Merge branch '2020-03-12-rsa-improvements' into next

(Description from AKASHI Takahiro)

extend rsa_verify() for UEFI secure boot:

The current rsa_verify() requires five parameters for a RSA public key
for efficiency while RSA, in theory, requires only two. In addition,
those parameters are expected to come from FIT image.

So this function won't fit very well when we want to use it for the
purpose of implementing UEFI secure boot, in particular, image
authentication as well as variable authentication, where the essential
two parameters are set to be retrieved from one of X509 certificates in
signature database.

So, in this patch, additional three parameters will be calculated on the
fly when rsa_verify() is called without fdt which should contain
parameters above.

This calculation heavily relies on "big-number (or multi-precision)
library." Therefore some routines from BearSSL under MIT license are
imported in this implementation.

2 files changed, 41 insertions, 5 deletions

diff --git a/include/image.h b/include/image.h
index b316d167d8..a1eea94f7d 100644
--- a/include/image.h
+++ b/include/image.h
@@ -1114,6 +1114,7 @@ int fit_conf_get_prop_node(const void *fit, int noffset,
 
 int fit_check_ramdisk(const void *fit, int os_noffset,
 		uint8_t arch, int verify);
+#endif /* IMAGE_ENABLE_FIT */
 
 int calculate_hash(const void *data, int data_len, const char *algo,
 			uint8_t *value, int *value_len);
@@ -1126,16 +1127,20 @@ int calculate_hash(const void *data, int data_len, const char *algo,
 # if defined(CONFIG_FIT_SIGNATURE)
 #  define IMAGE_ENABLE_SIGN	1
 #  define IMAGE_ENABLE_VERIFY	1
+#  define FIT_IMAGE_ENABLE_VERIFY	1
 #  include <openssl/evp.h>
 # else
 #  define IMAGE_ENABLE_SIGN	0
 #  define IMAGE_ENABLE_VERIFY	0
+#  define FIT_IMAGE_ENABLE_VERIFY	0
 # endif
 #else
 # define IMAGE_ENABLE_SIGN	0
-# define IMAGE_ENABLE_VERIFY	CONFIG_IS_ENABLED(FIT_SIGNATURE)
+# define IMAGE_ENABLE_VERIFY		CONFIG_IS_ENABLED(RSA_VERIFY)
+# define FIT_IMAGE_ENABLE_VERIFY	CONFIG_IS_ENABLED(FIT_SIGNATURE)
 #endif
 
+#if IMAGE_ENABLE_FIT
 #ifdef USE_HOSTCC
 void *image_get_host_blob(void);
 void image_set_host_blob(void *host_blob);
@@ -1149,6 +1154,7 @@ void image_set_host_blob(void *host_blob);
 #else
 #define IMAGE_ENABLE_BEST_MATCH	0
 #endif
+#endif /* IMAGE_ENABLE_FIT */
 
 /* Information passed to the signing routines */
 struct image_sign_info {
@@ -1164,18 +1170,21 @@ struct image_sign_info {
 	int required_keynode;		/* Node offset of key to use: -1=any */
 	const char *require_keys;	/* Value for 'required' property */
 	const char *engine_id;		/* Engine to use for signing */
+	/*
+	 * Note: the following two fields are always valid even w/o
+	 * RSA_VERIFY_WITH_PKEY in order to make sure this structure is
+	 * the same on target and host. Otherwise, vboot test may fail.
+	 */
+	const void *key;		/* Pointer to public key in DER */
+	int keylen;			/* Length of public key */
 };
 
-#endif /* Allow struct image_region to always be defined for rsa.h */
-
 /* A part of an image, used for hashing */
 struct image_region {
 	const void *data;
 	int size;
 };
 
-#if IMAGE_ENABLE_FIT
-
 #if IMAGE_ENABLE_VERIFY
 # include <u-boot/rsa-checksum.h>
 #endif
@@ -1276,6 +1285,8 @@ struct crypto_algo *image_get_crypto_algo(const char *full_name);
  */
 struct padding_algo *image_get_padding_algo(const char *name);
 
+#if IMAGE_ENABLE_FIT
+
 /**
  * fit_image_verify_required_sigs() - Verify signatures marked as 'required'
  *
@@ -1416,6 +1427,7 @@ struct cipher_algo *image_get_cipher_algo(const char *full_name);
 #endif /* CONFIG_FIT_VERBOSE */
 #endif /* CONFIG_FIT */
 
+#if !defined(USE_HOSTCC)
 #if defined(CONFIG_ANDROID_BOOT_IMAGE)
 struct andr_img_hdr;
 int android_image_check_header(const struct andr_img_hdr *hdr);
@@ -1437,6 +1449,7 @@ bool android_image_print_dtb_contents(ulong hdr_addr);
 #endif
 
 #endif /* CONFIG_ANDROID_BOOT_IMAGE */
+#endif /* !USE_HOSTCC */
 
 /**
  * board_fit_config_name_match() - Check for a matching board name
diff --git a/include/u-boot/rsa-mod-exp.h b/include/u-boot/rsa-mod-exp.h
index 8a428c4b6a..1da8af1bb8 100644
--- a/include/u-boot/rsa-mod-exp.h
+++ b/include/u-boot/rsa-mod-exp.h
@@ -27,6 +27,29 @@ struct key_prop {
 };
 
 /**
+ * rsa_gen_key_prop() - Generate key properties of RSA public key
+ * @key:	Specifies key data in DER format
+ * @keylen:	Length of @key
+ * @prop:	Generated key property
+ *
+ * This function takes a blob of encoded RSA public key data in DER
+ * format, parse it and generate all the relevant properties
+ * in key_prop structure.
+ * Return a pointer to struct key_prop in @prop on success.
+ *
+ * Return:	0 on success, negative on error
+ */
+int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **proc);
+
+/**
+ * rsa_free_key_prop() - Free key properties
+ * @prop:	Pointer to struct key_prop
+ *
+ * This function frees all the memories allocated by rsa_gen_key_prop().
+ */
+void rsa_free_key_prop(struct key_prop *prop);
+
+/**
  * rsa_mod_exp_sw() - Perform RSA Modular Exponentiation in sw
  *
  * Operation: out[] = sig ^ exponent % modulus