From b6ea0cb4adae620c68f381ac2f0a0e6d716e13f4 Mon Sep 17 00:00:00 2001
From: Joseph Chen <chenjh@rock-chips.com>
Date: Wed, 2 Dec 2020 10:17:40 +0800
Subject: [PATCH] lib: rsa-sign: add rockchip rsa key hash

SPL requires key hash to verify and flash it to OTP/EFUSE.

- hash@c:  n, e, c
- hash@np: n, e, np

/ {
    signature {
        key-dev {
            required = "conf";
            algo = "sha256,rsa2048";
            rsa,np = <...>;
            rsa,c = <...>;
            rsa,modulus = <...>;
            rsa,exponent-BN = <...>;
            ...
            key-name-hint = "dev";
            hash@np {
                algo = "sha256";
                value = <0x0934bc4d 0xfbc31ffe 0x9224d6c2 0x1a3aa280 0x881d881e 0xe2006246 0x01b9e724 0x35c03428>;
            };
            hash@c {
                algo = "sha256";
                value = <0x08962385 0x34585e06 0x0b73a496 0x374b148d 0xa2700a75 0x4aae08ad 0xb2a324a3 0x95ee6b52>;
            };
        };
    };
    ...
};

But after processed by scripts/fit.sh, only one of "hash@c" and "hash@np" would be left.

Signed-off-by: Joseph Chen <chenjh@rock-chips.com>
Change-Id: Id9454100f9fdb06b30f9a4b2a7bdd180f117cb68
---
 lib/rsa/rsa-sign.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/lib/rsa/rsa-sign.c b/lib/rsa/rsa-sign.c
index 39226ad4f2..9b49f6bd0b 100644
--- a/lib/rsa/rsa-sign.c
+++ b/lib/rsa/rsa-sign.c
@@ -700,6 +700,83 @@ int rsa_get_params(RSA *key, uint64_t *exponent, uint32_t *n0_invp,
 	return ret;
 }
 
+static void rsa_convert_big_endian(uint32_t *dst, const uint32_t *src, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		dst[i] = fdt32_to_cpu(src[len - 1 - i]);
+}
+
+static int rsa_set_key_hash(void *keydest, int key_node,
+			    int key_len, const char *csum_algo)
+{
+	const void *rsa_n, *rsa_e, *rsa_c, *rsa_np;
+	void *n, *e, *c, *np;
+	uint8_t value[FIT_MAX_HASH_LEN];
+	char hash_c[] = "hash@c";
+	char hash_np[] = "hash@np";
+	char *rsa_key;
+	int key_word;
+	int hash_node;
+	int value_len;
+	int ret = -ENOSPC;
+
+	rsa_key = malloc(key_len * 3);
+	if (!rsa_key)
+		return -ENOSPC;
+
+	rsa_n = fdt_getprop(keydest, key_node, "rsa,modulus", NULL);
+	rsa_e = fdt_getprop(keydest, key_node, "rsa,exponent-BN", NULL);
+	rsa_c = fdt_getprop(keydest, key_node, "rsa,c", NULL);
+	rsa_np = fdt_getprop(keydest, key_node, "rsa,np", NULL);
+	if (!rsa_c || !rsa_np || !rsa_n || !rsa_e)
+		goto err_nospc;
+
+	n = rsa_key;
+	e = rsa_key + key_len;
+	key_word = key_len / sizeof(uint32_t);
+	rsa_convert_big_endian(n, rsa_n, key_word);
+	rsa_convert_big_endian(e, rsa_e, key_word);
+
+	/* hash@c node: n, e, c */
+	c = rsa_key + key_len * 2;
+	rsa_convert_big_endian(c, rsa_c, key_word);
+	hash_node = fdt_add_subnode(keydest, key_node, hash_c);
+	if (hash_node < 0)
+		goto err_nospc;
+	ret = calculate_hash(rsa_key, key_len * 3, csum_algo, value, &value_len);
+	if (ret)
+		goto err_nospc;
+	ret = fdt_setprop(keydest, hash_node, FIT_VALUE_PROP, value, value_len);
+	if (ret)
+		goto err_nospc;
+	ret = fdt_setprop_string(keydest, hash_node, FIT_ALGO_PROP, csum_algo);
+	if (ret < 0)
+		goto err_nospc;
+
+	/* hash@np node: n, e, np */
+	np = rsa_key + key_len * 2;
+	rsa_convert_big_endian(np, rsa_np, key_word);
+	hash_node = fdt_add_subnode(keydest, key_node, hash_np);
+	if (hash_node < 0)
+		goto err_nospc;
+
+	ret = calculate_hash(rsa_key, key_len * 2 + 20, csum_algo, value, &value_len);
+	if (ret)
+		goto err_nospc;
+	ret = fdt_setprop(keydest, hash_node, FIT_VALUE_PROP, value, value_len);
+	if (ret < 0)
+		goto err_nospc;
+	ret = fdt_setprop_string(keydest, hash_node, FIT_ALGO_PROP, csum_algo);
+
+err_nospc:
+	if (rsa_key)
+		free(rsa_key);
+
+	return ret ? -ENOSPC : 0;
+}
+
 static int fdt_add_bignum(void *blob, int noffset, const char *prop_name,
 			  BIGNUM *num, int num_bits)
 {
@@ -854,6 +931,10 @@ int rsa_add_verify_data(struct image_sign_info *info, void *keydest)
 		ret = fdt_setprop_string(keydest, node, "required",
 					 info->require_keys);
 	}
+	if (!ret) {
+		ret = rsa_set_key_hash(keydest, node, info->crypto->key_len,
+				       info->checksum->name);
+	}
 done:
 	BN_free(modulus);
 	BN_free(r_squared);