diff --git a/tools/Makefile b/tools/Makefile
index d020c55d664..722355e9848 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -58,7 +58,7 @@ hostprogs-$(CONFIG_FIT_SIGNATURE) += fit_info fit_check_sign
 hostprogs-$(CONFIG_CMD_BOOTEFI_SELFTEST) += file2include
 
 FIT_OBJS-$(CONFIG_FIT) := fit_common.o fit_image.o image-host.o common/image-fit.o
-FIT_SIG_OBJS-$(CONFIG_FIT_SIGNATURE) := common/image-sig.o common/image-fit-sig.o
+FIT_SIG_OBJS-$(CONFIG_FIT_SIGNATURE) := image-sig-host.o common/image-fit-sig.o
 FIT_CIPHER_OBJS-$(CONFIG_FIT_CIPHER) := common/image-cipher.o
 
 # The following files are synced with upstream DTC.
diff --git a/tools/image-sig-host.c b/tools/image-sig-host.c
new file mode 100644
index 00000000000..8ed6998dab0
--- /dev/null
+++ b/tools/image-sig-host.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2013, Google Inc.
+ */
+
+#include "mkimage.h"
+#include <fdt_support.h>
+#include <time.h>
+#include <linux/libfdt.h>
+#include <image.h>
+#include <u-boot/ecdsa.h>
+#include <u-boot/rsa.h>
+#include <u-boot/hash-checksum.h>
+
+struct checksum_algo checksum_algos[] = {
+	{
+		.name = "sha1",
+		.checksum_len = SHA1_SUM_LEN,
+		.der_len = SHA1_DER_LEN,
+		.der_prefix = sha1_der_prefix,
+		.calculate_sign = EVP_sha1,
+		.calculate = hash_calculate,
+	},
+	{
+		.name = "sha256",
+		.checksum_len = SHA256_SUM_LEN,
+		.der_len = SHA256_DER_LEN,
+		.der_prefix = sha256_der_prefix,
+		.calculate_sign = EVP_sha256,
+		.calculate = hash_calculate,
+	},
+	{
+		.name = "sha384",
+		.checksum_len = SHA384_SUM_LEN,
+		.der_len = SHA384_DER_LEN,
+		.der_prefix = sha384_der_prefix,
+		.calculate_sign = EVP_sha384,
+		.calculate = hash_calculate,
+	},
+	{
+		.name = "sha512",
+		.checksum_len = SHA512_SUM_LEN,
+		.der_len = SHA512_DER_LEN,
+		.der_prefix = sha512_der_prefix,
+		.calculate_sign = EVP_sha512,
+		.calculate = hash_calculate,
+	},
+};
+
+struct crypto_algo crypto_algos[] = {
+	{
+		.name = "rsa2048",
+		.key_len = RSA2048_BYTES,
+		.sign = rsa_sign,
+		.add_verify_data = rsa_add_verify_data,
+		.verify = rsa_verify,
+	},
+	{
+		.name = "rsa4096",
+		.key_len = RSA4096_BYTES,
+		.sign = rsa_sign,
+		.add_verify_data = rsa_add_verify_data,
+		.verify = rsa_verify,
+	},
+	{
+		.name = "ecdsa256",
+		.key_len = ECDSA256_BYTES,
+		.sign = ecdsa_sign,
+		.add_verify_data = ecdsa_add_verify_data,
+		.verify = ecdsa_verify,
+	},
+};
+
+struct padding_algo padding_algos[] = {
+	{
+		.name = "pkcs-1.5",
+		.verify = padding_pkcs_15_verify,
+	},
+	{
+		.name = "pss",
+		.verify = padding_pss_verify,
+	}
+};
+
+struct checksum_algo *image_get_checksum_algo(const char *full_name)
+{
+	int i;
+	const char *name;
+
+	for (i = 0; i < ARRAY_SIZE(checksum_algos); i++) {
+		name = checksum_algos[i].name;
+		/* Make sure names match and next char is a comma */
+		if (!strncmp(name, full_name, strlen(name)) &&
+		    full_name[strlen(name)] == ',')
+			return &checksum_algos[i];
+	}
+
+	return NULL;
+}
+
+struct crypto_algo *image_get_crypto_algo(const char *full_name)
+{
+	int i;
+	const char *name;
+
+	/* Move name to after the comma */
+	name = strchr(full_name, ',');
+	if (!name)
+		return NULL;
+	name += 1;
+
+	for (i = 0; i < ARRAY_SIZE(crypto_algos); i++) {
+		if (!strcmp(crypto_algos[i].name, name))
+			return &crypto_algos[i];
+	}
+
+	return NULL;
+}
+
+struct padding_algo *image_get_padding_algo(const char *name)
+{
+	int i;
+
+	if (!name)
+		return NULL;
+
+	for (i = 0; i < ARRAY_SIZE(padding_algos); i++) {
+		if (!strcmp(padding_algos[i].name, name))
+			return &padding_algos[i];
+	}
+
+	return NULL;
+}