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diff --git a/stand/efi/loader/main.c b/stand/efi/loader/main.c
--- a/stand/efi/loader/main.c
+++ b/stand/efi/loader/main.c
@@ -57,6 +57,9 @@
#include <bootstrap.h>
#include <smbios.h>
+#include <dev/random/fortuna.h>
+#include <geom/eli/pkcs5v2.h>
+
#include "efizfs.h"
#include "framebuffer.h"
@@ -1250,11 +1253,27 @@
{
EFI_STATUS status;
EFI_RNG_PROTOCOL *rng;
- unsigned int size = 2048;
+ unsigned int size_efi = RANDOM_FORTUNA_DEFPOOLSIZE * RANDOM_FORTUNA_NPOOLS;
+ unsigned int size = RANDOM_FORTUNA_DEFPOOLSIZE * RANDOM_FORTUNA_NPOOLS;
+ void *buf_efi;
void *buf;
if (argc > 1) {
- size = strtol(argv[1], NULL, 0);
+ size_efi = strtol(argv[1], NULL, 0);
+
+ /* Don't *compress* the entropy we get from EFI. */
+ if (size_efi > size)
+ size = size_efi;
+
+ /*
+ * If the amount of entropy we get from EFI is less than the
+ * size of a single Fortuna pool -- i.e. not enough to ensure
+ * that Fortuna is safely seeded -- don't expand it since we
+ * don't want to trick Fortuna into thinking that it has been
+ * safely seeded when it has not.
+ */
+ if (size_efi < RANDOM_FORTUNA_DEFPOOLSIZE)
+ size = size_efi;
}
status = BS->LocateProtocol(&rng_guid, NULL, (VOID **)&rng);
@@ -1268,20 +1287,34 @@
return (CMD_ERROR);
}
+ if ((buf_efi = malloc(size_efi)) == NULL) {
+ free(buf);
+ command_errmsg = "out of memory";
+ return (CMD_ERROR);
+ }
+
TSENTER2("rng->GetRNG");
- status = rng->GetRNG(rng, NULL, size, (UINT8 *)buf);
+ status = rng->GetRNG(rng, NULL, size_efi, (UINT8 *)buf_efi);
TSEXIT();
if (status != EFI_SUCCESS) {
+ free(buf_efi);
free(buf);
command_errmsg = "GetRNG failed";
return (CMD_ERROR);
}
+ if (size_efi < size)
+ pkcs5v2_genkey_raw(buf, size, "", 0, buf_efi, size_efi, 1);
+ else
+ memcpy(buf, buf_efi, size);
if (file_addbuf("efi_rng_seed", "boot_entropy_platform", size, buf) != 0) {
+ free(buf_efi);
free(buf);
return (CMD_ERROR);
}
+ explicit_bzero(buf_efi, size_efi);
+ free(buf_efi);
free(buf);
return (CMD_OK);
}

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