Check whether or not a certificate is self-signed.

net/cert/x509_certificate_nss.cc

Index: net/cert/x509_certificate_nss.cc
diff --git a/net/cert/x509_certificate_nss.cc b/net/cert/x509_certificate_nss.cc
index 9019625869aacf35bcf3280a4733eeb2bac5ccc6..05ca13ba4526e74b0e05581c54cc5d8333a06ac0 100644
--- a/net/cert/x509_certificate_nss.cc
+++ b/net/cert/x509_certificate_nss.cc
@@ -266,4 +266,15 @@ void X509Certificate::GetPublicKeyInfo(OSCertHandle cert_handle,
   x509_util::GetPublicKeyInfo(cert_handle, size_bits, type);
 }
 
+// static
+bool X509Certificate::IsSelfSigned(OSCertHandle cert_handle) {
+  SECKEYPublicKey* public_key = CERT_ExtractPublicKey(cert_handle);
+  if (!public_key)
+    return false;
+
+  SECStatus verified = CERT_VerifySignedDataWithPublicKey(
+      &cert_handle->signatureWrap, public_key, NULL);
+  return verified == SECSuccess;
+}
+
 }  // namespace net