Fix RSA_W_ENC verify guard in signature wrapper

The DigestInfo length extraction in wc_SignatureVerifyHash was compiled
only when WOLFSSL_RSA_PUBLIC_ONLY was not defined, but the block depends
on ASN.1 support, not on private key support. In a public only build the
RSA verify path stays reachable and wc_SignatureVerify still DER encodes
the digest, so the length check fell through to the plain digest size
comparison and rejected every valid signature with BAD_LENGTH_E. The
same guard also broke compilation with NO_ASN and RSA enabled, since
asn.h is not included in that case and GetSequence and GetOctetString
are undeclared.

Guard the block on NO_ASN instead, matching the DER encode call site in
wc_SignatureVerify.

Fixes F-7412.

.github/configs/os-check-linux.json

@@ -336,5 +336,9 @@
 {"name": "opensslextra-no-filesystem-no-bio", "minutes": 0.9,
  "configure": ["--enable-opensslextra", "--disable-filesystem", "CPPFLAGS=-DNO_BIO"]},
 {"name": "no-examples-no-malloc", "minutes": 0.8,
- "configure": ["--disable-examples", "CPPFLAGS=-DWOLFSSL_NO_MALLOC"]}
+ "configure": ["--disable-examples", "CPPFLAGS=-DWOLFSSL_NO_MALLOC"]},
+{"name": "cryptonly-no-asn-rsa", "minutes": 0.2, "check": false,
+ "comment": "RSA with ASN.1 disabled. Build only, since wolfcrypt test and benchmark do not support this combination.",
+ "configure": ["--enable-cryptonly", "--disable-asn", "--enable-lowresource",
+  "--disable-crypttests", "--disable-examples"]}
 ]

wolfcrypt/src/signature.c

@@ -203,7 +203,7 @@ int wc_SignatureVerifyHash(
         return ret;
     }
 
-#if !defined(NO_RSA) && !defined(WOLFSSL_RSA_PUBLIC_ONLY)
+#if !defined(NO_RSA) && !defined(NO_ASN)
     /* For WC_SIGNATURE_TYPE_RSA_W_ENC, we need to extract the actual size of
      * the ASN.1-encoded hash.
      */