Botan 2.1.0 Crypto and TLS for C++11

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pem.cpp
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1 /*
2 * PEM Encoding/Decoding
3 * (C) 1999-2007 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7
8 #include <botan/pem.h>
9 #include <botan/base64.h>
10 #include <botan/parsing.h>
11 #include <botan/exceptn.h>
12
13 namespace Botan {
14
15 namespace PEM_Code {
16
17 namespace {
18
19 std::string linewrap(size_t width, const std::string& in)
20 {
21 std::string out;
22 for(size_t i = 0; i != in.size(); ++i)
23 {
24 if(i > 0 && i % width == 0)
25 {
26 out.push_back('\n');
27 }
28 out.push_back(in[i]);
29 }
30 if(out.size() > 0 && out[out.size()-1] != '\n')
31 {
32 out.push_back('\n');
33 }
34
35 return out;
36 }
37
38 }
39
40 /*
41 * PEM encode BER/DER-encoded objects
42 */
43 std::string encode(const uint8_t der[], size_t length, const std::string& label, size_t width)
44 {
45 const std::string PEM_HEADER = "-----BEGIN " + label + "-----\n";
46 const std::string PEM_TRAILER = "-----END " + label + "-----\n";
47
48 return (PEM_HEADER + linewrap(width, base64_encode(der, length)) + PEM_TRAILER);
49 }
50
51 /*
52 * Decode PEM down to raw BER/DER
53 */
54 secure_vector<uint8_t> decode_check_label(DataSource& source,
55 const std::string& label_want)
56 {
57 std::string label_got;
58 secure_vector<uint8_t> ber = decode(source, label_got);
59 if(label_got != label_want)
60 throw Decoding_Error("PEM: Label mismatch, wanted " + label_want +
61 ", got " + label_got);
62 return ber;
63 }
64
65 /*
66 * Decode PEM down to raw BER/DER
67 */
68 secure_vector<uint8_t> decode(DataSource& source, std::string& label)
69 {
70 const size_t RANDOM_CHAR_LIMIT = 8;
71
72 const std::string PEM_HEADER1 = "-----BEGIN ";
73 const std::string PEM_HEADER2 = "-----";
74 size_t position = 0;
75
76 while(position != PEM_HEADER1.length())
77 {
78 uint8_t b;
79 if(!source.read_byte(b))
80 throw Decoding_Error("PEM: No PEM header found");
81 if(b == PEM_HEADER1[position])
82 ++position;
83 else if(position >= RANDOM_CHAR_LIMIT)
84 throw Decoding_Error("PEM: Malformed PEM header");
85 else
86 position = 0;
87 }
88 position = 0;
89 while(position != PEM_HEADER2.length())
90 {
91 uint8_t b;
92 if(!source.read_byte(b))
93 throw Decoding_Error("PEM: No PEM header found");
94 if(b == PEM_HEADER2[position])
95 ++position;
96 else if(position)
97 throw Decoding_Error("PEM: Malformed PEM header");
98
99 if(position == 0)
100 label += static_cast<char>(b);
101 }
102
103 std::vector<char> b64;
104
105 const std::string PEM_TRAILER = "-----END " + label + "-----";
106 position = 0;
107 while(position != PEM_TRAILER.length())
108 {
109 uint8_t b;
110 if(!source.read_byte(b))
111 throw Decoding_Error("PEM: No PEM trailer found");
112 if(b == PEM_TRAILER[position])
113 ++position;
114 else if(position)
115 throw Decoding_Error("PEM: Malformed PEM trailer");
116
117 if(position == 0)
118 b64.push_back(b);
119 }
120
121 return base64_decode(b64.data(), b64.size());
122 }
123
124 secure_vector<uint8_t> decode_check_label(const std::string& pem,
125 const std::string& label_want)
126 {
127 DataSource_Memory src(pem);
128 return decode_check_label(src, label_want);
129 }
130
131 secure_vector<uint8_t> decode(const std::string& pem, std::string& label)
132 {
133 DataSource_Memory src(pem);
134 return decode(src, label);
135 }
136
137 /*
138 * Search for a PEM signature
139 */
140 bool matches(DataSource& source, const std::string& extra,
141 size_t search_range)
142 {
143 const std::string PEM_HEADER = "-----BEGIN " + extra;
144
145 secure_vector<uint8_t> search_buf(search_range);
146 size_t got = source.peek(search_buf.data(), search_buf.size(), 0);
147
148 if(got < PEM_HEADER.length())
149 return false;
150
151 size_t index = 0;
152
153 for(size_t j = 0; j != got; ++j)
154 {
155 if(search_buf[j] == PEM_HEADER[index])
156 ++index;
157 else
158 index = 0;
159 if(index == PEM_HEADER.size())
160 return true;
161 }
162 return false;
163 }
164
165 }
166
167 }
Botan::PEM_Code::decode
secure_vector< uint8_t > decode(DataSource &source, std::string &label)
Definition: pem.cpp:68
Botan::base64_decode
size_t base64_decode(uint8_t output[], const char input[], size_t input_length, size_t &input_consumed, bool final_inputs, bool ignore_ws)
Definition: base64.cpp:100
Botan::PEM_Code::encode
std::string encode(const uint8_t der[], size_t length, const std::string &label, size_t width)
Definition: pem.cpp:43
Botan::DataSource
Definition: data_src.h:21
Botan::DataSource::peek
virtual size_t peek(uint8_t out[], size_t length, size_t peek_offset) const BOTAN_WARN_UNUSED_RESULT=0
Botan::secure_vector
std::vector< T, secure_allocator< T >> secure_vector
Definition: secmem.h:121
Botan::Decoding_Error
Definition: exceptn.h:189
Botan
Definition: alg_id.cpp:13
Botan::DataSource::read_byte
size_t read_byte(uint8_t &out)
Definition: data_src.cpp:22
Botan::PEM_Code::matches
bool matches(DataSource &source, const std::string &extra, size_t search_range)
Definition: pem.cpp:140
Botan::PEM_Code::decode_check_label
secure_vector< uint8_t > decode_check_label(DataSource &source, const std::string &label_want)
Definition: pem.cpp:54
Botan::DataSource_Memory
Definition: data_src.h:98
Botan::base64_encode
size_t base64_encode(char out[], const uint8_t in[], size_t input_length, size_t &input_consumed, bool final_inputs)
Definition: base64.cpp:35