Annotation of embedaddon/lighttpd/src/base64.c, revision 1.1
1.1 ! misho 1: #include "first.h"
! 2:
! 3: #include "base64.h"
! 4:
! 5: /* reverse mapping:
! 6: * >= 0: base64 value
! 7: * -1: invalid character
! 8: * -2: skip character (whitespace/control)
! 9: * -3: padding
! 10: */
! 11:
! 12: /* BASE64_STANDARD: "A-Z a-z 0-9 + /" maps to 0-63, pad with "=" */
! 13: static const char base64_standard_table[66] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
! 14: static const short base64_standard_reverse_table[128] = {
! 15: /* 0 1 2 3 4 5 6 7 8 9 A B C D E F */
! 16: -1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, /* 0x00 - 0x0F */
! 17: -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, /* 0x10 - 0x1F */
! 18: -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, /* 0x20 - 0x2F */
! 19: 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -3, -1, -1, /* 0x30 - 0x3F */
! 20: -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 0x40 - 0x4F */
! 21: 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, /* 0x50 - 0x5F */
! 22: -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 0x60 - 0x6F */
! 23: 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, /* 0x70 - 0x7F */
! 24: };
! 25:
! 26: /* BASE64_URL: "A-Z a-z 0-9 - _" maps to 0-63, pad with "." */
! 27: static const char base64_url_table[66] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.";
! 28: static const short base64_url_reverse_table[128] = {
! 29: /* 0 1 2 3 4 5 6 7 8 9 A B C D E F */
! 30: -1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, /* 0x00 - 0x0F */
! 31: -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, /* 0x10 - 0x1F */
! 32: -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -3, -1, /* 0x20 - 0x2F */
! 33: 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, /* 0x30 - 0x3F */
! 34: -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 0x40 - 0x4F */
! 35: 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63, /* 0x50 - 0x5F */
! 36: -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 0x60 - 0x6F */
! 37: 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, /* 0x70 - 0x7F */
! 38: };
! 39:
! 40: unsigned char* buffer_append_base64_decode(buffer *out, const char* in, size_t in_length, base64_charset charset) {
! 41: unsigned char *result;
! 42: size_t out_pos = 0; /* current output character (position) that is decoded. can contain partial result */
! 43: unsigned int group = 0; /* how many base64 digits in the current group were decoded already. each group has up to 4 digits */
! 44: size_t i;
! 45: const short* base64_reverse_table;
! 46:
! 47: switch (charset) {
! 48: case BASE64_STANDARD:
! 49: base64_reverse_table = base64_standard_reverse_table;
! 50: break;
! 51: case BASE64_URL:
! 52: base64_reverse_table = base64_url_reverse_table;
! 53: break;
! 54: default:
! 55: return NULL;
! 56: }
! 57:
! 58: result = (unsigned char *) buffer_string_prepare_append(out, 3*(in_length / 4) + 3);
! 59:
! 60: /* run through the whole string, converting as we go */
! 61: for (i = 0; i < in_length; i++) {
! 62: unsigned char c = (unsigned char) in[i];
! 63: short ch;
! 64:
! 65: if (c == '\0') break;
! 66: if (c >= 128) return NULL; /* only 7-bit characters allowed */
! 67:
! 68: ch = base64_reverse_table[c];
! 69: if (-3 == ch) {
! 70: /* pad character; can only come after 2 base64 digits in a group */
! 71: if (group < 2) return NULL;
! 72: break;
! 73: } else if (-2 == ch) {
! 74: continue; /* skip character */
! 75: } else if (ch < 0) {
! 76: return NULL; /* invalid character, abort */
! 77: }
! 78:
! 79: switch(group) {
! 80: case 0:
! 81: result[out_pos] = ch << 2;
! 82: group = 1;
! 83: break;
! 84: case 1:
! 85: result[out_pos++] |= ch >> 4;
! 86: result[out_pos] = (ch & 0x0f) << 4;
! 87: group = 2;
! 88: break;
! 89: case 2:
! 90: result[out_pos++] |= ch >>2;
! 91: result[out_pos] = (ch & 0x03) << 6;
! 92: group = 3;
! 93: break;
! 94: case 3:
! 95: result[out_pos++] |= ch;
! 96: group = 0;
! 97: break;
! 98: }
! 99: }
! 100:
! 101: switch(group) {
! 102: case 0:
! 103: /* ended on boundary */
! 104: break;
! 105: case 1:
! 106: /* need at least 2 base64 digits per group */
! 107: return NULL;
! 108: case 2:
! 109: /* have 2 base64 digits in last group => one real octect, two zeroes padded */
! 110: case 3:
! 111: /* have 3 base64 digits in last group => two real octects, one zero padded */
! 112:
! 113: /* for both cases the current index already is on the first zero padded octet
! 114: * - check it really is zero (overlapping bits) */
! 115: if (0 != result[out_pos]) return NULL;
! 116: break;
! 117: }
! 118:
! 119: buffer_commit(out, out_pos);
! 120:
! 121: return result;
! 122: }
! 123:
! 124: size_t li_to_base64_no_padding(char* out, size_t out_length, const unsigned char* in, size_t in_length, base64_charset charset) {
! 125: const size_t full_tuples = in_length / 3;
! 126: const size_t in_tuple_remainder = in_length % 3;
! 127: const size_t out_tuple_remainder = in_tuple_remainder ? 1 + in_tuple_remainder : 0;
! 128: const size_t require_space = 4 * full_tuples + out_tuple_remainder;
! 129: const char* base64_table;
! 130: size_t i;
! 131: size_t out_pos = 0;
! 132:
! 133: switch (charset) {
! 134: case BASE64_STANDARD:
! 135: base64_table = base64_standard_table;
! 136: break;
! 137: case BASE64_URL:
! 138: base64_table = base64_url_table;
! 139: break;
! 140: default:
! 141: force_assert(0 && "invalid charset");
! 142: }
! 143:
! 144: /* check overflows */
! 145: force_assert(full_tuples <= 2*full_tuples);
! 146: force_assert(full_tuples <= 4*full_tuples);
! 147: force_assert(4*full_tuples <= 4*full_tuples + out_tuple_remainder);
! 148: force_assert(require_space <= out_length);
! 149:
! 150: for (i = 2; i < in_length; i += 3) {
! 151: unsigned int v = (in[i-2] << 16) | (in[i-1] << 8) | in[i];
! 152: out[out_pos+3] = base64_table[v & 0x3f]; v >>= 6;
! 153: out[out_pos+2] = base64_table[v & 0x3f]; v >>= 6;
! 154: out[out_pos+1] = base64_table[v & 0x3f]; v >>= 6;
! 155: out[out_pos+0] = base64_table[v & 0x3f];
! 156: out_pos += 4;
! 157: }
! 158: switch (in_tuple_remainder) {
! 159: case 0:
! 160: break;
! 161: case 1:
! 162: {
! 163: /* pretend in[i-1] = in[i] = 0, don't write last two (out_pos+3, out_pos+2) characters */
! 164: unsigned int v = (in[i-2] << 4);
! 165: out[out_pos+1] = base64_table[v & 0x3f]; v >>= 6;
! 166: out[out_pos+0] = base64_table[v & 0x3f];
! 167: out_pos += 2;
! 168: }
! 169: break;
! 170: case 2:
! 171: {
! 172: /* pretend in[i] = 0, don't write last (out_pos+3) character */
! 173: unsigned int v = (in[i-2] << 10) | (in[i-1] << 2);
! 174: out[out_pos+2] = base64_table[v & 0x3f]; v >>= 6;
! 175: out[out_pos+1] = base64_table[v & 0x3f]; v >>= 6;
! 176: out[out_pos+0] = base64_table[v & 0x3f];
! 177: out_pos += 3;
! 178: }
! 179: break;
! 180: }
! 181: force_assert(out_pos <= out_length);
! 182: return out_pos;
! 183: }
! 184:
! 185: size_t li_to_base64(char* out, size_t out_length, const unsigned char* in, size_t in_length, base64_charset charset) {
! 186: const size_t in_tuple_remainder = in_length % 3;
! 187: size_t padding_length = in_tuple_remainder ? 3 - in_tuple_remainder : 0;
! 188:
! 189: char padding;
! 190: size_t out_pos;
! 191:
! 192: switch (charset) {
! 193: case BASE64_STANDARD:
! 194: padding = base64_standard_table[64];
! 195: break;
! 196: case BASE64_URL:
! 197: padding = base64_url_table[64];
! 198: break;
! 199: default:
! 200: force_assert(0 && "invalid charset");
! 201: }
! 202:
! 203: force_assert(out_length >= padding_length);
! 204: out_pos = li_to_base64_no_padding(out, out_length - padding_length, in, in_length, charset);
! 205:
! 206: while (padding_length > 0) {
! 207: out[out_pos++] = padding;
! 208: padding_length--;
! 209: }
! 210:
! 211: force_assert(out_pos <= out_length);
! 212:
! 213: return out_pos;
! 214: }
! 215:
! 216:
! 217: char* buffer_append_base64_encode_no_padding(buffer *out, const unsigned char* in, size_t in_length, base64_charset charset) {
! 218: size_t reserve = 4*(in_length/3) + 4;
! 219: char* result = buffer_string_prepare_append(out, reserve);
! 220: size_t out_pos = li_to_base64_no_padding(result, reserve, in, in_length, charset);
! 221:
! 222: buffer_commit(out, out_pos);
! 223:
! 224: return result;
! 225: }
! 226:
! 227: char* buffer_append_base64_encode(buffer *out, const unsigned char* in, size_t in_length, base64_charset charset) {
! 228: size_t reserve = 4*(in_length/3) + 4;
! 229: char* result = buffer_string_prepare_append(out, reserve);
! 230: size_t out_pos = li_to_base64(result, reserve, in, in_length, charset);
! 231:
! 232: buffer_commit(out, out_pos);
! 233:
! 234: return result;
! 235: }
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to base64.c CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / lighttpd / src