integritysetup: Add support for hmac-sha512 and wrapped key HMAC algorithms phmac-sha256 and phmac-sha512 (#39719)

Currently the only supported integrity algorithm using HMAC is
`hmac-sha256`. Add `hmac-sha512` to the list of supported algorithms as
well.

Also add the `PHMAC` integrity algorithm to the list of supported
algorithms. The `PHMAC` algorithm is like the regular HMAC algorithm,
but it takes a wrapped key as input. A key for the `PHMAC` algorithm is
an opaque key blob, who's physical size has nothing to do with the
cryptographic size. Such a wrapped key can for example be a HSM
protected key. Currently PHMAC is only available for the s390x
architecture (Linux on IBM Z).

Support for PHMAC has just been added to the cryptsetup project via MR
https://gitlab.com/cryptsetup/cryptsetup/-/merge_requests/693 by commit

https://gitlab.com/cryptsetup/cryptsetup/-/commit/296eb39c60bd85228930caaea4bb1d2a766b7544

To allow automatic opening of integrity protected volumes that use PHMAC
via `/etc/integritytab`, this change in systemd's integritysetup tool is
needed as well.

src/integritysetup/integrity-util.c

@@ -11,7 +11,7 @@
 #include "time-util.h"
 
 static int supported_integrity_algorithm(char *user_supplied) {
-        if (!STR_IN_SET(user_supplied, "crc32", "crc32c", "xxhash64", "sha1", "sha256", "hmac-sha256"))
+        if (!STR_IN_SET(user_supplied, "crc32", "crc32c", "xxhash64", "sha1", "sha256", "hmac-sha256", "hmac-sha512", "phmac-sha256", "phmac-sha512"))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unsupported integrity algorithm (%s)", user_supplied);
         return 0;
 }

src/integritysetup/integrity-util.h

@@ -12,4 +12,7 @@ int parse_integrity_options(
                 char **ret_integrity_alg);
 
 #define DM_HMAC_256 "hmac(sha256)"
+#define DM_HMAC_512 "hmac(sha512)"
+#define DM_PHMAC_256 "phmac(sha256)"
+#define DM_PHMAC_512 "phmac(sha512)"
 #define DM_MAX_KEY_SIZE 4096            /* Maximum size of key allowed for dm-integrity */

src/integritysetup/integritysetup.c

@@ -77,6 +77,12 @@ static const char *integrity_algorithm_select(const void *key_file_buf) {
         if (arg_integrity_algorithm) {
                 if (streq("hmac-sha256", arg_integrity_algorithm))
                         return DM_HMAC_256;
+                if (streq("hmac-sha512", arg_integrity_algorithm))
+                        return DM_HMAC_512;
+                if (streq("phmac-sha256", arg_integrity_algorithm))
+                        return DM_PHMAC_256;
+                if (streq("phmac-sha512", arg_integrity_algorithm))
+                        return DM_PHMAC_512;
                 return arg_integrity_algorithm;
         } else if (key_file_buf)
                 return DM_HMAC_256;