mbedtls extract CDI key, ROM functions complete.

trial2/src/ROMfunctions.c

@@ -0,0 +1,182 @@
+#include <ROMfunctions.h>
+
+#define IDENTITY     "identity"
+
+int readUDS(uint8_t* UDSdigest)
+{
+  //Read 8 bytes from RANDFILE
+	//calculate sha256  	
+  //print digest
+
+  FILE *fp = NULL;
+  fp = fopen("RANDFILE","rb");
+  if (!fp)
+  {  
+    perror("File open failed\n");
+    return -1;    //FILENOTFOUND
+  }
+  //uint8_t UDSbuf[UDS_SIZE] = {0};	//{0Xe3,0xc5,0x58,0xaa,0x2f,0xd2,0x19,0x25};
+  uint8_t *UDSbuf = calloc(1, sizeof(uint8_t)*UDS_SIZE);
+  fread(UDSbuf,UDS_SIZE,1,fp);
+  fclose(fp);
+
+  uint8_t UDS_ID[UDS_DGST_SIZE] = {0};
+
+  //mbedtls_sha256_ret( &UDSbuf,sizeof(UDSbuf),UDS_ID,0 );
+  mbedtls_sha256_ret( UDSbuf,UDS_SIZE,UDSdigest,0 );
+
+
+	for (int i = 0; i < UDS_SIZE; i++)
+  		printf("%x", UDSbuf[i]);
+  printf(" :	fuse secret\n" );  	
+
+  for (int i = 0; i < UDS_DGST_SIZE; i++)
+  		printf("%x", UDSdigest[i]);
+  printf(" :  UDS ID\n" );
+
+  free(UDSbuf);
+	return RIOTSUCCESS;
+
+}
+
+
+int readFWID(uint8_t* FW_M)
+{
+
+//  //1. Read functions.c into memory
+//  //2. Calcualte hash into arg
+
+  FILE *fp = NULL;  
+  fp = fopen("functions.c", "r");
+  if (!fp)
+  {  
+    perror("File open failed\n");
+    return -1;    //FILENOTFOUND
+  }
+
+  fseek(fp, 0L, SEEK_END);
+  long FW_size = ftell(fp);
+  rewind(fp);
+
+  //uint8_t *source = calloc(1,sizeof(uint8_t)*FW_size);
+  uint8_t source[FW_size];
+
+  if (fread(&source, FW_size, 1, fp) < 0)
+  {
+    perror("File read failed");
+    return -1;
+  }
+  fclose(fp);
+  mbedtls_sha256_ret(source,FW_size,FW_M,0 );
+
+  //Print block. delete later
+   // for(int i = 0; i < 100; i++)
+   //   printf("%x,",source[i]);
+   // printf("\n");
+
+  //printf("File contnts : %s\n", source);
+
+  for(int i = 0; i < FW_DGST_SIZE; i++)
+    printf("%x",FW_M[i]);
+  printf(" :  FW digest\n");
+  
+  //free(source);
+  return RIOTSUCCESS;
+
+}
+
+int _calcCDID(uint8_t * CDID)
+{
+  //function should not expose any internal measurements
+  //ONLY CDI should be accessible outside layer 0
+
+  //call readUDS, store measurement
+  //call readFWID, store measurement
+  //calculate Composite Device Identity
+  //return CDI
+
+  uint8_t* UDS_ID = calloc(1,sizeof(uint8_t)*UDS_DGST_SIZE);
+  readUDS(UDS_ID);
+
+  uint8_t* FW_ID = calloc(1,sizeof(uint8_t)*FW_DGST_SIZE);
+  readFWID(FW_ID);
+
+  mbedtls_sha256_context * sha_ctx;
+  mbedtls_sha256_init(sha_ctx);
+  if(mbedtls_sha256_starts_ret(sha_ctx,0) < 0 )
+  {
+    perror("SHA session failed to start\n");
+    mbedtls_sha256_free(sha_ctx);
+    return -1;
+  }
+
+  if(mbedtls_sha256_update_ret(sha_ctx, UDS_ID, UDS_DGST_SIZE) < 0)
+  {
+    perror("SHA session update failed\n");
+    mbedtls_sha256_free(sha_ctx);
+    return -1;  
+  }
+
+  if(mbedtls_sha256_update_ret(sha_ctx, FW_ID, FW_DGST_SIZE) < 0)
+  {
+    perror("SHA session update failed\n");
+    mbedtls_sha256_free(sha_ctx);
+    return -1;  
+  }  
+
+  if(mbedtls_sha256_finish_ret(sha_ctx,CDID) < 0)
+  {
+    perror("SHA session update failed\n");
+    mbedtls_sha256_free(sha_ctx);
+    return -1;  
+  }
+
+    for(int i = 0; i < CDI_DGST_SIZE; i++)
+      printf("%x",CDID[i]);
+    printf(" :  CDID\n");
+  
+  free(UDS_ID);
+  free(FW_ID);
+  return RIOTSUCCESS;
+
+}
+
+/*int mbedtls_hkdf( const mbedtls_md_info_t *md, 
+                  const unsigned char *salt, size_t salt_len, 
+                  const unsigned char *ikm, size_t ikm_len,
+                  const unsigned char *info, size_t info_len,
+                  unsigned char *okm, size_t okm_len ); */
+
+int _calcCDIKEY(uint8_t * CDIKEY)
+{
+  uint8_t* KEYIN = calloc(1,sizeof(uint8_t)*CDI_DGST_SIZE);
+  _calcCDID(KEYIN);
+
+  for(int i = 0; i < SHA256_DGST_SIZE; i++)
+      printf("%x",KEYIN[i]);
+  printf(" :  CDID main\n");
+
+  const mbedtls_md_info_t * md_info;
+  if(!(md_info = mbedtls_md_info_from_type(HKDF_ALG)))
+  {
+    perror("MD alg type def failed\n");
+    return RIOTFAILURE;
+  }
+
+  uint8_t salt[32] = {0x30,0xe2,0x3e,0xcc,0x28,0xc5,0x7b,0xbb,0x38,0x7d,0xe6,0x66,0xbb,
+    0xbe,0x67,0x0a,0xf8,0xf3,0x92,0x0e,0xba,0x68,0xd1,0x56,0xea,0x34,0x3f,0xbc,0x4f,
+    0xf1,0xd9,0x1e};
+
+  mbedtls_hkdf(md_info, salt, sizeof(salt), KEYIN, CDI_DGST_SIZE,
+              IDENTITY, sizeof(IDENTITY), CDIKEY, CDI_KEY_SIZE);
+
+  //mbedtls_hkdf_extract( md_info, salt, sizeof(salt),KEYIN, CDI_DGST_SIZE, CDIKEY);
+
+  for(int i = 0; i < CDI_KEY_SIZE; i++)
+      printf("%x",CDIKEY[i]);
+  printf(" :  CDIKEY\n");
+
+  free(KEYIN);
+
+  return RIOTSUCCESS;
+}

trial2/src/functions.c

@@ -0,0 +1,42 @@
+#include <functions.h>
+
+//string used to test changing FWID
+
+
+void ROMprotocol(void)
+{
+  printf("Hello function!\n");
+
+  //readUDS function
+
+ //  uint8_t* UDS_ID = calloc(1,sizeof(uint8_t)*UDS_DGST_SIZE);
+	// readUDS(UDS_ID);
+
+	// for (int i = 0; i < UDS_ID_SIZE; i++)
+ //  	printf("%x", UDS_ID[i]);
+ //  printf(" :	UDS ID\n" );
+
+  	//readFWID function
+  // uint8_t* FW_ID = calloc(1,sizeof(uint8_t)*FW_DGST_SIZE);
+  // readFWID(FW_ID);
+
+  // for(int i = 0; i < SHA256_DGST_SIZE; i++)
+  //    printf("%x",FW_ID[i]);
+  //  printf(" : FW_ID\n");
+
+  // uint8_t* CDID = calloc(1,sizeof(uint8_t)*CDI_DGST_SIZE);
+  // _calcCDID(CDID);
+
+  // for(int i = 0; i < SHA256_DGST_SIZE; i++)
+  //    printf("%x",CDID[i]);
+  //  printf(" : CDID main\n");
+
+  uint8_t * CDIKEY = calloc(1, sizeof(uint8_t)*CDI_KEY_SIZE);
+  _calcCDIKEY(CDIKEY);
+
+    for(int i = 0; i < CDI_KEY_SIZE; i++)
+        printf("%x",CDIKEY[i]);
+    printf(" : CDIKEY main\n");
+
+  return;
+}

trial2/src/main.c

@@ -0,0 +1,13 @@
+#include <functions.h>
+
+
+void main()
+{
+	printf("Hello World!\n");
+  // call a function in another file
+  ROMprotocol();
+
+  printf("Successful exit\n");
+
+  return;
+}

trial2/src/makefile2

@@ -0,0 +1,23 @@
+CC=gcc
+IDIR=./include
+LDIR=./lib
+ODIR=./out
+_DEPS = layer2.h layer1.h
+DEPS = $(pathsbst %,(IDIR)/%,%(_DEPS))
+
+
+CFLAGS= -I. -T$(IDIR)
+
+
+.PHONY: all debug clean 
+
+all: main.c layer1.c
+	${CC} -o $(ODIR)/main main.c functions.c ROMfunctions.c -lssl -lcrypto
+
+debug:
+	${CC} -g -o $(ODIR)/dbg-main main.c functions.c ROMfunctions.c -lssl -lcrypto
+
+clean: 
+	rm -r $(ODIR)/*
+	rm -r ./keys/*
+