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| author | Roland Shoemaker <roland@golang.org> | 2021-06-09 11:31:27 -0700 |
|---|---|---|
| committer | Filippo Valsorda <filippo@golang.org> | 2021-07-12 20:58:00 +0000 |
| commit | a98589711da5e9d935e8d690cfca92892e86d557 (patch) | |
| tree | 681997c43c4dc353d23a6ba6410a87018a104cab /src/crypto | |
| parent | cfbd73ba33fc6a3635b3a63096fd6c6bff9d73e8 (diff) | |
| download | go-a98589711da5e9d935e8d690cfca92892e86d557.tar.gz go-a98589711da5e9d935e8d690cfca92892e86d557.zip | |
crypto/tls: test key type when casting
When casting the certificate public key in generateClientKeyExchange,
check the type is appropriate. This prevents a panic when a server
agrees to a RSA based key exchange, but then sends an ECDSA (or
other) certificate.
Fixes #47143
Fixes CVE-2021-34558
Thanks to Imre Rad for reporting this issue.
Change-Id: Iabccacca6052769a605cccefa1216a9f7b7f6aea
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1116723
Reviewed-by: Filippo Valsorda <valsorda@google.com>
Reviewed-by: Katie Hockman <katiehockman@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/334031
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Diffstat (limited to 'src/crypto')
| -rw-r--r-- | src/crypto/tls/key_agreement.go | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/crypto/tls/key_agreement.go b/src/crypto/tls/key_agreement.go index 8cfbd734f1..c28a64f3a8 100644 --- a/src/crypto/tls/key_agreement.go +++ b/src/crypto/tls/key_agreement.go @@ -86,7 +86,11 @@ func (ka rsaKeyAgreement) generateClientKeyExchange(config *Config, clientHello return nil, nil, err } - encrypted, err := rsa.EncryptPKCS1v15(config.rand(), cert.PublicKey.(*rsa.PublicKey), preMasterSecret) + rsaKey, ok := cert.PublicKey.(*rsa.PublicKey) + if !ok { + return nil, nil, errors.New("tls: server certificate contains incorrect key type for selected ciphersuite") + } + encrypted, err := rsa.EncryptPKCS1v15(config.rand(), rsaKey, preMasterSecret) if err != nil { return nil, nil, err } |