This function, and hence rsa_verify(), will perform RSA verification
with two essential parameters for a RSA public key in contract of
rsa_verify_with_keynode(), which requires additional three parameters
stored in FIT image.
It will be used in implementing UEFI secure boot, i.e. image authentication
and variable authentication.
Signed-off-by: AKASHI Takahiro <takahiro.aka...@linaro.org>
---
lib/rsa/rsa-verify.c | 129 +++++++++++++++++++++++++++++++++----------
1 file changed, 99 insertions(+), 30 deletions(-)
diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c
index 1df42f28c64a..43271a10bb84 100644
--- a/lib/rsa/rsa-verify.c
+++ b/lib/rsa/rsa-verify.c
@@ -17,9 +17,14 @@
#include "mkimage.h"
#include <fdt_support.h>
#endif
+#include <linux/kconfig.h>
#include <u-boot/rsa-mod-exp.h>
#include <u-boot/rsa.h>
+#ifndef __UBOOT__ /* for host tools */
+#undef CONFIG_RSA_VERIFY_WITH_PKEY
+#endif
+
/* Default public exponent for backward compatibility */
#define RSA_DEFAULT_PUBEXP 65537
@@ -344,6 +349,50 @@ static int rsa_verify_key(struct image_sign_info *info,
}
#endif
+#ifdef CONFIG_RSA_VERIFY_WITH_PKEY
+/**
+ * rsa_verify_with_pkey() - Verify a signature against some data using
+ * only modulus and exponent as RSA key properties.
+ * @info: Specifies key information
+ * @hash: Pointer to the expected hash
+ * @sig: Signature
+ * @sig_len: Number of bytes in signature
+ *
+ * Parse a RSA public key blob in DER format pointed to in @info and fill
+ * a key_prop structure with properties of the key. Then verify a RSA PKCS1.5
+ * signature against an expected hash using the calculated properties.
+ *
+ * Return 0 if verified, -ve on error
+ */
+static int rsa_verify_with_pkey(struct image_sign_info *info,
+ const void *hash, uint8_t *sig, uint sig_len)
+{
+ struct key_prop *prop;
+ int ret;
+
+ /* Public key is self-described to fill key_prop */
+ prop = rsa_gen_key_prop(info->key, info->keylen);
+ if (!prop) {
+ debug("Generating necessary parameter for decoding failed\n");
+ return -EACCES;
+ }
+
+ ret = rsa_verify_key(info, prop, sig, sig_len, hash,
+ info->crypto->key_len);
+
+ rsa_free_key_prop(prop);
+
+ return ret;
+}
+#else
+static int rsa_verify_with_pkey(struct image_sign_info *info,
+ const void *hash, uint8_t *sig, uint sig_len)
+{
+ return -EACCES;
+}
+#endif
+
+#if CONFIG_IS_ENABLED(FIT_SIGNATURE)
/**
* rsa_verify_with_keynode() - Verify a signature against some data using
* information in node with prperties of RSA Key like modulus, exponent etc.
@@ -397,18 +446,22 @@ static int rsa_verify_with_keynode(struct image_sign_info
*info,
return ret;
}
+#else
+static int rsa_verify_with_keynode(struct image_sign_info *info,
+ const void *hash, uint8_t *sig,
+ uint sig_len, int node)
+{
+ return -EACCES;
+}
+#endif
int rsa_verify(struct image_sign_info *info,
const struct image_region region[], int region_count,
uint8_t *sig, uint sig_len)
{
- const void *blob = info->fdt_blob;
/* Reserve memory for maximum checksum-length */
uint8_t hash[info->crypto->key_len];
- int ndepth, noffset;
- int sig_node, node;
- char name[100];
- int ret;
+ int ret = -EACCES;
/*
* Verify that the checksum-length does not exceed the
@@ -421,12 +474,6 @@ int rsa_verify(struct image_sign_info *info,
return -EINVAL;
}
- sig_node = fdt_subnode_offset(blob, 0, FIT_SIG_NODENAME);
- if (sig_node < 0) {
- debug("%s: No signature node found\n", __func__);
- return -ENOENT;
- }
-
/* Calculate checksum with checksum-algorithm */
ret = info->checksum->calculate(info->checksum->name,
region, region_count, hash);
@@ -435,30 +482,52 @@ int rsa_verify(struct image_sign_info *info,
return -EINVAL;
}
- /* See if we must use a particular key */
- if (info->required_keynode != -1) {
- ret = rsa_verify_with_keynode(info, hash, sig, sig_len,
- info->required_keynode);
- if (!ret)
- return ret;
- }
+ if (IS_ENABLED(CONFIG_RSA_VERIFY_WITH_PKEY) && !info->fdt_blob) {
+ /* don't rely on fdt properties */
+ ret = rsa_verify_with_pkey(info, hash, sig, sig_len);
- /* Look for a key that matches our hint */
- snprintf(name, sizeof(name), "key-%s", info->keyname);
- node = fdt_subnode_offset(blob, sig_node, name);
- ret = rsa_verify_with_keynode(info, hash, sig, sig_len, node);
- if (!ret)
return ret;
+ }
+
+ if (CONFIG_IS_ENABLED(FIT_SIGNATURE)) {
+ const void *blob = info->fdt_blob;
+ int ndepth, noffset;
+ int sig_node, node;
+ char name[100];
+
+ sig_node = fdt_subnode_offset(blob, 0, FIT_SIG_NODENAME);
+ if (sig_node < 0) {
+ debug("%s: No signature node found\n", __func__);
+ return -ENOENT;
+ }
- /* No luck, so try each of the keys in turn */
- for (ndepth = 0, noffset = fdt_next_node(info->fit, sig_node, &ndepth);
- (noffset >= 0) && (ndepth > 0);
- noffset = fdt_next_node(info->fit, noffset, &ndepth)) {
- if (ndepth == 1 && noffset != node) {
+ /* See if we must use a particular key */
+ if (info->required_keynode != -1) {
ret = rsa_verify_with_keynode(info, hash, sig, sig_len,
- noffset);
+ info->required_keynode);
if (!ret)
- break;
+ return ret;
+ }
+
+ /* Look for a key that matches our hint */
+ snprintf(name, sizeof(name), "key-%s", info->keyname);
+ node = fdt_subnode_offset(blob, sig_node, name);
+ ret = rsa_verify_with_keynode(info, hash, sig, sig_len, node);
+ if (!ret)
+ return ret;
+
+ /* No luck, so try each of the keys in turn */
+ for (ndepth = 0, noffset = fdt_next_node(info->fit, sig_node,
+ &ndepth);
+ (noffset >= 0) && (ndepth > 0);
+ noffset = fdt_next_node(info->fit, noffset, &ndepth)) {
+ if (ndepth == 1 && noffset != node) {
+ ret = rsa_verify_with_keynode(info, hash,
+ sig, sig_len,
+ noffset);
+ if (!ret)
+ break;
+ }
}
}
--
2.21.0
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