1 // SPDX-License-Identifier: GPL-2.0 <<
2 1
3 #include <linux/errno.h> 2 #include <linux/errno.h>
4 3
5 int ceph_armor(char *dst, const char *src, con 4 int ceph_armor(char *dst, const char *src, const char *end);
6 int ceph_unarmor(char *dst, const char *src, c 5 int ceph_unarmor(char *dst, const char *src, const char *end);
7 6
8 /* 7 /*
9 * base64 encode/decode. 8 * base64 encode/decode.
10 */ 9 */
11 10
12 static const char *pem_key = 11 static const char *pem_key =
13 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijk 12 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
14 13
15 static int encode_bits(int c) 14 static int encode_bits(int c)
16 { 15 {
17 return pem_key[c]; 16 return pem_key[c];
18 } 17 }
19 18
20 static int decode_bits(char c) 19 static int decode_bits(char c)
21 { 20 {
22 if (c >= 'A' && c <= 'Z') 21 if (c >= 'A' && c <= 'Z')
23 return c - 'A'; 22 return c - 'A';
24 if (c >= 'a' && c <= 'z') 23 if (c >= 'a' && c <= 'z')
25 return c - 'a' + 26; 24 return c - 'a' + 26;
26 if (c >= '' && c <= '9') 25 if (c >= '' && c <= '9')
27 return c - '' + 52; 26 return c - '' + 52;
28 if (c == '+') 27 if (c == '+')
29 return 62; 28 return 62;
30 if (c == '/') 29 if (c == '/')
31 return 63; 30 return 63;
32 if (c == '=') 31 if (c == '=')
33 return 0; /* just non-negative 32 return 0; /* just non-negative, please */
34 return -EINVAL; 33 return -EINVAL;
35 } 34 }
36 35
37 int ceph_armor(char *dst, const char *src, con 36 int ceph_armor(char *dst, const char *src, const char *end)
38 { 37 {
39 int olen = 0; 38 int olen = 0;
40 int line = 0; 39 int line = 0;
41 40
42 while (src < end) { 41 while (src < end) {
43 unsigned char a, b, c; 42 unsigned char a, b, c;
44 43
45 a = *src++; 44 a = *src++;
46 *dst++ = encode_bits(a >> 2); 45 *dst++ = encode_bits(a >> 2);
47 if (src < end) { 46 if (src < end) {
48 b = *src++; 47 b = *src++;
49 *dst++ = encode_bits(( 48 *dst++ = encode_bits(((a & 3) << 4) | (b >> 4));
50 if (src < end) { 49 if (src < end) {
51 c = *src++; 50 c = *src++;
52 *dst++ = encod 51 *dst++ = encode_bits(((b & 15) << 2) |
53 52 (c >> 6));
54 *dst++ = encod 53 *dst++ = encode_bits(c & 63);
55 } else { 54 } else {
56 *dst++ = encod 55 *dst++ = encode_bits((b & 15) << 2);
57 *dst++ = '='; 56 *dst++ = '=';
58 } 57 }
59 } else { 58 } else {
60 *dst++ = encode_bits(( 59 *dst++ = encode_bits(((a & 3) << 4));
61 *dst++ = '='; 60 *dst++ = '=';
62 *dst++ = '='; 61 *dst++ = '=';
63 } 62 }
64 olen += 4; 63 olen += 4;
65 line += 4; 64 line += 4;
66 if (line == 64) { 65 if (line == 64) {
67 line = 0; 66 line = 0;
68 *(dst++) = '\n'; 67 *(dst++) = '\n';
69 olen++; 68 olen++;
70 } 69 }
71 } 70 }
72 return olen; 71 return olen;
73 } 72 }
74 73
75 int ceph_unarmor(char *dst, const char *src, c 74 int ceph_unarmor(char *dst, const char *src, const char *end)
76 { 75 {
77 int olen = 0; 76 int olen = 0;
78 77
79 while (src < end) { 78 while (src < end) {
80 int a, b, c, d; 79 int a, b, c, d;
81 80
82 if (src[0] == '\n') { 81 if (src[0] == '\n') {
83 src++; 82 src++;
84 continue; 83 continue;
85 } 84 }
86 if (src + 4 > end) 85 if (src + 4 > end)
87 return -EINVAL; 86 return -EINVAL;
88 a = decode_bits(src[0]); 87 a = decode_bits(src[0]);
89 b = decode_bits(src[1]); 88 b = decode_bits(src[1]);
90 c = decode_bits(src[2]); 89 c = decode_bits(src[2]);
91 d = decode_bits(src[3]); 90 d = decode_bits(src[3]);
92 if (a < 0 || b < 0 || c < 0 || 91 if (a < 0 || b < 0 || c < 0 || d < 0)
93 return -EINVAL; 92 return -EINVAL;
94 93
95 *dst++ = (a << 2) | (b >> 4); 94 *dst++ = (a << 2) | (b >> 4);
96 if (src[2] == '=') 95 if (src[2] == '=')
97 return olen + 1; 96 return olen + 1;
98 *dst++ = ((b & 15) << 4) | (c 97 *dst++ = ((b & 15) << 4) | (c >> 2);
99 if (src[3] == '=') 98 if (src[3] == '=')
100 return olen + 2; 99 return olen + 2;
101 *dst++ = ((c & 3) << 6) | d; 100 *dst++ = ((c & 3) << 6) | d;
102 olen += 3; 101 olen += 3;
103 src += 4; 102 src += 4;
104 } 103 }
105 return olen; 104 return olen;
106 } 105 }
107 106
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