Fix to decrypt hexstrings

pdfi_read_hexstring() didn't check for whether it needed to decrypt
the string.  I just grabbed the similar code from pdfi_read_string(), so
hopefully this is correct.

I was fixing a bug where the Info wasn't displaying correctly with
-DPDFINFO, for example on file tests_private/pdf/PDF_1.7_FTS/fts_03_0301.pdf

Also disable string decryption while interpreting c_string.  This is
needed by annotations that construct hexstrings and send them through
the interpreter.

Also cleaned up implementation of pdfi_read_Info() to modernize the
dictionary calls.  It was probably really old code and was doing
unnecessary stuff about resolving an INDIRECT object that is now
handled in the dictionary code.

2 files changed, 23 insertions, 29 deletions

diff --git a/pdf/pdf_doc.c b/pdf/pdf_doc.c
index 4b4d87d07..5bdb188d8 100644
--- a/pdf/pdf_doc.c
+++ b/pdf/pdf_doc.c
@@ -90,46 +90,23 @@ int pdfi_read_Root(pdf_context *ctx)
 
 int pdfi_read_Info(pdf_context *ctx)
 {
-    pdf_obj *o, *o1;
+    pdf_dict *Info;
     int code;
 
     if (ctx->args.pdfdebug)
         dmprintf(ctx->memory, "%% Reading Info dictionary\n");
 
-    code = pdfi_dict_get(ctx, ctx->Trailer, "Info", &o1);
+    code = pdfi_dict_get_type(ctx, ctx->Trailer, "Info", PDF_DICT, (pdf_obj **)&Info);
     if (code < 0)
         return code;
 
-    if (o1->type == PDF_INDIRECT) {
-        code = pdfi_dereference(ctx, ((pdf_indirect_ref *)o1)->ref_object_num,  ((pdf_indirect_ref *)o1)->ref_generation_num, &o);
-        pdfi_countdown(o1);
-        if (code < 0)
-            return code;
-
-        if (o->type != PDF_DICT) {
-            pdfi_countdown(o);
-            return_error(gs_error_typecheck);
-        }
-
-        code = pdfi_dict_put(ctx, ctx->Trailer, "Info", o);
-        if (code < 0) {
-            pdfi_countdown(o);
-            return code;
-        }
-        o1 = o;
-    } else {
-        if (o1->type != PDF_DICT) {
-            pdfi_countdown(o1);
-            return_error(gs_error_typecheck);
-        }
-    }
-
     if (ctx->args.pdfdebug)
         dmprintf(ctx->memory, "\n");
-    /* We don't pdfi_countdown(o1) now, because we've transferred our
+
+    /* We don't pdfi_countdown(Info) now, because we've transferred our
      * reference to the pointer in the pdf_context structure.
      */
-    ctx->Info = (pdf_dict *)o1;
+    ctx->Info = Info;
     return 0;
 }
 
diff --git a/pdf/pdf_int.c b/pdf/pdf_int.c
index bdad20bf4..33d871eae 100644
--- a/pdf/pdf_int.c
+++ b/pdf/pdf_int.c
@@ -468,6 +468,12 @@ static int pdfi_read_hexstring(pdf_context *ctx, pdf_c_stream *s, uint32_t indir
     string->indirect_num = indirect_num;
     string->indirect_gen = indirect_gen;
 
+    if (ctx->encryption.is_encrypted && ctx->encryption.decrypt_strings) {
+        code = pdfi_decrypt_string(ctx, string);
+        if (code < 0)
+            return code;
+    }
+
     code = pdfi_push(ctx, (pdf_obj *)string);
     if (code < 0)
         pdfi_free_object((pdf_obj *)string);
@@ -1892,6 +1898,9 @@ pdfi_interpret_inner_content_c_string(pdf_context *ctx, char *content_string,
                                       bool stoponerror, const char *desc)
 {
     uint32_t length = (uint32_t)strlen(content_string);
+    bool decrypt_strings;
+    int code;
+
 
     /* Underlying buffer limit is uint32, so handle the extremely unlikely case that
      * our string is too big.
@@ -1899,8 +1908,16 @@ pdfi_interpret_inner_content_c_string(pdf_context *ctx, char *content_string,
     if (length != strlen(content_string))
         return_error(gs_error_limitcheck);
 
-    return pdfi_interpret_inner_content_buffer(ctx, (byte *)content_string, length,
+    /* Since this is a constructed string content, not part of the file, it can never
+     * be encrypted. So disable decryption during this call.
+     */
+    decrypt_strings = ctx->encryption.decrypt_strings;
+    ctx->encryption.decrypt_strings = false;
+    code = pdfi_interpret_inner_content_buffer(ctx, (byte *)content_string, length,
                                                stream_dict, page_dict, stoponerror, desc);
+    ctx->encryption.decrypt_strings = decrypt_strings;
+
+    return code;
 }
 
 /* Interpret inner content from a string