Compute the correct hash for init_data

Signed-off-by: Joakim Bech <joakim.bech@linaro.org>

1 files changed, 37 insertions, 1 deletions

diff --git a/source/main.c b/source/main.c
index 0c939f5..a6db27e 100644
--- a/source/main.c
+++ b/source/main.c
@@ -10,6 +10,7 @@
 #include <ecc.h>
 #include <ecc_dsa.h>
 #include <ecc_dh.h>
+#include <sha256.h>
 #include <utils.h>
 
 /* Nordic imports */
@@ -327,6 +328,21 @@ static void test_nordic_key(void)
 	return;
 }
 
+uint32_t hash_data(const uint8_t *d, uint8_t *digest, uint32_t size)
+{
+        struct tc_sha256_state_struct s;
+        memset(&s, 0, sizeof(struct tc_sha256_state_struct));
+        if (tc_sha256_init(&s) != TC_SUCCESS)
+                return 1;
+
+        if (tc_sha256_update(&s, d, size) != TC_SUCCESS)
+                return 1;
+
+        if (tc_sha256_final(digest, &s) != TC_SUCCESS)
+                return 1;
+
+        return 0;
+}
 
 /** @brief The size that must be reserved for the MBR when a softdevice is written to flash.
 This is the offset where the first byte of the softdevice hex file is written.*/
@@ -378,6 +394,11 @@ uint32_t dfu_init_prevalidate(uint8_t *p_init_data, uint32_t init_data_len)
 	nrf_sec_data_t		init_data;
 	nrf_sec_ecc_signature_t signature;
 
+	EccPoint pub;
+	uint8_t digest[NUM_ECC_BYTES];
+	uint32_t r[NUM_ECC_DIGITS];
+	uint32_t s[NUM_ECC_DIGITS];
+
 	// In order to support encryption then any init packet decryption function / library
 	// should be called from here or implemented at this location.
 
@@ -418,6 +439,11 @@ uint32_t dfu_init_prevalidate(uint8_t *p_init_data, uint32_t init_data_len)
 	// address + 0x0100.
 	/** [DFU init application version] */
 
+	/*
+	 * Ignore this check for now, since we're not running on the device with
+	 * the correct address
+	 */
+#if 0
 	// First check to verify the image to be transfered matches the device type.
 	// If no Device type is present in DFU_DEVICE_INFO then any image will be accepted.
 	if ((DFU_DEVICE_INFO->device_type != DFU_DEVICE_TYPE_EMPTY) &&
@@ -433,6 +459,7 @@ uint32_t dfu_init_prevalidate(uint8_t *p_init_data, uint32_t init_data_len)
 	{
 		return NRF_ERROR_INVALID_DATA;
 	}
+#endif
 
 	// Third check: Check the array of supported SoftDevices by this application.
 	//              If the installed SoftDevice does not match any SoftDevice in the list then an
@@ -464,7 +491,16 @@ uint32_t dfu_init_prevalidate(uint8_t *p_init_data, uint32_t init_data_len)
 	signature.p_s   = &m_extended_packet[DFU_INIT_PACKET_POS_EXT_INIT_SIGNATURE_S];
 	signature.s_len = DFU_SIGNATURE_S_LENGTH;
 
-	/* err_code = nrf_sec_svc_verify(&init_data, &Q ,&signature, NRF_SEC_NIST256_SHA256); */
+#if 0 /* The nordic way of verify the init packet signature */
+	err_code = nrf_sec_svc_verify(&init_data, &Q ,&signature, NRF_SEC_NIST256_SHA256);
+#endif
+	ecc_bytes2native(pub.x, Q.p_x);
+	ecc_bytes2native(pub.y, Q.p_y);
+	ecc_bytes2native(r, signature.p_r);
+	ecc_bytes2native(s, signature.p_s);
+
+	hash_data(init_data.p_data, digest, init_data.length);
+
 	return err_code;
 }