diff options
| -rw-r--r-- | src/crypto/tls/handshake_client.go | 8 | ||||
| -rw-r--r-- | src/crypto/tls/handshake_client_test.go | 78 | ||||
| -rw-r--r-- | src/crypto/tls/handshake_server.go | 4 |
3 files changed, 90 insertions, 0 deletions
diff --git a/src/crypto/tls/handshake_client.go b/src/crypto/tls/handshake_client.go index 63d86b9f3a..0ef87d4d77 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 { @@ -868,6 +872,10 @@ func (c *Conn) verifyServerCertificate(certificates [][]byte) error { c.sendAlert(alertBadCertificate) return errors.New("tls: failed to parse certificate from server: " + err.Error()) } + if cert.cert.PublicKeyAlgorithm == x509.RSA && cert.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) + } activeHandles[i] = cert certs[i] = cert.cert } diff --git a/src/crypto/tls/handshake_client_test.go b/src/crypto/tls/handshake_client_test.go index 22be38faff..6b5b61aed5 100644 --- a/src/crypto/tls/handshake_client_test.go +++ b/src/crypto/tls/handshake_client_test.go @@ -2616,3 +2616,81 @@ func TestClientHandshakeContextCancellation(t *testing.T) { t.Error("Client connection was not closed when the context was canceled") } } + +// discardConn wraps a net.Conn but discards all writes, but reports that they happened. +type discardConn struct { + net.Conn +} + +func (dc *discardConn) Write(data []byte) (int, error) { + return len(data), nil +} + +// largeRSAKeyCertPEM contains a 8193 bit RSA key +const largeRSAKeyCertPEM = `-----BEGIN CERTIFICATE----- +MIIInjCCBIWgAwIBAgIBAjANBgkqhkiG9w0BAQsFADASMRAwDgYDVQQDEwd0ZXN0 +aW5nMB4XDTIzMDYwNzIxMjMzNloXDTIzMDYwNzIzMjMzNlowEjEQMA4GA1UEAxMH +dGVzdGluZzCCBCIwDQYJKoZIhvcNAQEBBQADggQPADCCBAoCggQBAWdHsf6Rh2Ca +n2SQwn4t4OQrOjbLLdGE1pM6TBKKrHUFy62uEL8atNjlcfXIsa4aEu3xNGiqxqur +ZectlkZbm0FkaaQ1Wr9oikDY3KfjuaXdPdO/XC/h8AKNxlDOylyXwUSK/CuYb+1j +gy8yF5QFvVfwW/xwTlHmhUeSkVSQPosfQ6yXNNsmMzkd+ZPWLrfq4R+wiNtwYGu0 +WSBcI/M9o8/vrNLnIppoiBJJ13j9CR1ToEAzOFh9wwRWLY10oZhoh1ONN1KQURx4 +qedzvvP2DSjZbUccdvl2rBGvZpzfOiFdm1FCnxB0c72Cqx+GTHXBFf8bsa7KHky9 +sNO1GUanbq17WoDNgwbY6H51bfShqv0CErxatwWox3we4EcAmFHPVTCYL1oWVMGo +a3Eth91NZj+b/nGhF9lhHKGzXSv9brmLLkfvM1jA6XhNhA7BQ5Vz67lj2j3XfXdh +t/BU5pBXbL4Ut4mIhT1YnKXAjX2/LF5RHQTE8Vwkx5JAEKZyUEGOReD/B+7GOrLp +HduMT9vZAc5aR2k9I8qq1zBAzsL69lyQNAPaDYd1BIAjUety9gAYaSQffCgAgpRO +Gt+DYvxS+7AT/yEd5h74MU2AH7KrAkbXOtlwupiGwhMVTstncDJWXMJqbBhyHPF8 +3UmZH0hbL4PYmzSj9LDWQQXI2tv6vrCpfts3Cqhqxz9vRpgY7t1Wu6l/r+KxYYz3 +1pcGpPvRmPh0DJm7cPTiXqPnZcPt+ulSaSdlxmd19OnvG5awp0fXhxryZVwuiT8G +VDkhyARrxYrdjlINsZJZbQjO0t8ketXAELJOnbFXXzeCOosyOHkLwsqOO96AVJA8 +45ZVL5m95ClGy0RSrjVIkXsxTAMVG6SPAqKwk6vmTdRGuSPS4rhgckPVDHmccmuq +dfnT2YkX+wB2/M3oCgU+s30fAHGkbGZ0pCdNbFYFZLiH0iiMbTDl/0L/z7IdK0nH +GLHVE7apPraKC6xl6rPWsD2iSfrmtIPQa0+rqbIVvKP5JdfJ8J4alI+OxFw/znQe +V0/Rez0j22Fe119LZFFSXhRv+ZSvcq20xDwh00mzcumPWpYuCVPozA18yIhC9tNn +ALHndz0tDseIdy9vC71jQWy9iwri3ueN0DekMMF8JGzI1Z6BAFzgyAx3DkHtwHg7 +B7qD0jPG5hJ5+yt323fYgJsuEAYoZ8/jzZ01pkX8bt+UsVN0DGnSGsI2ktnIIk3J +l+8krjmUy6EaW79nITwoOqaeHOIp8m3UkjEcoKOYrzHRKqRy+A09rY+m/cAQaafW +4xp0Zv7qZPLwnu0jsqB4jD8Ll9yPB02ndsoV6U5PeHzTkVhPml19jKUAwFfs7TJg +kXy+/xFhYVUCAwEAATANBgkqhkiG9w0BAQsFAAOCBAIAAQnZY77pMNeypfpba2WK +aDasT7dk2JqP0eukJCVPTN24Zca+xJNPdzuBATm/8SdZK9lddIbjSnWRsKvTnO2r +/rYdlPf3jM5uuJtb8+Uwwe1s+gszelGS9G/lzzq+ehWicRIq2PFcs8o3iQMfENiv +qILJ+xjcrvms5ZPDNahWkfRx3KCg8Q+/at2n5p7XYjMPYiLKHnDC+RE2b1qT20IZ +FhuK/fTWLmKbfYFNNga6GC4qcaZJ7x0pbm4SDTYp0tkhzcHzwKhidfNB5J2vNz6l +Ur6wiYwamFTLqcOwWo7rdvI+sSn05WQBv0QZlzFX+OAu0l7WQ7yU+noOxBhjvHds +14+r9qcQZg2q9kG+evopYZqYXRUNNlZKo9MRBXhfrISulFAc5lRFQIXMXnglvAu+ +Ipz2gomEAOcOPNNVldhKAU94GAMJd/KfN0ZP7gX3YvPzuYU6XDhag5RTohXLm18w +5AF+ES3DOQ6ixu3DTf0D+6qrDuK+prdX8ivcdTQVNOQ+MIZeGSc6NWWOTaMGJ3lg +aZIxJUGdo6E7GBGiC1YTjgFKFbHzek1LRTh/LX3vbSudxwaG0HQxwsU9T4DWiMqa +Fkf2KteLEUA6HrR+0XlAZrhwoqAmrJ+8lCFX3V0gE9lpENfVHlFXDGyx10DpTB28 +DdjnY3F7EPWNzwf9P3oNT69CKW3Bk6VVr3ROOJtDxVu1ioWo3TaXltQ0VOnap2Pu +sa5wfrpfwBDuAS9JCDg4ttNp2nW3F7tgXC6xPqw5pvGwUppEw9XNrqV8TZrxduuv +rQ3NyZ7KSzIpmFlD3UwV/fGfz3UQmHS6Ng1evrUID9DjfYNfRqSGIGjDfxGtYD+j +Z1gLJZuhjJpNtwBkKRtlNtrCWCJK2hidK/foxwD7kwAPo2I9FjpltxCRywZUs07X +KwXTfBR9v6ij1LV6K58hFS+8ezZyZ05CeVBFkMQdclTOSfuPxlMkQOtjp8QWDj+F +j/MYziT5KBkHvcbrjdRtUJIAi4N7zCsPZtjik918AK1WBNRVqPbrgq/XSEXMfuvs +6JbfK0B76vdBDRtJFC1JsvnIrGbUztxXzyQwFLaR/AjVJqpVlysLWzPKWVX6/+SJ +u1NQOl2E8P6ycyBsuGnO89p0S4F8cMRcI2X1XQsZ7/q0NBrOMaEp5T3SrWo9GiQ3 +o2SBdbs3Y6MBPBtTu977Z/0RO63J3M5i2tjUiDfrFy7+VRLKr7qQ7JibohyB8QaR +9tedgjn2f+of7PnP/PEl1cCphUZeHM7QKUMPT8dbqwmKtlYY43EHXcvNOT5IBk3X +9lwJoZk/B2i+ZMRNSP34ztAwtxmasPt6RAWGQpWCn9qmttAHAnMfDqe7F7jVR6rS +u58= +-----END CERTIFICATE-----` + +func TestHandshakeRSATooBig(t *testing.T) { + testCert, _ := pem.Decode([]byte(largeRSAKeyCertPEM)) + + c := &Conn{conn: &discardConn{}, config: testConfig.Clone()} + + expectedErr := "tls: server sent certificate containing RSA key larger than 8192 bits" + err := c.verifyServerCertificate([][]byte{testCert.Bytes}) + if err == nil || err.Error() != expectedErr { + t.Errorf("Conn.verifyServerCertificate unexpected error: want %q, got %q", expectedErr, err) + } + + expectedErr = "tls: client sent certificate containing RSA key larger than 8192 bits" + err = c.processCertsFromClient(Certificate{Certificate: [][]byte{testCert.Bytes}}) + if err == nil || err.Error() != expectedErr { + t.Errorf("Conn.processCertsFromClient unexpected error: want %q, got %q", expectedErr, err) + } +} diff --git a/src/crypto/tls/handshake_server.go b/src/crypto/tls/handshake_server.go index e22f284cfb..9def927314 100644 --- a/src/crypto/tls/handshake_server.go +++ b/src/crypto/tls/handshake_server.go @@ -818,6 +818,10 @@ func (c *Conn) processCertsFromClient(certificate Certificate) error { c.sendAlert(alertBadCertificate) return errors.New("tls: failed to parse client certificate: " + err.Error()) } + if certs[i].PublicKeyAlgorithm == x509.RSA && certs[i].PublicKey.(*rsa.PublicKey).N.BitLen() > maxRSAKeySize { + c.sendAlert(alertBadCertificate) + return fmt.Errorf("tls: client sent certificate containing RSA key larger than %d bits", maxRSAKeySize) + } } if len(certs) == 0 && requiresClientCert(c.config.ClientAuth) { |