505 lines
8.6 KiB
C
505 lines
8.6 KiB
C
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#include "fitz.h"
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/* Pretend we have a filter that just copies data forever */
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fz_stream *
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fz_open_copy(fz_stream *chain)
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{
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return fz_keep_stream(chain);
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}
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/* Null filter copies a specified amount of data */
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struct null_filter
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{
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fz_stream *chain;
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int remain;
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};
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static int
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read_null(fz_stream *stm, unsigned char *buf, int len)
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{
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struct null_filter *state = stm->state;
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int amount = MIN(len, state->remain);
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int n = fz_read(state->chain, buf, amount);
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if (n < 0)
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return fz_rethrow(n, "read error in null filter");
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state->remain -= n;
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return n;
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}
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static void
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close_null(fz_stream *stm)
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{
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struct null_filter *state = stm->state;
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fz_close(state->chain);
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fz_free(state);
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}
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fz_stream *
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fz_open_null(fz_stream *chain, int len)
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{
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struct null_filter *state;
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state = fz_malloc(sizeof(struct null_filter));
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state->chain = chain;
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state->remain = len;
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return fz_new_stream(state, read_null, close_null);
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}
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/* ASCII Hex Decode */
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typedef struct fz_ahxd_s fz_ahxd;
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struct fz_ahxd_s
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{
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fz_stream *chain;
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int eod;
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};
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static inline int iswhite(int a)
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{
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switch (a) {
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case '\n': case '\r': case '\t': case ' ':
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case '\0': case '\f': case '\b': case 0177:
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return 1;
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}
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return 0;
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}
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static inline int ishex(int a)
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{
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return (a >= 'A' && a <= 'F') ||
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(a >= 'a' && a <= 'f') ||
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(a >= '0' && a <= '9');
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}
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static inline int unhex(int a)
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{
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if (a >= 'A' && a <= 'F') return a - 'A' + 0xA;
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if (a >= 'a' && a <= 'f') return a - 'a' + 0xA;
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if (a >= '0' && a <= '9') return a - '0';
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return 0;
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}
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static int
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read_ahxd(fz_stream *stm, unsigned char *buf, int len)
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{
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fz_ahxd *state = stm->state;
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unsigned char *p = buf;
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unsigned char *ep = buf + len;
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int a, b, c, odd;
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odd = 0;
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while (p < ep)
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{
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if (state->eod)
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return p - buf;
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c = fz_read_byte(state->chain);
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if (c < 0)
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return p - buf;
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if (ishex(c))
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{
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if (!odd)
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{
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a = unhex(c);
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odd = 1;
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}
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else
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{
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b = unhex(c);
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*p++ = (a << 4) | b;
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odd = 0;
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}
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}
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else if (c == '>')
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{
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if (odd)
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*p++ = (a << 4);
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state->eod = 1;
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}
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else if (!iswhite(c))
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{
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return fz_throw("bad data in ahxd: '%c'", c);
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}
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}
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return p - buf;
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}
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static void
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close_ahxd(fz_stream *stm)
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{
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fz_ahxd *state = stm->state;
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fz_close(state->chain);
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fz_free(state);
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}
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fz_stream *
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fz_open_ahxd(fz_stream *chain)
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{
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fz_ahxd *state;
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state = fz_malloc(sizeof(fz_ahxd));
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state->chain = chain;
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state->eod = 0;
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return fz_new_stream(state, read_ahxd, close_ahxd);
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}
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/* ASCII 85 Decode */
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typedef struct fz_a85d_s fz_a85d;
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struct fz_a85d_s
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{
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fz_stream *chain;
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unsigned char bp[4];
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unsigned char *rp, *wp;
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int eod;
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};
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static int
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read_a85d(fz_stream *stm, unsigned char *buf, int len)
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{
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fz_a85d *state = stm->state;
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unsigned char *p = buf;
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unsigned char *ep = buf + len;
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int count = 0;
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int word = 0;
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int c;
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while (state->rp < state->wp && p < ep)
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*p++ = *state->rp++;
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while (p < ep)
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{
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if (state->eod)
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return p - buf;
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c = fz_read_byte(state->chain);
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if (c < 0)
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return p - buf;
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if (c >= '!' && c <= 'u')
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{
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if (count == 4)
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{
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word = word * 85 + (c - '!');
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state->bp[0] = (word >> 24) & 0xff;
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state->bp[1] = (word >> 16) & 0xff;
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state->bp[2] = (word >> 8) & 0xff;
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state->bp[3] = (word) & 0xff;
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state->rp = state->bp;
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state->wp = state->bp + 4;
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word = 0;
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count = 0;
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}
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else
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{
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word = word * 85 + (c - '!');
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count ++;
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}
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}
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else if (c == 'z' && count == 0)
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{
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state->bp[0] = 0;
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state->bp[1] = 0;
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state->bp[2] = 0;
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state->bp[3] = 0;
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state->rp = state->bp;
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state->wp = state->bp + 4;
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}
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else if (c == '~')
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{
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c = fz_read_byte(state->chain);
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if (c != '>')
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fz_warn("bad eod marker in a85d");
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switch (count) {
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case 0:
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break;
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case 1:
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return fz_throw("partial final byte in a85d");
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case 2:
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word = word * (85 * 85 * 85) + 0xffffff;
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state->bp[0] = word >> 24;
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state->rp = state->bp;
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state->wp = state->bp + 1;
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break;
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case 3:
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word = word * (85 * 85) + 0xffff;
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state->bp[0] = word >> 24;
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state->bp[1] = word >> 16;
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state->rp = state->bp;
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state->wp = state->bp + 2;
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break;
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case 4:
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word = word * 85 + 0xff;
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state->bp[0] = word >> 24;
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state->bp[1] = word >> 16;
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state->bp[2] = word >> 8;
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state->rp = state->bp;
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state->wp = state->bp + 3;
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break;
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}
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state->eod = 1;
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}
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else if (!iswhite(c))
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{
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return fz_throw("bad data in a85d: '%c'", c);
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}
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while (state->rp < state->wp && p < ep)
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*p++ = *state->rp++;
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}
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return p - buf;
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}
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static void
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close_a85d(fz_stream *stm)
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{
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fz_a85d *state = stm->state;
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fz_close(state->chain);
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fz_free(state);
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}
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fz_stream *
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fz_open_a85d(fz_stream *chain)
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{
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fz_a85d *state;
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state = fz_malloc(sizeof(fz_a85d));
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state->chain = chain;
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state->rp = state->bp;
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state->wp = state->bp;
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state->eod = 0;
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return fz_new_stream(state, read_a85d, close_a85d);
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}
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/* Run Length Decode */
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typedef struct fz_rld_s fz_rld;
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struct fz_rld_s
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{
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fz_stream *chain;
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int run, n, c;
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};
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static int
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read_rld(fz_stream *stm, unsigned char *buf, int len)
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{
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fz_rld *state = stm->state;
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unsigned char *p = buf;
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unsigned char *ep = buf + len;
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while (p < ep)
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{
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if (state->run == 128)
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return p - buf;
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if (state->n == 0)
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{
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state->run = fz_read_byte(state->chain);
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if (state->run < 0)
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state->run = 128;
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if (state->run < 128)
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state->n = state->run + 1;
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if (state->run > 128)
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{
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state->n = 257 - state->run;
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state->c = fz_read_byte(state->chain);
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if (state->c < 0)
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return fz_throw("premature end of data in run length decode");
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}
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}
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if (state->run < 128)
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{
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while (p < ep && state->n)
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{
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int c = fz_read_byte(state->chain);
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if (c < 0)
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return fz_throw("premature end of data in run length decode");
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*p++ = c;
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state->n--;
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}
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}
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if (state->run > 128)
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{
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while (p < ep && state->n)
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{
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*p++ = state->c;
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state->n--;
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}
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}
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}
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return p - buf;
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}
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static void
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close_rld(fz_stream *stm)
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{
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fz_rld *state = stm->state;
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fz_close(state->chain);
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fz_free(state);
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}
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fz_stream *
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fz_open_rld(fz_stream *chain)
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{
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fz_rld *state;
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state = fz_malloc(sizeof(fz_rld));
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state->chain = chain;
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state->run = 0;
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state->n = 0;
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state->c = 0;
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return fz_new_stream(state, read_rld, close_rld);
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}
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/* RC4 Filter */
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typedef struct fz_arc4c_s fz_arc4c;
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struct fz_arc4c_s
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{
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fz_stream *chain;
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fz_arc4 arc4;
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};
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static int
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read_arc4(fz_stream *stm, unsigned char *buf, int len)
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{
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fz_arc4c *state = stm->state;
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int n;
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n = fz_read(state->chain, buf, len);
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if (n < 0)
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return fz_rethrow(n, "read error in arc4 filter");
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fz_arc4_encrypt(&state->arc4, buf, buf, n);
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return n;
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}
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static void
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close_arc4(fz_stream *stm)
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{
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fz_arc4c *state = stm->state;
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fz_close(state->chain);
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fz_free(state);
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}
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fz_stream *
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fz_open_arc4(fz_stream *chain, unsigned char *key, unsigned keylen)
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{
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fz_arc4c *state;
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state = fz_malloc(sizeof(fz_arc4c));
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state->chain = chain;
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fz_arc4_init(&state->arc4, key, keylen);
|
||
|
|
|
||
|
|
return fz_new_stream(state, read_arc4, close_arc4);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* AES Filter */
|
||
|
|
|
||
|
|
typedef struct fz_aesd_s fz_aesd;
|
||
|
|
|
||
|
|
struct fz_aesd_s
|
||
|
|
{
|
||
|
|
fz_stream *chain;
|
||
|
|
fz_aes aes;
|
||
|
|
unsigned char iv[16];
|
||
|
|
int ivcount;
|
||
|
|
unsigned char bp[16];
|
||
|
|
unsigned char *rp, *wp;
|
||
|
|
};
|
||
|
|
|
||
|
|
static int
|
||
|
|
read_aesd(fz_stream *stm, unsigned char *buf, int len)
|
||
|
|
{
|
||
|
|
fz_aesd *state = stm->state;
|
||
|
|
unsigned char *p = buf;
|
||
|
|
unsigned char *ep = buf + len;
|
||
|
|
|
||
|
|
while (state->ivcount < 16)
|
||
|
|
{
|
||
|
|
int c = fz_read_byte(state->chain);
|
||
|
|
if (c < 0)
|
||
|
|
return fz_throw("premature end in aes filter");
|
||
|
|
state->iv[state->ivcount++] = c;
|
||
|
|
}
|
||
|
|
|
||
|
|
while (state->rp < state->wp && p < ep)
|
||
|
|
*p++ = *state->rp++;
|
||
|
|
|
||
|
|
while (p < ep)
|
||
|
|
{
|
||
|
|
int n = fz_read(state->chain, state->bp, 16);
|
||
|
|
if (n < 0)
|
||
|
|
return fz_rethrow(n, "read error in aes filter");
|
||
|
|
else if (n == 0)
|
||
|
|
return p - buf;
|
||
|
|
else if (n < 16)
|
||
|
|
return fz_throw("partial block in aes filter");
|
||
|
|
|
||
|
|
aes_crypt_cbc(&state->aes, AES_DECRYPT, 16, state->iv, state->bp, state->bp);
|
||
|
|
state->rp = state->bp;
|
||
|
|
state->wp = state->bp + 16;
|
||
|
|
|
||
|
|
/* strip padding at end of file */
|
||
|
|
if (fz_is_eof(state->chain))
|
||
|
|
{
|
||
|
|
int pad = state->bp[15];
|
||
|
|
if (pad < 1 || pad > 16)
|
||
|
|
return fz_throw("aes padding out of range: %d", pad);
|
||
|
|
state->wp -= pad;
|
||
|
|
}
|
||
|
|
|
||
|
|
while (state->rp < state->wp && p < ep)
|
||
|
|
*p++ = *state->rp++;
|
||
|
|
}
|
||
|
|
|
||
|
|
return p - buf;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void
|
||
|
|
close_aesd(fz_stream *stm)
|
||
|
|
{
|
||
|
|
fz_aesd *state = stm->state;
|
||
|
|
fz_close(state->chain);
|
||
|
|
fz_free(state);
|
||
|
|
}
|
||
|
|
|
||
|
|
fz_stream *
|
||
|
|
fz_open_aesd(fz_stream *chain, unsigned char *key, unsigned keylen)
|
||
|
|
{
|
||
|
|
fz_aesd *state;
|
||
|
|
|
||
|
|
state = fz_malloc(sizeof(fz_aesd));
|
||
|
|
state->chain = chain;
|
||
|
|
aes_setkey_dec(&state->aes, key, keylen * 8);
|
||
|
|
state->ivcount = 0;
|
||
|
|
state->rp = state->bp;
|
||
|
|
state->wp = state->bp;
|
||
|
|
|
||
|
|
return fz_new_stream(state, read_aesd, close_aesd);
|
||
|
|
}
|