You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
192 lines
6.1 KiB
192 lines
6.1 KiB
2 years ago
|
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Daniel Axtens <dja@axtens.net>
|
||
|
|
Date: Thu, 1 Oct 2020 20:23:48 +1000
|
||
|
|
Subject: [PATCH] pgp: factor out rsa_pad
|
||
|
|
|
||
|
|
rsa_pad does the PKCS#1 v1.5 padding for the RSA signature scheme.
|
||
|
|
We want to use it in other RSA signature verification applications.
|
||
|
|
|
||
|
|
I considered and rejected putting it in lib/crypto.c. That file doesn't
|
||
|
|
currently require any MPI functions, but rsa_pad does. That's not so
|
||
|
|
much of a problem for the grub kernel and modules, but crypto.c also
|
||
|
|
gets built into all the grub utilities. So - despite the utils not
|
||
|
|
using any asymmetric ciphers - we would need to built the entire MPI
|
||
|
|
infrastructure in to them.
|
||
|
|
|
||
|
|
A better and simpler solution is just to spin rsa_pad out into its own
|
||
|
|
PKCS#1 v1.5 module.
|
||
|
|
|
||
|
|
Signed-off-by: Daniel Axtens <dja@axtens.net>
|
||
|
|
---
|
||
|
|
grub-core/Makefile.core.def | 8 ++++++
|
||
|
|
grub-core/commands/pgp.c | 28 ++-------------------
|
||
|
|
grub-core/lib/pkcs1_v15.c | 59 +++++++++++++++++++++++++++++++++++++++++++++
|
||
|
|
include/grub/pkcs1_v15.h | 27 +++++++++++++++++++++
|
||
|
|
4 files changed, 96 insertions(+), 26 deletions(-)
|
||
|
|
create mode 100644 grub-core/lib/pkcs1_v15.c
|
||
|
|
create mode 100644 include/grub/pkcs1_v15.h
|
||
|
|
|
||
|
|
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
|
||
|
|
index 81fc274148e..97347ae76f9 100644
|
||
|
|
--- a/grub-core/Makefile.core.def
|
||
|
|
+++ b/grub-core/Makefile.core.def
|
||
|
|
@@ -2510,6 +2510,14 @@ module = {
|
||
|
|
cppflags = '$(CPPFLAGS_GCRY)';
|
||
|
|
};
|
||
|
|
|
||
|
|
+module = {
|
||
|
|
+ name = pkcs1_v15;
|
||
|
|
+ common = lib/pkcs1_v15.c;
|
||
|
|
+
|
||
|
|
+ cflags = '$(CFLAGS_GCRY) -Wno-redundant-decls -Wno-sign-compare';
|
||
|
|
+ cppflags = '$(CPPFLAGS_GCRY)';
|
||
|
|
+};
|
||
|
|
+
|
||
|
|
module = {
|
||
|
|
name = all_video;
|
||
|
|
common = lib/fake_module.c;
|
||
|
|
diff --git a/grub-core/commands/pgp.c b/grub-core/commands/pgp.c
|
||
|
|
index 5daa1e9d00c..2408db4994f 100644
|
||
|
|
--- a/grub-core/commands/pgp.c
|
||
|
|
+++ b/grub-core/commands/pgp.c
|
||
|
|
@@ -24,6 +24,7 @@
|
||
|
|
#include <grub/file.h>
|
||
|
|
#include <grub/command.h>
|
||
|
|
#include <grub/crypto.h>
|
||
|
|
+#include <grub/pkcs1_v15.h>
|
||
|
|
#include <grub/i18n.h>
|
||
|
|
#include <grub/gcrypt/gcrypt.h>
|
||
|
|
#include <grub/pubkey.h>
|
||
|
|
@@ -411,32 +412,7 @@ static int
|
||
|
|
rsa_pad (gcry_mpi_t *hmpi, grub_uint8_t *hval,
|
||
|
|
const gcry_md_spec_t *hash, struct grub_public_subkey *sk)
|
||
|
|
{
|
||
|
|
- grub_size_t tlen, emlen, fflen;
|
||
|
|
- grub_uint8_t *em, *emptr;
|
||
|
|
- unsigned nbits = gcry_mpi_get_nbits (sk->mpis[0]);
|
||
|
|
- int ret;
|
||
|
|
- tlen = hash->mdlen + hash->asnlen;
|
||
|
|
- emlen = (nbits + 7) / 8;
|
||
|
|
- if (emlen < tlen + 11)
|
||
|
|
- return 1;
|
||
|
|
-
|
||
|
|
- em = grub_malloc (emlen);
|
||
|
|
- if (!em)
|
||
|
|
- return 1;
|
||
|
|
-
|
||
|
|
- em[0] = 0x00;
|
||
|
|
- em[1] = 0x01;
|
||
|
|
- fflen = emlen - tlen - 3;
|
||
|
|
- for (emptr = em + 2; emptr < em + 2 + fflen; emptr++)
|
||
|
|
- *emptr = 0xff;
|
||
|
|
- *emptr++ = 0x00;
|
||
|
|
- grub_memcpy (emptr, hash->asnoid, hash->asnlen);
|
||
|
|
- emptr += hash->asnlen;
|
||
|
|
- grub_memcpy (emptr, hval, hash->mdlen);
|
||
|
|
-
|
||
|
|
- ret = gcry_mpi_scan (hmpi, GCRYMPI_FMT_USG, em, emlen, 0);
|
||
|
|
- grub_free (em);
|
||
|
|
- return ret;
|
||
|
|
+ return grub_crypto_rsa_pad(hmpi, hval, hash, sk->mpis[0]);
|
||
|
|
}
|
||
|
|
|
||
|
|
struct grub_pubkey_context
|
||
|
|
diff --git a/grub-core/lib/pkcs1_v15.c b/grub-core/lib/pkcs1_v15.c
|
||
|
|
new file mode 100644
|
||
|
|
index 00000000000..dbacd563d01
|
||
|
|
--- /dev/null
|
||
|
|
+++ b/grub-core/lib/pkcs1_v15.c
|
||
|
|
@@ -0,0 +1,59 @@
|
||
|
|
+/*
|
||
|
|
+ * GRUB -- GRand Unified Bootloader
|
||
|
|
+ * Copyright (C) 2013 Free Software Foundation, Inc.
|
||
|
|
+ *
|
||
|
|
+ * GRUB is free software: you can redistribute it and/or modify
|
||
|
|
+ * it under the terms of the GNU General Public License as published by
|
||
|
|
+ * the Free Software Foundation, either version 3 of the License, or
|
||
|
|
+ * (at your option) any later version.
|
||
|
|
+ *
|
||
|
|
+ * GRUB is distributed in the hope that it will be useful,
|
||
|
|
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
+ * GNU General Public License for more details.
|
||
|
|
+ *
|
||
|
|
+ * You should have received a copy of the GNU General Public License
|
||
|
|
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
+ */
|
||
|
|
+
|
||
|
|
+#include <grub/dl.h>
|
||
|
|
+#include <grub/gcrypt/gcrypt.h>
|
||
|
|
+
|
||
|
|
+GRUB_MOD_LICENSE ("GPLv3+");
|
||
|
|
+
|
||
|
|
+/*
|
||
|
|
+ * Given a hash value 'hval', of hash specification 'hash', perform
|
||
|
|
+ * the EMSA-PKCS1-v1_5 padding suitable for a key with modulus 'mod'
|
||
|
|
+ * (see RFC 8017 s 9.2) and place the result in 'hmpi'.
|
||
|
|
+ */
|
||
|
|
+gcry_err_code_t
|
||
|
|
+grub_crypto_rsa_pad (gcry_mpi_t * hmpi, grub_uint8_t * hval,
|
||
|
|
+ const gcry_md_spec_t * hash, gcry_mpi_t mod)
|
||
|
|
+{
|
||
|
|
+ grub_size_t tlen, emlen, fflen;
|
||
|
|
+ grub_uint8_t *em, *emptr;
|
||
|
|
+ unsigned nbits = gcry_mpi_get_nbits (mod);
|
||
|
|
+ int ret;
|
||
|
|
+ tlen = hash->mdlen + hash->asnlen;
|
||
|
|
+ emlen = (nbits + 7) / 8;
|
||
|
|
+ if (emlen < tlen + 11)
|
||
|
|
+ return GPG_ERR_TOO_SHORT;
|
||
|
|
+
|
||
|
|
+ em = grub_malloc (emlen);
|
||
|
|
+ if (!em)
|
||
|
|
+ return 1;
|
||
|
|
+
|
||
|
|
+ em[0] = 0x00;
|
||
|
|
+ em[1] = 0x01;
|
||
|
|
+ fflen = emlen - tlen - 3;
|
||
|
|
+ for (emptr = em + 2; emptr < em + 2 + fflen; emptr++)
|
||
|
|
+ *emptr = 0xff;
|
||
|
|
+ *emptr++ = 0x00;
|
||
|
|
+ grub_memcpy (emptr, hash->asnoid, hash->asnlen);
|
||
|
|
+ emptr += hash->asnlen;
|
||
|
|
+ grub_memcpy (emptr, hval, hash->mdlen);
|
||
|
|
+
|
||
|
|
+ ret = gcry_mpi_scan (hmpi, GCRYMPI_FMT_USG, em, emlen, 0);
|
||
|
|
+ grub_free (em);
|
||
|
|
+ return ret;
|
||
|
|
+}
|
||
|
|
diff --git a/include/grub/pkcs1_v15.h b/include/grub/pkcs1_v15.h
|
||
|
|
new file mode 100644
|
||
|
|
index 00000000000..5c338c84a15
|
||
|
|
--- /dev/null
|
||
|
|
+++ b/include/grub/pkcs1_v15.h
|
||
|
|
@@ -0,0 +1,27 @@
|
||
|
|
+/*
|
||
|
|
+ * GRUB -- GRand Unified Bootloader
|
||
|
|
+ * Copyright (C) 2013 Free Software Foundation, Inc.
|
||
|
|
+ *
|
||
|
|
+ * GRUB is free software: you can redistribute it and/or modify
|
||
|
|
+ * it under the terms of the GNU General Public License as published by
|
||
|
|
+ * the Free Software Foundation, either version 3 of the License, or
|
||
|
|
+ * (at your option) any later version.
|
||
|
|
+ *
|
||
|
|
+ * GRUB is distributed in the hope that it will be useful,
|
||
|
|
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
+ * GNU General Public License for more details.
|
||
|
|
+ *
|
||
|
|
+ * You should have received a copy of the GNU General Public License
|
||
|
|
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
+ */
|
||
|
|
+
|
||
|
|
+/*
|
||
|
|
+ * Given a hash value 'hval', of hash specification 'hash', perform
|
||
|
|
+ * the EMSA-PKCS1-v1_5 padding suitable for a key with modulus 'mod'
|
||
|
|
+ * (See RFC 8017 s 9.2)
|
||
|
|
+ */
|
||
|
|
+gcry_err_code_t
|
||
|
|
+grub_crypto_rsa_pad (gcry_mpi_t * hmpi, grub_uint8_t * hval,
|
||
|
|
+ const gcry_md_spec_t * hash, gcry_mpi_t mod);
|
||
|
|
+
|