tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1
2#include <linux/errno.h>
3
4/*
5 * base64 encode/decode.
6 */
7
8const char *pem_key = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
9
10static int encode_bits(int c)
11{
12 return pem_key[c];
13}
14
15static int decode_bits(char c)
16{
17 if (c >= 'A' && c <= 'Z')
18 return c - 'A';
19 if (c >= 'a' && c <= 'z')
20 return c - 'a' + 26;
21 if (c >= '0' && c <= '9')
22 return c - '0' + 52;
23 if (c == '+')
24 return 62;
25 if (c == '/')
26 return 63;
27 if (c == '=')
28 return 0; /* just non-negative, please */
29 return -EINVAL;
30}
31
32int ceph_armor(char *dst, const char *src, const char *end)
33{
34 int olen = 0;
35 int line = 0;
36
37 while (src < end) {
38 unsigned char a, b, c;
39
40 a = *src++;
41 *dst++ = encode_bits(a >> 2);
42 if (src < end) {
43 b = *src++;
44 *dst++ = encode_bits(((a & 3) << 4) | (b >> 4));
45 if (src < end) {
46 c = *src++;
47 *dst++ = encode_bits(((b & 15) << 2) |
48 (c >> 6));
49 *dst++ = encode_bits(c & 63);
50 } else {
51 *dst++ = encode_bits((b & 15) << 2);
52 *dst++ = '=';
53 }
54 } else {
55 *dst++ = encode_bits(((a & 3) << 4));
56 *dst++ = '=';
57 *dst++ = '=';
58 }
59 olen += 4;
60 line += 4;
61 if (line == 64) {
62 line = 0;
63 *(dst++) = '\n';
64 olen++;
65 }
66 }
67 return olen;
68}
69
70int ceph_unarmor(char *dst, const char *src, const char *end)
71{
72 int olen = 0;
73
74 while (src < end) {
75 int a, b, c, d;
76
77 if (src < end && src[0] == '\n')
78 src++;
79 if (src + 4 > end)
80 return -EINVAL;
81 a = decode_bits(src[0]);
82 b = decode_bits(src[1]);
83 c = decode_bits(src[2]);
84 d = decode_bits(src[3]);
85 if (a < 0 || b < 0 || c < 0 || d < 0)
86 return -EINVAL;
87
88 *dst++ = (a << 2) | (b >> 4);
89 if (src[2] == '=')
90 return olen + 1;
91 *dst++ = ((b & 15) << 4) | (c >> 2);
92 if (src[3] == '=')
93 return olen + 2;
94 *dst++ = ((c & 3) << 6) | d;
95 olen += 3;
96 src += 4;
97 }
98 return olen;
99}