Check that ed25519 and ed448 are allowed by the security level

Signature algorithms not using an MD weren't checked that they're
allowed by the security level.
Reviewed-by: NTomáš Mráz <tmraz@fedoraproject.org>
GH: #11062

ssl/t1_lib.c

@@ -991,6 +991,31 @@ int tls_check_sigalg_curve(const SSL *s, int curve)
 }
 #endif
 
+/*
+ * Return the number of security bits for the signature algorithm, or 0 on
+ * error.
+ */
+static int sigalg_security_bits(const SIGALG_LOOKUP *lu)
+{
+    const EVP_MD *md = NULL;
+    int secbits = 0;
+
+    if (!tls1_lookup_md(lu, &md))
+        return 0;
+    if (md != NULL)
+    {
+        /* Security bits: half digest bits */
+        secbits = EVP_MD_size(md) * 4;
+    } else {
+        /* Values from https://tools.ietf.org/html/rfc8032#section-8.5 */
+        if (lu->sigalg == TLSEXT_SIGALG_ed25519)
+            secbits = 128;
+        else if (lu->sigalg == TLSEXT_SIGALG_ed448)
+            secbits = 224;
+    }
+    return secbits;
+}
+
 /*
  * Check signature algorithm is consistent with sent supported signature
  * algorithms and if so set relevant digest and signature scheme in
@@ -1004,6 +1029,7 @@ int tls12_check_peer_sigalg(SSL *s, uint16_t sig, EVP_PKEY *pkey)
     size_t sent_sigslen, i, cidx;
     int pkeyid = EVP_PKEY_id(pkey);
     const SIGALG_LOOKUP *lu;
+    int secbits = 0;
 
     /* Should never happen */
     if (pkeyid == -1)
@@ -1105,20 +1131,20 @@ int tls12_check_peer_sigalg(SSL *s, uint16_t sig, EVP_PKEY *pkey)
                  SSL_R_UNKNOWN_DIGEST);
         return 0;
     }
-    if (md != NULL) {
-        /*
-         * Make sure security callback allows algorithm. For historical
-         * reasons we have to pass the sigalg as a two byte char array.
-         */
-        sigalgstr[0] = (sig >> 8) & 0xff;
-        sigalgstr[1] = sig & 0xff;
-        if (!ssl_security(s, SSL_SECOP_SIGALG_CHECK,
-                    EVP_MD_size(md) * 4, EVP_MD_type(md),
-                    (void *)sigalgstr)) {
-            SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS12_CHECK_PEER_SIGALG,
-                     SSL_R_WRONG_SIGNATURE_TYPE);
-            return 0;
-        }
+    /*
+     * Make sure security callback allows algorithm. For historical
+     * reasons we have to pass the sigalg as a two byte char array.
+     */
+    sigalgstr[0] = (sig >> 8) & 0xff;
+    sigalgstr[1] = sig & 0xff;
+    secbits = sigalg_security_bits(lu);
+    if (secbits == 0 ||
+        !ssl_security(s, SSL_SECOP_SIGALG_CHECK, secbits,
+                      md != NULL ? EVP_MD_type(md) : NID_undef,
+                      (void *)sigalgstr)) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS12_CHECK_PEER_SIGALG,
+                 SSL_R_WRONG_SIGNATURE_TYPE);
+        return 0;
     }
     /* Store the sigalg the peer uses */
     s->s3->tmp.peer_sigalg = lu;
@@ -1625,11 +1651,8 @@ static int tls12_sigalg_allowed(const SSL *s, int op, const SIGALG_LOOKUP *lu)
         }
     }
 
-    if (lu->hash == NID_undef)
-        return 1;
-    /* Security bits: half digest bits */
-    secbits = EVP_MD_size(ssl_md(lu->hash_idx)) * 4;
     /* Finally see if security callback allows it */
+    secbits = sigalg_security_bits(lu);
     sigalgstr[0] = (lu->sigalg >> 8) & 0xff;
     sigalgstr[1] = lu->sigalg & 0xff;
     return ssl_security(s, op, secbits, lu->hash, (void *)sigalgstr);

test/ssl-tests/28-seclevel.conf

 # Generated with generate_ssl_tests.pl
 
-num_tests = 4
+num_tests = 6
 
 test-0 = 0-SECLEVEL 3 with default key
-test-1 = 1-SECLEVEL 3 with ED448 key
-test-2 = 2-SECLEVEL 3 with P-384 key, X25519 ECDHE
-test-3 = 3-SECLEVEL 3 with ED448 key, TLSv1.2
+test-1 = 1-SECLEVEL 4 with ED448 key
+test-2 = 2-SECLEVEL 5 server with ED448 key
+test-3 = 3-SECLEVEL 5 client with ED448 key
+test-4 = 4-SECLEVEL 3 with P-384 key, X25519 ECDHE
+test-5 = 5-SECLEVEL 3 with ED448 key, TLSv1.2
 # ===========================================================
 
 [0-SECLEVEL 3 with default key]
@@ -31,20 +33,20 @@ ExpectedResult = ServerFail
 
 # ===========================================================
 
-[1-SECLEVEL 3 with ED448 key]
-ssl_conf = 1-SECLEVEL 3 with ED448 key-ssl
+[1-SECLEVEL 4 with ED448 key]
+ssl_conf = 1-SECLEVEL 4 with ED448 key-ssl
 
-[1-SECLEVEL 3 with ED448 key-ssl]
-server = 1-SECLEVEL 3 with ED448 key-server
-client = 1-SECLEVEL 3 with ED448 key-client
+[1-SECLEVEL 4 with ED448 key-ssl]
+server = 1-SECLEVEL 4 with ED448 key-server
+client = 1-SECLEVEL 4 with ED448 key-client
 
-[1-SECLEVEL 3 with ED448 key-server]
+[1-SECLEVEL 4 with ED448 key-server]
 Certificate = ${ENV::TEST_CERTS_DIR}/server-ed448-cert.pem
-CipherString = DEFAULT:@SECLEVEL=3
+CipherString = DEFAULT:@SECLEVEL=4
 PrivateKey = ${ENV::TEST_CERTS_DIR}/server-ed448-key.pem
 
-[1-SECLEVEL 3 with ED448 key-client]
-CipherString = DEFAULT
+[1-SECLEVEL 4 with ED448 key-client]
+CipherString = DEFAULT:@SECLEVEL=4
 VerifyCAFile = ${ENV::TEST_CERTS_DIR}/root-ed448-cert.pem
 VerifyMode = Peer
 
@@ -54,49 +56,95 @@ ExpectedResult = Success
 
 # ===========================================================
 
-[2-SECLEVEL 3 with P-384 key, X25519 ECDHE]
-ssl_conf = 2-SECLEVEL 3 with P-384 key, X25519 ECDHE-ssl
+[2-SECLEVEL 5 server with ED448 key]
+ssl_conf = 2-SECLEVEL 5 server with ED448 key-ssl
+
+[2-SECLEVEL 5 server with ED448 key-ssl]
+server = 2-SECLEVEL 5 server with ED448 key-server
+client = 2-SECLEVEL 5 server with ED448 key-client
+
+[2-SECLEVEL 5 server with ED448 key-server]
+Certificate = ${ENV::TEST_CERTS_DIR}/server-ed448-cert.pem
+CipherString = DEFAULT:@SECLEVEL=5
+PrivateKey = ${ENV::TEST_CERTS_DIR}/server-ed448-key.pem
+
+[2-SECLEVEL 5 server with ED448 key-client]
+CipherString = DEFAULT:@SECLEVEL=4
+VerifyCAFile = ${ENV::TEST_CERTS_DIR}/root-ed448-cert.pem
+VerifyMode = Peer
+
+[test-2]
+ExpectedResult = ServerFail
+
+
+# ===========================================================
+
+[3-SECLEVEL 5 client with ED448 key]
+ssl_conf = 3-SECLEVEL 5 client with ED448 key-ssl
 
-[2-SECLEVEL 3 with P-384 key, X25519 ECDHE-ssl]
-server = 2-SECLEVEL 3 with P-384 key, X25519 ECDHE-server
-client = 2-SECLEVEL 3 with P-384 key, X25519 ECDHE-client
+[3-SECLEVEL 5 client with ED448 key-ssl]
+server = 3-SECLEVEL 5 client with ED448 key-server
+client = 3-SECLEVEL 5 client with ED448 key-client
 
-[2-SECLEVEL 3 with P-384 key, X25519 ECDHE-server]
+[3-SECLEVEL 5 client with ED448 key-server]
+Certificate = ${ENV::TEST_CERTS_DIR}/server-ed448-cert.pem
+CipherString = DEFAULT:@SECLEVEL=4
+PrivateKey = ${ENV::TEST_CERTS_DIR}/server-ed448-key.pem
+
+[3-SECLEVEL 5 client with ED448 key-client]
+CipherString = DEFAULT:@SECLEVEL=5
+VerifyCAFile = ${ENV::TEST_CERTS_DIR}/root-ed448-cert.pem
+VerifyMode = Peer
+
+[test-3]
+ExpectedResult = ServerFail
+
+
+# ===========================================================
+
+[4-SECLEVEL 3 with P-384 key, X25519 ECDHE]
+ssl_conf = 4-SECLEVEL 3 with P-384 key, X25519 ECDHE-ssl
+
+[4-SECLEVEL 3 with P-384 key, X25519 ECDHE-ssl]
+server = 4-SECLEVEL 3 with P-384 key, X25519 ECDHE-server
+client = 4-SECLEVEL 3 with P-384 key, X25519 ECDHE-client
+
+[4-SECLEVEL 3 with P-384 key, X25519 ECDHE-server]
 Certificate = ${ENV::TEST_CERTS_DIR}/p384-server-cert.pem
 CipherString = DEFAULT:@SECLEVEL=3
 Groups = X25519
 PrivateKey = ${ENV::TEST_CERTS_DIR}/p384-server-key.pem
 
-[2-SECLEVEL 3 with P-384 key, X25519 ECDHE-client]
+[4-SECLEVEL 3 with P-384 key, X25519 ECDHE-client]
 CipherString = ECDHE:@SECLEVEL=3
 VerifyCAFile = ${ENV::TEST_CERTS_DIR}/p384-root.pem
 VerifyMode = Peer
 
-[test-2]
+[test-4]
 ExpectedResult = Success
 
 
 # ===========================================================
 
-[3-SECLEVEL 3 with ED448 key, TLSv1.2]
-ssl_conf = 3-SECLEVEL 3 with ED448 key, TLSv1.2-ssl
+[5-SECLEVEL 3 with ED448 key, TLSv1.2]
+ssl_conf = 5-SECLEVEL 3 with ED448 key, TLSv1.2-ssl
 
-[3-SECLEVEL 3 with ED448 key, TLSv1.2-ssl]
-server = 3-SECLEVEL 3 with ED448 key, TLSv1.2-server
-client = 3-SECLEVEL 3 with ED448 key, TLSv1.2-client
+[5-SECLEVEL 3 with ED448 key, TLSv1.2-ssl]
+server = 5-SECLEVEL 3 with ED448 key, TLSv1.2-server
+client = 5-SECLEVEL 3 with ED448 key, TLSv1.2-client
 
-[3-SECLEVEL 3 with ED448 key, TLSv1.2-server]
+[5-SECLEVEL 3 with ED448 key, TLSv1.2-server]
 Certificate = ${ENV::TEST_CERTS_DIR}/server-ed448-cert.pem
 CipherString = DEFAULT:@SECLEVEL=3
 MaxProtocol = TLSv1.2
 PrivateKey = ${ENV::TEST_CERTS_DIR}/server-ed448-key.pem
 
-[3-SECLEVEL 3 with ED448 key, TLSv1.2-client]
+[5-SECLEVEL 3 with ED448 key, TLSv1.2-client]
 CipherString = DEFAULT
 VerifyCAFile = ${ENV::TEST_CERTS_DIR}/root-ed448-cert.pem
 VerifyMode = Peer
 
-[test-3]
+[test-5]
 ExpectedResult = Success
 
 

test/ssl-tests/28-seclevel.conf.in

@@ -23,13 +23,38 @@ our @tests = (
 
 our @tests_ec = (
     {
-        name => "SECLEVEL 3 with ED448 key",
-        server => { "CipherString" => "DEFAULT:\@SECLEVEL=3",
+        name => "SECLEVEL 4 with ED448 key",
+        server => { "CipherString" => "DEFAULT:\@SECLEVEL=4",
                     "Certificate" => test_pem("server-ed448-cert.pem"),
                     "PrivateKey" => test_pem("server-ed448-key.pem") },
-        client => { "VerifyCAFile" => test_pem("root-ed448-cert.pem") },
+        client => { "CipherString" => "DEFAULT:\@SECLEVEL=4",
+                    "VerifyCAFile" => test_pem("root-ed448-cert.pem") },
         test   => { "ExpectedResult" => "Success" },
     },
+    {
+        # The Ed488 signature algorithm will not be enabled.
+        # Because of the config order, the certificate is first loaded, and
+        # then the security level is chaged. If you try this with s_server
+        # the order will be reversed and it will instead fail to load the key.
+        name => "SECLEVEL 5 server with ED448 key",
+        server => { "CipherString" => "DEFAULT:\@SECLEVEL=5",
+                    "Certificate" => test_pem("server-ed448-cert.pem"),
+                    "PrivateKey" => test_pem("server-ed448-key.pem") },
+        client => { "CipherString" => "DEFAULT:\@SECLEVEL=4",
+                    "VerifyCAFile" => test_pem("root-ed448-cert.pem") },
+        test   => { "ExpectedResult" => "ServerFail" },
+    },
+    {
+        # The client will not sent the Ed488 signature algorithm, so the server
+        # doesn't have a useable signature algorithm for the certificate.
+        name => "SECLEVEL 5 client with ED448 key",
+        server => { "CipherString" => "DEFAULT:\@SECLEVEL=4",
+                    "Certificate" => test_pem("server-ed448-cert.pem"),
+                    "PrivateKey" => test_pem("server-ed448-key.pem") },
+        client => { "CipherString" => "DEFAULT:\@SECLEVEL=5",
+                    "VerifyCAFile" => test_pem("root-ed448-cert.pem") },
+        test   => { "ExpectedResult" => "ServerFail" },
+    },
     {
         name => "SECLEVEL 3 with P-384 key, X25519 ECDHE",
         server => { "CipherString" => "DEFAULT:\@SECLEVEL=3",