[sw/silicon_creator] Replace OTBN sigverify with new version.
The new version uses the custom mask ROM RSA wrapper, and the RSA
signature code instead of encrypt/decrypt.
Signed-off-by: Jade Philipoom <jadep@google.com>
diff --git a/sw/device/silicon_creator/lib/crypto/rsa_3072/rsa_3072_modexp.h b/sw/device/silicon_creator/lib/crypto/rsa_3072/rsa_3072_modexp.h
deleted file mode 100644
index 9c3b5c6..0000000
--- a/sw/device/silicon_creator/lib/crypto/rsa_3072/rsa_3072_modexp.h
+++ /dev/null
@@ -1,68 +0,0 @@
-// Copyright lowRISC contributors.
-// Licensed under the Apache License, Version 2.0, see LICENSE for details.
-// SPDX-License-Identifier: Apache-2.0
-
-#ifndef OPENTITAN_SW_DEVICE_SILICON_CREATOR_LIB_CRYPTO_RSA_3072_RSA_3072_MODEXP_H_
-#define OPENTITAN_SW_DEVICE_SILICON_CREATOR_LIB_CRYPTO_RSA_3072_RSA_3072_MODEXP_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include "sw/device/silicon_creator/lib/otbn_util.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif // __cplusplus
-
-enum {
- /* Length of the RSA-3072 modulus is 3072 bits */
- kRsa3072NumBits = 3072,
- /* Length of the RSA-3072 modulus in words */
- kRsa3072NumWords = kRsa3072NumBits / (sizeof(uint32_t) * 8),
-};
-
-/**
- * A type that holds an element of the RSA-3072 finite field (i.e. a 3072-bit
- * number).
- *
- * This type can be used for RSA-3072 signatures, keys, and intermediate values
- * during modular exponentiation.
- */
-typedef struct rsa_3072_int_t {
- uint32_t data[kRsa3072NumWords];
-} rsa_3072_int_t;
-
-/**
- * A type that holds an RSA-3072 public key.
- *
- * The public key consists of a 3072-bit modulus n and a public exponent e.
- */
-typedef struct rsa_3072_public_key_t {
- rsa_3072_int_t n;
- uint32_t e;
-} rsa_3072_public_key_t;
-
-/**
- * Performs modular exponentiation for signature verification.
- *
- * Computes (signature^e) mod n, where e and n are the exponent and modulus in
- * the public key respectively.
- *
- * Currently, only e=65537 is supported.
- *
- * @param signature Signature to be verified.
- * @param public_key Key to check the signature against.
- * @param m0_inv Precomputed Montgomery constant ((-(n^-1)) mod 2^256)
- * @param recoveredMessage Buffer in which to store output
- * @return Result of the operation (OK or error).
- */
-otbn_error_t run_otbn_rsa_3072_modexp(const rsa_3072_int_t *signature,
- const rsa_3072_public_key_t *public_key,
- const uint32_t *m0_inv,
- rsa_3072_int_t *recovered_message);
-
-#ifdef __cplusplus
-} // extern "C"
-#endif // __cplusplus
-
-#endif // OPENTITAN_SW_DEVICE_SILICON_CREATOR_LIB_CRYPTO_RSA_3072_RSA_3072_MODEXP_H_
diff --git a/sw/device/silicon_creator/lib/crypto/rsa_3072/rsa_3072_modexp.c b/sw/device/silicon_creator/lib/sigverify_mod_exp_otbn.c
similarity index 100%
rename from sw/device/silicon_creator/lib/crypto/rsa_3072/rsa_3072_modexp.c
rename to sw/device/silicon_creator/lib/sigverify_mod_exp_otbn.c
