Merge pull request #11026 from kojo1/sig_min_hash_test

Honor WC_SIG_MIN_HASH_TYPE override in signature decision test

tests/api/test_signature.c

@@ -337,10 +337,14 @@ int test_wc_SignatureDecisionCoverage(void)
 
 #ifndef NO_SHA
             /* Hash weaker than WC_SIG_MIN_HASH_TYPE (default SHA-256)
-             * rejected by wc_SignatureCheckHashStrength() */
+             * rejected by wc_SignatureCheckHashStrength(). Only assert
-            ExpectIntEQ(wc_SignatureVerify(WC_HASH_TYPE_SHA, sig_type,
+             * when SHA-1 is below the effective floor of this build. */
-                data, data_len, sig, sig_len, &ecc, key_len),
+            if (wc_HashGetDigestSize(WC_SIG_MIN_HASH_TYPE) >
-                WC_NO_ERR_TRACE(BAD_FUNC_ARG));
+                    wc_HashGetDigestSize(WC_HASH_TYPE_SHA)) {
+                ExpectIntEQ(wc_SignatureVerify(WC_HASH_TYPE_SHA, sig_type,
+                    data, data_len, sig, sig_len, &ecc, key_len),
+                    WC_NO_ERR_TRACE(BAD_FUNC_ARG));
+            }
 #endif
 
             /* Real signature that fails verification: SIG_VERIFY_E.
@@ -518,8 +522,11 @@ int test_wc_SignatureDecisionCoverage(void)
             }
 
 #ifndef NO_SHA
-            /* Weak hash rejected before any hashing/signing occurs */
+            /* Weak hash rejected before any hashing/signing occurs. Only
-            {
+             * assert when SHA-1 is below the effective floor of this
+             * build. */
+            if (wc_HashGetDigestSize(WC_SIG_MIN_HASH_TYPE) >
+                    wc_HashGetDigestSize(WC_HASH_TYPE_SHA)) {
                 word32 lenCopy = (word32)eccSigMax;
                 ExpectIntEQ(wc_SignatureGenerate(WC_HASH_TYPE_SHA, sig_type,
                     data, data_len, genSig, &lenCopy, &ecc, key_len, &rng),

wolfcrypt/src/signature.c

@@ -53,16 +53,6 @@
     #endif
 #endif
 
-/* Minimum hash strength accepted by the wc_SignatureVerify/Generate
- * convenience APIs. Default is SHA-256 to keep MD5 and SHA-1 (both with
- * known collision attacks) out of new code. Define WC_SIG_MIN_HASH_TYPE
- * to a weaker wc_HashType (e.g. WC_HASH_TYPE_SHA) to opt back into legacy
- * behavior. The lower-level wc_SignatureVerifyHash/wc_SignatureGenerateHash
- * APIs are unaffected. */
-#ifndef WC_SIG_MIN_HASH_TYPE
-    #define WC_SIG_MIN_HASH_TYPE WC_HASH_TYPE_SHA256
-#endif
-
 static int wc_SignatureCheckHashStrength(enum wc_HashType hash_type)
 {
     int min_sz, this_sz;

wolfssl/wolfcrypt/signature.h

@@ -35,6 +35,16 @@
     extern "C" {
 #endif
 
+/* Minimum hash strength accepted by the wc_SignatureVerify/Generate
+ * convenience APIs. Default is SHA-256 to keep MD5 and SHA-1 (both with
+ * known collision attacks) out of new code. Define WC_SIG_MIN_HASH_TYPE
+ * to a weaker wc_HashType (e.g. WC_HASH_TYPE_SHA) to opt back into legacy
+ * behavior. The lower-level wc_SignatureVerifyHash/wc_SignatureGenerateHash
+ * APIs are unaffected. */
+#ifndef WC_SIG_MIN_HASH_TYPE
+    #define WC_SIG_MIN_HASH_TYPE WC_HASH_TYPE_SHA256
+#endif
+
 enum wc_SignatureType {
     WC_SIGNATURE_TYPE_NONE = 0,
     WC_SIGNATURE_TYPE_ECC = 1,