diff options
Diffstat (limited to 'src/crypto/tls/handshake_client.go')
| -rw-r--r-- | src/crypto/tls/handshake_client.go | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/crypto/tls/handshake_client.go b/src/crypto/tls/handshake_client.go index 898d2e9af6..1c3d16714b 100644 --- a/src/crypto/tls/handshake_client.go +++ b/src/crypto/tls/handshake_client.go @@ -857,6 +857,10 @@ func (hs *clientHandshakeState) sendFinished(out []byte) error { return nil } +// maxRSAKeySize is the maximum RSA key size in bits that we are willing +// to verify the signatures of during a TLS handshake. +const maxRSAKeySize = 8192 + // verifyServerCertificate parses and verifies the provided chain, setting // c.verifiedChains and c.peerCertificates or sending the appropriate alert. func (c *Conn) verifyServerCertificate(certificates [][]byte) error { @@ -867,6 +871,10 @@ func (c *Conn) verifyServerCertificate(certificates [][]byte) error { c.sendAlert(alertBadCertificate) return errors.New("tls: failed to parse certificate from server: " + err.Error()) } + if cert.PublicKeyAlgorithm == x509.RSA && cert.PublicKey.(*rsa.PublicKey).N.BitLen() > maxRSAKeySize { + c.sendAlert(alertBadCertificate) + return fmt.Errorf("tls: server sent certificate containing RSA key larger than %d bits", maxRSAKeySize) + } certs[i] = cert } |