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 BSSL_PKI_PEM_H_ 6 #define BSSL_PKI_PEM_H_ 7 8 #include "fillins/openssl_util.h" 9 #include <stddef.h> 10 11 #include <string> 12 #include <vector> 13 14 #include <string_view> 15 16 17 18 namespace bssl { 19 20 // PEMTokenizer is a utility class for the parsing of data encapsulated 21 // using RFC 1421, Privacy Enhancement for Internet Electronic Mail. It 22 // does not implement the full specification, most notably it does not 23 // support the Encapsulated Header Portion described in Section 4.4. 24 class OPENSSL_EXPORT PEMTokenizer { 25 public: 26 // Create a new PEMTokenizer that iterates through |str| searching for 27 // instances of PEM encoded blocks that are of the |allowed_block_types|. 28 // |str| must remain valid for the duration of the PEMTokenizer. 29 PEMTokenizer(std::string_view str, 30 const std::vector<std::string>& allowed_block_types); 31 32 PEMTokenizer(const PEMTokenizer&) = delete; 33 PEMTokenizer& operator=(const PEMTokenizer&) = delete; 34 35 ~PEMTokenizer(); 36 37 // Attempts to decode the next PEM block in the string. Returns false if no 38 // PEM blocks can be decoded. The decoded PEM block will be available via 39 // data(). 40 bool GetNext(); 41 42 // Returns the PEM block type (eg: CERTIFICATE) of the last successfully 43 // decoded PEM block. 44 // GetNext() must have returned true before calling this method. block_type()45 const std::string& block_type() const { return block_type_; } 46 47 // Returns the raw, Base64-decoded data of the last successfully decoded 48 // PEM block. 49 // GetNext() must have returned true before calling this method. data()50 const std::string& data() const { return data_; } 51 52 private: 53 void Init(std::string_view str, 54 const std::vector<std::string>& allowed_block_types); 55 56 // A simple cache of the allowed PEM header and footer for a given PEM 57 // block type, so that it is only computed once. 58 struct PEMType; 59 60 // The string to search, which must remain valid for as long as this class 61 // is around. 62 std::string_view str_; 63 64 // The current position within |str_| that searching should begin from, 65 // or std::string_view::npos if iteration is complete 66 std::string_view::size_type pos_; 67 68 // The type of data that was encoded, as indicated in the PEM 69 // Pre-Encapsulation Boundary (eg: CERTIFICATE, PKCS7, or 70 // PRIVACY-ENHANCED MESSAGE). 71 std::string block_type_; 72 73 // The types of PEM blocks that are allowed. PEM blocks that are not of 74 // one of these types will be skipped. 75 std::vector<PEMType> block_types_; 76 77 // The raw (Base64-decoded) data of the last successfully decoded block. 78 std::string data_; 79 }; 80 81 // Encodes |data| in the encapsulated message format described in RFC 1421, 82 // with |type| as the PEM block type (eg: CERTIFICATE). 83 OPENSSL_EXPORT std::string PEMEncode(std::string_view data, 84 const std::string& type); 85 86 } // namespace net 87 88 #endif // BSSL_PKI_PEM_H_ 89