1 // Copyright 2011 The Chromium Authors 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_H_ 6 #define NET_CERT_PEM_H_ 7 8 #include <stddef.h> 9 10 #include <string> 11 #include <vector> 12 13 #include "base/strings/string_piece.h" 14 #include "net/base/net_export.h" 15 16 namespace net { 17 18 // PEMTokenizer is a utility class for the parsing of data encapsulated 19 // using RFC 1421, Privacy Enhancement for Internet Electronic Mail. It 20 // does not implement the full specification, most notably it does not 21 // support the Encapsulated Header Portion described in Section 4.4. 22 class NET_EXPORT_PRIVATE PEMTokenizer { 23 public: 24 // Create a new PEMTokenizer that iterates through |str| searching for 25 // instances of PEM encoded blocks that are of the |allowed_block_types|. 26 // |str| must remain valid for the duration of the PEMTokenizer. 27 PEMTokenizer(base::StringPiece str, 28 const std::vector<std::string>& allowed_block_types); 29 30 PEMTokenizer(const PEMTokenizer&) = delete; 31 PEMTokenizer& operator=(const PEMTokenizer&) = delete; 32 33 ~PEMTokenizer(); 34 35 // Attempts to decode the next PEM block in the string. Returns false if no 36 // PEM blocks can be decoded. The decoded PEM block will be available via 37 // data(). 38 bool GetNext(); 39 40 // Returns the PEM block type (eg: CERTIFICATE) of the last successfully 41 // decoded PEM block. 42 // GetNext() must have returned true before calling this method. block_type()43 const std::string& block_type() const { return block_type_; } 44 45 // Returns the raw, Base64-decoded data of the last successfully decoded 46 // PEM block. 47 // GetNext() must have returned true before calling this method. data()48 const std::string& data() const { return data_; } 49 50 private: 51 void Init(base::StringPiece str, 52 const std::vector<std::string>& allowed_block_types); 53 54 // A simple cache of the allowed PEM header and footer for a given PEM 55 // block type, so that it is only computed once. 56 struct PEMType; 57 58 // The string to search, which must remain valid for as long as this class 59 // is around. 60 base::StringPiece str_; 61 62 // The current position within |str_| that searching should begin from, 63 // or StringPiece::npos if iteration is complete 64 base::StringPiece::size_type pos_; 65 66 // The type of data that was encoded, as indicated in the PEM 67 // Pre-Encapsulation Boundary (eg: CERTIFICATE, PKCS7, or 68 // PRIVACY-ENHANCED MESSAGE). 69 std::string block_type_; 70 71 // The types of PEM blocks that are allowed. PEM blocks that are not of 72 // one of these types will be skipped. 73 std::vector<PEMType> block_types_; 74 75 // The raw (Base64-decoded) data of the last successfully decoded block. 76 std::string data_; 77 }; 78 79 // Encodes |data| in the encapsulated message format described in RFC 1421, 80 // with |type| as the PEM block type (eg: CERTIFICATE). 81 NET_EXPORT_PRIVATE std::string PEMEncode(base::StringPiece data, 82 const std::string& type); 83 84 } // namespace net 85 86 #endif // NET_CERT_PEM_H_ 87