Custom cipher constants

Add some custom ctrls for Engine specific use.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

include/openssl/evp.h

@@ -427,6 +427,18 @@ struct evp_cipher_st {
 # define         EVP_CTRL_TLS1_1_MULTIBLOCK_DECRYPT      0x1b
 # define         EVP_CTRL_TLS1_1_MULTIBLOCK_MAX_BUFSIZE  0x1c
 
+/* For engine-specific control values */
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM0          0x1000
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM1          0x1001
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM2          0x1002
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM3          0x1003
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM4          0x1004
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM5          0x1005
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM6          0x1006
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM7          0x1007
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM8          0x1008
+# define         EVP_CTRL_ENGINE_CIPHER_CUSTOM9          0x1009
+
 /* RFC 5246 defines additional data to be 13 bytes in length */
 # define         EVP_AEAD_TLS1_AAD_LEN           13