[NSS] ported mozilla upstream changes:

- Bug 1552254 internal_error alert on Certificate Request with sha1+ecdsa in TLS 1.3 (be6a9782)
- Bug 1753535 - Remove obsolete stateEnd check in SEC_ASN1DecoderUpdate. r=rrelyea (800111fa)
- Bug 1756271 - Remove token member from NSSSlot struct. r=rrelyea (55052f78)
- Bug 1396616 - Update nssUTF8_Length to RFC 3629 and fix buffer overrun. r=nss-reviewers,jschanck (2f2c8564)
- Bug 1755264 - TLS 1.3 Illegal legacy_version handling/alerts. r=djackson (7d931c59)
- Bug 1751305 - Remove expired explicitly distrusted certificates from certdata.txt. r=KathleenWilson (b722e523)
- Bug 1751298 - Add Telia Root CA v2 root certificate. r=KathleenWilson (1fcbbd7e)
- Bug 1754890 - Add two D-TRUST 2020 root certificates. r=KathleenWilson (f63fb86d)

security/nss/lib/ssl/tls13con.c

@@ -1585,7 +1585,8 @@ tls13_SelectServerCert(sslSocket *ss)
                                      cert->serverKeyPair->privKey,
                                      ss->xtnData.sigSchemes,
                                      ss->xtnData.numSigSchemes,
-                                     PR_FALSE);
+                                     PR_FALSE,
+                                     &ss->ssl3.hs.signatureScheme);
         if (rv == SECSuccess) {
             /* Found one. */
             ss->sec.serverCert = cert;
@@ -5808,6 +5809,17 @@ tls13_ClientReadSupportedVersion(sslSocket *ss)
         return SECFailure;
     }
 
+    /* Any endpoint receiving a Hello message with...ServerHello.legacy_version
+     * set to 0x0300 (SSL3) MUST abort the handshake with a "protocol_version"
+     * alert. [RFC8446, Section D.5]
+     *
+     * The ServerHello.legacy_version is read into the ss->version field by
+     * ssl_ClientReadVersion(). */
+    if (ss->version == SSL_LIBRARY_VERSION_3_0) {
+        FATAL_ERROR(ss, SSL_ERROR_RX_MALFORMED_SERVER_HELLO, protocol_version);
+        return SECFailure;
+    }
+
     ss->version = SSL_LIBRARY_VERSION_TLS_1_3;
     return SECSuccess;
 }