Botan  1.11.11
pem.cpp
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1 /*
2 * PEM Encoding/Decoding
3 * (C) 1999-2007 Jack Lloyd
4 *
5 * Distributed under the terms of the Botan license
6 */
7 
8 #include <botan/pem.h>
9 #include <botan/filters.h>
10 #include <botan/parsing.h>
11 
12 namespace Botan {
13 
14 namespace PEM_Code {
15 
16 /*
17 * PEM encode BER/DER-encoded objects
18 */
19 std::string encode(const byte der[], size_t length, const std::string& label,
20  size_t width)
21  {
22  const std::string PEM_HEADER = "-----BEGIN " + label + "-----\n";
23  const std::string PEM_TRAILER = "-----END " + label + "-----\n";
24 
25  Pipe pipe(new Base64_Encoder(true, width));
26  pipe.process_msg(der, length);
27  return (PEM_HEADER + pipe.read_all_as_string() + PEM_TRAILER);
28  }
29 
30 /*
31 * Decode PEM down to raw BER/DER
32 */
34  const std::string& label_want)
35  {
36  std::string label_got;
37  secure_vector<byte> ber = decode(source, label_got);
38  if(label_got != label_want)
39  throw Decoding_Error("PEM: Label mismatch, wanted " + label_want +
40  ", got " + label_got);
41  return ber;
42  }
43 
44 /*
45 * Decode PEM down to raw BER/DER
46 */
47 secure_vector<byte> decode(DataSource& source, std::string& label)
48  {
49  const size_t RANDOM_CHAR_LIMIT = 8;
50 
51  const std::string PEM_HEADER1 = "-----BEGIN ";
52  const std::string PEM_HEADER2 = "-----";
53  size_t position = 0;
54 
55  while(position != PEM_HEADER1.length())
56  {
57  byte b;
58  if(!source.read_byte(b))
59  throw Decoding_Error("PEM: No PEM header found");
60  if(b == PEM_HEADER1[position])
61  ++position;
62  else if(position >= RANDOM_CHAR_LIMIT)
63  throw Decoding_Error("PEM: Malformed PEM header");
64  else
65  position = 0;
66  }
67  position = 0;
68  while(position != PEM_HEADER2.length())
69  {
70  byte b;
71  if(!source.read_byte(b))
72  throw Decoding_Error("PEM: No PEM header found");
73  if(b == PEM_HEADER2[position])
74  ++position;
75  else if(position)
76  throw Decoding_Error("PEM: Malformed PEM header");
77 
78  if(position == 0)
79  label += static_cast<char>(b);
80  }
81 
82  Pipe base64(new Base64_Decoder);
83  base64.start_msg();
84 
85  const std::string PEM_TRAILER = "-----END " + label + "-----";
86  position = 0;
87  while(position != PEM_TRAILER.length())
88  {
89  byte b;
90  if(!source.read_byte(b))
91  throw Decoding_Error("PEM: No PEM trailer found");
92  if(b == PEM_TRAILER[position])
93  ++position;
94  else if(position)
95  throw Decoding_Error("PEM: Malformed PEM trailer");
96 
97  if(position == 0)
98  base64.write(b);
99  }
100  base64.end_msg();
101  return base64.read_all();
102  }
103 
105  const std::string& label_want)
106  {
107  DataSource_Memory src(pem);
108  return decode_check_label(src, label_want);
109  }
110 
111 secure_vector<byte> decode(const std::string& pem, std::string& label)
112  {
113  DataSource_Memory src(pem);
114  return decode(src, label);
115  }
116 
117 /*
118 * Search for a PEM signature
119 */
120 bool matches(DataSource& source, const std::string& extra,
121  size_t search_range)
122  {
123  const std::string PEM_HEADER = "-----BEGIN " + extra;
124 
125  secure_vector<byte> search_buf(search_range);
126  size_t got = source.peek(&search_buf[0], search_buf.size(), 0);
127 
128  if(got < PEM_HEADER.length())
129  return false;
130 
131  size_t index = 0;
132 
133  for(size_t j = 0; j != got; ++j)
134  {
135  if(search_buf[j] == PEM_HEADER[index])
136  ++index;
137  else
138  index = 0;
139  if(index == PEM_HEADER.size())
140  return true;
141  }
142  return false;
143  }
144 
145 }
146 
147 }
void start_msg()
Definition: pipe.cpp:158
std::string read_all_as_string(message_id=DEFAULT_MESSAGE)
Definition: pipe_rw.cpp:110
void write(const byte in[], size_t length)
Definition: pipe_rw.cpp:35
void end_msg()
Definition: pipe.cpp:172
std::vector< T, secure_allocator< T >> secure_vector
Definition: secmem.h:92
virtual size_t peek(byte out[], size_t length, size_t peek_offset) const =0
uint8_t byte
Definition: types.h:30
size_t read_byte(byte &out)
Definition: data_src.cpp:19
Definition: buf_comp.h:15
bool matches(DataSource &source, const std::string &extra, size_t search_range)
Definition: pem.cpp:120
secure_vector< byte > read_all(message_id msg=DEFAULT_MESSAGE)
Definition: pipe_rw.cpp:98
std::string encode(const byte der[], size_t length, const std::string &label, size_t width)
Definition: pem.cpp:19
void process_msg(const byte in[], size_t length)
Definition: pipe.cpp:117
secure_vector< byte > decode(DataSource &source, std::string &label)
Definition: pem.cpp:47
secure_vector< byte > decode_check_label(DataSource &source, const std::string &label_want)
Definition: pem.cpp:33