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#include "mupdf/fitz.h"
#include "mupdf/pdf.h"
#include "../fitz/fitz-imp.h"
#include <string.h>
static void pdf_print_designated_name(pdf_pkcs7_designated_name *name, char *buf, int buflen)
{
int i, n;
const char *part[] = {
"/CN=", name->cn,
"/O=", name->o,
"/OU=", name->ou,
"/emailAddress=", name->email,
"/C=", name->c};
if (buflen)
buf[0] = 0;
n = sizeof(part)/sizeof(*part);
for (i = 0; i < n; i++)
if (part[i])
fz_strlcat(buf, part[i], buflen);
}
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 *in = NULL;
int (*brange)[2] = NULL;
int brange_len = pdf_array_len(ctx, byte_range)/2;
unsigned char *digest = NULL;
int digest_len;
fz_var(in);
fz_var(brange);
if (hexdigest_length < 4)
fz_throw(ctx, FZ_ERROR_GENERIC, "Bad parameters to pdf_write_digest");
fz_try(ctx)
{
int i, res;
in = fz_stream_from_output(ctx, out);
brange = fz_calloc(ctx, brange_len, sizeof(*brange));
for (i = 0; i < brange_len; i++)
{
brange[i][0] = pdf_to_int(ctx, pdf_array_get(ctx, byte_range, 2*i));
brange[i][1] = pdf_to_int(ctx, pdf_array_get(ctx, byte_range, 2*i+1));
}
digest_len = (hexdigest_length - 2) / 2;
digest = fz_malloc(ctx, digest_len);
res = pdf_pkcs7_create_digest(ctx, in, brange, brange_len, signer, digest, &digest_len);
if (!res)
fz_throw(ctx, FZ_ERROR_GENERIC, "pdf_pkcs7_create_digest failed");
fz_drop_stream(ctx, in);
in = 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, in);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
}
int pdf_check_signature(fz_context *ctx, pdf_document *doc, pdf_widget *widget, char *ebuf, int ebufsize)
{
int (*byte_range)[2] = NULL;
int byte_range_len;
char *contents = NULL;
int contents_len;
int res = 0;
if (pdf_xref_obj_is_unsaved_signature(doc, ((pdf_annot *)widget)->obj))
{
fz_strlcpy(ebuf, "Signed but document yet to be saved", ebufsize);
if (ebufsize > 0)
ebuf[ebufsize-1] = 0;
return 0;
}
fz_var(byte_range);
fz_var(res);
fz_try(ctx)
{
byte_range_len = pdf_signature_widget_byte_range(ctx, doc, widget, NULL);
if (byte_range_len)
{
byte_range = fz_calloc(ctx, byte_range_len, sizeof(*byte_range));
pdf_signature_widget_byte_range(ctx, doc, widget, byte_range);
}
contents_len = pdf_signature_widget_contents(ctx, doc, widget, &contents);
if (byte_range && contents)
{
SignatureError err = pdf_pkcs7_check_digest(ctx, doc->file, contents, contents_len, byte_range, byte_range_len);
if (err == SignatureError_Okay)
err = pdf_pkcs7_check_certificate(contents, contents_len);
switch (err)
{
case SignatureError_Okay:
ebuf[0] = 0;
res = 1;
break;
case SignatureError_NoSignatures:
fz_strlcpy(ebuf, "No signatures", ebufsize);
break;
case SignatureError_NoCertificate:
fz_strlcpy(ebuf, "No certificate", ebufsize);
break;
case SignatureError_DocumentChanged:
fz_strlcpy(ebuf, "Document changed since signing", ebufsize);
break;
case SignatureError_SelfSigned:
fz_strlcpy(ebuf, "Self-signed certificate", ebufsize);
break;
case SignatureError_SelfSignedInChain:
fz_strlcpy(ebuf, "Self-signed certificate in chain", ebufsize);
break;
case SignatureError_NotTrusted:
fz_strlcpy(ebuf, "Certificate not trusted", ebufsize);
break;
default:
case SignatureError_Unknown:
fz_strlcpy(ebuf, "Unknown error", ebufsize);
break;
}
switch (err)
{
case SignatureError_SelfSigned:
case SignatureError_SelfSignedInChain:
case SignatureError_NotTrusted:
{
pdf_pkcs7_designated_name *name = pdf_cert_designated_name(ctx, contents, contents_len);
if (name)
{
int len;
fz_strlcat(ebuf, ": ", ebufsize);
len = strlen(ebuf);
pdf_print_designated_name(name, ebuf + len, ebufsize - len);
pdf_pkcs7_drop_designated_name(ctx, name);
}
}
break;
default:
break;
}
}
else
{
res = 0;
fz_strlcpy(ebuf, "Not signed", ebufsize);
}
}
fz_always(ctx)
{
fz_free(ctx, byte_range);
}
fz_catch(ctx)
{
res = 0;
fz_strlcpy(ebuf, fz_caught_message(ctx), ebufsize);
}
if (ebufsize > 0)
ebuf[ebufsize-1] = 0;
return res;
}
void pdf_sign_signature(fz_context *ctx, pdf_document *doc, pdf_widget *widget, const char *sigfile, const char *password)
{
pdf_pkcs7_signer *signer = pdf_pkcs7_read_pfx(ctx, sigfile, password);
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 = fz_empty_rect;
pdf_signature_set_value(ctx, doc, wobj, signer);
pdf_to_rect(ctx, pdf_dict_get(ctx, wobj, PDF_NAME_Rect), &rect);
/* Create an appearance stream only if the signature is intended to be visible */
if (!fz_is_empty_rect(&rect))
{
dn = pdf_pkcs7_signer_designated_name(ctx, 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_set_signature_appearance(ctx, doc, (pdf_annot *)widget, dn->cn, dn_str, NULL);
}
}
fz_always(ctx)
{
pdf_pkcs7_drop_signer(ctx, signer);
pdf_pkcs7_drop_designated_name(ctx, dn);
fz_drop_buffer(ctx, fzbuf);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
}
int pdf_signatures_supported(fz_context *ctx)
{
return pdf_pkcs7_supported(ctx);
}
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