Made m64 implementations of elliptic curves the default (when available).
[BearSSL] / T0 / BlobWriter.cs
1 /*
2 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25 using System;
26 using System.IO;
27 using System.Text;
28
29 /*
30 * A simple class for writing out bytes as hexadecimal constants or
31 * explicit expressions for the initializer of a C array of 'unsigned
32 * char'. It starts every line with a given number of tabs, and aims at
33 * keeping lines below a given threshold (each indentation tab counts as
34 * 8 characters). An explicit newline is inserted before the first
35 * element, and commas are used as separators.
36 */
37
38 class BlobWriter {
39
40 TextWriter w;
41 int maxLineLen;
42 int indent;
43 int lineLen;
44
45 /*
46 * Create a new instance. 'maxLineLen' is in characters, and
47 * 'indent' is the number of tab characters at the start of
48 * each line.
49 */
50 internal BlobWriter(TextWriter w, int maxLineLen, int indent)
51 {
52 this.w = w;
53 this.maxLineLen = maxLineLen;
54 this.indent = indent;
55 lineLen = -1;
56 }
57
58 void DoNL()
59 {
60 w.WriteLine();
61 for (int i = 0; i < indent; i ++) {
62 w.Write('\t');
63 }
64 lineLen = (indent << 3);
65 }
66
67 /*
68 * Append a new byte value; it will be converted to an hexadecimal
69 * constant in the output.
70 */
71 internal void Append(byte b)
72 {
73 if (lineLen < 0) {
74 DoNL();
75 } else {
76 w.Write(',');
77 lineLen ++;
78 if ((lineLen + 5) > maxLineLen) {
79 DoNL();
80 } else {
81 w.Write(' ');
82 lineLen ++;
83 }
84 }
85 w.Write("0x{0:X2}", b);
86 lineLen += 4;
87 }
88
89 /*
90 * Append a C expression, which will be used as is. The expression
91 * may resolve to several bytes if it uses internal commas. The
92 * writer will try to honour the expected line length, but it
93 * won't insert a newline character inside the expression.
94 */
95 internal void Append(string expr)
96 {
97 if (lineLen < 0) {
98 DoNL();
99 } else {
100 w.Write(',');
101 lineLen ++;
102 if ((lineLen + 1 + expr.Length) > maxLineLen) {
103 DoNL();
104 } else {
105 w.Write(' ');
106 lineLen ++;
107 }
108 }
109 w.Write("{0}", expr);
110 lineLen += expr.Length;
111 }
112 }