eBookReaderSwitch/mupdf/source/pdf/pdf-signature.c

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C
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#include "mupdf/fitz.h"
#include "mupdf/pdf.h"
#include "../fitz/fitz-imp.h"
#include <string.h>
void pdf_write_digest(fz_context *ctx, fz_output *out, pdf_obj *byte_range, int hexdigest_offset, int hexdigest_length, pdf_pkcs7_signer *signer)
{
fz_stream *stm = NULL;
fz_stream *in = NULL;
fz_range *brange = NULL;
int brange_len = pdf_array_len(ctx, byte_range)/2;
unsigned char *digest = NULL;
int digest_len;
fz_var(stm);
fz_var(in);
fz_var(brange);
fz_var(digest);
if (hexdigest_length < 4)
fz_throw(ctx, FZ_ERROR_GENERIC, "Bad parameters to pdf_write_digest");
fz_try(ctx)
{
int i, res;
brange = fz_calloc(ctx, brange_len, sizeof(*brange));
for (i = 0; i < brange_len; i++)
{
brange[i].offset = pdf_array_get_int(ctx, byte_range, 2*i);
brange[i].length = pdf_array_get_int(ctx, byte_range, 2*i+1);
}
stm = fz_stream_from_output(ctx, out);
in = fz_open_range_filter(ctx, stm, brange, brange_len);
digest_len = (hexdigest_length - 2) / 2;
digest = fz_malloc(ctx, digest_len);
res = signer->create_digest(signer, in, digest, &digest_len);
if (!res)
fz_throw(ctx, FZ_ERROR_GENERIC, "pdf_pkcs7_create_digest failed");
fz_drop_stream(ctx, in);
in = NULL;
fz_drop_stream(ctx, stm);
stm = NULL;
fz_seek_output(ctx, out, hexdigest_offset+1, SEEK_SET);
for (i = 0; i < digest_len; i++)
fz_write_printf(ctx, out, "%02x", digest[i]);
}
fz_always(ctx)
{
fz_free(ctx, digest);
fz_free(ctx, brange);
fz_drop_stream(ctx, stm);
fz_drop_stream(ctx, in);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
}
void pdf_sign_signature(fz_context *ctx, pdf_document *doc, pdf_widget *widget, pdf_pkcs7_signer *signer)
{
pdf_pkcs7_designated_name *dn = NULL;
fz_buffer *fzbuf = NULL;
fz_try(ctx)
{
const char *dn_str;
pdf_obj *wobj = ((pdf_annot *)widget)->obj;
fz_rect rect;
rect = pdf_dict_get_rect(ctx, wobj, PDF_NAME(Rect));
/* Create an appearance stream only if the signature is intended to be visible */
if (!fz_is_empty_rect(rect))
{
dn = signer->designated_name(signer);
fzbuf = fz_new_buffer(ctx, 256);
if (!dn->cn)
fz_throw(ctx, FZ_ERROR_GENERIC, "Certificate has no common name");
fz_append_printf(ctx, fzbuf, "cn=%s", dn->cn);
if (dn->o)
fz_append_printf(ctx, fzbuf, ", o=%s", dn->o);
if (dn->ou)
fz_append_printf(ctx, fzbuf, ", ou=%s", dn->ou);
if (dn->email)
fz_append_printf(ctx, fzbuf, ", email=%s", dn->email);
if (dn->c)
fz_append_printf(ctx, fzbuf, ", c=%s", dn->c);
dn_str = fz_string_from_buffer(ctx, fzbuf);
pdf_update_signature_appearance(ctx, (pdf_annot *)widget, dn->cn, dn_str, NULL);
}
pdf_signature_set_value(ctx, doc, wobj, signer);
}
fz_always(ctx)
{
signer->drop_designated_name(signer, dn);
fz_drop_buffer(ctx, fzbuf);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
}
void pdf_clear_signature(fz_context *ctx, pdf_document *doc, pdf_widget *widget)
{
int flags;
flags = pdf_dict_get_int(ctx, ((pdf_annot *) widget)->obj, PDF_NAME(F));
flags &= ~PDF_ANNOT_IS_LOCKED;
if (flags)
pdf_dict_put_int(ctx, ((pdf_annot *) widget)->obj, PDF_NAME(F), flags);
else
pdf_dict_del(ctx, ((pdf_annot *) widget)->obj, PDF_NAME(F));
pdf_dict_del(ctx, ((pdf_annot *) widget)->obj, PDF_NAME(V));
pdf_update_signature_appearance(ctx, widget, NULL, NULL, NULL);
}