1 | // SPDX-License-Identifier: GPL-2.0 |
2 | |
3 | #include <linux/errno.h> |
4 | |
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 | |
8 | /* |
9 | * base64 encode/decode. |
10 | */ |
11 | |
12 | static const char *pem_key = |
13 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" ; |
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(c: a >> 2); |
47 | if (src < end) { |
48 | b = *src++; |
49 | *dst++ = encode_bits(c: ((a & 3) << 4) | (b >> 4)); |
50 | if (src < end) { |
51 | c = *src++; |
52 | *dst++ = encode_bits(c: ((b & 15) << 2) | |
53 | (c >> 6)); |
54 | *dst++ = encode_bits(c: c & 63); |
55 | } else { |
56 | *dst++ = encode_bits(c: (b & 15) << 2); |
57 | *dst++ = '='; |
58 | } |
59 | } else { |
60 | *dst++ = encode_bits(c: ((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 | |
82 | if (src[0] == '\n') { |
83 | src++; |
84 | continue; |
85 | } |
86 | if (src + 4 > end) |
87 | return -EINVAL; |
88 | a = decode_bits(c: src[0]); |
89 | b = decode_bits(c: src[1]); |
90 | c = decode_bits(c: src[2]); |
91 | d = decode_bits(c: 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 | } |
107 | |