/* * Build a filter for reading raw stream data. * This is a null filter to constrain reading to the * stream length, followed by a decryption filter. */ static fz_error * buildrawfilter(fz_filter **filterp, pdf_xref *xref, fz_obj *stmobj, int oid, int gen) { fz_error *error; fz_filter *base; fz_obj *stmlen; int len; stmlen = fz_dictgets(stmobj, "Length"); error = pdf_resolve(&stmlen, xref); if (error) return fz_rethrow(error, "cannot resolve stream /Length"); len = fz_toint(stmlen); fz_dropobj(stmlen); error = fz_newnullfilter(&base, len); if (error) return fz_rethrow(error, "cannot create null filter"); if (xref->crypt) { fz_filter *crypt; fz_filter *pipe; error = pdf_cryptstream(&crypt, xref->crypt, oid, gen); if (error) { fz_dropfilter(base); return fz_rethrow(error, "cannot create decryption filter"); } error = fz_newpipeline(&pipe, base, crypt); fz_dropfilter(base); fz_dropfilter(crypt); if (error) return fz_rethrow(error, "cannot create pipeline filter"); *filterp = pipe; } else { *filterp = base; } return fz_okay; }
static fz_error * writestream(fz_stream *out, pdf_xref *xref, pdf_crypt *encrypt, int oid, int gen) { fz_error *error; fz_stream *dststm; fz_stream *srcstm; unsigned char buf[4096]; fz_filter *ef; int n; fz_print(out, "stream\n"); if (encrypt) { error = pdf_cryptstream(&ef, encrypt, oid, gen); if (error) return error; error = fz_openrfilter(&dststm, ef, out); fz_dropfilter(ef); if (error) return error; } else { dststm = fz_keepstream(out); } error = pdf_openrawstream(&srcstm, xref, oid, gen); if (error) goto cleanupdst; while (1) { n = fz_read(srcstm, buf, sizeof buf); if (n == 0) break; if (n < 0) { error = fz_ioerror(srcstm); goto cleanupsrc; } n = fz_write(dststm, buf, n); if (n < 0) { error = fz_ioerror(dststm); goto cleanupsrc; } } fz_dropstream(srcstm); fz_dropstream(dststm); fz_print(out, "endstream\n"); return nil; cleanupsrc: fz_dropstream(srcstm); cleanupdst: fz_dropstream(dststm); return error; }