res_srtp: Add support for libsrtp2.x on openSUSE.

Since ASTERISK-26976, libSRTP 2.x can be used for sRTP. However, that change
added a private header which is not available on openSUSE for example. To
remain compatibility with very old libSRTP versions, the affected/missing
symbols AES_128_ICM and HMAC_SHA1 are defined manually.

ASTERISK-27733

Change-Id: I25c5cb8fa966043d1506ebef449e5a724412b4b6

res/res_srtp.c

@@ -41,7 +41,6 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #if HAVE_SRTP_VERSION > 1
 # include <srtp2/srtp.h>
-# include <srtp2/crypto_types.h>
 # include "srtp/srtp_compat.h"
 # include <openssl/rand.h>
 #else

res/srtp/srtp_compat.h

@@ -5,12 +5,8 @@
 
 #define crypto_policy_t srtp_crypto_policy_t
 
-#if defined(SRTP_AES_ICM_128)
-#define AES_128_ICM SRTP_AES_ICM_128
-#else
-#define AES_128_ICM SRTP_AES_ICM
-#endif
-#define HMAC_SHA1 SRTP_HMAC_SHA1
+#define AES_128_ICM 1
+#define HMAC_SHA1 3
 
 #define err_status_t srtp_err_status_t
 #define err_status_ok srtp_err_status_ok