AES cipher: make padding optional

[Rob--W]

In the bad PDF of #5152, there is a block at some point without padding. This can be found by setting a breakpoint at

pdf.js/src/core/crypto.js

Line 981 in 669a4d1

outputLength -= lastBlock[15];

. When the breakpoint is hit for the second time, it consists of a value that is greater than 16. Consequently the outputLength does not match the byte size of the result, and in the loop thereafter, "RangeError: Source is too large" is thrown.

I've fixed this by checking whether the tail is really a padding before removing it from the output.

[Snuffleupagus]

/botio-linux preview

[pdfjsbot]

From: Bot.io (Linux)

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Command cmd_preview from @Snuffleupagus received. Current queue size: 0

Live output at: http://107.21.233.14:8877/cd2aacf332d681b/output.txt

[pdfjsbot]

From: Bot.io (Linux)

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Success

Full output at http://107.21.233.14:8877/cd2aacf332d681b/output.txt

Total script time: 0.75 mins

Published

• Viewer: http://107.21.233.14:8877/cd2aacf332d681b/web/viewer.html
• B2G Viewer: http://107.21.233.14:8877/cd2aacf332d681b/extensions/b2g/content/web/viewer.html
• Extension: http://107.21.233.14:8877/cd2aacf332d681b/extensions/firefox/pdf.js.xpi
• Extension (AMO): http://107.21.233.14:8877/cd2aacf332d681b/extensions/firefox/pdf.js.amo.xpi

[yurydelendik]

Looks good. Thanks

[yurydelendik]

Ops, forgot testing :)

/botio test

[pdfjsbot]

From: Bot.io (Linux)

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Command cmd_test from @yurydelendik received. Current queue size: 1

Live output at: http://107.21.233.14:8877/06a8eaf950b3977/output.txt

[pdfjsbot]

From: Bot.io (Windows)

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Command cmd_test from @yurydelendik received. Current queue size: 1

Live output at: http://107.22.172.223:8877/594f23fc311e730/output.txt

[pdfjsbot]

From: Bot.io (Windows)

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Success

Full output at http://107.22.172.223:8877/594f23fc311e730/output.txt

Total script time: 19.59 mins

• Font tests: Passed
• Unit tests: Passed
• Regression tests: Passed

[pdfjsbot]

From: Bot.io (Linux)

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Success

Full output at http://107.21.233.14:8877/06a8eaf950b3977/output.txt

Total script time: 22.55 mins

• Font tests: Passed
• Unit tests: Passed
• Regression tests: Passed