Add support for TBBR using ECDSA keys in ARM platforms

- fixed compile error when KEY_ALG=ecdsa
    - add new option ecdsa for TF_MBEDTLS_KEY_ALG
    - add new option devel_ecdsa for ARM_ROTPK_LOCATION
    - add ecdsa key at plat/arm/board/common/rotpk/
    - reduce the mbedtls heap memory size to 13k

Change-Id: I3f7a6170af93fdbaaa7bf2fffb4680a9f6113c13
Signed-off-by: Qixiang Xu <qixiang.xu@arm.com>

docs/user-guide.rst

@@ -643,6 +643,11 @@ ARM development platform specific build options
       ``arm_rotpk_rsa.der``, located in ``plat/arm/board/common/rotpk``. To use
       this option, ``arm_rotprivk_rsa.pem`` must be specified as ``ROT_KEY`` when
       creating the certificates.
+   -  ``devel_ecdsa`` : return a development public key hash embedded in the BL1
+      and BL2 binaries. This hash has been obtained from the ECDSA public key
+      ``arm_rotpk_ecdsa.der``, located in ``plat/arm/board/common/rotpk``. To use
+      this option, ``arm_rotprivk_ecdsa.pem`` must be specified as ``ROT_KEY``
+      when creating the certificates.
 
 -  ``ARM_TSP_RAM_LOCATION``: location of the TSP binary. Options:
 
@@ -990,6 +995,10 @@ images with support for these features:
       in the ARM platform port. The private/public RSA key pair may be
       found in ``plat/arm/board/common/rotpk``.
 
+   -  ``ARM_ROTPK_LOCATION=devel_ecdsa``: use the ROTPK hash that is hardcoded
+      in the ARM platform port. The private/public ECDSA key pair may be
+      found in ``plat/arm/board/common/rotpk``.
+
    Example of command line using RSA development keys:
 
    ::

drivers/auth/mbedtls/mbedtls_common.c

@@ -15,7 +15,7 @@
  * mbed TLS heap
  */
 #if (TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_ECDSA)
-#define MBEDTLS_HEAP_SIZE		(14*1024)
+#define MBEDTLS_HEAP_SIZE		(13*1024)
 #elif (TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA)
 #define MBEDTLS_HEAP_SIZE		(7*1024)
 #endif

include/drivers/auth/mbedtls/mbedtls_config.h

@@ -9,8 +9,8 @@
 /*
  * Key algorithms currently supported on mbed TLS libraries
  */
-#define TF_MBEDTLS_RSA		1
-#define TF_MBEDTLS_ECDSA	2
+#define TF_MBEDTLS_RSA			1
+#define TF_MBEDTLS_ECDSA		2
 
 /*
  * Configuration file to build mbed TLS with the required features for
@@ -30,7 +30,6 @@
 #define MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION
 #define MBEDTLS_X509_CHECK_KEY_USAGE
 #define MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE
-#define MBEDTLS_X509_RSASSA_PSS_SUPPORT
 
 #define MBEDTLS_ASN1_PARSE_C
 #define MBEDTLS_ASN1_WRITE_C
@@ -56,6 +55,7 @@
 #define MBEDTLS_ECP_DP_SECP256R1_ENABLED
 #elif (TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA)
 #define MBEDTLS_RSA_C
+#define MBEDTLS_X509_RSASSA_PSS_SUPPORT
 #endif
 
 #define MBEDTLS_SHA256_C

plat/arm/board/common/board_arm_trusted_boot.c

@@ -18,6 +18,7 @@
 /* ROTPK locations */
 #define ARM_ROTPK_REGS_ID		1
 #define ARM_ROTPK_DEVEL_RSA_ID		2
+#define ARM_ROTPK_DEVEL_ECDSA_ID	3
 
 static const unsigned char rotpk_hash_hdr[] =		\
 		"\x30\x31\x30\x0D\x06\x09\x60\x86\x48"	\
@@ -41,6 +42,12 @@ static const unsigned char arm_devel_rotpk_hash[] =	\
 		"\x37\x7A\x72\x47\x1B\xEC\x32\x73"	\
 		"\xE9\x92\x32\xE2\x49\x59\xF6\x5E"	\
 		"\x8B\x4A\x4A\x46\xD8\x22\x9A\xDA";
+#elif (ARM_ROTPK_LOCATION_ID == ARM_ROTPK_DEVEL_ECDSA_ID)
+static const unsigned char arm_devel_rotpk_hash[] =	\
+		"\x2E\x40\xBF\x6E\xF9\x12\xBB\x98"	\
+		"\x31\x71\x09\x0E\x1E\x15\x3D\x0B"	\
+		"\xFD\xD1\xCC\x69\x4A\x98\xEB\x8B"	\
+		"\xA0\xB0\x20\x86\x4E\x6C\x07\x17";
 #endif
 
 /*
@@ -69,7 +76,8 @@ int plat_get_rotpk_info(void *cookie, void **key_ptr, unsigned int *key_len,
 	memcpy(rotpk_hash_der, rotpk_hash_hdr, rotpk_hash_hdr_len);
 	dst = (uint8_t *)&rotpk_hash_der[rotpk_hash_hdr_len];
 
-#if (ARM_ROTPK_LOCATION_ID == ARM_ROTPK_DEVEL_RSA_ID)
+#if (ARM_ROTPK_LOCATION_ID == ARM_ROTPK_DEVEL_RSA_ID) \
+	|| (ARM_ROTPK_LOCATION_ID == ARM_ROTPK_DEVEL_ECDSA_ID)
 	memcpy(dst, arm_devel_rotpk_hash, SHA256_BYTES);
 #elif (ARM_ROTPK_LOCATION_ID == ARM_ROTPK_REGS_ID)
 	uint32_t *src, tmp;
@@ -121,7 +129,8 @@ int plat_get_rotpk_info(void *cookie, void **key_ptr, unsigned int *key_len,
 		*dst++ = (uint8_t)((tmp >> 8) & 0xFF);
 		*dst++ = (uint8_t)(tmp & 0xFF);
 	}
-#endif /* (ARM_ROTPK_LOCATION_ID == ARM_ROTPK_DEVEL_RSA_ID) */
+#endif /* (ARM_ROTPK_LOCATION_ID == ARM_ROTPK_DEVEL_RSA_ID) \
+		  || (ARM_ROTPK_LOCATION_ID == ARM_ROTPK_DEVEL_ECDSA_ID) */
 
 	*key_ptr = (void *)rotpk_hash_der;
 	*key_len = (unsigned int)sizeof(rotpk_hash_der);

plat/arm/board/common/board_common.mk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -22,7 +22,11 @@ ifneq (${TRUSTED_BOARD_BOOT},0)
     ifeq (${ARM_ROTPK_LOCATION}, regs)
         ARM_ROTPK_LOCATION_ID = ARM_ROTPK_REGS_ID
     else ifeq (${ARM_ROTPK_LOCATION}, devel_rsa)
+        KEY_ALG := rsa
         ARM_ROTPK_LOCATION_ID = ARM_ROTPK_DEVEL_RSA_ID
+    else ifeq (${ARM_ROTPK_LOCATION}, devel_ecdsa)
+        KEY_ALG := ecdsa
+        ARM_ROTPK_LOCATION_ID = ARM_ROTPK_DEVEL_ECDSA_ID
     else
         $(error "Unsupported ARM_ROTPK_LOCATION value")
     endif

plat/arm/board/common/rotpk/arm_rotpk_ecdsa_sha256.bin

@@ -0,0 +1 @@
+.@<40>n<EFBFBD><12><>1q	=<0B><><EFBFBD>iJ<69>닠<EFBFBD> <20>Nl

plat/arm/board/common/rotpk/arm_rotprivk_ecdsa.pem

@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEINSaX6nvzS3teiBJA7WlTLRKJOajpy29o2cArLbUXoZBoAoGCCqGSM49
+AwEHoUQDQgAEm+ZIvTQ44aKk83DhVLsvsFpKDP/Ch9vA+4Hp+fmVfX6gDH8K1OBi
+SpRf7FJ9RGPIn2H6xst+a1OtLMWUDRqGkQ==
+-----END EC PRIVATE KEY-----

plat/arm/board/juno/platform.mk

@@ -91,6 +91,3 @@ include plat/arm/common/arm_common.mk
 include plat/arm/soc/common/soc_css.mk
 include plat/arm/css/common/css_common.mk
 
-ifeq (${KEY_ALG},ecdsa)
-    $(error "ECDSA key algorithm is not fully supported on Juno.")
-endif