I am working on an application hosted on Heroku that communicates with an apple system that requires SSL certificates to be in place. Apple requires that an ECC certificate be used where Heroku does not support ECC certificates - only RSA.
I am curious to know if I can generate my signing request with an ECC signature and use this to generate the certificate from apple but then convert this ECC key to an RSA key so that Heroku can still interpret this.
Do I have a drastic misunderstanding of how these two certificates are implemented that means this approach is not possible or do I just need to do the right openSSL commands to the cert to generate the key formats I need?
Related
I have a root certificate with a Signature algorithm md5RSA which is currently used by our clients.
I wish to create another root certificate with Signature algorithm ECDSA SHA-256 that will be above the older certificate in order to be backward compatible (so clients could authenticate with both the older MD5 certificate and the newer SHA-256 certificate using WCF).
How can i achieve this?
Thanks.
I'm trying to generate a certificate for my web server with Let's Encrypt. I want to manually generate key and csr with openssl, and then use letsencrypt / certbot to get the certificate. I specifically want the certificate to use sha256withecdsa. In particular I would like to use the curve secp521r1 (a.k.a. P-521).
The key generation and csr generation work fine, however, when I input the command
certbot certonly --apache -d [censored] --csr mycsr.csr --agree-tos
I get the following error:
The request message was malformed :: Invalid key in certificate request :: ECDSA curve P-521 not allowed
Is ECDSA still unsupported, or am I doing anything wrong?
While P-521 is valid for use in X.509 certificates, most browsers dropped support for it as it is not a part of Suite B and isn't very popular. As a result, Certbot doesn't allow certificates to be generated using P-521 since the browsers would reject it anyway. You can still generate certificates using the P-256 and P-384 curves. See the Mozilla and Google bugreports for details.
Besides my comments on #AfroThundr reply, in fact the definitive source of information on this is https://letsencrypt.org/docs/integration-guide/ and it says:
Supported Key Algorithms
Let’s Encrypt accepts RSA keys from 2048 to 4096 bits in length, and P-256 and P-384 ECDSA keys. That’s true for both account keys and certificate keys. You can’t reuse an account key as a certificate key.
Our recommendation is to serve a dual-cert config, offering an RSA certificate by default, and a (much smaller) ECDSA certificate to those clients that indicate support.
I need information related to ECDSA certificates. As far as I know ECDSA certificate should contain the ECDSA signature but I see that facebook and google server certificates have the ECDSA certificates with RSA signature.
Is it possible to have the ECDSA certificates with RSA signatures?
The signature for a certificate is created by the issuer using the key of the issuer. Thus if the certificate A has an ECC key inside (i.e. ECDSA certificate) but the issuer B has an RSA key then the signature for A will be an RSA signature, because this is what the issuer has for signing.
For example in the case of facebook.com the certificate itself has an ECC key, but the issuers certificate DigiCert SHA2 High Assurance Server CA has an RSA key. Because the signature for the facebook certificate is done by the issuer with the issuers key it must use RSA too.
Steffen's answer is correct for X.509 standard and many browsers
which are based on standard SSL libraries support the case. However, in this rough real world, I found some devices rejecting ECDSA certificate which has RSA signatures, with TLS 1.2 negotiation.
I think the reason is that the authors of the devices followed the RFC-4492, (** is mine)
2.2. ECDHE_ECDSA
In ECDHE_ECDSA, the server's certificate **MUST** contain an ECDSA-
capable public key and **be signed with ECDSA.**
The server sends its ephemeral ECDH public key and a specification of
the corresponding curve in the ServerKeyExchange message. These
parameters MUST be signed with ECDSA using the private key
corresponding to the public key in the server's Certificate.
though RFC-5246, TLS1.2, loosened this restriction. (** is mine):
7.4.4. Certificate Request
...
If the client provided a "signature_algorithms" extension, then all
certificates provided by the server MUST be signed by a
hash/signature algorithm pair that appears in that extension. **Note
that this implies that a certificate containing a key for one
signature algorithm MAY be signed using a different signature
algorithm (for instance, an RSA key signed with a DSA key). This is
a departure from TLS 1.1, which required that the algorithms be the
same.** Note that this also implies that the DH_DSS, DH_RSA,
ECDH_ECDSA, and ECDH_RSA key exchange algorithms do not restrict the
algorithm used to sign the certificate. Fixed DH certificates MAY be
signed with any hash/signature algorithm pair appearing in the
extension. The names DH_DSS, DH_RSA, ECDH_ECDSA, and ECDH_RSA are
historical.
So be warned that such a device exists.
Using EJBCA (6.2.0), after adding an ecdsa entity certificate on the Ejbca's "Admin" server, I tried to use the Ejbca public web to enroll this entity certificate, however, it only provides the choice to select RSA key bit length but not the named curves that I need ( note: I have all the certificate CA, profile configured as ECDSA). After spending few days to google on this topic, I come to the impression EJBCA only capable of using ECDSA to sign certificate but not to generate ECDSA keys!
I wonder if there is a way to workaround this issue ? Any help is greatly appreciated !
Thanks,
Harold T
This depends on which key pair you are generating. When generating a CA in EJBCA up to three keys and certificates are generated:
A CA signing keypair and certificate
An encryption keypair, used for encrypting keyrecovery information
An OCSP signer keypair and certificate
When using ECDSA keys, the CA signing keypair and the OCSP signer keypair will be the ECDSA keytype you select when creating the CA. The CA signing and OCSP signing certificate will be signed using your selected signature algorithm.
The encryption keypair will always be RSA, using 1024 or 2048 bit key length. It uses the key length set in the admin-GUI or 2048 bit by default using the cli. A dummy encryption certificate will be created using SHA1WithRSA.
using batch tool you can edit conf/batchtool.properties to achieve what you are asking for.
Future versions will support it in the gui as well.
We are in the process of setting up AS2 over https. https uses asymmetric key encryption and the certs are signed by a common CA. AS2 uses symmetric key encryption.
For AS2, it is my understanding that:
setting up a self-signed key (and exporting the cert or public key) is sufficient.
All I need to do next is pass on the cert to the trading partner
there isn't much advantage in getting the AS2 cert signed by a CA
if I do get the cert signed by a CA (say VeriSign), the advantage will be that I do not need to send the cert to the trading partner (effectively step 2 is not required)
Let me know if the above is correct.