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-rw-r--r--lib/rsa/rsa-sign.c727
1 files changed, 727 insertions, 0 deletions
diff --git a/lib/rsa/rsa-sign.c b/lib/rsa/rsa-sign.c
new file mode 100644
index 00000000000..2304030e32f
--- /dev/null
+++ b/lib/rsa/rsa-sign.c
@@ -0,0 +1,727 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2013, Google Inc.
+ */
+
+#define OPENSSL_API_COMPAT 0x10101000L
+
+#include "mkimage.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <image.h>
+#include <time.h>
+#include <u-boot/fdt-libcrypto.h>
+#include <openssl/bn.h>
+#include <openssl/ec.h>
+#include <openssl/rsa.h>
+#include <openssl/pem.h>
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+#include <openssl/evp.h>
+#include <openssl/engine.h>
+
+static int rsa_err(const char *msg)
+{
+ unsigned long sslErr = ERR_get_error();
+
+ fprintf(stderr, "%s", msg);
+ fprintf(stderr, ": %s\n",
+ ERR_error_string(sslErr, 0));
+
+ return -1;
+}
+
+/**
+ * rsa_pem_get_pub_key() - read a public key from a .crt file
+ *
+ * @keydir: Directory containins the key
+ * @name Name of key file (will have a .crt extension)
+ * @evpp Returns EVP_PKEY object, or NULL on failure
+ * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
+ */
+static int rsa_pem_get_pub_key(const char *keydir, const char *name, EVP_PKEY **evpp)
+{
+ char path[1024];
+ EVP_PKEY *key = NULL;
+ X509 *cert;
+ FILE *f;
+ int ret;
+
+ if (!evpp)
+ return -EINVAL;
+
+ *evpp = NULL;
+ snprintf(path, sizeof(path), "%s/%s.crt", keydir, name);
+ f = fopen(path, "r");
+ if (!f) {
+ fprintf(stderr, "Couldn't open RSA certificate: '%s': %s\n",
+ path, strerror(errno));
+ return -EACCES;
+ }
+
+ /* Read the certificate */
+ cert = NULL;
+ if (!PEM_read_X509(f, &cert, NULL, NULL)) {
+ rsa_err("Couldn't read certificate");
+ ret = -EINVAL;
+ goto err_cert;
+ }
+
+ /* Get the public key from the certificate. */
+ key = X509_get_pubkey(cert);
+ if (!key) {
+ rsa_err("Couldn't read public key\n");
+ ret = -EINVAL;
+ goto err_pubkey;
+ }
+
+ fclose(f);
+ *evpp = key;
+ X509_free(cert);
+
+ return 0;
+
+err_pubkey:
+ X509_free(cert);
+err_cert:
+ fclose(f);
+ return ret;
+}
+
+/**
+ * rsa_engine_get_pub_key() - read a public key from given engine
+ *
+ * @keydir: Key prefix
+ * @name Name of key
+ * @engine Engine to use
+ * @evpp Returns EVP_PKEY object, or NULL on failure
+ * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
+ */
+static int rsa_engine_get_pub_key(const char *keydir, const char *name,
+ ENGINE *engine, EVP_PKEY **evpp)
+{
+ const char *engine_id;
+ char key_id[1024];
+ EVP_PKEY *key = NULL;
+ const char *const pkcs11_schema = "pkcs11:";
+ const char *pkcs11_uri_prepend = "";
+
+ if (!evpp)
+ return -EINVAL;
+
+ *evpp = NULL;
+
+ engine_id = ENGINE_get_id(engine);
+
+ if (engine_id && !strcmp(engine_id, "pkcs11")) {
+ if (keydir) {
+ // Check for legacy keydir spec and prepend
+ if (strncmp(pkcs11_schema, keydir, strlen(pkcs11_schema))) {
+ pkcs11_uri_prepend = pkcs11_schema;
+ fprintf(stderr, "WARNING: Legacy URI specified. Please add '%s'.\n", pkcs11_schema);
+ }
+
+ if (strstr(keydir, "object="))
+ snprintf(key_id, sizeof(key_id),
+ "%s%s;type=public",
+ pkcs11_uri_prepend, keydir);
+ else
+ snprintf(key_id, sizeof(key_id),
+ "%s%s;object=%s;type=public",
+ pkcs11_uri_prepend, keydir, name);
+ } else {
+ snprintf(key_id, sizeof(key_id),
+ "pkcs11:object=%s;type=public",
+ name);
+ }
+ } else if (engine_id) {
+ if (keydir)
+ snprintf(key_id, sizeof(key_id),
+ "%s%s",
+ keydir, name);
+ else
+ snprintf(key_id, sizeof(key_id),
+ "%s",
+ name);
+ } else {
+ fprintf(stderr, "Engine not supported\n");
+ return -ENOTSUP;
+ }
+
+ key = ENGINE_load_public_key(engine, key_id, NULL, NULL);
+ if (!key)
+ return rsa_err("Failure loading public key from engine");
+
+ *evpp = key;
+
+ return 0;
+}
+
+/**
+ * rsa_get_pub_key() - read a public key
+ *
+ * @keydir: Directory containing the key (PEM file) or key prefix (engine)
+ * @name Name of key file (will have a .crt extension)
+ * @engine Engine to use
+ * @evpp Returns EVP_PKEY object, or NULL on failure
+ * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
+ */
+static int rsa_get_pub_key(const char *keydir, const char *name,
+ ENGINE *engine, EVP_PKEY **evpp)
+{
+ if (engine)
+ return rsa_engine_get_pub_key(keydir, name, engine, evpp);
+ return rsa_pem_get_pub_key(keydir, name, evpp);
+}
+
+/**
+ * rsa_pem_get_priv_key() - read a private key from a .key file
+ *
+ * @keydir: Directory containing the key
+ * @name Name of key file (will have a .key extension)
+ * @evpp Returns EVP_PKEY object, or NULL on failure
+ * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
+ */
+static int rsa_pem_get_priv_key(const char *keydir, const char *name,
+ const char *keyfile, EVP_PKEY **evpp)
+{
+ char path[1024] = {0};
+ FILE *f = NULL;
+
+ if (!evpp)
+ return -EINVAL;
+
+ *evpp = NULL;
+ if (keydir && name)
+ snprintf(path, sizeof(path), "%s/%s.key", keydir, name);
+ else if (keyfile)
+ snprintf(path, sizeof(path), "%s", keyfile);
+ else
+ return -EINVAL;
+
+ f = fopen(path, "r");
+ if (!f) {
+ fprintf(stderr, "Couldn't open RSA private key: '%s': %s\n",
+ path, strerror(errno));
+ return -ENOENT;
+ }
+
+ if (!PEM_read_PrivateKey(f, evpp, NULL, path)) {
+ rsa_err("Failure reading private key");
+ fclose(f);
+ return -EPROTO;
+ }
+ fclose(f);
+
+ return 0;
+}
+
+/**
+ * rsa_engine_get_priv_key() - read a private key from given engine
+ *
+ * @keydir: Key prefix
+ * @name Name of key
+ * @engine Engine to use
+ * @evpp Returns EVP_PKEY object, or NULL on failure
+ * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
+ */
+static int rsa_engine_get_priv_key(const char *keydir, const char *name,
+ const char *keyfile,
+ ENGINE *engine, EVP_PKEY **evpp)
+{
+ const char *engine_id;
+ char key_id[1024];
+ EVP_PKEY *key = NULL;
+ const char *const pkcs11_schema = "pkcs11:";
+ const char *pkcs11_uri_prepend = "";
+
+ if (!evpp)
+ return -EINVAL;
+
+ engine_id = ENGINE_get_id(engine);
+
+ if (engine_id && !strcmp(engine_id, "pkcs11")) {
+ if (!keydir && !name) {
+ fprintf(stderr, "Please use 'keydir' with PKCS11\n");
+ return -EINVAL;
+ }
+ if (keydir) {
+ // Check for legacy keydir spec and prepend
+ if (strncmp(pkcs11_schema, keydir, strlen(pkcs11_schema))) {
+ pkcs11_uri_prepend = pkcs11_schema;
+ fprintf(stderr, "WARNING: Legacy URI specified. Please add '%s'.\n", pkcs11_schema);
+ }
+
+ if (strstr(keydir, "object="))
+ snprintf(key_id, sizeof(key_id),
+ "%s%s;type=private",
+ pkcs11_uri_prepend, keydir);
+ else
+ snprintf(key_id, sizeof(key_id),
+ "%s%s;object=%s;type=private",
+ pkcs11_uri_prepend, keydir, name);
+ } else {
+ snprintf(key_id, sizeof(key_id),
+ "pkcs11:object=%s;type=private",
+ name);
+ }
+ } else if (engine_id) {
+ if (keydir && name)
+ snprintf(key_id, sizeof(key_id),
+ "%s%s",
+ keydir, name);
+ else if (name)
+ snprintf(key_id, sizeof(key_id),
+ "%s",
+ name ? name : "");
+ else if (keyfile)
+ snprintf(key_id, sizeof(key_id), "%s", keyfile);
+ else
+ return -EINVAL;
+
+ } else {
+ fprintf(stderr, "Engine not supported\n");
+ return -ENOTSUP;
+ }
+
+ key = ENGINE_load_private_key(engine, key_id, NULL, NULL);
+ if (!key)
+ return rsa_err("Failure loading private key from engine");
+
+ *evpp = key;
+
+ return 0;
+}
+
+/**
+ * rsa_get_priv_key() - read a private key
+ *
+ * @keydir: Directory containing the key (PEM file) or key prefix (engine)
+ * @name Name of key
+ * @engine Engine to use for signing
+ * @evpp Returns EVP_PKEY object, or NULL on failure
+ * Return: 0 if ok, -ve on error (in which case *evpp will be set to NULL)
+ */
+static int rsa_get_priv_key(const char *keydir, const char *name,
+ const char *keyfile, ENGINE *engine, EVP_PKEY **evpp)
+{
+ if (engine)
+ return rsa_engine_get_priv_key(keydir, name, keyfile, engine,
+ evpp);
+ return rsa_pem_get_priv_key(keydir, name, keyfile, evpp);
+}
+
+static int rsa_init(void)
+{
+ int ret;
+
+ ret = OPENSSL_init_ssl(0, NULL);
+ if (!ret) {
+ fprintf(stderr, "Failure to init SSL library\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int rsa_engine_init(const char *engine_id, ENGINE **pe)
+{
+ const char *key_pass;
+ ENGINE *e;
+ int ret;
+
+ ENGINE_load_builtin_engines();
+
+ e = ENGINE_by_id(engine_id);
+ if (!e) {
+ fprintf(stderr, "Engine '%s' isn't available\n", engine_id);
+ ERR_print_errors_fp(stderr);
+ return -1;
+ }
+
+ if (!ENGINE_init(e)) {
+ fprintf(stderr, "Couldn't initialize engine\n");
+ ret = -1;
+ goto err_engine_init;
+ }
+
+ if (!ENGINE_set_default_RSA(e)) {
+ fprintf(stderr, "Couldn't set engine as default for RSA\n");
+ ret = -1;
+ goto err_set_rsa;
+ }
+
+ key_pass = getenv("MKIMAGE_SIGN_PIN");
+ if (key_pass) {
+ if (!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0)) {
+ fprintf(stderr, "Couldn't set PIN\n");
+ ret = -1;
+ goto err_set_pin;
+ }
+ }
+
+ *pe = e;
+
+ return 0;
+
+err_set_pin:
+err_set_rsa:
+ ENGINE_finish(e);
+err_engine_init:
+ ENGINE_free(e);
+ return ret;
+}
+
+static void rsa_engine_remove(ENGINE *e)
+{
+ if (e) {
+ ENGINE_finish(e);
+ ENGINE_free(e);
+ }
+}
+
+static int rsa_sign_with_key(EVP_PKEY *pkey, struct padding_algo *padding_algo,
+ struct checksum_algo *checksum_algo,
+ const struct image_region region[], int region_count,
+ uint8_t **sigp, uint *sig_size)
+{
+ EVP_PKEY_CTX *ckey;
+ EVP_MD_CTX *context;
+ int ret = 0;
+ size_t size;
+ uint8_t *sig;
+ int i;
+
+ size = EVP_PKEY_size(pkey);
+ sig = malloc(size);
+ if (!sig) {
+ fprintf(stderr, "Out of memory for signature (%zu bytes)\n",
+ size);
+ ret = -ENOMEM;
+ goto err_alloc;
+ }
+
+ context = EVP_MD_CTX_new();
+ if (!context) {
+ ret = rsa_err("EVP context creation failed");
+ goto err_create;
+ }
+
+ ckey = EVP_PKEY_CTX_new(pkey, NULL);
+ if (!ckey) {
+ ret = rsa_err("EVP key context creation failed");
+ goto err_create;
+ }
+
+ if (EVP_DigestSignInit(context, &ckey,
+ checksum_algo->calculate_sign(),
+ NULL, pkey) <= 0) {
+ ret = rsa_err("Signer setup failed");
+ goto err_sign;
+ }
+
+ if (CONFIG_IS_ENABLED(FIT_RSASSA_PSS) && padding_algo &&
+ !strcmp(padding_algo->name, "pss")) {
+ if (EVP_PKEY_CTX_set_rsa_padding(ckey,
+ RSA_PKCS1_PSS_PADDING) <= 0) {
+ ret = rsa_err("Signer padding setup failed");
+ goto err_sign;
+ }
+ }
+
+ for (i = 0; i < region_count; i++) {
+ if (!EVP_DigestSignUpdate(context, region[i].data,
+ region[i].size)) {
+ ret = rsa_err("Signing data failed");
+ goto err_sign;
+ }
+ }
+
+ if (!EVP_DigestSignFinal(context, sig, &size)) {
+ ret = rsa_err("Could not obtain signature");
+ goto err_sign;
+ }
+
+ EVP_MD_CTX_free(context);
+
+ debug("Got signature: %zu bytes, expected %d\n", size, EVP_PKEY_size(pkey));
+ *sigp = sig;
+ *sig_size = size;
+
+ return 0;
+
+err_sign:
+ EVP_MD_CTX_free(context);
+err_create:
+ free(sig);
+err_alloc:
+ return ret;
+}
+
+int rsa_sign(struct image_sign_info *info,
+ const struct image_region region[], int region_count,
+ uint8_t **sigp, uint *sig_len)
+{
+ EVP_PKEY *pkey = NULL;
+ ENGINE *e = NULL;
+ int ret;
+
+ ret = rsa_init();
+ if (ret)
+ return ret;
+
+ if (info->engine_id) {
+ ret = rsa_engine_init(info->engine_id, &e);
+ if (ret)
+ return ret;
+ }
+
+ ret = rsa_get_priv_key(info->keydir, info->keyname, info->keyfile,
+ e, &pkey);
+ if (ret)
+ goto err_priv;
+ ret = rsa_sign_with_key(pkey, info->padding, info->checksum, region,
+ region_count, sigp, sig_len);
+ if (ret)
+ goto err_sign;
+
+ EVP_PKEY_free(pkey);
+ if (info->engine_id)
+ rsa_engine_remove(e);
+
+ return ret;
+
+err_sign:
+ EVP_PKEY_free(pkey);
+err_priv:
+ if (info->engine_id)
+ rsa_engine_remove(e);
+ return ret;
+}
+
+/*
+ * rsa_get_exponent(): - Get the public exponent from an RSA key
+ */
+static int rsa_get_exponent(RSA *key, uint64_t *e)
+{
+ int ret;
+ BIGNUM *bn_te;
+ const BIGNUM *key_e;
+ uint64_t te;
+
+ ret = -EINVAL;
+ bn_te = NULL;
+
+ if (!e)
+ goto cleanup;
+
+ RSA_get0_key(key, NULL, &key_e, NULL);
+ if (BN_num_bits(key_e) > 64)
+ goto cleanup;
+
+ *e = BN_get_word(key_e);
+
+ if (BN_num_bits(key_e) < 33) {
+ ret = 0;
+ goto cleanup;
+ }
+
+ bn_te = BN_dup(key_e);
+ if (!bn_te)
+ goto cleanup;
+
+ if (!BN_rshift(bn_te, bn_te, 32))
+ goto cleanup;
+
+ if (!BN_mask_bits(bn_te, 32))
+ goto cleanup;
+
+ te = BN_get_word(bn_te);
+ te <<= 32;
+ *e |= te;
+ ret = 0;
+
+cleanup:
+ if (bn_te)
+ BN_free(bn_te);
+
+ return ret;
+}
+
+/*
+ * rsa_get_params(): - Get the important parameters of an RSA public key
+ */
+int rsa_get_params(RSA *key, uint64_t *exponent, uint32_t *n0_invp,
+ BIGNUM **modulusp, BIGNUM **r_squaredp)
+{
+ BIGNUM *big1, *big2, *big32, *big2_32;
+ BIGNUM *n, *r, *r_squared, *tmp;
+ const BIGNUM *key_n;
+ BN_CTX *bn_ctx = BN_CTX_new();
+ int ret = 0;
+
+ /* Initialize BIGNUMs */
+ big1 = BN_new();
+ big2 = BN_new();
+ big32 = BN_new();
+ r = BN_new();
+ r_squared = BN_new();
+ tmp = BN_new();
+ big2_32 = BN_new();
+ n = BN_new();
+ if (!big1 || !big2 || !big32 || !r || !r_squared || !tmp || !big2_32 ||
+ !n) {
+ fprintf(stderr, "Out of memory (bignum)\n");
+ return -ENOMEM;
+ }
+
+ if (0 != rsa_get_exponent(key, exponent))
+ ret = -1;
+
+ RSA_get0_key(key, &key_n, NULL, NULL);
+ if (!BN_copy(n, key_n) || !BN_set_word(big1, 1L) ||
+ !BN_set_word(big2, 2L) || !BN_set_word(big32, 32L))
+ ret = -1;
+
+ /* big2_32 = 2^32 */
+ if (!BN_exp(big2_32, big2, big32, bn_ctx))
+ ret = -1;
+
+ /* Calculate n0_inv = -1 / n[0] mod 2^32 */
+ if (!BN_mod_inverse(tmp, n, big2_32, bn_ctx) ||
+ !BN_sub(tmp, big2_32, tmp))
+ ret = -1;
+ *n0_invp = BN_get_word(tmp);
+
+ /* Calculate R = 2^(# of key bits) */
+ if (!BN_set_word(tmp, BN_num_bits(n)) ||
+ !BN_exp(r, big2, tmp, bn_ctx))
+ ret = -1;
+
+ /* Calculate r_squared = R^2 mod n */
+ if (!BN_copy(r_squared, r) ||
+ !BN_mul(tmp, r_squared, r, bn_ctx) ||
+ !BN_mod(r_squared, tmp, n, bn_ctx))
+ ret = -1;
+
+ *modulusp = n;
+ *r_squaredp = r_squared;
+
+ BN_free(big1);
+ BN_free(big2);
+ BN_free(big32);
+ BN_free(r);
+ BN_free(tmp);
+ BN_free(big2_32);
+ if (ret) {
+ fprintf(stderr, "Bignum operations failed\n");
+ return -ENOMEM;
+ }
+
+ return ret;
+}
+
+int rsa_add_verify_data(struct image_sign_info *info, void *keydest)
+{
+ BIGNUM *modulus, *r_squared;
+ uint64_t exponent;
+ uint32_t n0_inv;
+ int parent, node = -FDT_ERR_NOTFOUND;
+ char name[100];
+ int ret;
+ int bits;
+ RSA *rsa;
+ EVP_PKEY *pkey = NULL;
+ ENGINE *e = NULL;
+
+ debug("%s: Getting verification data\n", __func__);
+ if (info->engine_id) {
+ ret = rsa_engine_init(info->engine_id, &e);
+ if (ret)
+ return ret;
+ }
+ ret = rsa_get_pub_key(info->keydir, info->keyname, e, &pkey);
+ if (ret)
+ goto err_get_pub_key;
+
+ rsa = (RSA *)EVP_PKEY_get0_RSA(pkey);
+ ret = rsa_get_params(rsa, &exponent, &n0_inv, &modulus, &r_squared);
+ if (ret)
+ goto err_get_params;
+ bits = BN_num_bits(modulus);
+ parent = fdt_subnode_offset(keydest, 0, FIT_SIG_NODENAME);
+ if (parent == -FDT_ERR_NOTFOUND) {
+ parent = fdt_add_subnode(keydest, 0, FIT_SIG_NODENAME);
+ if (parent < 0) {
+ ret = parent;
+ if (ret != -FDT_ERR_NOSPACE) {
+ fprintf(stderr, "Couldn't create signature node: %s\n",
+ fdt_strerror(parent));
+ }
+ }
+ }
+ if (ret)
+ goto done;
+
+ /* Either create or overwrite the named key node */
+ snprintf(name, sizeof(name), "key-%s", info->keyname);
+ node = fdt_subnode_offset(keydest, parent, name);
+ if (node == -FDT_ERR_NOTFOUND) {
+ node = fdt_add_subnode(keydest, parent, name);
+ if (node < 0) {
+ ret = node;
+ if (ret != -FDT_ERR_NOSPACE) {
+ fprintf(stderr, "Could not create key subnode: %s\n",
+ fdt_strerror(node));
+ }
+ }
+ } else if (node < 0) {
+ fprintf(stderr, "Cannot select keys parent: %s\n",
+ fdt_strerror(node));
+ ret = node;
+ }
+
+ if (!ret) {
+ ret = fdt_setprop_string(keydest, node, FIT_KEY_HINT,
+ info->keyname);
+ }
+ if (!ret)
+ ret = fdt_setprop_u32(keydest, node, "rsa,num-bits", bits);
+ if (!ret)
+ ret = fdt_setprop_u32(keydest, node, "rsa,n0-inverse", n0_inv);
+ if (!ret) {
+ ret = fdt_setprop_u64(keydest, node, "rsa,exponent", exponent);
+ }
+ if (!ret) {
+ ret = fdt_add_bignum(keydest, node, "rsa,modulus", modulus,
+ bits);
+ }
+ if (!ret) {
+ ret = fdt_add_bignum(keydest, node, "rsa,r-squared", r_squared,
+ bits);
+ }
+ if (!ret) {
+ ret = fdt_setprop_string(keydest, node, FIT_ALGO_PROP,
+ info->name);
+ }
+ if (!ret && info->require_keys) {
+ ret = fdt_setprop_string(keydest, node, FIT_KEY_REQUIRED,
+ info->require_keys);
+ }
+done:
+ BN_free(modulus);
+ BN_free(r_squared);
+ if (ret)
+ ret = ret == -FDT_ERR_NOSPACE ? -ENOSPC : -EIO;
+err_get_params:
+ EVP_PKEY_free(pkey);
+err_get_pub_key:
+ if (info->engine_id)
+ rsa_engine_remove(e);
+
+ if (ret)
+ return ret;
+
+ return node;
+}
generated by cgit v1.2.3 (git 2.0.4) at 2025-07-30 17:14:49 +0000