diff options
Diffstat (limited to 'apps/pdfclean.c')
| -rw-r--r-- | apps/pdfclean.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/apps/pdfclean.c b/apps/pdfclean.c new file mode 100644 index 00000000..7a8cc0fc --- /dev/null +++ b/apps/pdfclean.c @@ -0,0 +1,504 @@ +/* + * PDF cleaning tool: general purpose pdf syntax washer. + * + * Rewrite PDF with pretty printed objects. + * Garbage collect unreachable objects. + * Inflate compressed streams. + * Encrypt output. + */ + +#include "fitz.h" +#include "mupdf.h" + +static pdf_xref *xref = NULL; +static fz_obj *id = NULL; + +static pdf_crypt *outcrypt = NULL; +static FILE *out = NULL; + +static char *uselist = NULL; +static int *ofslist = NULL; +static int *genlist = NULL; + +int doencrypt = 0; +int dogarbage = 0; +int doexpand = 0; + +void die(fz_error *eo) +{ + fflush(stdout); + fz_printerror(eo); + fz_droperror(eo); + fflush(stderr); + exit(1); +} + +void openxref(char *filename, char *password) +{ + fz_error *error; + fz_obj *obj; + + error = pdf_newxref(&xref); + if (error) + die(error); + + error = pdf_loadxref(xref, filename); + if (error) + { + fz_printerror(error); + fz_droperror(error); + fz_warn("trying to repair"); + error = pdf_repairxref(xref, filename); + if (error) + die(error); + } + + error = pdf_decryptxref(xref); + if (error) + die(error); + + if (xref->crypt) + { + int okay = pdf_setpassword(xref->crypt, password); + if (!okay) + die(fz_throw("invalid password")); + } + + /* TODO: move into mupdf lib, see pdfapp_open in pdfapp.c */ + obj = fz_dictgets(xref->trailer, "Root"); + if (!obj) + die(error); + + error = pdf_loadindirect(&xref->root, xref, obj); + if (error) + die(error); + + obj = fz_dictgets(xref->trailer, "Info"); + if (obj) + { + error = pdf_loadindirect(&xref->info, xref, obj); + if (error) + die(error); + } +} + +/* + * Garbage collect objects not reachable from the trailer. + */ + +static fz_error *sweepref(pdf_xref *xref, fz_obj *ref); + +static fz_error *sweepobj(pdf_xref *xref, fz_obj *obj) +{ + fz_error *error; + int i; + + if (fz_isdict(obj)) + { + for (i = 0; i < fz_dictlen(obj); i++) + { + error = sweepobj(xref, fz_dictgetval(obj, i)); + if (error) + return error; /* too deeply nested for rethrow */ + } + } + + if (fz_isarray(obj)) + { + for (i = 0; i < fz_arraylen(obj); i++) + { + error = sweepobj(xref, fz_arrayget(obj, i)); + if (error) + return error; /* too deeply nested for rethrow */ + } + } + + if (fz_isindirect(obj)) + return sweepref(xref, obj); + + return fz_okay; +} + +static fz_error *sweepref(pdf_xref *xref, fz_obj *ref) +{ + fz_error *error; + fz_obj *obj; + fz_obj *len; + int oid, gen; + + oid = fz_tonum(ref); + gen = fz_tonum(ref); + + if (oid < 0 || oid >= xref->len) + return fz_throw("object out of range (%d %d R)", oid, gen); + + if (uselist[oid]) + return fz_okay; + + uselist[oid] = 1; + + error = pdf_loadindirect(&obj, xref, ref); + if (error) + return fz_rethrow(error, "cannot load indirect object"); + + /* Bake in /Length in stream objects */ + if (xref->table[oid].stmofs) + { + len = fz_dictgets(obj, "Length"); + if (fz_isindirect(len)) + { + pdf_loadindirect(&len, xref, len); + fz_dictputs(obj, "Length", len); + } + } + + error = sweepobj(xref, obj); + if (error) + { + fz_dropobj(obj); + return error; /* too deeply nested for rethrow */ + } + + fz_dropobj(obj); + return fz_okay; +} + +void preloadobjstms(void) +{ + fz_error *error; + fz_obj *obj; + int oid; + + for (oid = 0; oid < xref->len; oid++) + { + if (xref->table[oid].type == 'o') + { + error = pdf_loadobject(&obj, xref, oid, 0); + if (error) + die(error); + fz_dropobj(obj); + } + } +} + +void copystream(fz_obj *obj, int oid, int gen) +{ + fz_error *error; + fz_buffer *buf; + + error = pdf_loadrawstream(&buf, xref, oid, gen); + if (error) + die(error); + + if (doencrypt) + pdf_cryptbuffer(outcrypt, buf, oid, gen); + + fprintf(out, "%d %d obj\n", oid, gen); + if (doencrypt) + pdf_cryptobj(outcrypt, obj, oid, gen); + fz_fprintobj(out, obj, !doexpand); + if (doencrypt) + pdf_cryptobj(outcrypt, obj, oid, gen); + fprintf(out, "stream\n"); + fwrite(buf->rp, 1, buf->wp - buf->rp, out); + fprintf(out, "endstream\nendobj\n\n"); + + fz_dropbuffer(buf); +} + +void expandstream(fz_obj *obj, int oid, int gen) +{ + fz_error *error; + fz_buffer *buf; + fz_obj *newdict, *newlen; + + error = pdf_loadstream(&buf, xref, oid, gen); + if (error) + die(error); + + if (doencrypt) + pdf_cryptbuffer(outcrypt, buf, oid, gen); + + fz_copydict(&newdict, obj); + fz_dictdels(newdict, "Filter"); + fz_dictdels(newdict, "DecodeParms"); + + fz_newint(&newlen, buf->wp - buf->rp); + fz_dictputs(newdict, "Length", newlen); + fz_dropobj(newlen); + + fprintf(out, "%d %d obj\n", oid, gen); + if (doencrypt) + pdf_cryptobj(outcrypt, obj, oid, gen); + fz_fprintobj(out, newdict, !doexpand); + if (doencrypt) + pdf_cryptobj(outcrypt, obj, oid, gen); + fprintf(out, "stream\n"); + fwrite(buf->rp, 1, buf->wp - buf->rp, out); + fprintf(out, "endstream\nendobj\n\n"); + + fz_dropobj(newdict); + + fz_dropbuffer(buf); +} + +void saveobject(int oid, int gen) +{ + fz_error *error; + fz_obj *obj; + fz_obj *type; + + error = pdf_loadobject(&obj, xref, oid, gen); + if (error) + die(error); + + /* skip ObjStm and XRef objects */ + if (fz_isdict(obj)) + { + type = fz_dictgets(obj, "Type"); + if (fz_isname(type) && !strcmp(fz_toname(type), "ObjStm")) + { + uselist[oid] = 0; + fz_dropobj(obj); + return; + } + if (fz_isname(type) && !strcmp(fz_toname(type), "XRef")) + { + uselist[oid] = 0; + fz_dropobj(obj); + return; + } + } + + + if (!xref->table[oid].stmofs) + { + fprintf(out, "%d %d obj\n", oid, gen); + if (doencrypt) + pdf_cryptobj(outcrypt, obj, oid, gen); + fz_fprintobj(out, obj, !doexpand); + if (doencrypt) + pdf_cryptobj(outcrypt, obj, oid, gen); + fprintf(out, "endobj\n\n"); + } + else + { + if (doexpand) + expandstream(obj, oid, gen); + else + copystream(obj, oid, gen); + } + + + fz_dropobj(obj); +} + +void savexref(void) +{ + fz_obj *trailer; + fz_obj *obj; + int startxref; + int oid; + + startxref = ftell(out); + + fprintf(out, "xref\n0 %d\n", xref->len + doencrypt); + for (oid = 0; oid < xref->len + doencrypt; oid++) + { + if (uselist[oid]) + fprintf(out, "%010d %05d n \n", ofslist[oid], genlist[oid]); + else + fprintf(out, "%010d %05d f \n", ofslist[oid], genlist[oid]); + } + fprintf(out, "\n"); + + fz_newdict(&trailer, 5); + + fz_newint(&obj, xref->len); + fz_dictputs(trailer, "Size", obj); + fz_dropobj(obj); + + obj = fz_dictgets(xref->trailer, "Info"); + if (obj) + fz_dictputs(trailer, "Info", obj); + + obj = fz_dictgets(xref->trailer, "Root"); + if (obj) + fz_dictputs(trailer, "Root", obj); + + if (doencrypt) + { + fz_newindirect(&obj, xref->len, 0); + fz_dictputs(trailer, "Encrypt", obj); + fz_dropobj(obj); + } + + fz_dictputs(trailer, "ID", id); + + fprintf(out, "trailer\n"); + fz_fprintobj(out, trailer, !doexpand); + fprintf(out, "\n"); + + fprintf(out, "startxref\n%d\n%%%%EOF\n", startxref); +} + +void cleanusage(void) +{ + fprintf(stderr, + "usage: pdfclean [options] input.pdf [outfile.pdf]\n" + " -d -\tpassword for decryption\n" + " -g \tgarbage collect unused objects\n" + " -x \texpand compressed streams\n" + " -e \tencrypt output\n" + " -u -\tset user password for encryption\n" + " -o -\tset owner password\n" + " -p -\tset permissions (combine letters 'pmca')\n" + " -n -\tkey length in bits: 40 <= n <= 128\n"); + exit(1); +} + +int main(int argc, char **argv) +{ + char *infile; + char *outfile = "out.pdf"; + char *userpw = ""; + char *ownerpw = ""; + unsigned perms = 0xfffff0c0; /* nothing allowed */ + int keylen = 40; + char *password = ""; + fz_error *error; + int c, oid; + int lastfree; + + + while ((c = getopt(argc, argv, "d:egn:o:p:u:x")) != -1) + { + switch (c) + { + case 'p': + /* see TABLE 3.15 User access permissions */ + perms = 0xfffff0c0; + if (strchr(optarg, 'p')) /* print */ + perms |= (1 << 2) | (1 << 11); + if (strchr(optarg, 'm')) /* modify */ + perms |= (1 << 3) | (1 << 10); + if (strchr(optarg, 'c')) /* copy */ + perms |= (1 << 4) | (1 << 9); + if (strchr(optarg, 'a')) /* annotate / forms */ + perms |= (1 << 5) | (1 << 8); + break; + case 'd': password = optarg; break; + case 'e': doencrypt ++; break; + case 'g': dogarbage ++; break; + case 'n': keylen = atoi(optarg); break; + case 'o': ownerpw = optarg; break; + case 'u': userpw = optarg; break; + case 'x': doexpand ++; break; + default: cleanusage(); break; + } + } + + if (argc - optind < 1) + cleanusage(); + + infile = argv[optind++]; + if (argc - optind > 0) + outfile = argv[optind++]; + + openxref(infile, password); + + id = fz_dictgets(xref->trailer, "ID"); + if (!id) + { + error = fz_packobj(&id, "[(ABCDEFGHIJKLMNOP)(ABCDEFGHIJKLMNOP)]"); + if (error) + die(error); + } + else + { + fz_keepobj(id); + } + + if (doencrypt) + { + error = pdf_newencrypt(&outcrypt, userpw, ownerpw, perms, keylen, id); + if (error) + die(error); + } + + out = fopen(outfile, "wb"); + if (!out) + die(fz_throw("cannot open output file '%s'", outfile)); + + fprintf(out, "%%PDF-%d.%d\n", xref->version / 10, xref->version % 10); + fprintf(out, "%%\342\343\317\323\n\n"); + + uselist = malloc(sizeof (char) * (xref->len + 1)); + ofslist = malloc(sizeof (int) * (xref->len + 1)); + genlist = malloc(sizeof (int) * (xref->len + 1)); + + for (oid = 0; oid < xref->len; oid++) + { + uselist[oid] = 0; + ofslist[oid] = 0; + genlist[oid] = 0; + } + + /* Make sure any objects hidden in compressed streams have been loaded */ + preloadobjstms(); + + /* Sweep & mark objects from the trailer */ + error = sweepobj(xref, xref->trailer); + if (error) + die(fz_rethrow(error, "cannot mark used objects")); + + for (oid = 0; oid < xref->len; oid++) + { + if (xref->table[oid].type == 'f') + uselist[oid] = 0; + + if (xref->table[oid].type == 'f') + genlist[oid] = xref->table[oid].gen; + if (xref->table[oid].type == 'n') + genlist[oid] = xref->table[oid].gen; + if (xref->table[oid].type == 'o') + genlist[oid] = 0; + + if (dogarbage && !uselist[oid]) + continue; + + if (xref->table[oid].type == 'n' || xref->table[oid].type == 'o') + { + ofslist[oid] = ftell(out); + saveobject(oid, genlist[oid]); + } + } + + /* add new encryption dictionary to xref */ + if (doencrypt) + { + ofslist[xref->len] = ftell(out); + genlist[xref->len] = 0; + uselist[xref->len] = 1; + fprintf(out, "%d %d obj\n", xref->len, 0); + fz_fprintobj(out, outcrypt->encrypt, !doexpand); + fprintf(out, "endobj\n\n"); + } + + /* construct linked list of free object slots */ + lastfree = 0; + for (oid = 0; oid < xref->len + doencrypt; oid++) + { + if (!uselist[oid]) + { + genlist[oid]++; + ofslist[lastfree] = oid; + lastfree = oid; + } + } + + savexref(); + + pdf_closexref(xref); +} + |