Sigil unable to read in Epub

z537815 · Yesterday, 08:27 AM

I'm having this problem with one (1) particular epub, and it occurs with 2.6.2. as well as 2.7.0:

Error info: Kan bestand C:\Userdata\Media\Books\Work in Progress\The Book of Dust #1 - La Belle Sauvage (Philip Pullman).epub niet inlezen: C:/Users/z5378/AppData/Local/sigil-ebook/sigil/workspace/Sigil-xQiaCc/OEBPS/Fonts/font00318.otf: http://ns.adobe.com/pdf/enc#RC:
Sigil version: 2.7.0
Runtime Qt: 6.9.3
Compiled Qt: 6.9.3
System: Windows 11 Version 24H2
Architecture: x86_64

(sorry, is Dutch: Sigil cannot read <file>: etc)

Is Sigil missing a font? Something else?

Thx for any info.

Turtle91 · Yesterday, 11:06 AM

I would hazard a guess that the Adobe Font is secured in some manner, such as font obfuscation, which Sigil does not unlock. I would think that if you delete the Font file, and references to it, that you would be able to read it. After all your edits are done you can add any licensed font back in.

Cheers!!

KevinH · Yesterday, 11:12 AM

It appears that there is a problem reading an .otf font is specified either in the list of obfuscated fonts, in the opf manifest, or in the book's css that should be inside the epub:

OEBPS/Fonts/font00318.otf

It may be improperly stripped, or obfuscated. There is also this piece of the error message that I am not sure why it is present:

Code:

http://ns.adobe.com/pdf/enc#RC:

So I would guess that epub is corrupted and would not pass epubcheck.

Does Sigil continue? Can you still use Sigil's editor properly? If so you might try removing that embedded font and all references to it? Or just return that epub to whereever you bought it and ask for an uncorrupted copy.

KevinH · Yesterday, 11:14 AM

FWIW, Sigil does properly obfuscate and unobfuscate fonts that have not had their OPF book id played with by someone who does not understand that obfuscation is tied to that value.

z537815 · Yesterday, 03:32 PM

Sigil says it really cannot read the file. So I changed the file-extension and had a look inside.

This epub does have an OEBPS/Fonts/font00318.otf, and this entry is mentioned in its <manifest>: <item id="item73" media-type="application/x-font-opentype" href="Fonts/font00318.otf"/>

Not sure whether this makes any difference.

Strange thing is - well, to me - that neither ADE 4.5.12 nor Thorium Reader V3.3.0 seem to have any problem reading the epub.

Anyway, I'll keep digging.

KevinH · Yesterday, 03:45 PM

Be careful, some ereaders default to local fonts and not publisher fonts. Others ignore broken fonts.

Is that font file obfuscated? Does your epub have an encryption.xml file in its META-INF folder? You would have to manually unzip the epub to check.

z537815 · Today, 06:23 AM

I think I solved my problem. Kind of.

I first changed the file-extension from .EPUB to .ZIP. This gets me a compressed map with 3 entries: /METAINF, /OEBPS and a mimetype-file.

And indeed, /META-INF does contain a "encryption.xml". /OEBPS contains a /Fonts with 2 entries: font00318.otf and font00319.otf, and the "content.opf" has the <manifest> specifying 2 entries: one each for the abovementioned fonts.

I decided to get rid of those 2 fonts (simply deleted them) and funny enough, this - somehow - got rid of /Fonts and the "encryption.xml". Didn't touch the <manifest>.

I then changed the file-extension back to .EPUB and behold! The problem has disappeared.

KevinH · Today, 12:02 PM

Your fonts were obfuscated as a way to prevent their theft or use outside that epub. The "key" to deobfuscate the font files back to working order depends on the value of the identifier pointed to by the book id attribute in the opf tag (that is how they tie it to the epub) and on the declared obfuscation method as specified in the encryption.xml file.

So somehow your epub has either improperly specified the font obfuscation method in the encryption.xml file or someone or something has created a new different unique identifier in the content.opf or edited the old one which breaks the de-obfuscation routine.

Both typically can happen when poor quality DeDRM software is used which plays with the book unique identifier to try to try to hide the fact this book was created by removing DRM.

Good quality DeDRM software knows enough to not change that book id, until all fonts have been deobfuscated and the encryption.xml file has been removed from the epub completely.

KevinH · Today, 12:25 PM

On the off chance they just mistakenly left in the encryption.xml file. you could try starting with a fresh copy of that epub, unzipping it and removing just the encryption.xml file, then save it. Try that. If the fonts still do not work, then they are still obfuscated and there is no way to recover them without the proper content.opf unique book id metadata value.

Might be worth a shot.

Alternatively the encryption.xml file may simply have the wrong paths to the font files in inside that epub, those paths should be from the root of the epub, NOT from the META-INF folder itself. If so you may be able to just fix the paths in the encryption.xml file, and everything may work as designed.

Yesterday, 11:12 AM	#3
KevinH Sigil Developer Posts: 9,171 Karma: 6565346 Join Date: Nov 2009 Device: many	It appears that there is a problem reading an .otf font is specified either in the list of obfuscated fonts, in the opf manifest, or in the book's css that should be inside the epub: OEBPS/Fonts/font00318.otf It may be improperly stripped, or obfuscated. There is also this piece of the error message that I am not sure why it is present: Code: http://ns.adobe.com/pdf/enc#RC: So I would guess that epub is corrupted and would not pass epubcheck. Does Sigil continue? Can you still use Sigil's editor properly? If so you might try removing that embedded font and all references to it? Or just return that epub to whereever you bought it and ask for an uncorrupted copy.

Yesterday, 03:45 PM	#6
KevinH Sigil Developer Posts: 9,171 Karma: 6565346 Join Date: Nov 2009 Device: many	Be careful, some ereaders default to local fonts and not publisher fonts. Others ignore broken fonts. Is that font file obfuscated? Does your epub have an encryption.xml file in its META-INF folder? You would have to manually unzip the epub to check. Last edited by KevinH; Yesterday at 04:03 PM.

Today, 12:02 PM	#8
KevinH Sigil Developer Posts: 9,171 Karma: 6565346 Join Date: Nov 2009 Device: many	Your fonts were obfuscated as a way to prevent their theft or use outside that epub. The "key" to deobfuscate the font files back to working order depends on the value of the identifier pointed to by the book id attribute in the opf tag (that is how they tie it to the epub) and on the declared obfuscation method as specified in the encryption.xml file. So somehow your epub has either improperly specified the font obfuscation method in the encryption.xml file or someone or something has created a new different unique identifier in the content.opf or edited the old one which breaks the de-obfuscation routine. Both typically can happen when poor quality DeDRM software is used which plays with the book unique identifier to try to try to hide the fact this book was created by removing DRM. Good quality DeDRM software knows enough to not change that book id, until all fonts have been deobfuscated and the encryption.xml file has been removed from the epub completely. Last edited by KevinH; Today at 12:05 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
sigil unable to run	luckyqing111	Sigil	2	08-15-2022 12:06 PM
Unable to read epub comic book	cuso4	Viewer	3	04-18-2021 11:33 PM
Unable to open epub book after editing with Sigil	danshand84	Sigil	8	11-03-2013 07:40 PM
Unable to start Sigil	weedfreak	Sigil	3	08-15-2011 04:28 AM
PRS-600 Unable to read an ePub	eosrose	Sony Reader	4	05-20-2010 04:34 PM

Yesterday, 08:27 AM	#1
z537815 Enthusiast Posts: 30 Karma: 10 Join Date: Aug 2019 Device: Lenovo TB-X704F	Sigil unable to read in Epub I'm having this problem with one (1) particular epub, and it occurs with 2.6.2. as well as 2.7.0: Error info: Kan bestand C:\Userdata\Media\Books\Work in Progress\The Book of Dust #1 - La Belle Sauvage (Philip Pullman).epub niet inlezen: C:/Users/z5378/AppData/Local/sigil-ebook/sigil/workspace/Sigil-xQiaCc/OEBPS/Fonts/font00318.otf: http://ns.adobe.com/pdf/enc#RC: Sigil version: 2.7.0 Runtime Qt: 6.9.3 Compiled Qt: 6.9.3 System: Windows 11 Version 24H2 Architecture: x86_64 (sorry, is Dutch: Sigil cannot read <file>: etc) Is Sigil missing a font? Something else? Thx for any info.

Yesterday, 11:06 AM	#2
Turtle91 A Hairy Wizard Posts: 3,418 Karma: 20212733 Join Date: Dec 2012 Location: Charleston, SC today Device: iPhone 15/11/X/6/iPad 1,2,Air & Air Pro/Surface Pro/Kindle PW & Fire	I would hazard a guess that the Adobe Font is secured in some manner, such as font obfuscation, which Sigil does not unlock. I would think that if you delete the Font file, and references to it, that you would be able to read it. After all your edits are done you can add any licensed font back in. Cheers!!

Yesterday, 11:14 AM	#4
KevinH Sigil Developer Posts: 9,171 Karma: 6565346 Join Date: Nov 2009 Device: many	FWIW, Sigil does properly obfuscate and unobfuscate fonts that have not had their OPF book id played with by someone who does not understand that obfuscation is tied to that value.

Yesterday, 03:32 PM	#5
z537815 Enthusiast Posts: 30 Karma: 10 Join Date: Aug 2019 Device: Lenovo TB-X704F	Sigil says it really cannot read the file. So I changed the file-extension and had a look inside. This epub does have an OEBPS/Fonts/font00318.otf, and this entry is mentioned in its <manifest>: <item id="item73" media-type="application/x-font-opentype" href="Fonts/font00318.otf"/> Not sure whether this makes any difference. Strange thing is - well, to me - that neither ADE 4.5.12 nor Thorium Reader V3.3.0 seem to have any problem reading the epub. Anyway, I'll keep digging.

Today, 06:23 AM	#7
z537815 Enthusiast Posts: 30 Karma: 10 Join Date: Aug 2019 Device: Lenovo TB-X704F	I think I solved my problem. Kind of. I first changed the file-extension from .EPUB to .ZIP. This gets me a compressed map with 3 entries: /METAINF, /OEBPS and a mimetype-file. And indeed, /META-INF does contain a "encryption.xml". /OEBPS contains a /Fonts with 2 entries: font00318.otf and font00319.otf, and the "content.opf" has the <manifest> specifying 2 entries: one each for the abovementioned fonts. I decided to get rid of those 2 fonts (simply deleted them) and funny enough, this - somehow - got rid of /Fonts and the "encryption.xml". Didn't touch the <manifest>. I then changed the file-extension back to .EPUB and behold! The problem has disappeared.

Today, 12:25 PM	#9
KevinH Sigil Developer Posts: 9,171 Karma: 6565346 Join Date: Nov 2009 Device: many	On the off chance they just mistakenly left in the encryption.xml file. you could try starting with a fresh copy of that epub, unzipping it and removing just the encryption.xml file, then save it. Try that. If the fonts still do not work, then they are still obfuscated and there is no way to recover them without the proper content.opf unique book id metadata value. Might be worth a shot. Alternatively the encryption.xml file may simply have the wrong paths to the font files in inside that epub, those paths should be from the root of the epub, NOT from the META-INF folder itself. If so you may be able to just fix the paths in the encryption.xml file, and everything may work as designed.