Check SRP parameters early.

Check SRP parameters when they are received so we can send back an
appropriate alert.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>

ssl/ssl_locl.h

@@ -1390,6 +1390,9 @@ void ssl3_cbc_digest_record(
 void tls_fips_digest_extra(
 	const EVP_CIPHER_CTX *cipher_ctx, EVP_MD_CTX *mac_ctx,
 	const unsigned char *data, size_t data_len, size_t orig_len);
+
+int srp_verify_server_param(SSL *s, int *al);
+
 #else
 
 #define ssl_init_wbio_buffer SSL_test_functions()->p_ssl_init_wbio_buffer