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 >= '0' && c <= '9') 26 return c - '0' + 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