1
2 #include <linux/errno.h>
3
4 int ceph_armor(char *dst, const char *src, const char *end);
5 int ceph_unarmor(char *dst, const char *src, const char *end);
6
7 /*
8 * base64 encode/decode.
9 */
10
11 static const char *pem_key =
12 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
13
14 static int encode_bits(int c)
15 {
16 return pem_key[c];
17 }
18
19 static int decode_bits(char c)
20 {
21 if (c >= 'A' && c <= 'Z')
22 return c - 'A';
23 if (c >= 'a' && c <= 'z')
24 return c - 'a' + 26;
25 if (c >= '' && c <= '9')
26 return c - '' + 52;
27 if (c == '+')
28 return 62;
29 if (c == '/')
30 return 63;
31 if (c == '=')
32 return 0; /* just non-negative, please */
33 return -EINVAL;
34 }
35
36 int ceph_armor(char *dst, const char *src, const char *end)
37 {
38 int olen = 0;
39 int line = 0;
40
41 while (src < end) {
42 unsigned char a, b, c;
43
44 a = *src++;
45 *dst++ = encode_bits(a >> 2);
46 if (src < end) {
47 b = *src++;
48 *dst++ = encode_bits(((a & 3) << 4) | (b >> 4));
49 if (src < end) {
50 c = *src++;
51 *dst++ = encode_bits(((b & 15) << 2) |
52 (c >> 6));
53 *dst++ = encode_bits(c & 63);
54 } else {
55 *dst++ = encode_bits((b & 15) << 2);
56 *dst++ = '=';
57 }
58 } else {
59 *dst++ = encode_bits(((a & 3) << 4));
60 *dst++ = '=';
61 *dst++ = '=';
62 }
63 olen += 4;
64 line += 4;
65 if (line == 64) {
66 line = 0;
67 *(dst++) = '\n';
68 olen++;
69 }
70 }
71 return olen;
72 }
73
74 int ceph_unarmor(char *dst, const char *src, const char *end)
75 {
76 int olen = 0;
77
78 while (src < end) {
79 int a, b, c, d;
80
81 if (src[0] == '\n') {
82 src++;
83 continue;
84 }
85 if (src + 4 > end)
86 return -EINVAL;
87 a = decode_bits(src[0]);
88 b = decode_bits(src[1]);
89 c = decode_bits(src[2]);
90 d = decode_bits(src[3]);
91 if (a < 0 || b < 0 || c < 0 || d < 0)
92 return -EINVAL;
93
94 *dst++ = (a << 2) | (b >> 4);
95 if (src[2] == '=')
96 return olen + 1;
97 *dst++ = ((b & 15) << 4) | (c >> 2);
98 if (src[3] == '=')
99 return olen + 2;
100 *dst++ = ((c & 3) << 6) | d;
101 olen += 3;
102 src += 4;
103 }
104 return olen;
105 }
106
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