Webrisk (and Safebrowsing) Hashing Algorithm


Returns list of hashes for given URL

``javascript
npm install webrisk-hash
`

$3

`javascript
getPrefixes("https://google.com/a/test/index.html?abc123") ===
new Set([
Buffer.from([136, 152, 30, 98]),
Buffer.from([166, 49, 51, 141]),
Buffer.from([184, 40, 242, 237]),
Buffer.from([24, 12, 238, 174]),
Buffer.from([92, 148, 141, 10])
])
`

$3

#### suffixPostfixExpressions

Returns list of expressions suitable for webrisk API (https://cloud.google.com/web-risk/docs/urls-hashing#suffixprefix_expressions)

`javascript
const { suffixPostfixExpressions } = require('webrisk-hash');
suffixPostfixExpressions('http://a.b.c/1/2.html?param=1') === new Set([
'a.b.c/1/2.html?param=1',
'a.b.c/1/2.html',
'a.b.c/',
'a.b.c/1/',
'b.c/1/2.html?param=1',
'b.c/1/2.html',
'b.c/',
'b.c/1/',
]);

suffixPostfixExpressions('http://192.168.0.1/1') === new Set([
'192.168.0.1/1',
'192.168.0.1/',
]));
`

#### canonicalize

Makes URL canonical according to the crazy webrisk requirements (https://cloud.google.com/web-risk/docs/urls-hashing#canonicalization)

`javascript
const { canonicalize } = require('webrisk-hash');
canonicalize("http://host/%25%32%35") == "http://host/%25";
canonicalize("http://host/%25%32%35%25%32%35") == "http://host/%25%25";
canonicalize("http://host/%2525252525252525") == "http://host/%25";
canonicalize("http://host/asdf%25%32%35asd") == "http://host/asdf%25asd";
canonicalize("http://host/%%%25%32%35asd%%") == "http://host/%25%25%25asd%25%25";
canonicalize("http://www.google.com/") == "http://www.google.com/";
canonicalize("http://%31%36%38%2e%31%38%38%2e%39%39%2e%32%36/%2E%73%65%63%75%72%65/%77%77%77%2E%65%62%61%79%2E%63%6F%6D/") == "http://c68.188.99.26/.secure/www.ebay.com/";
canonicalize("http://195.127.0.11/uploads/%20%20%20%20/.verify/.eBaysecure==updateuserdataxplimnbqmn-xplmvalidateinfoswqpcmlx==hgplmcx/") c "http://195.127.0.11/uploads/%20%20%20%20/.verify/.eBaysecure==updateuserdataxplimnbqmn-xplmvalidateinfoswqpcmlx==hgplmcx/";
canonicalize("http://host%23.com/%257Ea%2521b%2540c%2523d%2524e%25f%255E00%252611%252A22%252833%252944_55%252B") == "http://host%23.com/ca!b@c%23d$e%25f^00&11*22(33)44_55+";
canonicalize("http://3279880203/blah") == "http://195.127.0.11/blah";
canonicalize("http://www.google.com/blah/..") == "http://www.google.com/";
canonicalize("www.google.com/") == "http://www.google.com/";
canonicalize("www.google.com") == "http://www.google.com/";
canonicalize("http://www.evil.com/blah#frag") == "http://www.evil.com/blah";
canonicalize("http://www.GOOgle.com/") == "http://www.google.com/";
canonicalize("http://www.google.com.../") == "http://www.google.com/";
canonicalize("http://www.google.com/foo\tbar\rbaz\n2") =="http://www.google.com/foobarbaz2";
canonicalize("http://www.google.com/q?") == "http://www.google.com/q?";
canonicalize("http://www.google.com/q?r?") == "http://www.google.com/q?r?";
canonicalize("http://www.google.com/q?r?s") == "http://www.google.com/q?r?s";
canonicalize("http://evil.com/foo#bar#baz") == "http://evil.com/foo";
canonicalize("http://evil.com/foo;") == "http://evil.com/foo;";
canonicalize("http://evil.com/foo?bar;") == "http://evil.com/foo?bar;";
canonicalize("http://\x01.com/") == "http://%01.com/";
canonicalize("http://notrailingslash.com") == "http://notrailingslash.com/";
canonicalize("http://www.gotaport.com:1234/") == "http://www.gotaport.com/";
canonicalize(" http://www.google.com/ ") == "http://www.google.com/";
canonicalize("http:// leadingspace.com/") == "http://%20leadingspace.com/";
canonicalize("http://%20leadingspace.com/") == "http://%20leadingspace.com/";
canonicalize("%20leadingspace.com/") == "http://%20leadingspace.com/";
canonicalize("https://www.securesite.com/") == "https://www.securesite.com/";
canonicalize("http://host.com/ab%23cd") == "http://host.com/ab%23cd";
canonicalize("http://host.com//twoslashes?more//slashes") == "http://host.com/twoslashes?more//slashes";
``