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@@ -0,0 +1,134 @@
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+// SPDX-License-Identifier: GPL-2.0+
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+/*
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+ * ECDSA signature verification for u-boot
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+ *
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+ * This implements the firmware-side wrapper for ECDSA verification. It bridges
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+ * the struct crypto_algo API to the ECDSA uclass implementations.
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+ *
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+ * Copyright (c) 2020, Alexandru Gagniuc <mr.nuke.me@gmail.com>
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+ */
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+
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+#include <crypto/ecdsa-uclass.h>
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+#include <dm/uclass.h>
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+#include <u-boot/ecdsa.h>
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+
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+/*
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+ * Derive size of an ECDSA key from the curve name
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+ *
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+ * While it's possible to extract the key size by using string manipulation,
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+ * use a list of known curves for the time being.
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+ */
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+static int ecdsa_key_size(const char *curve_name)
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+{
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+ if (!strcmp(curve_name, "prime256v1"))
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+ return 256;
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+ else
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+ return 0;
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+}
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+
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+static int fdt_get_key(struct ecdsa_public_key *key, const void *fdt, int node)
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+{
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+ int x_len, y_len;
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+
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+ key->curve_name = fdt_getprop(fdt, node, "ecdsa,curve", NULL);
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+ key->size_bits = ecdsa_key_size(key->curve_name);
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+ if (key->size_bits == 0) {
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+ debug("Unknown ECDSA curve '%s'", key->curve_name);
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+ return -EINVAL;
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+ }
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+
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+ key->x = fdt_getprop(fdt, node, "ecdsa,x-point", &x_len);
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+ key->y = fdt_getprop(fdt, node, "ecdsa,y-point", &y_len);
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+
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+ if (!key->x || !key->y)
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+ return -EINVAL;
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+
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+ if (x_len != (key->size_bits / 8) || y_len != (key->size_bits / 8)) {
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+ printf("%s: node=%d, curve@%p x@%p+%i y@%p+%i\n", __func__,
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+ node, key->curve_name, key->x, x_len, key->y, y_len);
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+ return -EINVAL;
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+ }
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+
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+ return 0;
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+}
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+
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+static int ecdsa_verify_hash(struct udevice *dev,
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+ const struct image_sign_info *info,
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+ const void *hash, const void *sig, uint sig_len)
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+{
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+ const struct ecdsa_ops *ops = device_get_ops(dev);
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+ const struct checksum_algo *algo = info->checksum;
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+ struct ecdsa_public_key key;
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+ int sig_node, key_node, ret;
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+
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+ if (!ops || !ops->verify)
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+ return -ENODEV;
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+
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+ if (info->required_keynode > 0) {
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+ ret = fdt_get_key(&key, info->fdt_blob, info->required_keynode);
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+ if (ret < 0)
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+ return ret;
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+
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+ return ops->verify(dev, &key, hash, algo->checksum_len,
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+ sig, sig_len);
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+ }
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+
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+ sig_node = fdt_subnode_offset(info->fdt_blob, 0, FIT_SIG_NODENAME);
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+ if (sig_node < 0)
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+ return -ENOENT;
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+
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+ /* Try all possible keys under the "/signature" node */
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+ fdt_for_each_subnode(key_node, info->fdt_blob, sig_node) {
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+ ret = fdt_get_key(&key, info->fdt_blob, key_node);
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+ if (ret < 0)
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+ continue;
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+
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+ ret = ops->verify(dev, &key, hash, algo->checksum_len,
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+ sig, sig_len);
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+
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+ /* On success, don't worry about remaining keys */
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+ if (!ret)
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+ return 0;
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+ }
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+
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+ return -EPERM;
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+}
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+
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+int ecdsa_verify(struct image_sign_info *info,
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+ const struct image_region region[], int region_count,
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+ uint8_t *sig, uint sig_len)
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+{
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+ const struct checksum_algo *algo = info->checksum;
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+ uint8_t hash[algo->checksum_len];
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+ struct udevice *dev;
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+ int ret;
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+
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+ ret = uclass_first_device_err(UCLASS_ECDSA, &dev);
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+ if (ret) {
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+ debug("ECDSA: Could not find ECDSA implementation: %d\n", ret);
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+ return ret;
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+ }
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+
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+ ret = algo->calculate(algo->name, region, region_count, hash);
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+ if (ret < 0)
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+ return -EINVAL;
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+
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+ return ecdsa_verify_hash(dev, info, hash, sig, sig_len);
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+}
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+
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+U_BOOT_CRYPTO_ALGO(ecdsa) = {
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+ .name = "ecdsa256",
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+ .key_len = ECDSA256_BYTES,
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+ .verify = ecdsa_verify,
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+};
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+
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+/*
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+ * uclass definition for ECDSA API
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+ *
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+ * We don't implement any wrappers around ecdsa_ops->verify() because it's
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+ * trivial to call ops->verify().
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+ */
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+UCLASS_DRIVER(ecdsa) = {
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+ .id = UCLASS_ECDSA,
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+ .name = "ecdsa_verifier",
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+};
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