[PATCH v4 10/16] crypto: add public_key functions
Sascha Hauer
s.hauer at pengutronix.de
Fri Sep 13 00:59:18 PDT 2024
Now that we have a struct public_key as a general container for keys
create and use functions making use of it. Move the list from struct
rsa_public_key to struct public_key, add public_key_verify() and use
it instead of rsa_verify(), move key_name_hint to struct public_key.
With this we do not need to bother the FIT image code when adding
support for ECDSA keys.
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
common/image-fit.c | 20 ++++----
crypto/public-keys.c | 92 ++++++++++++++++++++++++++++++-------
crypto/rsa.c | 74 +++++++++--------------------
include/crypto/public_key.h | 15 ++++++
include/rsa.h | 16 +------
scripts/keytoc.c | 3 +-
6 files changed, 126 insertions(+), 94 deletions(-)
diff --git a/common/image-fit.c b/common/image-fit.c
index 4a69049abc..c5d2196bda 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -20,7 +20,7 @@
#include <errno.h>
#include <linux/err.h>
#include <stringlist.h>
-#include <rsa.h>
+#include <crypto/public_key.h>
#include <uncompress.h>
#include <image-fit.h>
@@ -253,10 +253,10 @@ static struct digest *fit_alloc_digest(struct device_node *sig_node,
return digest;
}
-static int fit_check_rsa_signature(struct device_node *sig_node,
- enum hash_algo algo, void *hash)
+static int fit_check_signature(struct device_node *sig_node,
+ enum hash_algo algo, void *hash)
{
- const struct rsa_public_key *key;
+ const struct public_key *key;
const char *key_name = NULL;
int sig_len;
const char *sig_value;
@@ -270,19 +270,19 @@ static int fit_check_rsa_signature(struct device_node *sig_node,
of_property_read_string(sig_node, "key-name-hint", &key_name);
if (key_name) {
- key = rsa_get_key(key_name);
+ key = public_key_get(key_name);
if (key) {
- ret = rsa_verify(key, sig_value, sig_len, hash, algo);
+ ret = public_key_verify(key, sig_value, sig_len, hash, algo);
if (!ret)
goto ok;
}
}
- for_each_rsa_key(key) {
+ for_each_public_key(key) {
if (key_name && !strcmp(key->key_name_hint, key_name))
continue;
- ret = rsa_verify(key, sig_value, sig_len, hash, algo);
+ ret = public_key_verify(key, sig_value, sig_len, hash, algo);
if (!ret)
goto ok;
}
@@ -341,7 +341,7 @@ static int fit_verify_signature(struct device_node *sig_node, const void *fit)
hash = xzalloc(digest_length(digest));
digest_final(digest, hash);
- ret = fit_check_rsa_signature(sig_node, algo, hash);
+ ret = fit_check_signature(sig_node, algo, hash);
if (ret)
goto out_free_hash;
@@ -464,7 +464,7 @@ static int fit_image_verify_signature(struct fit_handle *handle,
hash = xzalloc(digest_length(digest));
digest_final(digest, hash);
- ret = fit_check_rsa_signature(sig_node, algo, hash);
+ ret = fit_check_signature(sig_node, algo, hash);
free(hash);
diff --git a/crypto/public-keys.c b/crypto/public-keys.c
index a3ef3bafc8..36c308908d 100644
--- a/crypto/public-keys.c
+++ b/crypto/public-keys.c
@@ -2,31 +2,91 @@
#include <crypto/public_key.h>
#include <rsa.h>
+static LIST_HEAD(public_keys);
+
+const struct public_key *public_key_next(const struct public_key *prev)
+{
+ prev = list_prepare_entry(prev, &public_keys, list);
+ list_for_each_entry_continue(prev, &public_keys, list)
+ return prev;
+
+ return NULL;
+}
+
+const struct public_key *public_key_get(const char *name)
+{
+ const struct public_key *key;
+
+ list_for_each_entry(key, &public_keys, list) {
+ if (!strcmp(key->key_name_hint, name))
+ return key;
+ }
+
+ return NULL;
+}
+
+int public_key_add(struct public_key *key)
+{
+ if (public_key_get(key->key_name_hint))
+ return -EEXIST;
+
+ list_add_tail(&key->list, &public_keys);
+
+ return 0;
+}
+
+static struct public_key *public_key_dup(const struct public_key *key)
+{
+ struct public_key *k = xzalloc(sizeof(*k));
+
+ k->type = key->type;
+ if (key->key_name_hint)
+ k->key_name_hint = xstrdup(key->key_name_hint);
+
+ switch (key->type) {
+ case PUBLIC_KEY_TYPE_RSA:
+ k->rsa = rsa_key_dup(key->rsa);
+ if (!k->rsa)
+ goto err;
+ break;
+ default:
+ goto err;
+ }
+
+ return k;
+err:
+ free(k->key_name_hint);
+ free(k);
+
+ return NULL;
+}
+
+int public_key_verify(const struct public_key *key, const uint8_t *sig,
+ const uint32_t sig_len, const uint8_t *hash,
+ enum hash_algo algo)
+{
+ switch (key->type) {
+ case PUBLIC_KEY_TYPE_RSA:
+ return rsa_verify(key->rsa, sig, sig_len, hash, algo);
+ }
+
+ return -ENOKEY;
+}
+
extern const struct public_key * const __public_keys_start;
extern const struct public_key * const __public_keys_end;
static int init_public_keys(void)
{
const struct public_key * const *iter;
- int ret;
for (iter = &__public_keys_start; iter != &__public_keys_end; iter++) {
- struct rsa_public_key *rsa_key;
-
- switch ((*iter)->type) {
- case PUBLIC_KEY_TYPE_RSA:
- rsa_key = rsa_key_dup((*iter)->rsa);
- if (!rsa_key)
- continue;
-
- ret = rsa_key_add(rsa_key);
- if (ret)
- pr_err("Cannot add rsa key: %pe\n", ERR_PTR(ret));
- break;
- default:
- pr_err("Ignoring unknown key type %u\n", (*iter)->type);
- }
+ struct public_key *key = public_key_dup(*iter);
+
+ if (!key)
+ continue;
+ public_key_add(key);
}
return 0;
diff --git a/crypto/rsa.c b/crypto/rsa.c
index 8eab07beed..969dbfb32b 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -15,6 +15,7 @@
#include <asm/byteorder.h>
#include <errno.h>
#include <rsa.h>
+#include <crypto/public_key.h>
#include <asm/unaligned.h>
#define UINT64_MULT32(v, multby) (((uint64_t)(v)) * ((uint32_t)(multby)))
@@ -380,105 +381,74 @@ static void rsa_convert_big_endian(uint32_t *dst, const uint32_t *src, int len)
dst[i] = fdt32_to_cpu(src[len - 1 - i]);
}
-struct rsa_public_key *rsa_of_read_key(struct device_node *node)
+struct public_key *rsa_of_read_key(struct device_node *node)
{
const void *modulus, *rr;
const uint64_t *public_exponent;
int length;
- struct rsa_public_key *key;
+ struct public_key *key;
+ struct rsa_public_key *rsa;
int err;
if (strncmp(node->name, "key-", 4))
return ERR_PTR(-EINVAL);
key = xzalloc(sizeof(*key));
+ rsa = key->rsa = xzalloc(sizeof(*rsa));
key->key_name_hint = xstrdup(node->name + 4);
- of_property_read_u32(node, "rsa,num-bits", &key->len);
- of_property_read_u32(node, "rsa,n0-inverse", &key->n0inv);
+ of_property_read_u32(node, "rsa,num-bits", &rsa->len);
+ of_property_read_u32(node, "rsa,n0-inverse", &rsa->n0inv);
public_exponent = of_get_property(node, "rsa,exponent", &length);
if (!public_exponent || length < sizeof(*public_exponent))
- key->exponent = RSA_DEFAULT_PUBEXP;
+ rsa->exponent = RSA_DEFAULT_PUBEXP;
else
- key->exponent = fdt64_to_cpu(*public_exponent);
+ rsa->exponent = fdt64_to_cpu(*public_exponent);
modulus = of_get_property(node, "rsa,modulus", NULL);
rr = of_get_property(node, "rsa,r-squared", NULL);
- if (!key->len || !modulus || !rr) {
+ if (!rsa->len || !modulus || !rr) {
pr_debug("%s: Missing RSA key info", __func__);
err = -EFAULT;
goto out;
}
/* Sanity check for stack size */
- if (key->len > RSA_MAX_KEY_BITS || key->len < RSA_MIN_KEY_BITS) {
+ if (rsa->len > RSA_MAX_KEY_BITS || rsa->len < RSA_MIN_KEY_BITS) {
pr_debug("RSA key bits %u outside allowed range %d..%d\n",
- key->len, RSA_MIN_KEY_BITS, RSA_MAX_KEY_BITS);
+ rsa->len, RSA_MIN_KEY_BITS, RSA_MAX_KEY_BITS);
err = -EFAULT;
goto out;
}
- key->len /= sizeof(uint32_t) * 8;
+ rsa->len /= sizeof(uint32_t) * 8;
- key->modulus = xzalloc(RSA_MAX_KEY_BITS / 8);
- key->rr = xzalloc(RSA_MAX_KEY_BITS / 8);
+ rsa->modulus = xzalloc(RSA_MAX_KEY_BITS / 8);
+ rsa->rr = xzalloc(RSA_MAX_KEY_BITS / 8);
- rsa_convert_big_endian(key->modulus, modulus, key->len);
- rsa_convert_big_endian(key->rr, rr, key->len);
+ rsa_convert_big_endian(rsa->modulus, modulus, rsa->len);
+ rsa_convert_big_endian(rsa->rr, rr, rsa->len);
err = 0;
out:
- if (err)
+ if (err) {
free(key);
+ free(rsa);
+ }
return err ? ERR_PTR(err) : key;
}
void rsa_key_free(struct rsa_public_key *key)
{
- list_del(&key->list);
-
free(key->modulus);
free(key->rr);
free(key);
}
-static LIST_HEAD(rsa_keys);
-
-const struct rsa_public_key *rsa_key_next(const struct rsa_public_key *prev)
-{
- prev = list_prepare_entry(prev, &rsa_keys, list);
- list_for_each_entry_continue(prev, &rsa_keys, list)
- return prev;
-
- return NULL;
-}
-
-const struct rsa_public_key *rsa_get_key(const char *name)
-{
- const struct rsa_public_key *key;
-
- list_for_each_entry(key, &rsa_keys, list) {
- if (!strcmp(key->key_name_hint, name))
- return key;
- }
-
- return NULL;
-}
-
-int rsa_key_add(struct rsa_public_key *key)
-{
- if (rsa_get_key(key->key_name_hint))
- return -EEXIST;
-
- list_add_tail(&key->list, &rsa_keys);
-
- return 0;
-}
-
struct rsa_public_key *rsa_key_dup(const struct rsa_public_key *key)
{
struct rsa_public_key *new;
@@ -493,7 +463,7 @@ struct rsa_public_key *rsa_key_dup(const struct rsa_public_key *key)
static void rsa_init_keys_of(void)
{
struct device_node *sigs, *sig;
- struct rsa_public_key *key;
+ struct public_key *key;
int ret;
if (!IS_ENABLED(CONFIG_OFTREE))
@@ -511,7 +481,7 @@ static void rsa_init_keys_of(void)
continue;
}
- ret = rsa_key_add(key);
+ ret = public_key_add(key);
if (ret)
pr_err("Cannot add rsa key %s: %s\n",
key->key_name_hint, strerror(-ret));
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 83e8401aed..1b91063042 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -1,6 +1,8 @@
#ifndef __CRYPTO_PUBLIC_KEY_H
#define __CRYPTO_PUBLIC_KEY_H
+#include <digest.h>
+
struct rsa_public_key;
struct ecdsa_public_key;
@@ -10,6 +12,8 @@ enum pulic_key_type {
struct public_key {
enum pulic_key_type type;
+ struct list_head list;
+ char *key_name_hint;
union {
struct rsa_public_key *rsa;
@@ -17,4 +21,15 @@ struct public_key {
};
};
+int public_key_add(struct public_key *key);
+const struct public_key *public_key_get(const char *name);
+const struct public_key *public_key_next(const struct public_key *prev);
+
+#define for_each_public_key(key) \
+ for (key = public_key_next(NULL); key; key = public_key_next(key))
+
+int public_key_verify(const struct public_key *key, const uint8_t *sig,
+ const uint32_t sig_len, const uint8_t *hash,
+ enum hash_algo algo);
+
#endif /* __CRYPTO_PUBLIC_KEY_H */
diff --git a/include/rsa.h b/include/rsa.h
index ecb2f42957..ef03a925b8 100644
--- a/include/rsa.h
+++ b/include/rsa.h
@@ -29,8 +29,6 @@ struct rsa_public_key {
uint32_t *modulus; /* modulus as little endian array */
uint32_t *rr; /* R^2 as little endian array */
uint64_t exponent; /* public exponent */
- char *key_name_hint;
- struct list_head list;
};
/**
@@ -54,24 +52,12 @@ int rsa_verify(const struct rsa_public_key *key, const uint8_t *sig,
struct device_node;
-struct rsa_public_key *rsa_of_read_key(struct device_node *node);
+struct public_key *rsa_of_read_key(struct device_node *node);
void rsa_key_free(struct rsa_public_key *key);
-const struct rsa_public_key *rsa_get_key(const char *name);
-
-const struct rsa_public_key *rsa_key_next(const struct rsa_public_key *prev);
-
-#define for_each_rsa_key(key) \
- for (key = rsa_key_next(NULL); key; key = rsa_key_next(key))
#ifdef CONFIG_CRYPTO_RSA
-int rsa_key_add(struct rsa_public_key *key);
struct rsa_public_key *rsa_key_dup(const struct rsa_public_key *key);
#else
-static inline int rsa_key_add(struct rsa_public_key *key)
-{
- return -ENOSYS;
-}
-
static inline struct rsa_public_key *rsa_key_dup(const struct rsa_public_key *key);
{
return NULL;
diff --git a/scripts/keytoc.c b/scripts/keytoc.c
index e66c5989bf..8b29118c95 100644
--- a/scripts/keytoc.c
+++ b/scripts/keytoc.c
@@ -491,6 +491,7 @@ static int gen_key_ecdsa(EVP_PKEY *key, const char *key_name, const char *key_na
if (!standalone) {
fprintf(outfilep, "\nstatic struct public_key %s_public_key = {\n", key_name_c);
fprintf(outfilep, "\t.type = PUBLIC_KEY_TYPE_ECDSA,\n");
+ fprintf(outfilep, "\t.key_name_hint = \"%s\",\n", key_name);
fprintf(outfilep, "\t.ecdsa = &%s,\n", key_name_c);
fprintf(outfilep, "};");
fprintf(outfilep, "\nstruct public_key *%s_ecdsa_p __attribute__((section(\".public_keys.rodata.%s\"))) = &%s_public_key;\n",
@@ -551,12 +552,12 @@ static int gen_key_rsa(EVP_PKEY *key, const char *key_name, const char *key_name
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", key_name);
fprintf(outfilep, "};\n");
if (!standalone) {
fprintf(outfilep, "\nstatic struct public_key %s_public_key = {\n", key_name_c);
fprintf(outfilep, "\t.type = PUBLIC_KEY_TYPE_RSA,\n");
+ fprintf(outfilep, "\t.key_name_hint = \"%s\",\n", key_name);
fprintf(outfilep, "\t.rsa = &%s,\n", key_name_c);
fprintf(outfilep, "};");
fprintf(outfilep, "\nstruct public_key *%sp __attribute__((section(\".public_keys.rodata.%s\"))) = &%s_public_key;\n",
--
2.39.2
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