Blocking based on file size in Bluecoat Proxy SG

For blocking the download based on file size, you would have to apply that under the Visual Policy Manager. It would be under the Web Access Layer and under Destination. Click set and select Response Header. Set the Header Name to Content-Length and add the Header Regex below according to the file size. Note that those regex below will block the file size specified and above.

500kb :

[0-9]{7,12}|[5-9][0-9]{4}

1 MB :

[0-9]{8,12}|[1-9][0-9]{6}

2 MB :

[0-9]{8,12}|[2-9][0-9]{6}

3 MB :

[0-9]{8,12}|[3-9][0-9]{6}

5 MB :

[0-9]{8,12}|[5-9][0-9]{6}

10 MB :

[0-9]{9,12}|[1-9][0-9]{8}

20 MB :

[0-9]{9,12}|[2-9][0-9]{8}

50 MB :

[0-9]{9,12}|[5-9][0-9]{8}

100 MB :

[0-9]{10,12}|[1-9][0-9]{10}