Initial ECDSA implementation.

ecdh.h

@@ -16,7 +16,7 @@ ECC_SOFT_MULT64 - For platforms that do not have instructions to allow a fast 64
 #define ECC_USE_NAF 1
 #define ECC_SOFT_MULT64 1
 
-#define ECC_CURVE secp128r1
+#define ECC_CURVE secp160r1
 
 #define secp128r1 4
 #define secp160r1 5
@@ -38,5 +38,15 @@ typedef struct EccPoint
 
 int ecdh_shared_secret(uint32_t p_secret[NUM_ECC_DIGITS], EccPoint *p_publicKey, uint32_t p_privateKey[NUM_ECC_DIGITS]);
 int ecdh_make_key(EccPoint *p_publicKey, uint32_t p_privateKey[NUM_ECC_DIGITS], uint32_t p_random[NUM_ECC_DIGITS]);
+int ecc_valid_public_key(EccPoint *p_publicKey);
+
+/* Note: It is recommended that you hash the result of ecdh_shared_secret before using it for symmetric encryption or HMAC.
+If you do not hash the shared secret, you must call ecc_valid_public_key() to verify that the remote side's public key is valid.
+If this is not done, an attacker could create a public key that would cause your use of the shared secret to leak information
+about your private key. */
+
+int ecdsa_sign(uint32_t p_privateKey[NUM_ECC_DIGITS], uint32_t p_random[NUM_ECC_DIGITS], uint32_t p_hash[NUM_ECC_DIGITS],
+    uint32_t r[NUM_ECC_DIGITS], uint32_t s[NUM_ECC_DIGITS]);
+int ecdsa_verify(EccPoint *p_publicKey, uint32_t p_hash[NUM_ECC_DIGITS], uint32_t r[NUM_ECC_DIGITS], uint32_t s[NUM_ECC_DIGITS]);
 
 #endif /* _MICRO_ECDH_H_ */

test/check_dsa.c

@@ -0,0 +1,81 @@
+#include "ecdh.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+extern void EccPoint_mult(EccPoint *p_result, EccPoint *p_point, uint32_t *p_scalar);
+
+void vli_print(uint32_t *p_vli, unsigned int p_size)
+{
+	while(p_size)
+	{
+		printf("%08X ", (unsigned)p_vli[p_size - 1]);
+		--p_size;
+	}
+}
+
+int randfd;
+
+void getRandomBytes(void *p_dest, unsigned p_size)
+{
+    if(read(randfd, p_dest, p_size) != (int)p_size)
+    {
+        printf("Failed to get random bytes.\n");
+    }
+}
+
+int main()
+{
+    EccPoint l_public;
+	uint32_t l_private[NUM_ECC_DIGITS];
+
+	uint32_t l_hash[NUM_ECC_DIGITS];
+	uint32_t l_random[NUM_ECC_DIGITS];
+	
+	uint32_t r[NUM_ECC_DIGITS];
+	uint32_t s[NUM_ECC_DIGITS];
+	
+	int i;
+	
+    randfd = open("/dev/urandom", O_RDONLY);
+	if(randfd == -1)
+	{
+        printf("No access to urandom\n");
+        return -1;
+	}
+	
+	printf("Testing 256 signatures\n");
+	
+	for(i=0; i<256; ++i)
+	{
+		printf(".");
+		fflush(stdout);
+		getRandomBytes((char *)l_private, NUM_ECC_DIGITS * sizeof(uint32_t));
+		
+        ecdh_make_key(&l_public, l_private, l_private);
+        
+        getRandomBytes((char *)l_hash, NUM_ECC_DIGITS * sizeof(uint32_t));
+        getRandomBytes((char *)l_random, NUM_ECC_DIGITS * sizeof(uint32_t));
+        
+        if(!ecdsa_sign(l_private, l_random, l_hash, r, s))
+        {
+            printf("ecdsa_sign() failed\n");
+            continue;
+        }
+        
+        if(!ecc_valid_public_key(&l_public))
+        {
+            printf("Not a valid public key!\n");
+			continue;
+        }
+        
+        if(!ecdsa_verify(&l_public, l_hash, r, s))
+        {
+            printf("ecdsa_verify() failed\n");
+        }
+	}
+	
+	return 0;
+}

test/dsa1.c

@@ -0,0 +1,55 @@
+#include "ecdh.h"
+
+#if (ECC_CURVE == secp160r1)
+
+#include <string.h>
+#include <stdio.h>
+
+void vli_print(uint32_t *p_vli, unsigned int p_size)
+{
+	while(p_size)
+	{
+		printf("%08X ", (unsigned)p_vli[p_size - 1]);
+		--p_size;
+	}
+}
+
+/* Test data from http://www.secg.org/collateral/gec2.pdf page 2
+   Requires that ECC_CURVE be set to secp160r1. */
+
+int main()
+{
+    uint32_t l_privateKey[NUM_ECC_DIGITS] = {0xB2A4E982, 0x72CB6D57, 0xB0733079, 0x3CE144E6, 0xAA374FFC};
+    EccPoint l_publicKey = {
+        {0x51419DC0, 0x3C032062, 0x0E75A24A, 0xECC406ED, 0x51B4496F},
+        {0x1756AA6C, 0x4F381CCC, 0x68D79389, 0x73A514B4, 0xC28DCB4B}
+    };
+    uint32_t l_random[NUM_ECC_DIGITS] = {0xdecd52da, 0x2ac5d528, 0xb9185c8b, 0x681a3f28, 0x7b012db7};
+    uint32_t l_hash[NUM_ECC_DIGITS] = {0x9cd0d89d, 0x7850c26c, 0xba3e2571, 0x4706816a, 0xa9993e36};
+    
+    uint32_t r[NUM_ECC_DIGITS];
+    uint32_t s[NUM_ECC_DIGITS];
+    
+    if(!ecdsa_sign(l_privateKey, l_random, l_hash, r, s))
+    {
+        printf("ecdsa_sign() failed\n");
+    }
+    
+    printf("r: ");
+    vli_print(r, NUM_ECC_DIGITS);
+    printf("\n");
+    printf("s: ");
+    vli_print(s, NUM_ECC_DIGITS);
+    printf("\n");
+    
+    if(!ecdsa_verify(&l_publicKey, l_hash, r, s))
+    {
+        printf("ecdsa_verify() failed\n");
+    }
+	
+	return 0;
+}
+
+#endif
+
+