internal: derive WOLFSSH_NO_MLDSA when every level is off

.github/workflows/mldsa-composite-config.yml

@@ -1,6 +1,6 @@
 name: ML-DSA Composite Configs
 
-# Builds wolfSSH with ML-DSA on but traditional halves off, exercising the
+# Builds wolfSSH with ML-DSA levels or traditional halves off, exercising the
 # per-composite gates in wolfssh/internal.h in states the all-on and all-off
 # builds never reach.
 
@@ -68,6 +68,16 @@ jobs:
             defines: -DWOLFSSH_NO_ECDSA_SHA2_NISTP256 -DWOLFSSH_NO_ECDSA_SHA2_NISTP384 -DWOLFSSH_NO_ED25519 -DWOLFSSH_NO_MLDSA87
             expect: ''
             exclude_tests: tests/api.test tests/testsuite.test
+          # No level left, so WOLFSSH_NO_MLDSA itself must be derived;
+          # test_MlDsaLevelsDisabled in unit.test checks that.
+          - name: no-levels
+            defines: -DWOLFSSH_NO_MLDSA44 -DWOLFSSH_NO_MLDSA65 -DWOLFSSH_NO_MLDSA87
+            mldsa_off: true
+            expect: ''
+          # ML-DSA-44 alone off; its composites go, 65 and 87 stay.
+          - name: no-mldsa44
+            defines: -DWOLFSSH_NO_MLDSA44
+            expect: ssh-mldsa65-ed25519@wolfssl.com ssh-mldsa65-es256@wolfssl.com ssh-mldsa87-ed448@wolfssl.com ssh-mldsa87-es384@wolfssl.com
           # Sets one gate directly rather than deriving it, the rest left on
           # to expose a missed site. Only row with --enable-ossh-certs.
           - name: single-composite-gate
@@ -143,14 +153,20 @@ jobs:
           # A crash must not pass vacuously with an empty list.
           echo "$out" | grep -q '^Set Key: '
           keys=$(echo "$out" | sed -n 's/^Set Key: //p')
-          # ML-DSA itself must be on, or an empty composite list proves nothing.
-          echo "$keys" | grep -q 'ssh-mldsa-44'
+          acc=$(echo "$out" | sed -n 's/^Set Key Accepted: //p')
+          if [ '${{ matrix.mldsa_off }}' = 'true' ]; then
+              # No ML-DSA name of any kind in either table. A bare `!` does
+              # not trip bash -e, so fail explicitly.
+              if echo "$keys,$acc" | grep -q 'ssh-mldsa'; then exit 1; fi
+          else
+              # ML-DSA itself must be on, or an empty composite list proves nothing.
+              echo "$keys" | grep -q 'ssh-mldsa-[0-9]'
+          fi
           got=$(echo "$keys" | tr ',' '\n' | { grep -o 'ssh-mldsa[0-9][0-9]-.*' || true; } | LC_ALL=C sort -u | tr '\n' ' ' | sed 's/ $//')
           echo "composites offered: '$got'"
           test "$got" = "${{ matrix.expect }}"
           # Second table, gated in parallel with the host-key one.
           echo "$out" | grep -q '^Set Key Accepted: '
-          acc=$(echo "$out" | sed -n 's/^Set Key Accepted: //p')
           gotAcc=$(echo "$acc" | tr ',' '\n' | { grep -o 'ssh-mldsa[0-9][0-9]-.*' || true; } | LC_ALL=C sort -u | tr '\n' ' ' | sed 's/ $//')
           echo "composites accepted: '$gotAcc'"
           test "$gotAcc" = "${{ matrix.expect }}"

src/internal.c

@@ -211,7 +211,8 @@ typedef char wolfSSH_channel_overhead_check[
     HAVE_ED25519_KEY_EXPORT are all set. Disables ssh-ed25519 server and
     user authentication as well as the ML-DSA+Ed25519 composites.
   WOLFSSH_NO_MLDSA
-    Set when MLDSA is disabled and/or not included in wolfssl downloaded.
+    Set when MLDSA is disabled and/or not included in wolfssl downloaded,
+    or when WOLFSSH_NO_MLDSA44, 65 and 87 are all set.
   WOLFSSH_NO_MLDSA44
     Set for ML-DSA-44.
   WOLFSSH_NO_MLDSA65

tests/unit.c

@@ -1031,6 +1031,12 @@ static int test_KDF(void)
 }
 
 
+/* Checks the internal.h derivation directly, independent of any API. */
+#if defined(WOLFSSH_NO_MLDSA44) && defined(WOLFSSH_NO_MLDSA65) && \
+    defined(WOLFSSH_NO_MLDSA87) && !defined(WOLFSSH_NO_MLDSA)
+    #error "WOLFSSH_NO_MLDSA must follow from all three levels being off"
+#endif
+
 /* Key Generation Unit Test */
 
 #ifdef WOLFSSH_KEYGEN
@@ -1369,6 +1375,25 @@ static int test_MlDsaCompositesDisabled(void)
 
 #endif /* WOLFSSH_NO_MLDSA */
 
+/* API behaviour with no level built; the #error above covers the derivation. */
+#if defined(WOLFSSH_NO_MLDSA44) && defined(WOLFSSH_NO_MLDSA65) && \
+    defined(WOLFSSH_NO_MLDSA87)
+static int test_MlDsaLevelsDisabled(void)
+{
+    byte dummy[1];
+    int result = 0;
+    int sz;
+
+    sz = wolfSSH_MakeMlDsaKey(dummy, sizeof(dummy), WOLFSSH_MLDSAKEY_44);
+    if (sz != WS_NOT_COMPILED) {
+        printf("MlDsaLevelsDisabled: MakeMlDsaKey wrong result %d\n", sz);
+        result = -133;
+    }
+
+    return result;
+}
+#endif
+
 #endif /* WOLFSSH_KEYGEN */
 
 /* Exercises the malformed-input error paths of the WOLFSSH_FORMAT_OPENSSH
@@ -13223,7 +13248,7 @@ static int test_KEY_clean_osshCert(void)
 }
 #endif /* WOLFSSH_OSSH_CERTS */
 
-#if !defined(WOLFSSH_NO_MLDSA)
+#if !defined(WOLFSSH_NO_MLDSA) && !defined(WOLFSSH_NO_MLDSA44)
 /* keys/server-key-mldsa44.der - MlDsa44 OneAsymmetricKey */
 static const byte unitTestMlDsaPrivKey[] = {
     0x30, 0x82, 0x0a, 0x3e, 0x02, 0x01, 0x00, 0x30,
@@ -13556,7 +13581,7 @@ static const byte unitTestMlDsaPrivKey[] = {
     0x27, 0xfe, 0x32, 0x26, 0x3c, 0x33, 0x83, 0xda,
     0x18, 0xc9
 };
-#endif /* !WOLFSSH_NO_MLDSA */
+#endif /* !WOLFSSH_NO_MLDSA && !WOLFSSH_NO_MLDSA44 */
 
 #ifndef WOLFSSH_NO_ECDSA
 /* P-256 DER with the OID last byte changed 0x07 -> 0x01 (secp192r1).
@@ -23755,6 +23780,13 @@ int wolfSSH_UnitTest(int argc, char** argv)
     testResult = testResult || unitResult;
 #endif /* WOLFSSH_NO_MLDSA_COMPOSITES */
 #endif
+#if defined(WOLFSSH_NO_MLDSA44) && defined(WOLFSSH_NO_MLDSA65) && \
+    defined(WOLFSSH_NO_MLDSA87)
+    unitResult = test_MlDsaLevelsDisabled();
+    printf("MlDsaLevelsDisabled: %s\n",
+            (unitResult == 0 ? "SUCCESS" : "FAILED"));
+    testResult = testResult || unitResult;
+#endif
 #endif /* WOLFSSH_KEYGEN */
     unitResult = test_OpenSshPemNegative();
     printf("OpenSshPemNegative: %s\n",

wolfssh/internal.h

@@ -146,6 +146,12 @@ extern "C" {
     #define WOLFSSH_NO_MLDSA65
     #define WOLFSSH_NO_MLDSA87
 #endif
+/* Each composite needs its ML-DSA level, so no level leaves no ML-DSA. */
+#if defined(WOLFSSH_NO_MLDSA44) && defined(WOLFSSH_NO_MLDSA65) && \
+    defined(WOLFSSH_NO_MLDSA87)
+    #undef WOLFSSH_NO_MLDSA
+    #define WOLFSSH_NO_MLDSA
+#endif
 
 #ifdef NO_SHA
     #undef WOLFSSH_NO_SHA1