crypto/test/file_test.cc - boringssl - Git at Google

 /* Copyright (c) 2015, Google Inc.
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

 #include "file_test.h"

 #include <algorithm>
 #include <utility>

 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
 #include <limits.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include <openssl/err.h>
 #include <openssl/mem.h>

 #include "../internal.h"
 #include "./test_util.h"


 FileTest::FileTest(std::unique_ptr<FileTest::LineReader> reader,
                    std::function<void(const std::string &)> comment_callback,
                    bool is_kas_test)
     : reader_(std::move(reader)),
       is_kas_test_(is_kas_test),
       comment_callback_(std::move(comment_callback)) {}

 FileTest::~FileTest() {}

 // FindDelimiter returns a pointer to the first '=' or ':' in |str| or nullptr
 // if there is none.
 static const char *FindDelimiter(const char *str) {
   while (*str) {
     if (*str == ':' || *str == '=') {
       return str;
     }
     str++;
   }
   return nullptr;
 }

 // StripSpace returns a string containing up to |len| characters from |str| with
 // leading and trailing whitespace removed.
 static std::string StripSpace(const char *str, size_t len) {
   // Remove leading space.
   while (len > 0 && OPENSSL_isspace(*str)) {
     str++;
     len--;
   }
   while (len > 0 && OPENSSL_isspace(str[len - 1])) {
     len--;
   }
   return std::string(str, len);
 }

 static std::pair<std::string, std::string> ParseKeyValue(const char *str, const size_t len) {
   const char *delimiter = FindDelimiter(str);
   std::string key, value;
   if (delimiter == nullptr) {
     key = StripSpace(str, len);
   } else {
     key = StripSpace(str, delimiter - str);
     value = StripSpace(delimiter + 1, str + len - delimiter - 1);
   }
   return {key, value};
 }

 FileTest::ReadResult FileTest::ReadNext() {
   // If the previous test had unused attributes or instructions, it is an error.
   if (!unused_attributes_.empty()) {
     for (const std::string &key : unused_attributes_) {
       PrintLine("Unused attribute: %s", key.c_str());
     }
     return kReadError;
   }
   if (!unused_instructions_.empty()) {
     for (const std::string &key : unused_instructions_) {
       PrintLine("Unused instruction: %s", key.c_str());
     }
     return kReadError;
   }

   ClearTest();

   static const size_t kBufLen = 8192 * 4;
   std::unique_ptr<char[]> buf(new char[kBufLen]);

   bool in_instruction_block = false;
   is_at_new_instruction_block_ = false;

   while (true) {
     // Read the next line.
     switch (reader_->ReadLine(buf.get(), kBufLen)) {
       case kReadError:
         fprintf(stderr, "Error reading from input at line %u.\n", line_ + 1);
         return kReadError;
       case kReadEOF:
         // EOF is a valid terminator for a test.
         return start_line_ > 0 ? kReadSuccess : kReadEOF;
       case kReadSuccess:
         break;
     }

     line_++;
     size_t len = strlen(buf.get());
     if (buf[0] == '\n' || buf[0] == '\r' || buf[0] == '\0') {
       // Empty lines delimit tests.
       if (start_line_ > 0) {
         return kReadSuccess;
       }
       if (in_instruction_block) {
         in_instruction_block = false;
         // Delimit instruction block from test with a blank line.
         current_test_ += "\r\n";
       } else if (is_kas_test_) {
         // KAS tests have random blank lines scattered around.
         current_test_ += "\r\n";
       }
     } else if (buf[0] == '#') {
       if (is_kas_test_ && seen_non_comment_) {
         // KAS tests have comments after the initial comment block which need
         // to be included in the corresponding place in the output.
         current_test_ += std::string(buf.get());
       } else if (comment_callback_) {
         comment_callback_(buf.get());
       }
       // Otherwise ignore comments.
     } else if (strcmp("[B.4.2 Key Pair Generation by Testing Candidates]\r\n",
                       buf.get()) == 0) {
       // The above instruction-like line is ignored because the FIPS lab's
       // request files are hopelessly inconsistent.
     } else if (buf[0] == '[') {  // Inside an instruction block.
       is_at_new_instruction_block_ = true;
       seen_non_comment_ = true;
       if (start_line_ != 0) {
         // Instructions should be separate blocks.
         fprintf(stderr, "Line %u is an instruction in a test case.\n", line_);
         return kReadError;
       }
       if (!in_instruction_block) {
         ClearInstructions();
         in_instruction_block = true;
       }

       // Parse the line as an instruction ("[key = value]" or "[key]").

       // KAS tests contain invalid syntax.
       std::string kv = buf.get();
       const bool is_broken_kas_instruction =
           is_kas_test_ &&
           (kv == "[SHA(s) supported (Used for hashing Z): SHA512 \r\n");

       if (!is_broken_kas_instruction) {
         kv = StripSpace(buf.get(), len);
         if (kv[kv.size() - 1] != ']') {
           fprintf(stderr, "Line %u, invalid instruction: '%s'\n", line_,
                   kv.c_str());
           return kReadError;
         }
       } else {
         // Just remove the newline for the broken instruction.
         kv = kv.substr(0, kv.size() - 2);
       }

       current_test_ += kv + "\r\n";
       kv = std::string(kv.begin() + 1, kv.end() - 1);

       for (;;) {
         size_t idx = kv.find(',');
         if (idx == std::string::npos) {
           idx = kv.size();
         }
         std::string key, value;
         std::tie(key, value) = ParseKeyValue(kv.c_str(), idx);
         instructions_[key] = value;
         if (idx == kv.size())
           break;
         kv = kv.substr(idx + 1);
       }
     } else {
       // Parsing a test case.
       if (in_instruction_block) {
         // Some NIST CAVP test files (TDES) have a test case immediately
         // following an instruction block, without a separate blank line, some
         // of the time.
         in_instruction_block = false;
       }

       current_test_ += std::string(buf.get(), len);
       std::string key, value;
       std::tie(key, value) = ParseKeyValue(buf.get(), len);

       // Duplicate keys are rewritten to have “/2”, “/3”, … suffixes.
       std::string mapped_key = key;
       // If absent, the value will be zero-initialized.
       const size_t num_occurrences = ++attribute_count_[key];
       if (num_occurrences > 1) {
         mapped_key += "/" + std::to_string(num_occurrences);
       }

       unused_attributes_.insert(mapped_key);
       attributes_[mapped_key] = value;
       if (start_line_ == 0) {
         // This is the start of a test.
         type_ = mapped_key;
         parameter_ = value;
         start_line_ = line_;
         for (const auto &kv : instructions_) {
           unused_instructions_.insert(kv.first);
         }
       }
     }
   }
 }

 void FileTest::PrintLine(const char *format, ...) {
   va_list args;
   va_start(args, format);

   fprintf(stderr, "Line %u: ", start_line_);
   vfprintf(stderr, format, args);
   fprintf(stderr, "\n");

   va_end(args);
 }

 const std::string &FileTest::GetType() {
   OnKeyUsed(type_);
   return type_;
 }

 const std::string &FileTest::GetParameter() {
   OnKeyUsed(type_);
   return parameter_;
 }

 bool FileTest::HasAttribute(const std::string &key) {
   OnKeyUsed(key);
   return attributes_.count(key) > 0;
 }

 bool FileTest::GetAttribute(std::string *out_value, const std::string &key) {
   OnKeyUsed(key);
   auto iter = attributes_.find(key);
   if (iter == attributes_.end()) {
     PrintLine("Missing attribute '%s'.", key.c_str());
     return false;
   }
   *out_value = iter->second;
   return true;
 }

 const std::string &FileTest::GetAttributeOrDie(const std::string &key) {
   if (!HasAttribute(key)) {
     abort();
   }
   return attributes_[key];
 }

 bool FileTest::HasInstruction(const std::string &key) {
   OnInstructionUsed(key);
   return instructions_.count(key) > 0;
 }

 bool FileTest::GetInstruction(std::string *out_value, const std::string &key) {
   OnInstructionUsed(key);
   auto iter = instructions_.find(key);
   if (iter == instructions_.end()) {
     PrintLine("Missing instruction '%s'.", key.c_str());
     return false;
   }
   *out_value = iter->second;
   return true;
 }

 void FileTest::IgnoreAllUnusedInstructions() {
   unused_instructions_.clear();
 }

 const std::string &FileTest::GetInstructionOrDie(const std::string &key) {
   if (!HasInstruction(key)) {
     abort();
   }
   return instructions_[key];
 }

 bool FileTest::GetInstructionBytes(std::vector<uint8_t> *out,
                                    const std::string &key) {
   std::string value;
   return GetInstruction(&value, key) && ConvertToBytes(out, value);
 }

 const std::string &FileTest::CurrentTestToString() const {
   return current_test_;
 }

 bool FileTest::GetBytes(std::vector<uint8_t> *out, const std::string &key) {
   std::string value;
   return GetAttribute(&value, key) && ConvertToBytes(out, value);
 }

 void FileTest::ClearTest() {
   start_line_ = 0;
   type_.clear();
   parameter_.clear();
   attribute_count_.clear();
   attributes_.clear();
   unused_attributes_.clear();
   unused_instructions_.clear();
   current_test_ = "";
 }

 void FileTest::ClearInstructions() {
   instructions_.clear();
   unused_attributes_.clear();
 }

 void FileTest::OnKeyUsed(const std::string &key) {
   unused_attributes_.erase(key);
 }

 void FileTest::OnInstructionUsed(const std::string &key) {
   unused_instructions_.erase(key);
 }

 bool FileTest::ConvertToBytes(std::vector<uint8_t> *out,
                               const std::string &value) {
   if (value.size() >= 2 && value[0] == '"' && value[value.size() - 1] == '"') {
     out->assign(value.begin() + 1, value.end() - 1);
     return true;
   }

   if (!DecodeHex(out, value)) {
     PrintLine("Error decoding value: %s", value.c_str());
     return false;
   }
   return true;
 }

 bool FileTest::IsAtNewInstructionBlock() const {
   return is_at_new_instruction_block_;
 }

 void FileTest::InjectInstruction(const std::string &key,
                                  const std::string &value) {
   instructions_[key] = value;
 }

 class FileLineReader : public FileTest::LineReader {
  public:
   explicit FileLineReader(const char *path) : file_(fopen(path, "r")) {}
   ~FileLineReader() override {
     if (file_ != nullptr) {
       fclose(file_);
     }
   }

   // is_open returns true if the file was successfully opened.
   bool is_open() const { return file_ != nullptr; }

   FileTest::ReadResult ReadLine(char *out, size_t len) override {
     assert(len > 0);
     if (file_ == nullptr) {
       return FileTest::kReadError;
     }

     len = std::min(len, size_t{INT_MAX});
     if (fgets(out, static_cast<int>(len), file_) == nullptr) {
       return feof(file_) ? FileTest::kReadEOF : FileTest::kReadError;
     }

     if (strlen(out) == len - 1 && out[len - 2] != '\n' && !feof(file_)) {
       fprintf(stderr, "Line too long.\n");
       return FileTest::kReadError;
     }

     return FileTest::kReadSuccess;
   }

  private:
   FILE *file_;

   FileLineReader(const FileLineReader &) = delete;
   FileLineReader &operator=(const FileLineReader &) = delete;
 };

 int FileTestMain(FileTestFunc run_test, void *arg, const char *path) {
   FileTest::Options opts;
   opts.callback = run_test;
   opts.arg = arg;
   opts.path = path;

   return FileTestMain(opts);
 }

 int FileTestMain(const FileTest::Options &opts) {
   std::unique_ptr<FileLineReader> reader(
       new FileLineReader(opts.path));
   if (!reader->is_open()) {
     fprintf(stderr, "Could not open file %s: %s.\n", opts.path,
             strerror(errno));
     return 1;
   }

   FileTest t(std::move(reader), opts.comment_callback, opts.is_kas_test);

   bool failed = false;
   while (true) {
     FileTest::ReadResult ret = t.ReadNext();
     if (ret == FileTest::kReadError) {
       return 1;
     } else if (ret == FileTest::kReadEOF) {
       break;
     }

     bool result = opts.callback(&t, opts.arg);
     if (t.HasAttribute("Error")) {
       if (result) {
         t.PrintLine("Operation unexpectedly succeeded.");
         failed = true;
         continue;
       }
       uint32_t err = ERR_peek_error();
       if (ERR_reason_error_string(err) != t.GetAttributeOrDie("Error")) {
         t.PrintLine("Unexpected error; wanted '%s', got '%s'.",
                     t.GetAttributeOrDie("Error").c_str(),
                     ERR_reason_error_string(err));
         failed = true;
         ERR_clear_error();
         continue;
       }
       ERR_clear_error();
     } else if (!result) {
       // In case the test itself doesn't print output, print something so the
       // line number is reported.
       t.PrintLine("Test failed");
       ERR_print_errors_fp(stderr);
       failed = true;
       continue;
     }
   }

   if (!opts.silent && !failed) {
     printf("PASS\n");
   }

   return failed ? 1 : 0;
 }

 void FileTest::SkipCurrent() {
   ClearTest();
 }
	/* Copyright (c) 2015, Google Inc.
	*
	* Permission to use, copy, modify, and/or distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
	* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
	* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
	* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

	#include "file_test.h"

	#include <algorithm>
	#include <utility>

	#include <assert.h>
	#include <ctype.h>
	#include <errno.h>
	#include <limits.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>

	#include <openssl/err.h>
	#include <openssl/mem.h>

	#include "../internal.h"
	#include "./test_util.h"


	FileTest::FileTest(std::unique_ptr<FileTest::LineReader> reader,
	std::function<void(const std::string &)> comment_callback,
	bool is_kas_test)
	: reader_(std::move(reader)),
	is_kas_test_(is_kas_test),
	comment_callback_(std::move(comment_callback)) {}

	FileTest::~FileTest() {}

	// FindDelimiter returns a pointer to the first '=' or ':' in \|str\| or nullptr
	// if there is none.
	static const char FindDelimiter(const char str) {
	while (*str) {
	if (str == ':' \|\| str == '=') {
	return str;
	}
	str++;
	}
	return nullptr;
	}

	// StripSpace returns a string containing up to \|len\| characters from \|str\| with
	// leading and trailing whitespace removed.
	static std::string StripSpace(const char *str, size_t len) {
	// Remove leading space.
	while (len > 0 && OPENSSL_isspace(*str)) {
	str++;
	len--;
	}
	while (len > 0 && OPENSSL_isspace(str[len - 1])) {
	len--;
	}
	return std::string(str, len);
	}

	static std::pair<std::string, std::string> ParseKeyValue(const char *str, const size_t len) {
	const char *delimiter = FindDelimiter(str);
	std::string key, value;
	if (delimiter == nullptr) {
	key = StripSpace(str, len);
	} else {
	key = StripSpace(str, delimiter - str);
	value = StripSpace(delimiter + 1, str + len - delimiter - 1);
	}
	return {key, value};
	}

	FileTest::ReadResult FileTest::ReadNext() {
	// If the previous test had unused attributes or instructions, it is an error.
	if (!unused_attributes_.empty()) {
	for (const std::string &key : unused_attributes_) {
	PrintLine("Unused attribute: %s", key.c_str());
	}
	return kReadError;
	}
	if (!unused_instructions_.empty()) {
	for (const std::string &key : unused_instructions_) {
	PrintLine("Unused instruction: %s", key.c_str());
	}
	return kReadError;
	}

	ClearTest();

	static const size_t kBufLen = 8192 * 4;
	std::unique_ptr<char[]> buf(new char[kBufLen]);

	bool in_instruction_block = false;
	is_at_new_instruction_block_ = false;

	while (true) {
	// Read the next line.
	switch (reader_->ReadLine(buf.get(), kBufLen)) {
	case kReadError:
	fprintf(stderr, "Error reading from input at line %u.\n", line_ + 1);
	return kReadError;
	case kReadEOF:
	// EOF is a valid terminator for a test.
	return start_line_ > 0 ? kReadSuccess : kReadEOF;
	case kReadSuccess:
	break;
	}

	line_++;
	size_t len = strlen(buf.get());
	if (buf[0] == '\n' \|\| buf[0] == '\r' \|\| buf[0] == '\0') {
	// Empty lines delimit tests.
	if (start_line_ > 0) {
	return kReadSuccess;
	}
	if (in_instruction_block) {
	in_instruction_block = false;
	// Delimit instruction block from test with a blank line.
	current_test_ += "\r\n";
	} else if (is_kas_test_) {
	// KAS tests have random blank lines scattered around.
	current_test_ += "\r\n";
	}
	} else if (buf[0] == '#') {
	if (is_kas_test_ && seen_non_comment_) {
	// KAS tests have comments after the initial comment block which need
	// to be included in the corresponding place in the output.
	current_test_ += std::string(buf.get());
	} else if (comment_callback_) {
	comment_callback_(buf.get());
	}
	// Otherwise ignore comments.
	} else if (strcmp("[B.4.2 Key Pair Generation by Testing Candidates]\r\n",
	buf.get()) == 0) {
	// The above instruction-like line is ignored because the FIPS lab's
	// request files are hopelessly inconsistent.
	} else if (buf[0] == '[') { // Inside an instruction block.
	is_at_new_instruction_block_ = true;
	seen_non_comment_ = true;
	if (start_line_ != 0) {
	// Instructions should be separate blocks.
	fprintf(stderr, "Line %u is an instruction in a test case.\n", line_);
	return kReadError;
	}
	if (!in_instruction_block) {
	ClearInstructions();
	in_instruction_block = true;
	}

	// Parse the line as an instruction ("[key = value]" or "[key]").

	// KAS tests contain invalid syntax.
	std::string kv = buf.get();
	const bool is_broken_kas_instruction =
	is_kas_test_ &&
	(kv == "[SHA(s) supported (Used for hashing Z): SHA512 \r\n");

	if (!is_broken_kas_instruction) {
	kv = StripSpace(buf.get(), len);
	if (kv[kv.size() - 1] != ']') {
	fprintf(stderr, "Line %u, invalid instruction: '%s'\n", line_,
	kv.c_str());
	return kReadError;
	}
	} else {
	// Just remove the newline for the broken instruction.
	kv = kv.substr(0, kv.size() - 2);
	}

	current_test_ += kv + "\r\n";
	kv = std::string(kv.begin() + 1, kv.end() - 1);

	for (;;) {
	size_t idx = kv.find(',');
	if (idx == std::string::npos) {
	idx = kv.size();
	}
	std::string key, value;
	std::tie(key, value) = ParseKeyValue(kv.c_str(), idx);
	instructions_[key] = value;
	if (idx == kv.size())
	break;
	kv = kv.substr(idx + 1);
	}
	} else {
	// Parsing a test case.
	if (in_instruction_block) {
	// Some NIST CAVP test files (TDES) have a test case immediately
	// following an instruction block, without a separate blank line, some
	// of the time.
	in_instruction_block = false;
	}

	current_test_ += std::string(buf.get(), len);
	std::string key, value;
	std::tie(key, value) = ParseKeyValue(buf.get(), len);

	// Duplicate keys are rewritten to have “/2”, “/3”, … suffixes.
	std::string mapped_key = key;
	// If absent, the value will be zero-initialized.
	const size_t num_occurrences = ++attribute_count_[key];
	if (num_occurrences > 1) {
	mapped_key += "/" + std::to_string(num_occurrences);
	}

	unused_attributes_.insert(mapped_key);
	attributes_[mapped_key] = value;
	if (start_line_ == 0) {
	// This is the start of a test.
	type_ = mapped_key;
	parameter_ = value;
	start_line_ = line_;
	for (const auto &kv : instructions_) {
	unused_instructions_.insert(kv.first);
	}
	}
	}
	}
	}

	void FileTest::PrintLine(const char *format, ...) {
	va_list args;
	va_start(args, format);

	fprintf(stderr, "Line %u: ", start_line_);
	vfprintf(stderr, format, args);
	fprintf(stderr, "\n");

	va_end(args);
	}

	const std::string &FileTest::GetType() {
	OnKeyUsed(type_);
	return type_;
	}

	const std::string &FileTest::GetParameter() {
	OnKeyUsed(type_);
	return parameter_;
	}

	bool FileTest::HasAttribute(const std::string &key) {
	OnKeyUsed(key);
	return attributes_.count(key) > 0;
	}

	bool FileTest::GetAttribute(std::string *out_value, const std::string &key) {
	OnKeyUsed(key);
	auto iter = attributes_.find(key);
	if (iter == attributes_.end()) {
	PrintLine("Missing attribute '%s'.", key.c_str());
	return false;
	}
	*out_value = iter->second;
	return true;
	}

	const std::string &FileTest::GetAttributeOrDie(const std::string &key) {
	if (!HasAttribute(key)) {
	abort();
	}
	return attributes_[key];
	}

	bool FileTest::HasInstruction(const std::string &key) {
	OnInstructionUsed(key);
	return instructions_.count(key) > 0;
	}

	bool FileTest::GetInstruction(std::string *out_value, const std::string &key) {
	OnInstructionUsed(key);
	auto iter = instructions_.find(key);
	if (iter == instructions_.end()) {
	PrintLine("Missing instruction '%s'.", key.c_str());
	return false;
	}
	*out_value = iter->second;
	return true;
	}

	void FileTest::IgnoreAllUnusedInstructions() {
	unused_instructions_.clear();
	}

	const std::string &FileTest::GetInstructionOrDie(const std::string &key) {
	if (!HasInstruction(key)) {
	abort();
	}
	return instructions_[key];
	}

	bool FileTest::GetInstructionBytes(std::vector<uint8_t> *out,
	const std::string &key) {
	std::string value;
	return GetInstruction(&value, key) && ConvertToBytes(out, value);
	}

	const std::string &FileTest::CurrentTestToString() const {
	return current_test_;
	}

	bool FileTest::GetBytes(std::vector<uint8_t> *out, const std::string &key) {
	std::string value;
	return GetAttribute(&value, key) && ConvertToBytes(out, value);
	}

	void FileTest::ClearTest() {
	start_line_ = 0;
	type_.clear();
	parameter_.clear();
	attribute_count_.clear();
	attributes_.clear();
	unused_attributes_.clear();
	unused_instructions_.clear();
	current_test_ = "";
	}

	void FileTest::ClearInstructions() {
	instructions_.clear();
	unused_attributes_.clear();
	}

	void FileTest::OnKeyUsed(const std::string &key) {
	unused_attributes_.erase(key);
	}

	void FileTest::OnInstructionUsed(const std::string &key) {
	unused_instructions_.erase(key);
	}

	bool FileTest::ConvertToBytes(std::vector<uint8_t> *out,
	const std::string &value) {
	if (value.size() >= 2 && value[0] == '"' && value[value.size() - 1] == '"') {
	out->assign(value.begin() + 1, value.end() - 1);
	return true;
	}

	if (!DecodeHex(out, value)) {
	PrintLine("Error decoding value: %s", value.c_str());
	return false;
	}
	return true;
	}

	bool FileTest::IsAtNewInstructionBlock() const {
	return is_at_new_instruction_block_;
	}

	void FileTest::InjectInstruction(const std::string &key,
	const std::string &value) {
	instructions_[key] = value;
	}

	class FileLineReader : public FileTest::LineReader {
	public:
	explicit FileLineReader(const char *path) : file_(fopen(path, "r")) {}
	~FileLineReader() override {
	if (file_ != nullptr) {
	fclose(file_);
	}
	}

	// is_open returns true if the file was successfully opened.
	bool is_open() const { return file_ != nullptr; }

	FileTest::ReadResult ReadLine(char *out, size_t len) override {
	assert(len > 0);
	if (file_ == nullptr) {
	return FileTest::kReadError;
	}

	len = std::min(len, size_t{INT_MAX});
	if (fgets(out, static_cast<int>(len), file_) == nullptr) {
	return feof(file_) ? FileTest::kReadEOF : FileTest::kReadError;
	}

	if (strlen(out) == len - 1 && out[len - 2] != '\n' && !feof(file_)) {
	fprintf(stderr, "Line too long.\n");
	return FileTest::kReadError;
	}

	return FileTest::kReadSuccess;
	}

	private:
	FILE *file_;

	FileLineReader(const FileLineReader &) = delete;
	FileLineReader &operator=(const FileLineReader &) = delete;
	};

	int FileTestMain(FileTestFunc run_test, void arg, const char path) {
	FileTest::Options opts;
	opts.callback = run_test;
	opts.arg = arg;
	opts.path = path;

	return FileTestMain(opts);
	}

	int FileTestMain(const FileTest::Options &opts) {
	std::unique_ptr<FileLineReader> reader(
	new FileLineReader(opts.path));
	if (!reader->is_open()) {
	fprintf(stderr, "Could not open file %s: %s.\n", opts.path,
	strerror(errno));
	return 1;
	}

	FileTest t(std::move(reader), opts.comment_callback, opts.is_kas_test);

	bool failed = false;
	while (true) {
	FileTest::ReadResult ret = t.ReadNext();
	if (ret == FileTest::kReadError) {
	return 1;
	} else if (ret == FileTest::kReadEOF) {
	break;
	}

	bool result = opts.callback(&t, opts.arg);
	if (t.HasAttribute("Error")) {
	if (result) {
	t.PrintLine("Operation unexpectedly succeeded.");
	failed = true;
	continue;
	}
	uint32_t err = ERR_peek_error();
	if (ERR_reason_error_string(err) != t.GetAttributeOrDie("Error")) {
	t.PrintLine("Unexpected error; wanted '%s', got '%s'.",
	t.GetAttributeOrDie("Error").c_str(),
	ERR_reason_error_string(err));
	failed = true;
	ERR_clear_error();
	continue;
	}
	ERR_clear_error();
	} else if (!result) {
	// In case the test itself doesn't print output, print something so the
	// line number is reported.
	t.PrintLine("Test failed");
	ERR_print_errors_fp(stderr);
	failed = true;
	continue;
	}
	}

	if (!opts.silent && !failed) {
	printf("PASS\n");
	}

	return failed ? 1 : 0;
	}

	void FileTest::SkipCurrent() {
	ClearTest();
	}