Summary
The crypto/tls/generate_cert.go utility should only set the template
x509.Certificate's KeyUsage field to a value with the
x509.KeyUsageKeyEncipherment bits set when the certificate subject
public key is an RSA public key, not an ECDSA or ED25519 public key.
Background
RFC 5480 describes the usage of ECDSA elliptic curve subject keys with
X.509. Unfortunately while Section 3 "Key Usages Bits" indicates which
key usage bits MAY be used with a certificate that indicates
id-ecPublicKey in the SubjectPublicKeyInfo field it doesn't provide
guidance on which usages should *not* be included (e.g. the
keyEncipherment bit, which is particular to RSA key exchange). The same
problem is present in RFC 8410 Section 5 describing Key Usage Bits for
ED25519 elliptic curve subject keys.
There's an update to RFC 5480 in last call stage within the IETF LAMPS
WG, draft-ietf-lamps-5480-ku-clarifications-00. This update is meant
to clarify the allowed Key Usages extension values for certificates with
ECDSA subject public keys by adding:
> If the keyUsage extension is present in a certificate that indicates
> id-ecPublicKey as algorithm of AlgorithmIdentifier [RFC2986] in
> SubjectPublicKeyInfo, then following values MUST NOT be present:
>
> keyEncipherment; and
> dataEncipherment.
I don't believe there is an update for RFC 8410 in the works but I
suspect it will be clarified similarly in the future.
This commit updates generate_cert.go to ensure when the certificate
public key is ECDSA or ED25519 the generated certificate has the
x509.Certificate.KeyUsage field set to a value that doesn't include KUs
specific to RSA. For ECDSA keys this will adhere to the updated RFC 5480
language.
Fixes#36499
Change-Id: Ib1b0757c039b7fe97fc6d1e826fe6b88856c1964
GitHub-Last-Rev: a8f34fb33dde90e09b6f9a27b2598a82b3023abb
GitHub-Pull-Request: golang/go#36500
Reviewed-on: https://go-review.googlesource.com/c/go/+/214337
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We should keep a consistent way of formatting errors
in this file.
Fixes#34848
Change-Id: Ibb75908504f381fccab0281a42e788ef8c716b6f
Reviewed-on: https://go-review.googlesource.com/c/go/+/200679
Run-TryBot: Johan Brandhorst <johan.brandhorst@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Support for Ed25519 certificates was added in CL 175478, this wires them
up into the TLS stack according to RFC 8422 (TLS 1.2) and RFC 8446 (TLS 1.3).
RFC 8422 also specifies support for TLS 1.0 and 1.1, and I initially
implemented that, but even OpenSSL doesn't take the complexity, so I
just dropped it. It would have required keeping a buffer of the
handshake transcript in order to do the direct Ed25519 signatures. We
effectively need to support TLS 1.2 because it shares ClientHello
signature algorithms with TLS 1.3.
While at it, reordered the advertised signature algorithms in the rough
order we would want to use them, also based on what curves have fast
constant-time implementations.
Client and client auth tests changed because of the change in advertised
signature algorithms in ClientHello and CertificateRequest.
Fixes#25355
Change-Id: I9fdd839afde4fd6b13fcbc5cc7017fd8c35085ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/177698
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
I don't expect these to hit often, but we should still alert users if
we fail to write the correct data to the file, or fail to close it.
Change-Id: I33774e94108f7f18ed655ade8cca229b1993d4d2
Reviewed-on: https://go-review.googlesource.com/91456
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Users (like myself) may be tempted to think the higher-numbered curve
is somehow better or more secure, but P256 is currently the best
ECDSA implementation, due to its better support in TLS clients, and a
constant time implementation.
For example, sites that present a certificate signed with P521
currently fail to load in Chrome stable, and the error on the Go side
says simply "remote error: tls: illegal parameter".
Fixes#19901.
Change-Id: Ia5e689e7027ec423624627420e33029c56f0bd82
Reviewed-on: https://go-review.googlesource.com/40211
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
