()
+{
+    try
+    {
+        doChecks();
+    }
+    catch (std::runtime_error const& e)
+    {
+        std::cerr << "runtime_error: " << e.what() << std::endl;
+    }
+}
+
+extern "C" int LLVMFuzzerTestOneInput(unsigned char const* data, size_t size)
+{
+    FuzzHelper f(data, size);
+    f.run();
+    return 0;
+}

fuzz/flate_fuzzer.cc

@@ -0,0 +1,52 @@
+#include <qpdf/Pl_Discard.hh>
+#include <qpdf/Pl_Flate.hh>
+#include <iostream>
+#include <stdexcept>
+
+class FuzzHelper
+{
+  public:
+    FuzzHelper(unsigned char const* data, size_t size);
+    void run();
+
+  private:
+    void doChecks();
+
+    unsigned char const* data;
+    size_t size;
+};
+
+FuzzHelper::FuzzHelper(unsigned char const* data, size_t size) :
+    data(data),
+    size(size)
+{
+}
+
+void
+FuzzHelper::doChecks()
+{
+    Pl_Discard discard;
+    Pl_Flate p("decode", &discard, Pl_Flate::a_deflate);
+    p.write(const_cast<unsigned char*>(data), size);
+    p.finish();
+}
+
+void
+FuzzHelper::run()
+{
+    try
+    {
+        doChecks();
+    }
+    catch (std::runtime_error const& e)
+    {
+        std::cerr << "runtime_error: " << e.what() << std::endl;
+    }
+}
+
+extern "C" int LLVMFuzzerTestOneInput(unsigned char const* data, size_t size)
+{
+    FuzzHelper f(data, size);
+    f.run();
+    return 0;
+}

fuzz/hex_fuzzer.cc

@@ -0,0 +1,52 @@
+#include <qpdf/Pl_Discard.hh>
+#include <qpdf/Pl_ASCIIHexDecoder.hh>
+#include <iostream>
+#include <stdexcept>
+
+class FuzzHelper
+{
+  public:
+    FuzzHelper(unsigned char const* data, size_t size);
+    void run();
+
+  private:
+    void doChecks();
+
+    unsigned char const* data;
+    size_t size;
+};
+
+FuzzHelper::FuzzHelper(unsigned char const* data, size_t size) :
+    data(data),
+    size(size)
+{
+}
+
+void
+FuzzHelper::doChecks()
+{
+    Pl_Discard discard;
+    Pl_ASCIIHexDecoder p("decode", &discard);
+    p.write(const_cast<unsigned char*>(data), size);
+    p.finish();
+}
+
+void
+FuzzHelper::run()
+{
+    try
+    {
+        doChecks();
+    }
+    catch (std::runtime_error const& e)
+    {
+        std::cerr << "runtime_error: " << e.what() << std::endl;
+    }
+}
+
+extern "C" int LLVMFuzzerTestOneInput(unsigned char const* data, size_t size)
+{
+    FuzzHelper f(data, size);
+    f.run();
+    return 0;
+}

fuzz/hex_fuzzer_seed_corpus/1c43fc2a41e55a9e1cecce2013254b632f5afac4

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