Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
8b6e4f2d SW |
2 | |
3 | #include <linux/errno.h> | |
4 | ||
cd84db6e YS |
5 | int ceph_armor(char *dst, const char *src, const char *end); |
6 | int ceph_unarmor(char *dst, const char *src, const char *end); | |
7 | ||
8b6e4f2d SW |
8 | /* |
9 | * base64 encode/decode. | |
10 | */ | |
11 | ||
cd84db6e YS |
12 | static const char *pem_key = |
13 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
8b6e4f2d SW |
14 | |
15 | static int encode_bits(int c) | |
16 | { | |
17 | return pem_key[c]; | |
18 | } | |
19 | ||
20 | static int decode_bits(char c) | |
21 | { | |
22 | if (c >= 'A' && c <= 'Z') | |
23 | return c - 'A'; | |
24 | if (c >= 'a' && c <= 'z') | |
25 | return c - 'a' + 26; | |
26 | if (c >= '0' && c <= '9') | |
27 | return c - '0' + 52; | |
28 | if (c == '+') | |
29 | return 62; | |
30 | if (c == '/') | |
31 | return 63; | |
32 | if (c == '=') | |
33 | return 0; /* just non-negative, please */ | |
34 | return -EINVAL; | |
35 | } | |
36 | ||
37 | int ceph_armor(char *dst, const char *src, const char *end) | |
38 | { | |
39 | int olen = 0; | |
40 | int line = 0; | |
41 | ||
42 | while (src < end) { | |
43 | unsigned char a, b, c; | |
44 | ||
45 | a = *src++; | |
46 | *dst++ = encode_bits(a >> 2); | |
47 | if (src < end) { | |
48 | b = *src++; | |
49 | *dst++ = encode_bits(((a & 3) << 4) | (b >> 4)); | |
50 | if (src < end) { | |
51 | c = *src++; | |
52 | *dst++ = encode_bits(((b & 15) << 2) | | |
53 | (c >> 6)); | |
54 | *dst++ = encode_bits(c & 63); | |
55 | } else { | |
56 | *dst++ = encode_bits((b & 15) << 2); | |
57 | *dst++ = '='; | |
58 | } | |
59 | } else { | |
60 | *dst++ = encode_bits(((a & 3) << 4)); | |
61 | *dst++ = '='; | |
62 | *dst++ = '='; | |
63 | } | |
64 | olen += 4; | |
65 | line += 4; | |
66 | if (line == 64) { | |
67 | line = 0; | |
68 | *(dst++) = '\n'; | |
69 | olen++; | |
70 | } | |
71 | } | |
72 | return olen; | |
73 | } | |
74 | ||
75 | int ceph_unarmor(char *dst, const char *src, const char *end) | |
76 | { | |
77 | int olen = 0; | |
78 | ||
79 | while (src < end) { | |
80 | int a, b, c, d; | |
81 | ||
b09734b1 | 82 | if (src[0] == '\n') { |
8b6e4f2d | 83 | src++; |
b09734b1 TV |
84 | continue; |
85 | } | |
8b6e4f2d SW |
86 | if (src + 4 > end) |
87 | return -EINVAL; | |
88 | a = decode_bits(src[0]); | |
89 | b = decode_bits(src[1]); | |
90 | c = decode_bits(src[2]); | |
91 | d = decode_bits(src[3]); | |
92 | if (a < 0 || b < 0 || c < 0 || d < 0) | |
93 | return -EINVAL; | |
94 | ||
95 | *dst++ = (a << 2) | (b >> 4); | |
96 | if (src[2] == '=') | |
97 | return olen + 1; | |
98 | *dst++ = ((b & 15) << 4) | (c >> 2); | |
99 | if (src[3] == '=') | |
100 | return olen + 2; | |
101 | *dst++ = ((c & 3) << 6) | d; | |
102 | olen += 3; | |
103 | src += 4; | |
104 | } | |
105 | return olen; | |
106 | } |