ZacharyZhang-NY
b7fca0146d
ElyDoc, ElyTable, ElyShow (LibreOfficeKit), ElyPDF (MuPDF), ElyTree (Git), ElyMark (Milkdown and CodeMirror in CEF). ElyMail and ElyAgent follow.
75 lines
2.5 KiB
C
75 lines
2.5 KiB
C
/* Permissions and protected copies (PDF-11). */
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#include <string.h>
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#include "ely_shim.h"
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enum { MAY_PRINT = 1, MAY_COPY = 2, MAY_EDIT = 4, MAY_ANNOTATE = 8, MAY_FILL = 16, MAY_ASSEMBLE = 32 };
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/* What the document allows, as Ely's bits. */
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int ely_permissions(fz_context *ctx, fz_document *doc)
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{
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int may = 0;
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fz_try(ctx)
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{
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pdf_document *pdf = ely_pdf_of(ctx, doc);
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int edit = pdf_has_permission(ctx, pdf, FZ_PERMISSION_EDIT) != 0;
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int annotate = pdf_has_permission(ctx, pdf, FZ_PERMISSION_ANNOTATE) != 0;
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may |= pdf_has_permission(ctx, pdf, FZ_PERMISSION_PRINT) ? MAY_PRINT : 0;
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may |= pdf_has_permission(ctx, pdf, FZ_PERMISSION_COPY) ? MAY_COPY : 0;
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may |= edit ? MAY_EDIT : 0;
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may |= annotate ? MAY_ANNOTATE : 0;
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may |= annotate || pdf_has_permission(ctx, pdf, FZ_PERMISSION_FORM) ? MAY_FILL : 0;
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may |= edit || pdf_has_permission(ctx, pdf, FZ_PERMISSION_ASSEMBLE) ? MAY_ASSEMBLE : 0;
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}
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fz_catch(ctx)
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return ely_fail(ctx);
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return may;
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}
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/* PDF's permission bits for Ely's `may`. */
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static int pdf_bits(int may)
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{
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int p = ~(PDF_PERM_PRINT | PDF_PERM_MODIFY | PDF_PERM_COPY | PDF_PERM_ANNOTATE | PDF_PERM_FORM |
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PDF_PERM_ASSEMBLE | PDF_PERM_PRINT_HQ | 3);
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p |= may & MAY_PRINT ? PDF_PERM_PRINT | PDF_PERM_PRINT_HQ : 0;
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p |= may & MAY_COPY ? PDF_PERM_COPY : 0;
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p |= may & MAY_EDIT ? PDF_PERM_MODIFY : 0;
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p |= may & MAY_ANNOTATE ? PDF_PERM_ANNOTATE : 0;
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p |= may & MAY_FILL ? PDF_PERM_FORM : 0;
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p |= may & MAY_ASSEMBLE ? PDF_PERM_ASSEMBLE : 0;
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return p;
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}
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static void put_password(fz_context *ctx, char *into, const char *password)
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{
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if (strlen(password) >= 128)
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fz_throw(ctx, FZ_ERROR_ARGUMENT, "a password longer than 127 bytes");
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strcpy(into, password);
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}
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/* Writes `out` with AES-256 and `may`, or unprotected. */
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int ely_protect(fz_context *ctx, fz_document *doc, const char *raw, const char *out, const char *password,
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int protect, const char *user, const char *owner, int may)
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{
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fz_try(ctx)
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{
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pdf_write_options opts = pdf_default_write_options;
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opts.do_encrypt = protect ? PDF_ENCRYPT_AES_256 : PDF_ENCRYPT_NONE;
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if (protect)
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{
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if (!*owner)
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fz_throw(ctx, FZ_ERROR_ARGUMENT, "an owner password is needed");
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if (!strcmp(user, owner))
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fz_throw(ctx, FZ_ERROR_ARGUMENT, "the owner password equals the open password");
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put_password(ctx, opts.upwd_utf8, user);
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put_password(ctx, opts.opwd_utf8, owner);
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opts.permissions = pdf_bits(may);
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}
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ely_save_copy(ctx, ely_pdf_of(ctx, doc), raw, out, password, &opts, NULL, NULL);
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}
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fz_catch(ctx)
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return ely_fail(ctx);
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return 0;
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}
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