gnostr 0.0.48

git+nostr workflow utility
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254

/* Licensed under BSD-MIT - see LICENSE file for details */
#include "base64.h"

#include <errno.h>
#include <string.h>
#include <assert.h>
#include <stdint.h>

/**
 * sixbit_to_b64 - maps a 6-bit value to the base64 alphabet
 * @param map A base 64 map (see base64_init_map)
 * @param sixbit Six-bit value to map
 * @return a base 64 character
 */
static char sixbit_to_b64(const base64_maps_t *maps, const uint8_t sixbit)
{
	assert(sixbit <= 63);

	return maps->encode_map[(unsigned char)sixbit];
}

/**
 * sixbit_from_b64 - maps a base64-alphabet character to its 6-bit value
 * @param maps A base 64 maps structure (see base64_init_maps)
 * @param sixbit Six-bit value to map
 * @return a six-bit value
 */
static int8_t sixbit_from_b64(const base64_maps_t *maps,
			      const unsigned char b64letter)
{
	int8_t ret;

	ret = maps->decode_map[(unsigned char)b64letter];
	if (ret == (char)0xff) {
		errno = EDOM;
		return -1;
	}

	return ret;
}

bool base64_char_in_alphabet(const base64_maps_t *maps, const char b64char)
{
	return (maps->decode_map[(const unsigned char)b64char] != (char)0xff);
}

void base64_init_maps(base64_maps_t *dest, const char src[64])
{
	unsigned char i;

	memcpy(dest->encode_map,src,64);
	memset(dest->decode_map,0xff,256);
	for (i=0; i<64; i++) {
		dest->decode_map[(unsigned char)src[i]] = i;
	}
}

size_t base64_encoded_length(size_t srclen)
{
	return ((srclen + 2) / 3) * 4;
}

void base64_encode_triplet_using_maps(const base64_maps_t *maps,
				      char dest[4], const char src[3])
{
	char a = src[0];
	char b = src[1];
	char c = src[2];

	dest[0] = sixbit_to_b64(maps, (a & 0xfc) >> 2);
	dest[1] = sixbit_to_b64(maps, ((a & 0x3) << 4) | ((b & 0xf0) >> 4));
	dest[2] = sixbit_to_b64(maps, ((c & 0xc0) >> 6) | ((b & 0xf) << 2));
	dest[3] = sixbit_to_b64(maps, c & 0x3f);
}

void base64_encode_tail_using_maps(const base64_maps_t *maps, char dest[4],
				   const char *src, const size_t srclen)
{
	char longsrc[3] = { 0 };

	assert(srclen <= 3);

	memcpy(longsrc, src, srclen);
	base64_encode_triplet_using_maps(maps, dest, longsrc);
	memset(dest+1+srclen, '=', 3-srclen);
}

ssize_t base64_encode_using_maps(const base64_maps_t *maps,
				 char *dest, const size_t destlen,
				 const char *src, const size_t srclen)
{
	size_t src_offset = 0;
	size_t dest_offset = 0;

	if (destlen < base64_encoded_length(srclen)) {
		errno = EOVERFLOW;
		return -1;
	}

	while (srclen - src_offset >= 3) {
		base64_encode_triplet_using_maps(maps, &dest[dest_offset], &src[src_offset]);
		src_offset += 3;
		dest_offset += 4;
	}

	if (src_offset < srclen) {
		base64_encode_tail_using_maps(maps, &dest[dest_offset], &src[src_offset], srclen-src_offset);
		dest_offset += 4;
	}

	memset(&dest[dest_offset], '\0', destlen-dest_offset);

	return dest_offset;
}

size_t base64_decoded_length(size_t srclen)
{
	return ((srclen+3)/4*3);
}

ssize_t base64_decode_quartet_using_maps(const base64_maps_t *maps, char dest[3],
				     const char src[4])
{
	signed char a;
	signed char b;
	signed char c;
	signed char d;

	a = sixbit_from_b64(maps, src[0]);
	b = sixbit_from_b64(maps, src[1]);
	c = sixbit_from_b64(maps, src[2]);
	d = sixbit_from_b64(maps, src[3]);

	if ((a == -1) || (b == -1) || (c == -1) || (d == -1)) {
		return -1;
	}

	dest[0] = (a << 2) | (b >> 4);
	dest[1] = ((b & 0xf) << 4) | (c >> 2);
	dest[2] = ((c & 0x3) << 6) | d;

	return 0;
}


ssize_t base64_decode_tail_using_maps(const base64_maps_t *maps, char dest[3],
				  const char * src, const size_t srclen)
{
	char longsrc[4];
	int quartet_result;
	size_t insize = srclen;

	while (insize != 0 &&
	       src[insize-1] == '=') { /* throw away padding symbols */
		insize--;
	}
	if (insize == 0) {
		return 0;
	}
	if (insize == 1) {
		/* the input is malformed.... */
		errno = EINVAL;
		return -1;
	}
	memcpy(longsrc, src, insize);
	memset(longsrc+insize, 'A', 4-insize);
	quartet_result = base64_decode_quartet_using_maps(maps, dest, longsrc);
	if (quartet_result == -1) {
		return -1;
	}

	return insize - 1;
}

ssize_t base64_decode_using_maps(const base64_maps_t *maps,
				 char *dest, const size_t destlen,
				 const char *src, const size_t srclen)
{
	ssize_t dest_offset = 0;
	ssize_t i;
	ssize_t more;

	if (destlen < base64_decoded_length(srclen)) {
		errno = EOVERFLOW;
		return -1;
	}

	for(i=0; srclen - i > 4; i+=4) {
		if (base64_decode_quartet_using_maps(maps, &dest[dest_offset], &src[i]) == -1) {
			return -1;
		}
		dest_offset += 3;
	}

	more = base64_decode_tail_using_maps(maps, &dest[dest_offset], &src[i], srclen - i);
	if (more == -1) {
		return -1;
	}
	dest_offset += more;

	memset(&dest[dest_offset], '\0', destlen-dest_offset);

	return dest_offset;
}




/**
 * base64_maps_rfc4648 - pregenerated maps struct for rfc4648
 */
const base64_maps_t base64_maps_rfc4648 = {
  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",

  "\xff\xff\xff\xff\xff" /* 0 */					\
  "\xff\xff\xff\xff\xff" /* 5 */					\
  "\xff\xff\xff\xff\xff" /* 10 */					\
  "\xff\xff\xff\xff\xff" /* 15 */					\
  "\xff\xff\xff\xff\xff" /* 20 */					\
  "\xff\xff\xff\xff\xff" /* 25 */					\
  "\xff\xff\xff\xff\xff" /* 30 */					\
  "\xff\xff\xff\xff\xff" /* 35 */					\
  "\xff\xff\xff\x3e\xff" /* 40 */					\
  "\xff\xff\x3f\x34\x35" /* 45 */					\
  "\x36\x37\x38\x39\x3a" /* 50 */					\
  "\x3b\x3c\x3d\xff\xff" /* 55 */					\
  "\xff\xff\xff\xff\xff" /* 60 */					\
  "\x00\x01\x02\x03\x04" /* 65 A */					\
  "\x05\x06\x07\x08\x09" /* 70 */					\
  "\x0a\x0b\x0c\x0d\x0e" /* 75 */					\
  "\x0f\x10\x11\x12\x13" /* 80 */					\
  "\x14\x15\x16\x17\x18" /* 85 */					\
  "\x19\xff\xff\xff\xff" /* 90 */					\
  "\xff\xff\x1a\x1b\x1c" /* 95 */					\
  "\x1d\x1e\x1f\x20\x21" /* 100 */					\
  "\x22\x23\x24\x25\x26" /* 105 */					\
  "\x27\x28\x29\x2a\x2b" /* 110 */					\
  "\x2c\x2d\x2e\x2f\x30" /* 115 */					\
  "\x31\x32\x33\xff\xff" /* 120 */					\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 125 */			\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 155 */			\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 185 */			\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 215 */			\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 245 */
};