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| #include "cache.h" | |
| #undef DEBUG_85 | |
| #ifdef DEBUG_85 | |
| #define say(a) fprintf(stderr, a) | |
| #define say1(a,b) fprintf(stderr, a, b) | |
| #define say2(a,b,c) fprintf(stderr, a, b, c) | |
| #else | |
| #define say(a) do { /* nothing */ } while (0) | |
| #define say1(a,b) do { /* nothing */ } while (0) | |
| #define say2(a,b,c) do { /* nothing */ } while (0) | |
| #endif | |
| static const char en85[] = { | |
| '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', | |
| 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', | |
| 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', | |
| 'U', 'V', 'W', 'X', 'Y', 'Z', | |
| 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', | |
| 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', | |
| 'u', 'v', 'w', 'x', 'y', 'z', | |
| '!', '#', '$', '%', '&', '(', ')', '*', '+', '-', | |
| ';', '<', '=', '>', '?', '@', '^', '_', '`', '{', | |
| '|', '}', '~' | |
| }; | |
| static char de85[256]; | |
| static void prep_base85(void) | |
| { | |
| int i; | |
| if (de85['Z']) | |
| return; | |
| for (i = 0; i < ARRAY_SIZE(en85); i++) { | |
| int ch = en85[i]; | |
| de85[ch] = i + 1; | |
| } | |
| } | |
| int decode_85(char *dst, const char *buffer, int len) | |
| { | |
| prep_base85(); | |
| say2("decode 85 <%.*s>", len / 4 * 5, buffer); | |
| while (len) { | |
| unsigned acc = 0; | |
| int de, cnt = 4; | |
| unsigned char ch; | |
| do { | |
| ch = *buffer++; | |
| de = de85[ch]; | |
| if (--de < 0) | |
| return error("invalid base85 alphabet %c", ch); | |
| acc = acc * 85 + de; | |
| } while (--cnt); | |
| ch = *buffer++; | |
| de = de85[ch]; | |
| if (--de < 0) | |
| return error("invalid base85 alphabet %c", ch); | |
| /* Detect overflow. */ | |
| if (0xffffffff / 85 < acc || | |
| 0xffffffff - de < (acc *= 85)) | |
| return error("invalid base85 sequence %.5s", buffer-5); | |
| acc += de; | |
| say1(" %08x", acc); | |
| cnt = (len < 4) ? len : 4; | |
| len -= cnt; | |
| do { | |
| acc = (acc << 8) | (acc >> 24); | |
| *dst++ = acc; | |
| } while (--cnt); | |
| } | |
| say("\n"); | |
| return 0; | |
| } | |
| void encode_85(char *buf, const unsigned char *data, int bytes) | |
| { | |
| say("encode 85"); | |
| while (bytes) { | |
| unsigned acc = 0; | |
| int cnt; | |
| for (cnt = 24; cnt >= 0; cnt -= 8) { | |
| unsigned ch = *data++; | |
| acc |= ch << cnt; | |
| if (--bytes == 0) | |
| break; | |
| } | |
| say1(" %08x", acc); | |
| for (cnt = 4; cnt >= 0; cnt--) { | |
| int val = acc % 85; | |
| acc /= 85; | |
| buf[cnt] = en85[val]; | |
| } | |
| buf += 5; | |
| } | |
| say("\n"); | |
| *buf = 0; | |
| } | |
| #ifdef DEBUG_85 | |
| int main(int ac, char **av) | |
| { | |
| char buf[1024]; | |
| if (!strcmp(av[1], "-e")) { | |
| int len = strlen(av[2]); | |
| encode_85(buf, av[2], len); | |
| if (len <= 26) len = len + 'A' - 1; | |
| else len = len + 'a' - 26 - 1; | |
| printf("encoded: %c%s\n", len, buf); | |
| return 0; | |
| } | |
| if (!strcmp(av[1], "-d")) { | |
| int len = *av[2]; | |
| if ('A' <= len && len <= 'Z') len = len - 'A' + 1; | |
| else len = len - 'a' + 26 + 1; | |
| decode_85(buf, av[2]+1, len); | |
| printf("decoded: %.*s\n", len, buf); | |
| return 0; | |
| } | |
| if (!strcmp(av[1], "-t")) { | |
| char t[4] = { -1,-1,-1,-1 }; | |
| encode_85(buf, t, 4); | |
| printf("encoded: D%s\n", buf); | |
| return 0; | |
| } | |
| } | |
| #endif |