boulder/sa/rate_limits.go

103 lines
3.0 KiB
Go

package sa
import (
"database/sql"
"strings"
"time"
"github.com/letsencrypt/boulder/features"
"github.com/weppos/publicsuffix-go/publicsuffix"
"golang.org/x/net/context"
)
// baseDomain returns the eTLD+1 of a domain name for the purpose of rate
// limiting. For a domain name that is itself an eTLD, it returns its input.
func baseDomain(name string) string {
eTLDPlusOne, err := publicsuffix.Domain(name)
if err != nil {
// publicsuffix.Domain will return an error if the input name is itself a
// public suffix. In that case we use the input name as the key for rate
// limiting. Since all of its subdomains will have separate keys for rate
// limiting (e.g. "foo.bar.publicsuffix.com" will have
// "bar.publicsuffix.com", this means that domains exactly equal to a
// public suffix get their own rate limit bucket. This is important
// because otherwise they might be perpetually unable to issue, assuming
// the rate of issuance from their subdomains was high enough.
return name
}
return eTLDPlusOne
}
// addCertificatesPerName adds 1 to the rate limit count for the provided domains,
// in a specific time bucket. It must be executed in a transaction, and the
// input timeToTheHour must be a time rounded to an hour.
func (ssa *SQLStorageAuthority) addCertificatesPerName(
ctx context.Context,
db dbSelectExecer,
names []string,
timeToTheHour time.Time,
) error {
if !features.Enabled(features.FasterRateLimit) {
return nil
}
// De-duplicate the base domains.
baseDomainsMap := make(map[string]bool)
var qmarks []string
var values []interface{}
for _, name := range names {
base := baseDomain(name)
if !baseDomainsMap[base] {
baseDomainsMap[base] = true
values = append(values, base, timeToTheHour, 1)
qmarks = append(qmarks, "(?, ?, ?)")
}
}
_, err := db.Exec(`INSERT INTO certificatesPerName (eTLDPlusOne, time, count) VALUES `+
strings.Join(qmarks, ", ")+` ON DUPLICATE KEY UPDATE count=count+1;`,
values...)
if err != nil {
return err
}
return nil
}
// countCertificatesFaster returns, for a single domain, the count of
// certificates issued in the given time range for that domain's eTLD+1 (aka
// base domain). It uses the certificatesPerName table to make this lookup fast.
// This function can replace both countCertificatesByName and
// countCertificatesByExactName because domains that are exactly equal to an
// public suffix have their issuances counted under a separate bucket from their
// subdomains.
func (ssa *SQLStorageAuthority) countCertificatesFaster(
db dbSelector,
domain string,
earliest,
latest time.Time,
) (int, error) {
base := baseDomain(domain)
var counts []int
_, err := db.Select(
&counts,
`SELECT count FROM certificatesPerName
WHERE eTLDPlusOne = :baseDomain AND
time > :earliest AND
time <= :latest`,
map[string]interface{}{
"baseDomain": base,
"earliest": earliest,
"latest": latest,
})
if err == sql.ErrNoRows {
return 0, nil
} else if err != nil {
return 0, err
}
var total int
for _, count := range counts {
total += count
}
return total, nil
}