Botan  1.10.9
hex_filt.cpp
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1 /*
2 * Hex Encoder/Decoder
3 * (C) 1999-2007 Jack Lloyd
4 *
5 * Distributed under the terms of the Botan license
6 */
7 
8 #include <botan/hex_filt.h>
9 #include <botan/hex.h>
10 #include <botan/parsing.h>
11 #include <botan/charset.h>
12 #include <botan/exceptn.h>
13 #include <algorithm>
14 
15 namespace Botan {
16 
17 /**
18 * Size used for internal buffer in hex encoder/decoder
19 */
20 const size_t HEX_CODEC_BUFFER_SIZE = 256;
21 
22 /*
23 * Hex_Encoder Constructor
24 */
25 Hex_Encoder::Hex_Encoder(bool breaks, size_t length, Case c) :
26  casing(c), line_length(breaks ? length : 0)
27  {
28  in.resize(HEX_CODEC_BUFFER_SIZE);
29  out.resize(2*in.size());
30  counter = position = 0;
31  }
32 
33 /*
34 * Hex_Encoder Constructor
35 */
36 Hex_Encoder::Hex_Encoder(Case c) : casing(c), line_length(0)
37  {
38  in.resize(HEX_CODEC_BUFFER_SIZE);
39  out.resize(2*in.size());
40  counter = position = 0;
41  }
42 
43 /*
44 * Encode and send a block
45 */
46 void Hex_Encoder::encode_and_send(const byte block[], size_t length)
47  {
48  hex_encode(reinterpret_cast<char*>(&out[0]),
49  block, length,
50  casing == Uppercase);
51 
52  if(line_length == 0)
53  send(out, 2*length);
54  else
55  {
56  size_t remaining = 2*length, offset = 0;
57  while(remaining)
58  {
59  size_t sent = std::min(line_length - counter, remaining);
60  send(&out[offset], sent);
61  counter += sent;
62  remaining -= sent;
63  offset += sent;
64  if(counter == line_length)
65  {
66  send('\n');
67  counter = 0;
68  }
69  }
70  }
71  }
72 
73 /*
74 * Convert some data into hex format
75 */
76 void Hex_Encoder::write(const byte input[], size_t length)
77  {
78  in.copy(position, input, length);
79  if(position + length >= in.size())
80  {
81  encode_and_send(&in[0], in.size());
82  input += (in.size() - position);
83  length -= (in.size() - position);
84  while(length >= in.size())
85  {
86  encode_and_send(input, in.size());
87  input += in.size();
88  length -= in.size();
89  }
90  in.copy(input, length);
91  position = 0;
92  }
93  position += length;
94  }
95 
96 /*
97 * Flush buffers
98 */
100  {
101  encode_and_send(&in[0], position);
102  if(counter && line_length)
103  send('\n');
104  counter = position = 0;
105  }
106 
107 /*
108 * Hex_Decoder Constructor
109 */
111  {
112  in.resize(HEX_CODEC_BUFFER_SIZE);
113  out.resize(in.size() / 2);
114  position = 0;
115  }
116 
117 /*
118 * Convert some data from hex format
119 */
120 void Hex_Decoder::write(const byte input[], size_t length)
121  {
122  while(length)
123  {
124  size_t to_copy = std::min<size_t>(length, in.size() - position);
125  copy_mem(&in[position], input, to_copy);
126  position += to_copy;
127 
128  size_t consumed = 0;
129  size_t written = hex_decode(&out[0],
130  reinterpret_cast<const char*>(&in[0]),
131  position,
132  consumed,
133  checking != FULL_CHECK);
134 
135  send(out, written);
136 
137  if(consumed != position)
138  {
139  copy_mem(&in[0], &in[consumed], position - consumed);
140  position = position - consumed;
141  }
142  else
143  position = 0;
144 
145  length -= to_copy;
146  input += to_copy;
147  }
148  }
149 
150 /*
151 * Flush buffers
152 */
154  {
155  size_t consumed = 0;
156  size_t written = hex_decode(&out[0],
157  reinterpret_cast<const char*>(&in[0]),
158  position,
159  consumed,
160  checking != FULL_CHECK);
161 
162  send(out, written);
163 
164  const bool not_full_bytes = consumed != position;
165 
166  position = 0;
167 
168  if(not_full_bytes)
169  throw std::invalid_argument("Hex_Decoder: Input not full bytes");
170  }
171 
172 }
void resize(size_t n)
Definition: secmem.h:211
size_t hex_decode(byte output[], const char input[], size_t input_length, size_t &input_consumed, bool ignore_ws)
Definition: hex.cpp:55
const size_t HEX_CODEC_BUFFER_SIZE
Definition: hex_filt.cpp:20
Hex_Decoder(Decoder_Checking checking=NONE)
Definition: hex_filt.cpp:110
void copy(const T in[], size_t n)
Definition: secmem.h:120
unsigned char byte
Definition: types.h:22
void send(const byte in[], size_t length)
Definition: filter.cpp:28
size_t size() const
Definition: secmem.h:29
void copy_mem(T *out, const T *in, size_t n)
Definition: mem_ops.h:22
Hex_Encoder(Case the_case)
Definition: hex_filt.cpp:36
void write(const byte[], size_t)
Definition: hex_filt.cpp:120
void write(const byte in[], size_t length)
Definition: hex_filt.cpp:76
Decoder_Checking
Definition: filter.h:155
void hex_encode(char output[], const byte input[], size_t input_length, bool uppercase)
Definition: hex.cpp:14