Gerador de chaves DKIM
Generate a DKIM key pair, get the DNS record and private key it produces, or paste a record you already have and check it. The key pair is generated locally in your browser and never sent anywhere.
O que é o DKIM?
DKIM (DomainKeys Identified Mail) attaches a digital signature to every message you send, using a private key only your mail server knows. The receiving mailbox looks up the matching public key in your DNS and checks the signature, proof the message really came from you and wasn't altered in transit.
The key pair is generated once. The private key stays on your mail server or your email service provider, where it signs outgoing mail. The public key goes into a DNS TXT record at a location called the selector. That's the only part this tool publishes for you.
Selector
A short name that lets you run more than one key at once, useful for rotating keys or running several sending services side by side.
Chave pública (DNS)
Published as a TXT record at selector._domainkey.yourdomain.com. Anyone can look it up: that's the point.
Chave privada (o seu servidor)
Mantida em segredo e instalada onde quer que o seu email seja efetivamente assinado. Nunca a publique nem a envie para outro local.
DKIM on its own only proves a message wasn't tampered with. It's DMARC that decides what happens when a message fails. Once DKIM is signing cleanly, the DMARC policy generator is the natural next step.
Gere a sua chave
Fill in your domain and selector, pick a key size, and generate. The DNS record on the right updates with it. Already have a record? Paste it in to check it.
Gerar um par de chaves
Runs entirely in your browser. The private key is never sent anywhere.
Tamanho da chave
2048-bit é a recomendação atual. 1024-bit é mais fraco mas mais curto, o que importa se o seu fornecedor de DNS tiver dificuldades com registos TXT longos.
Restringir hashes a SHA-256
hOnly allow SHA-256 signatures. Leaving this off also accepts the older, weaker SHA-1. Most senders should keep this on.
Restringir a email
sLimitar esta chave à assinatura de email, para que não possa ser reutilizada para assinar qualquer outra coisa que verifique a tag s.
Modo de teste
t=yAsk receivers not to act on a signature failure yet. Useful while you roll this out. Turn it off once mail is signing and passing cleanly.
Correspondência estrita de subdomínio
t=sExigir que o domínio de assinatura corresponda exatamente ao seu domínio From, para que esta chave não possa ser usada para assinar por um subdomínio.
Chave privada
Gere um par de chaves para ver a sua chave privada aqui.
Registo DNS
Publique este registo TXT no seu domínio.
Add this as a new record at your DNS provider. “Type” and “Host” are the fields it asks for. Some providers want just mail._domainkey in the host field and add the domain for you.
Paste an existing record here to check it. It won't recover a private key.