[PATCH v2 12/19] keytoc: add ecdsa support
Sascha Hauer
s.hauer at pengutronix.de
Wed Jul 31 22:57:30 PDT 2024
This extends the keytoc utility to also handle ecdsa keys.
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
scripts/keytoc.c | 191 +++++++++++++++++++++++++++++++++++++++--------
1 file changed, 161 insertions(+), 30 deletions(-)
diff --git a/scripts/keytoc.c b/scripts/keytoc.c
index 891425cecc..0883ca64f7 100644
--- a/scripts/keytoc.c
+++ b/scripts/keytoc.c
@@ -20,6 +20,8 @@
#include <openssl/engine.h>
#include <openssl/provider.h>
#include <openssl/core_names.h>
+#include <openssl/param_build.h>
+#include <openssl/store.h>
static int dts, standalone;
@@ -377,44 +379,131 @@ static int print_bignum(BIGNUM *num, int num_bits)
return 0;
}
-static int gen_key(const char *keyname, const char *path)
+/*
+ * When imported from a HSM the key doesn't have the EC point parameters,
+ * only the pubkey itself exists. Exporting the pubkey and creating a new
+ * pkey from it resolves this. This can likely (hopefully) be improved, but
+ * I don't have an idea how.
+ */
+static EVP_PKEY *reimport_key(EVP_PKEY *pkey)
{
- BIGNUM *modulus, *r_squared;
- uint64_t exponent = 0;
- uint32_t n0_inv;
+ char group[128] = {};
+ size_t outlen;
+ OSSL_PARAM *params;
+ OSSL_PARAM_BLD *param_bld = NULL;
+ unsigned char pub[128] = {};
+ size_t len;
+ EVP_PKEY *pkey_out = NULL;
+ EVP_PKEY_CTX *pkey_ctx;
int ret;
- int bits;
- EVP_PKEY *key;
- char *tmp, *key_name_c;
- tmp = key_name_c = strdup(keyname);
+ ret = EVP_PKEY_get_utf8_string_param(pkey, "group", group, sizeof(group), &outlen);
+ if (!ret)
+ return NULL;
- while (*tmp) {
- if (*tmp == '-')
- *tmp = '_';
- tmp++;
- }
+ ret = EVP_PKEY_get_octet_string_param(pkey, OSSL_PKEY_PARAM_PUB_KEY,
+ pub, sizeof(pub), &len);
+ if (ret <= 0)
+ return NULL;
- 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;
- }
+ param_bld = OSSL_PARAM_BLD_new();
+ if (!param_bld)
+ return NULL;
- if (!strncmp(path, "pkcs11:", 7)) {
- ret = engine_get_pub_key(path, &key);
- if (ret)
- exit(1);
+ ret = OSSL_PARAM_BLD_push_utf8_string(param_bld, "group", group, 0);
+ if (ret <= 0)
+ return NULL;
+
+ ret = OSSL_PARAM_BLD_push_octet_string(param_bld, "pub", pub, len);
+ if (ret <= 0)
+ return NULL;
+
+ params = OSSL_PARAM_BLD_to_param(param_bld);
+ if (!params)
+ return NULL;
+
+ pkey_ctx = EVP_PKEY_CTX_new_from_pkey(NULL, pkey, NULL);
+ if (!pkey_ctx)
+ return NULL;
+
+ ret = EVP_PKEY_fromdata_init(pkey_ctx);
+ if (ret <= 0)
+ return NULL;
+
+ ret = EVP_PKEY_fromdata(pkey_ctx, &pkey_out, EVP_PKEY_PUBLIC_KEY, params);
+ if (ret <= 0)
+ return NULL;
+
+ return pkey_out;
+}
+
+static int gen_key_ecdsa(EVP_PKEY *key, const char *key_name, const char *key_name_c)
+{
+ char group[128];
+ size_t outlen;
+ int ret, bits;
+ BIGNUM *key_x = NULL, *key_y = NULL;
+
+ key = reimport_key(key);
+ if (!key)
+ return -EINVAL;
+
+ ret = EVP_PKEY_get_int_param(key, "bits", &bits);
+ if (!ret)
+ return -EINVAL;
+ ret = EVP_PKEY_get_utf8_string_param(key, "group", group, sizeof(group), &outlen);
+ if (!ret)
+ return -EINVAL;
+
+ ret = EVP_PKEY_get_bn_param(key, OSSL_PKEY_PARAM_EC_PUB_X, &key_x);
+ if (!ret)
+ return -EINVAL;
+
+ ret = EVP_PKEY_get_bn_param(key, OSSL_PKEY_PARAM_EC_PUB_Y, &key_y);
+ if (!ret)
+ return -EINVAL;
+
+ if (dts) {
+ fprintf(outfilep, "\t\tkey-%s {\n", key_name_c);
+ fprintf(outfilep, "\t\t\tecdsa,x-point = <");
+ print_bignum(key_x, bits);
+ fprintf(outfilep, ">;\n");
+ fprintf(outfilep, "\t\t\tecdsa,y-point = <");
+ print_bignum(key_y, bits);
+ fprintf(outfilep, ">;\n");
+ fprintf(outfilep, "\t\t\tecdsa,curve = \"%s\";\n", group);
+ fprintf(outfilep, "\t\t};\n");
} else {
- ret = pem_get_pub_key(path, &key);
- if (ret)
- exit(1);
+ fprintf(outfilep, "\nstatic uint32_t %s_x[] = {", key_name_c);
+ print_bignum(key_x, bits);
+ fprintf(outfilep, "\n};\n\n");
+
+ fprintf(outfilep, "static uint32_t %s_y[] = {", key_name_c);
+ print_bignum(key_y, bits);
+ fprintf(outfilep, "\n};\n\n");
+
+ fprintf(outfilep, "static struct ecdsa_public_key %s = {\n", key_name_c);
+
+ fprintf(outfilep, "\t.curve_name = \"%s\",\n", group);
+ fprintf(outfilep, "\t.x = %s_x,\n", key_name_c);
+ fprintf(outfilep, "\t.y = %s_y,\n", key_name_c);
+ fprintf(outfilep, "};\n");
+ if (!standalone)
+ fprintf(outfilep, "\nstruct ecdsa_public_key *%s_ecdsa_p __attribute__((section(\".ecdsa_keys.rodata.%s\"))) = &%s;\n",
+ key_name_c, key_name_c, key_name_c);
}
+ return 0;
+}
+
+static int gen_key_rsa(EVP_PKEY *key, const char *key_name, const char *key_name_c)
+{
+ BIGNUM *modulus, *r_squared;
+ uint64_t exponent = 0;
+ uint32_t n0_inv;
+ int bits;
+ int ret;
+
ret = rsa_get_params(key, &exponent, &n0_inv, &modulus, &r_squared);
if (ret)
return ret;
@@ -457,7 +546,7 @@ static int gen_key(const char *keyname, const char *path)
fprintf(outfilep, "\t.modulus = %s_modulus,\n", key_name_c);
fprintf(outfilep, "\t.rr = %s_rr,\n", key_name_c);
fprintf(outfilep, "\t.exponent = 0x%0lx,\n", exponent);
- fprintf(outfilep, "\t.key_name_hint = \"%s\",\n", keyname);
+ fprintf(outfilep, "\t.key_name_hint = \"%s\",\n", key_name);
fprintf(outfilep, "};\n");
if (!standalone)
@@ -468,6 +557,47 @@ static int gen_key(const char *keyname, const char *path)
return 0;
}
+static int gen_key(const char *keyname, const char *path)
+{
+ int ret;
+ EVP_PKEY *key;
+ 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 = engine_get_pub_key(path, &key);
+ if (ret)
+ exit(1);
+ } else {
+ ret = pem_get_pub_key(path, &key);
+ if (ret)
+ exit(1);
+ }
+
+ ret = gen_key_ecdsa(key, keyname, key_name_c);
+ if (ret)
+ ret = gen_key_rsa(key, keyname, key_name_c);
+
+ return 0;
+}
+
int main(int argc, char *argv[])
{
char *path, *keyname;
@@ -515,6 +645,7 @@ int main(int argc, char *argv[])
else
fprintf(outfilep, "\tsignature {\n");
} else if (standalone) {
+ fprintf(outfilep, "#include <ecdsa.h>\n");
fprintf(outfilep, "#include <rsa.h>\n");
}
--
2.39.2
More information about the barebox
mailing list