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-rw-r--r--include/mupdf/pdf/document.h6
-rw-r--r--source/helpers/pkcs7/pkcs7-openssl.c30
-rw-r--r--source/pdf/pdf-form.c39
-rw-r--r--source/pdf/pdf-write.c30
4 files changed, 75 insertions, 30 deletions
diff --git a/include/mupdf/pdf/document.h b/include/mupdf/pdf/document.h
index 9e9121df..7d2110b7 100644
--- a/include/mupdf/pdf/document.h
+++ b/include/mupdf/pdf/document.h
@@ -556,7 +556,10 @@ typedef pdf_pkcs7_designated_name *(pdf_pkcs7_designated_name_fn)(pdf_pkcs7_sign
/* Free the resources associated with previously obtained designated name information */
typedef void (pdf_pkcs7_drop_designated_name_fn)(pdf_pkcs7_signer *signer, pdf_pkcs7_designated_name *name);
-/* Create a signature based on ranges of bytes drawn from a steam */
+/* Predict the size of the digest. The actual digest returned by create_digest will be no greater in size */
+typedef int (pdf_pkcs7_max_digest_size_fn)(pdf_pkcs7_signer *signer);
+
+/* Create a signature based on ranges of bytes drawn from a stream */
typedef int (pdf_pkcs7_create_digest_fn)(pdf_pkcs7_signer *signer, fz_stream *in, unsigned char *digest, int *digest_len);
struct pdf_pkcs7_signer_s
@@ -565,6 +568,7 @@ struct pdf_pkcs7_signer_s
pdf_pkcs7_drop_fn *drop;
pdf_pkcs7_designated_name_fn *designated_name;
pdf_pkcs7_drop_designated_name_fn *drop_designated_name;
+ pdf_pkcs7_max_digest_size_fn *max_digest_size;
pdf_pkcs7_create_digest_fn *create_digest;
};
diff --git a/source/helpers/pkcs7/pkcs7-openssl.c b/source/helpers/pkcs7/pkcs7-openssl.c
index 1468b7e1..58dbf65f 100644
--- a/source/helpers/pkcs7/pkcs7-openssl.c
+++ b/source/helpers/pkcs7/pkcs7-openssl.c
@@ -633,10 +633,12 @@ static int signer_create_digest(pdf_pkcs7_signer *signer, fz_stream *in, unsigne
unsigned char *p7_ptr;
int p7_len;
- bdata = BIO_new_stream(ctx, in);
- if (bdata == NULL)
- goto exit;
-
+ if (in != NULL)
+ {
+ bdata = BIO_new_stream(ctx, in);
+ if (bdata == NULL)
+ goto exit;
+ }
p7 = PKCS7_new();
if (p7 == NULL)
@@ -657,7 +659,7 @@ static int signer_create_digest(pdf_pkcs7_signer *signer, fz_stream *in, unsigne
if (bp7in == NULL)
goto exit;
- while(1)
+ while(bdata) /* bdata knowingly not changed in the loop */
{
char buf[4096];
int n = BIO_read(bdata, buf, sizeof(buf));
@@ -677,10 +679,12 @@ static int signer_create_digest(pdf_pkcs7_signer *signer, fz_stream *in, unsigne
goto exit;
p7_len = BIO_get_mem_data(bp7, &p7_ptr);
- if (p7_len > *digest_len)
+ if (digest && p7_len > *digest_len)
goto exit;
- memcpy(digest, p7_ptr, p7_len);
+ if (digest)
+ memcpy(digest, p7_ptr, p7_len);
+
*digest_len = p7_len;
res = 1;
@@ -692,6 +696,17 @@ exit:
return res;
}
+static int max_digest_size(pdf_pkcs7_signer *signer)
+{
+ /* Perform a test digest generation to find the required size. Size
+ * is assumed independent of data being hashed */
+ int digest_len = 0;
+
+ signer_create_digest(signer, NULL, NULL, &digest_len);
+
+ return digest_len;
+}
+
pdf_pkcs7_signer *pkcs7_openssl_read_pfx(fz_context *ctx, const char *pfile, const char *pw)
{
BIO *pfxbio = NULL;
@@ -710,6 +725,7 @@ pdf_pkcs7_signer *pkcs7_openssl_read_pfx(fz_context *ctx, const char *pfile, con
signer->base.drop = drop_signer;
signer->base.designated_name = signer_designated_name;
signer->base.drop_designated_name = signer_drop_designated_name;
+ signer->base.max_digest_size = max_digest_size;
signer->base.create_digest = signer_create_digest;
signer->ctx = ctx;
signer->refs = 1;
diff --git a/source/pdf/pdf-form.c b/source/pdf/pdf-form.c
index af0f572d..d5dad22b 100644
--- a/source/pdf/pdf-form.c
+++ b/source/pdf/pdf-form.c
@@ -1289,40 +1289,45 @@ void pdf_signature_set_value(fz_context *ctx, pdf_document *doc, pdf_obj *field,
int vnum;
pdf_obj *byte_range;
pdf_obj *contents;
- char buf[2048];
-
- memset(buf, 0, sizeof(buf));
+ int max_digest_size;
+ char *buf = NULL;
vnum = pdf_create_object(ctx, doc);
indv = pdf_new_indirect(ctx, doc, vnum, 0);
pdf_dict_put_drop(ctx, field, PDF_NAME(V), indv);
+ max_digest_size = signer->max_digest_size(signer);
+
fz_var(v);
+ fz_var(buf);
fz_try(ctx)
{
v = pdf_new_dict(ctx, doc, 4);
pdf_update_object(ctx, doc, vnum, v);
+
+ buf = fz_calloc(ctx, max_digest_size, 1);
+
+ byte_range = pdf_new_array(ctx, doc, 4);
+ pdf_dict_put_drop(ctx, v, PDF_NAME(ByteRange), byte_range);
+
+ contents = pdf_new_string(ctx, buf, max_digest_size);
+ pdf_dict_put_drop(ctx, v, PDF_NAME(Contents), contents);
+
+ pdf_dict_put(ctx, v, PDF_NAME(Filter), PDF_NAME(Adobe_PPKLite));
+ pdf_dict_put(ctx, v, PDF_NAME(SubFilter), PDF_NAME(adbe_pkcs7_detached));
+
+ /* Record details within the document structure so that contents
+ * and byte_range can be updated with their correct values at
+ * saving time */
+ pdf_xref_store_unsaved_signature(ctx, doc, field, signer);
}
fz_always(ctx)
{
pdf_drop_obj(ctx, v);
+ fz_free(ctx, buf);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
-
- byte_range = pdf_new_array(ctx, doc, 4);
- pdf_dict_put_drop(ctx, v, PDF_NAME(ByteRange), byte_range);
-
- contents = pdf_new_string(ctx, buf, sizeof(buf));
- pdf_dict_put_drop(ctx, v, PDF_NAME(Contents), contents);
-
- pdf_dict_put(ctx, v, PDF_NAME(Filter), PDF_NAME(Adobe_PPKLite));
- pdf_dict_put(ctx, v, PDF_NAME(SubFilter), PDF_NAME(adbe_pkcs7_detached));
-
- /* Record details within the document structure so that contents
- * and byte_range can be updated with their correct values at
- * saving time */
- pdf_xref_store_unsaved_signature(ctx, doc, field, signer);
}
diff --git a/source/pdf/pdf-write.c b/source/pdf/pdf-write.c
index 26fcd9d1..227258d8 100644
--- a/source/pdf/pdf-write.c
+++ b/source/pdf/pdf-write.c
@@ -13,6 +13,8 @@
/* #define DEBUG_HEAP_SORT */
/* #define DEBUG_WRITING */
+#define SIG_EXTRAS_SIZE (1024)
+
typedef struct pdf_write_state_s pdf_write_state;
/*
@@ -2627,12 +2629,14 @@ static void presize_unsaved_signature_byteranges(fz_context *ctx, pdf_document *
static void complete_signatures(fz_context *ctx, pdf_document *doc, pdf_write_state *opts)
{
pdf_unsaved_sig *usig;
- char buf[5120];
+ char *buf = NULL;
+ int buf_size;
int s;
int i;
int last_end;
fz_stream *stm = NULL;
fz_var(stm);
+ fz_var(buf);
fz_try(ctx)
{
@@ -2643,6 +2647,18 @@ static void complete_signatures(fz_context *ctx, pdf_document *doc, pdf_write_st
if (xref->unsaved_sigs)
{
pdf_obj *byte_range;
+ buf_size = 0;
+
+ for (usig = xref->unsaved_sigs; usig; usig = usig->next)
+ {
+ int size = usig->signer->max_digest_size(usig->signer);
+
+ buf_size = fz_maxi(buf_size, size);
+ }
+
+ buf_size = buf_size * 2 + SIG_EXTRAS_SIZE;
+
+ buf = fz_calloc(ctx, buf_size, 1);
stm = fz_stream_from_output(ctx, opts->out);
/* Locate the byte ranges and contents in the saved file */
@@ -2651,8 +2667,8 @@ static void complete_signatures(fz_context *ctx, pdf_document *doc, pdf_write_st
char *bstr, *cstr, *fstr;
int pnum = pdf_obj_parent_num(ctx, pdf_dict_getl(ctx, usig->field, PDF_NAME(V), PDF_NAME(ByteRange), NULL));
fz_seek(ctx, stm, opts->ofs_list[pnum], SEEK_SET);
- (void)fz_read(ctx, stm, (unsigned char *)buf, sizeof(buf));
- buf[sizeof(buf)-1] = 0;
+ (void)fz_read(ctx, stm, (unsigned char *)buf, buf_size);
+ buf[buf_size-1] = 0;
bstr = strstr(buf, "/ByteRange");
cstr = strstr(buf, "/Contents");
@@ -2690,8 +2706,8 @@ static void complete_signatures(fz_context *ctx, pdf_document *doc, pdf_write_st
pdf_dict_putl_drop(ctx, usig->field, pdf_copy_array(ctx, byte_range), PDF_NAME(V), PDF_NAME(ByteRange), NULL);
/* Write the byte range into buf, padding with spaces*/
- i = pdf_sprint_obj(ctx, buf, sizeof(buf), byte_range, 1);
- memset(buf+i, ' ', sizeof(buf)-i);
+ i = pdf_sprint_obj(ctx, buf, buf_size, byte_range, 1);
+ memset(buf+i, ' ', buf_size-i);
/* Write the byte range to the file */
for (usig = xref->unsaved_sigs; usig; usig = usig->next)
@@ -2714,12 +2730,16 @@ static void complete_signatures(fz_context *ctx, pdf_document *doc, pdf_write_st
}
xref->unsaved_sigs_end = NULL;
+
+ fz_free(ctx, buf);
+ buf = NULL;
}
}
}
fz_catch(ctx)
{
fz_drop_stream(ctx, stm);
+ fz_free(ctx, buf);
fz_rethrow(ctx);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-03 00:12:22 +0000