1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef NET_CERT_PEM_TOKENIZER_H_ 6 #define NET_CERT_PEM_TOKENIZER_H_ 7 8 #include <string> 9 #include <vector> 10 11 #include "base/strings/string_piece.h" 12 #include "net/base/net_export.h" 13 14 namespace net { 15 16 // PEMTokenizer is a utility class for the parsing of data encapsulated 17 // using RFC 1421, Privacy Enhancement for Internet Electronic Mail. It 18 // does not implement the full specification, most notably it does not 19 // support the Encapsulated Header Portion described in Section 4.4. 20 class NET_EXPORT_PRIVATE PEMTokenizer { 21 public: 22 // Create a new PEMTokenizer that iterates through |str| searching for 23 // instances of PEM encoded blocks that are of the |allowed_block_types|. 24 // |str| must remain valid for the duration of the PEMTokenizer. 25 PEMTokenizer(const base::StringPiece& str, 26 const std::vector<std::string>& allowed_block_types); 27 ~PEMTokenizer(); 28 29 // Attempts to decode the next PEM block in the string. Returns false if no 30 // PEM blocks can be decoded. The decoded PEM block will be available via 31 // data(). 32 bool GetNext(); 33 34 // Returns the PEM block type (eg: CERTIFICATE) of the last successfully 35 // decoded PEM block. 36 // GetNext() must have returned true before calling this method. 37 const std::string& block_type() const { return block_type_; } 38 39 // Returns the raw, Base64-decoded data of the last successfully decoded 40 // PEM block. 41 // GetNext() must have returned true before calling this method. 42 const std::string& data() const { return data_; } 43 44 private: 45 void Init(const base::StringPiece& str, 46 const std::vector<std::string>& allowed_block_types); 47 48 // A simple cache of the allowed PEM header and footer for a given PEM 49 // block type, so that it is only computed once. 50 struct PEMType; 51 52 // The string to search, which must remain valid for as long as this class 53 // is around. 54 base::StringPiece str_; 55 56 // The current position within |str_| that searching should begin from, 57 // or StringPiece::npos if iteration is complete 58 base::StringPiece::size_type pos_; 59 60 // The type of data that was encoded, as indicated in the PEM 61 // Pre-Encapsulation Boundary (eg: CERTIFICATE, PKCS7, or 62 // PRIVACY-ENHANCED MESSAGE). 63 std::string block_type_; 64 65 // The types of PEM blocks that are allowed. PEM blocks that are not of 66 // one of these types will be skipped. 67 std::vector<PEMType> block_types_; 68 69 // The raw (Base64-decoded) data of the last successfully decoded block. 70 std::string data_; 71 72 DISALLOW_COPY_AND_ASSIGN(PEMTokenizer); 73 }; 74 75 } // namespace net 76 77 #endif // NET_CERT_PEM_TOKENIZER_H_ 78
