Hello Sascha,
On 10/15/19 9:55 AM, Sascha Hauer wrote:
> The rsatoc tool converts rsa public keys into C structs suitable to
> compile with barebox. Most of the openssl rsa related stuff has been
> taken from the U-Boot mkimage tool.
I don't have any FIT image or RSA options enabled, yet my build fails now with:
RSAKEY crypto/rsa-keys.h
/bin/sh: 1: ./scripts/rsatoc: not found
./crypto/Makefile:27: recipe for target 'crypto/rsa-keys.h' failed
make[2]: *** [crypto/rsa-keys.h] Error 127
./Makefile:802: recipe for target 'crypto' failed
make[1]: *** [crypto] Error 2
Cheers
Ahmad
>
> Signed-off-by: Sascha Hauer <s.ha...@pengutronix.de>
> ---
> scripts/.gitignore | 1 +
> scripts/Makefile | 3 +
> scripts/rsatoc.c | 445 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 449 insertions(+)
> create mode 100644 scripts/rsatoc.c
>
> diff --git a/scripts/.gitignore b/scripts/.gitignore
> index 45c81bf8f4..76ea271abb 100644
> --- a/scripts/.gitignore
> +++ b/scripts/.gitignore
> @@ -29,3 +29,4 @@ mxs-usb-loader
> omap4_usbboot
> omap3-usb-loader
> mips-relocs
> +rsatoc
> diff --git a/scripts/Makefile b/scripts/Makefile
> index dffab53c73..81d1a501b0 100644
> --- a/scripts/Makefile
> +++ b/scripts/Makefile
> @@ -10,6 +10,9 @@ hostprogs-y += fix_size
> hostprogs-y += bareboxenv
> hostprogs-y += bareboxcrc32
> hostprogs-y += kernel-install
> +hostprogs-$(CONFIG_CRYPTO_RSA_BUILTIN_KEYS) += rsatoc
> +HOSTCFLAGS_rsatoc = `pkg-config --cflags openssl`
> +HOSTLDLIBS_rsatoc = `pkg-config --libs openssl`
> hostprogs-$(CONFIG_IMD) += bareboximd
> hostprogs-$(CONFIG_KALLSYMS) += kallsyms
> hostprogs-$(CONFIG_MIPS) += mips-relocs
> diff --git a/scripts/rsatoc.c b/scripts/rsatoc.c
> new file mode 100644
> index 0000000000..f853691908
> --- /dev/null
> +++ b/scripts/rsatoc.c
> @@ -0,0 +1,445 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * rsatoc - utility to convert an RSA key to a C struct
> + *
> + * This tool converts an RSA key given as file or PKCS#11
> + * URI to a C struct suitable to compile with barebox.
> + */
> +#include <stdio.h>
> +#include <string.h>
> +#include <time.h>
> +#include <openssl/bn.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)
> + * @rsap Returns RSA object, or NULL on failure
> + * @return 0 if ok, -ve on error (in which case *rsap will be set to NULL)
> + */
> +static int rsa_pem_get_pub_key(const char *path, RSA **rsap)
> +{
> + EVP_PKEY *key;
> + X509 *cert;
> + RSA *rsa;
> + FILE *f;
> + int ret;
> +
> + *rsap = NULL;
> + 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;
> + }
> +
> + /* Convert to a RSA_style key. */
> + rsa = EVP_PKEY_get1_RSA(key);
> + if (!rsa) {
> + rsa_err("Couldn't convert to a RSA style key");
> + ret = -EINVAL;
> + goto err_rsa;
> + }
> + fclose(f);
> + EVP_PKEY_free(key);
> + X509_free(cert);
> + *rsap = rsa;
> +
> + return 0;
> +
> +err_rsa:
> + EVP_PKEY_free(key);
> +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
> + * @rsap Returns RSA object, or NULL on failure
> + * @return 0 if ok, -ve on error (in which case *rsap will be set to NULL)
> + */
> +static int rsa_engine_get_pub_key(const char *key_id,
> + ENGINE *engine, RSA **rsap)
> +{
> + EVP_PKEY *key;
> + RSA *rsa;
> + int ret;
> +
> + *rsap = NULL;
> +
> + key = ENGINE_load_public_key(engine, key_id, NULL, NULL);
> + if (!key)
> + return rsa_err("Failure loading public key from engine");
> +
> + /* Convert to a RSA_style key. */
> + rsa = EVP_PKEY_get1_RSA(key);
> + if (!rsa) {
> + rsa_err("Couldn't convert to a RSA style key");
> + ret = -EINVAL;
> + goto err_rsa;
> + }
> +
> + EVP_PKEY_free(key);
> + *rsap = rsa;
> +
> + return 0;
> +
> +err_rsa:
> + EVP_PKEY_free(key);
> + 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;
> +}
> +
> +static int rsa_engine_init(ENGINE **pe)
> +{
> + ENGINE *e;
> + int ret;
> +
> + ENGINE_load_builtin_engines();
> +
> + e = ENGINE_by_id("pkcs11");
> + if (!e) {
> + fprintf(stderr, "Engine isn't available\n");
> + ret = -1;
> + goto err_engine_by_id;
> + }
> +
> + 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;
> + }
> +
> + *pe = e;
> +
> + return 0;
> +
> +err_set_rsa:
> + ENGINE_finish(e);
> +err_engine_init:
> + ENGINE_free(e);
> +err_engine_by_id:
> +#if OPENSSL_VERSION_NUMBER < 0x10100000L || \
> + (defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER <
> 0x02070000fL)
> + ENGINE_cleanup();
> +#endif
> + return ret;
> +}
> +
> +static int print_bignum(BIGNUM *num, int num_bits)
> +{
> + BIGNUM *tmp, *big2, *big32, *big2_32;
> + BN_CTX *ctx;
> + int i;
> +
> + tmp = BN_new();
> + big2 = BN_new();
> + big32 = BN_new();
> + big2_32 = BN_new();
> +
> + /*
> + * Note: This code assumes that all of the above succeed, or all fail.
> + * In practice memory allocations generally do not fail (unless the
> + * process is killed), so it does not seem worth handling each of these
> + * as a separate case. Technicaly this could leak memory on failure,
> + * but a) it won't happen in practice, and b) it doesn't matter as we
> + * will immediately exit with a failure code.
> + */
> + if (!tmp || !big2 || !big32 || !big2_32) {
> + fprintf(stderr, "Out of memory (bignum)\n");
> + return -ENOMEM;
> + }
> + ctx = BN_CTX_new();
> + if (!tmp) {
> + fprintf(stderr, "Out of memory (bignum context)\n");
> + return -ENOMEM;
> + }
> + BN_set_word(big2, 2L);
> + BN_set_word(big32, 32L);
> + BN_exp(big2_32, big2, big32, ctx); /* B = 2^32 */
> +
> + for (i = 0; i < num_bits / 32; i++) {
> + BN_mod(tmp, num, big2_32, ctx); /* n = N mod B */
> + if (i % 4)
> + printf(" ");
> + else
> + printf("\n\t");
> + printf("0x%08lx,", BN_get_word(tmp));
> + BN_rshift(num, num, 32); /* N = N/B */
> + }
> +
> + BN_free(tmp);
> + BN_free(big2);
> + BN_free(big32);
> + BN_free(big2_32);
> +
> + return 0;
> +}
> +
> +static int gen_key(const char *keyname, const char *path)
> +{
> + BIGNUM *modulus, *r_squared;
> + uint64_t exponent;
> + uint32_t n0_inv;
> + int ret;
> + int bits;
> + RSA *rsa;
> + ENGINE *e = NULL;
> + char *tmp, *key_name_c;
> +
> + tmp = key_name_c = strdup(keyname);
> +
> + while (*tmp) {
> + if (*tmp == '-')
> + *tmp = '_';
> + tmp++;
> + }
> +
> + if (!strncmp(path, "__ENV__", 7)) {
> + const char *var = getenv(path + 7);
> + if (!var) {
> + fprintf(stderr,
> + "environment variable \"%s\" is empty\n", path
> + 7);
> + exit(1);
> + }
> + path = var;
> + }
> +
> + if (!strncmp(path, "pkcs11:", 7)) {
> + ret = rsa_engine_init(&e);
> + if (ret)
> + exit(1);
> + ret = rsa_engine_get_pub_key(path, e, &rsa);
> + if (ret)
> + exit(1);
> + } else {
> + ret = rsa_pem_get_pub_key(path, &rsa);
> + if (ret)
> + exit(1);
> + }
> +
> + ret = rsa_get_params(rsa, &exponent, &n0_inv, &modulus, &r_squared);
> + if (ret)
> + return ret;
> +
> + bits = BN_num_bits(modulus);
> +
> + printf("\nstatic uint32_t %s_modulus[] = {", key_name_c);
> + print_bignum(modulus, bits);
> + printf("\n};\n\n");
> +
> + printf("static uint32_t %s_rr[] = {", key_name_c);
> + print_bignum(r_squared, bits);
> + printf("\n};\n\n");
> +
> + printf("static struct rsa_public_key %s = {\n", key_name_c);
> + printf("\t.len = %d,\n", bits / 32);
> + printf("\t.n0inv = 0x%0x,\n", n0_inv);
> + printf("\t.modulus = %s_modulus,\n", key_name_c);
> + printf("\t.rr = %s_rr,\n", key_name_c);
> + printf("\t.exponent = 0x%0lx,\n", exponent);
> + printf("\t.key_name_hint = \"%s\",\n", keyname);
> + printf("};\n\n");
> +
> + printf("struct rsa_public_key *%sp
> __attribute__((section(\".rsa_keys.rodata.%s\"))) = &%s;\n",
> + key_name_c, key_name_c, key_name_c);
> +
> + return 0;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + char *path, *keyname;
> + int i;
> +
> + if (argc < 2) {
> + fprintf(stderr, "Usage: %s <key_name_hint>:<crt> ...\n",
> argv[0]);
> + exit(1);
> + }
> +
> + for (i = 1; i < argc; i++) {
> + keyname = argv[i];
> +
> + path = strchr(keyname, ':');
> + if (!path) {
> + fprintf(stderr,
> + "keys must be given as
> <key_name_hint>:<crt>\n");
> + exit(1);
> + }
> +
> + *path = 0;
> + path++;
> +
> + gen_key(keyname, path);
> + }
> +
> + exit(0);
> +}
>
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
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