{
    "scheme": "v1",
    "message": "v1\\n{log}\\n{contact}\\n{broadcast}\\n{url}",
    "mac": "HMAC-SHA256 -> base64url (no padding) -> first 27 chars",
    "param": "sig=1.<mac>",
    "key": "3d0f2b1c4a5e6f708192a3b4c5d6e7f8091a2b3c4d5e6f708192a3b4c5d6e7f8",
    "cases": [
        {
            "name": "plain",
            "log": "16235109",
            "contact": "15297179",
            "broadcast": "68",
            "url": "https://example.com/offer",
            "sig": "1.SRzxJm4bGuRd8cMiGTc1guUxcPP"
        },
        {
            "name": "query-and-plus",
            "log": "1",
            "contact": "2",
            "broadcast": "3",
            "url": "https://example.com/path?a=1&b=x+y&c=%20",
            "sig": "1.Zu0yfIUHxTX6QajnFdCVGoyX6UT"
        },
        {
            "name": "unicode",
            "log": "99",
            "contact": "7",
            "broadcast": "",
            "url": "https://例え.テスト/ページ?q=café",
            "sig": "1.mCfr1T-oF8iI0uS6W1HdXVpgJ0F"
        },
        {
            "name": "empty-broadcast-trigger",
            "log": "4444",
            "contact": "5555",
            "broadcast": "",
            "url": "http://shop.example.net/",
            "sig": "1.5DOMGB0oBjntK7Rhh-6eFo31v82"
        },
        {
            "name": "long-ids",
            "log": "9007199254740991",
            "contact": "123456789012",
            "broadcast": "98765",
            "url": "https://a.b.c.example.org/x/y/z#frag",
            "sig": "1.fBfvqyage4SuSogkKqKRSiqELR1"
        }
    ]
}