新华字典 as CSV download available?
First, there is no legal source to download both of them.
More specific, they're content of copyright. The Commercial Press has made great effort to ban online version to protect its interest. So you can hardly find the website which is providing PDF or other format.   

However, there's another way, but you'd pay a little money(~$2). Visit the greatest online market in China, Taobao(Taobao.com), search for the sellers who provide the  electronic version book finding service. You can ask them on Ali Wangwang.  

As far as I know, there are no latest version(6) available and most of downloadable are in PDF format. Some claim they're, but actually not. You may try this, it contains a mdb database which is 100MB, it's easy to convert it into CSV. I haven't tested whether it is the content of 现代汉语词典, because I'm using Linux OS.
For 新华字典, there are too many apps named as the name. You can search for some android app, unpack apk installer, often you should find a large file in it, and often it's in SQLite 3 format.

All the methods I mentioned above are not tested, you'd better carefully try them.
I also tried to find such files but I gave up because it's hard to deal with, both in legal and technology.
I finally selected an alternative, HanDian. They provided a series of contents and tools for free. Part of them can be found here. Though it's chm format, but to organize the content just a matter of extract and regexp, no any OCR or any other things involved.