[tls] Split out hybrid MD5+SHA1 algorithm used in TLS version 1.1

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/md5_sha1.h

@@ -0,0 +1,42 @@
+#ifndef _IPXE_MD5_SHA1_H
+#define _IPXE_MD5_SHA1_H
+
+/** @file
+ *
+ * Hybrid MD5+SHA1 hash as used by TLSv1.1 and earlier
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
+
+#include <stdint.h>
+#include <ipxe/crypto.h>
+#include <ipxe/md5.h>
+#include <ipxe/sha1.h>
+
+/** An MD5+SHA1 context */
+struct md5_sha1_context {
+	/** MD5 context */
+	uint8_t md5[MD5_CTX_SIZE];
+	/** SHA-1 context */
+	uint8_t sha1[SHA1_CTX_SIZE];
+} __attribute__ (( packed ));
+
+/** MD5+SHA1 context size */
+#define MD5_SHA1_CTX_SIZE sizeof ( struct md5_sha1_context )
+
+/** An MD5+SHA1 digest */
+struct md5_sha1_digest {
+	/** MD5 digest */
+	uint8_t md5[MD5_DIGEST_SIZE];
+	/** SHA-1 digest */
+	uint8_t sha1[SHA1_DIGEST_SIZE];
+} __attribute__ (( packed ));
+
+/** MD5+SHA1 digest size */
+#define MD5_SHA1_DIGEST_SIZE sizeof ( struct md5_sha1_digest )
+
+extern struct digest_algorithm md5_sha1_algorithm;
+
+#endif /* _IPXE_MD5_SHA1_H */

src/include/ipxe/tls.h

@@ -307,28 +307,6 @@ struct tls_client_random {
 	uint8_t random[32];
 } __attribute__ (( packed ));
 
-/** An MD5+SHA1 context */
-struct md5_sha1_context {
-	/** MD5 context */
-	uint8_t md5[MD5_CTX_SIZE];
-	/** SHA-1 context */
-	uint8_t sha1[SHA1_CTX_SIZE];
-} __attribute__ (( packed ));
-
-/** MD5+SHA1 context size */
-#define MD5_SHA1_CTX_SIZE sizeof ( struct md5_sha1_context )
-
-/** An MD5+SHA1 digest */
-struct md5_sha1_digest {
-	/** MD5 digest */
-	uint8_t md5[MD5_DIGEST_SIZE];
-	/** SHA-1 digest */
-	uint8_t sha1[SHA1_DIGEST_SIZE];
-} __attribute__ (( packed ));
-
-/** MD5+SHA1 digest size */
-#define MD5_SHA1_DIGEST_SIZE sizeof ( struct md5_sha1_digest )
-
 /** A TLS session */
 struct tls_session {
 	/** Reference counter */