tpm2-util: add helper for formatting PCR masks as string

2 files changed, 21 insertions, 0 deletions

diff --git a/src/shared/tpm2-util.c b/src/shared/tpm2-util.c
index f5b97fae73..7c9eb77f95 100644
--- a/src/shared/tpm2-util.c
+++ b/src/shared/tpm2-util.c
@@ -2160,3 +2160,22 @@ int tpm2_load_pcr_public_key(const char *path, void **ret_pubkey, size_t *ret_pu
 
         return 0;
 }
+
+int pcr_mask_to_string(uint32_t mask, char **ret) {
+        _cleanup_free_ char *buf = NULL;
+        int r;
+
+        assert(ret);
+
+        for (unsigned i = 0; i < TPM2_PCRS_MAX; i++) {
+                if (!(mask & (UINT32_C(1) << i)))
+                        continue;
+
+                r = strextendf_with_separator(&buf, "+", "%u", i);
+                if (r < 0)
+                        return r;
+        }
+
+        *ret = TAKE_PTR(buf);
+        return 0;
+}
diff --git a/src/shared/tpm2-util.h b/src/shared/tpm2-util.h
index 2ff7c0eb63..554ca58df6 100644
--- a/src/shared/tpm2-util.h
+++ b/src/shared/tpm2-util.h
@@ -146,3 +146,5 @@ int tpm2_parse_pcr_argument(const char *arg, uint32_t *mask);
 
 int tpm2_load_pcr_signature(const char *path, JsonVariant **ret);
 int tpm2_load_pcr_public_key(const char *path, void **ret_pubkey, size_t *ret_pubkey_size);
+
+int pcr_mask_to_string(uint32_t mask, char **ret);