Assignment 7 sgximl: lib

Assignment 7 - SGX Hands-on/lib/rsa.c

@@ -0,0 +1,200 @@
+#include "rsa.h"
+#include <gmp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int random_prime(mpz_t prime, const size_t size) {
+    u8 tmp[size];
+    FILE *urandom = fopen("/dev/urandom", "rb");
+    
+    if((urandom == NULL) || (prime == NULL))
+        return 0;
+
+    fread(tmp, 1, size, urandom);
+    mpz_import(prime, size, 1, 1, 1, 0, tmp);
+    mpz_nextprime(prime, prime);
+
+    fclose(urandom);
+    return 1;
+}
+
+static int rsa_keygen(rsa_key *key) {
+    // null pointer handling
+    if(key == NULL)
+        return 0;
+
+    // init bignums
+    mpz_init_set_ui(key->e, 65537);
+    mpz_inits(key->p, key->q, key->n, key->d, NULL);
+    
+    // prime gen
+    if ((!random_prime(key->p, MODULUS_SIZE/2)) || (!random_prime(key->q, MODULUS_SIZE/2)))
+        return 0;
+
+    // compute n
+    mpz_mul(key->n, key->p, key->q);
+
+    // compute phi(n)
+    mpz_t phi_n; mpz_init(phi_n);
+    mpz_sub_ui(key->p, key->p, 1);
+    mpz_sub_ui(key->q, key->q, 1);
+    mpz_mul(phi_n, key->p, key->q);
+    mpz_add_ui(key->p, key->p, 1);
+    mpz_add_ui(key->q, key->q, 1);
+    
+    // compute d
+    if(mpz_invert(key->d, key->e, phi_n) == 0) {
+        return 0;
+    }
+    
+    // free temporary phi_n and return true
+    mpz_clear(phi_n);
+    return 1;
+}
+
+static int rsa_export(rsa_key *key) {
+    
+}
+
+static int rsa_import(rsa_key *key) {
+    return 0;
+}
+
+int rsa_init(rsa_key *key) {
+    if(rsa_import(key)) {
+        return 1;
+    } else {
+        return rsa_keygen(key);
+    }
+    return 0;
+}
+
+int rsa_public_init(rsa_public_key *key) {
+    // null pointer handling
+    if(key == NULL)
+        return 0;
+
+    mpz_init_set_ui(key->e, 65537);
+    mpz_init_set_str(key->n, "", 0);
+}
+
+void rsa_free(rsa_key *key) {
+    // free bignums
+    mpz_clears(key->p, key->q, key->n, key->e, key->d, NULL);
+}
+
+void rsa_public_free(rsa_public_key *key) {
+    // free bignums
+    mpz_clears(key->e, key->n, NULL);
+}
+
+static int pkcs1(mpz_t message, const u8 *data, const size_t length) {
+    // temporary buffer
+    u8 padded_bytes[MODULUS_SIZE];
+
+    // calculate padding size (how many 0xff bytes)
+    size_t padding_length = MODULUS_SIZE - length - 3;
+
+    if ((padding_length < 8) || (message == NULL) || (data == NULL)) {
+        // message to big
+        // or null pointer
+        return 0;
+    }
+
+    // set padding bytes
+    padded_bytes[0] = 0x00;
+    padded_bytes[1] = 0x01;
+    padded_bytes[2 + padding_length] = 0x00;
+
+    for (size_t i = 2; i < padding_length + 2; i++) {
+        padded_bytes[i] = 0xff;
+    }
+
+    // copy message bytes
+    memcpy(padded_bytes + padding_length + 3, data, length);
+
+    // convert padded message to mpz_t
+    mpz_import(message, MODULUS_SIZE, 1, 1, 0, 0, padded_bytes);
+    return 1;
+}
+
+size_t rsa_sign(u8 *sig, const u8 *sha256, const rsa_key *key) {
+    // null pointer handling
+    if((sig == NULL) || (sha256 == NULL) || (key == NULL))
+        return 0;
+    
+    // init bignum message
+    mpz_t message; mpz_init(message);
+    mpz_t blinder; mpz_init(blinder);
+
+    // get random blinder
+    random_prime(blinder, MODULUS_SIZE - 10);
+
+    // add padding
+    if(!pkcs1(message, sha256, 32)) {
+        return 0;
+    }
+
+    // blind
+    mpz_mul(message, message, blinder);
+    mpz_mod(message, message, key->n);
+    mpz_invert(blinder, blinder, key->n);
+    mpz_powm(blinder, blinder, key->d, key->n);
+
+    // compute signature
+    mpz_powm(message, message, key->d, key->n);
+
+    // unblind
+    mpz_mul(message, message, blinder);
+    mpz_mod(message, message, key->n);
+
+    // export signature
+    size_t size = (mpz_sizeinbase(message, 2) + 7) / 8;
+    mpz_export(sig, &size, 1, 1, 0, 0, message);
+
+    // free bignum and return true
+    mpz_clears(message, blinder, NULL);
+    return size;
+}
+
+int rsa_verify(const u8 *sig, const size_t sig_length, const u8 *sha256, const rsa_public_key *pk) {
+    // null pointer handling
+    if((sig == NULL) || (sha256 == NULL) || (pk == NULL))
+        return 0;
+
+    // initialize bignums
+    mpz_t signature, message; 
+    mpz_inits(signature, message, NULL);
+
+    // import signature
+    mpz_import(signature, (sig_length < MODULUS_SIZE) ? sig_length : MODULUS_SIZE, 1, 1, 0, 0, sig);
+
+    // revert rsa signing process
+    mpz_powm(signature, signature, pk->e, pk->n);
+
+    // rebuild signed message
+    if(!pkcs1(message, sha256, 32))
+        return 0;
+    
+    // compare signature with expected value
+    if(mpz_cmp(signature, message) != 0)
+        return 0;
+
+    // free bignums and return valid signature
+    mpz_clears(signature, message, NULL);
+    return 1;
+}
+
+void rsa_print(const rsa_key *key) {
+    gmp_printf("%Zx\n", key->p);
+    gmp_printf("%Zx\n", key->q);
+    gmp_printf("%Zx\n", key->n);
+    gmp_printf("%Zx\n", key->e);
+    gmp_printf("%Zx\n", key->d);
+}
+
+void rsa_public_print(const rsa_public_key *pk) {
+    gmp_printf("%Zx\n", pk->e);
+    gmp_printf("%Zx\n", pk->n);
+}

Assignment 7 - SGX Hands-on/lib/rsa.h

@@ -0,0 +1,41 @@
+#ifndef RSA_H
+#define RSA_H
+
+#include <gmp.h>
+#include <stdint.h>
+
+#ifndef MODULUS_SIZE
+#define MODULUS_SIZE 256ULL
+#endif
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef struct {
+    mpz_t p;
+    mpz_t q;
+    mpz_t n;
+    mpz_t e;
+    mpz_t d;
+} rsa_key;
+
+typedef struct {
+    mpz_t e;
+    mpz_t n;
+} rsa_public_key;
+
+void rsa_print(const rsa_key *key);
+void rsa_public_print(const rsa_public_key *pk);
+
+int rsa_init(rsa_key *key);
+void rsa_free(rsa_key *key);
+
+int rsa_public_init(rsa_public_key *key);
+void rsa_public_free(rsa_public_key *key);
+
+size_t rsa_sign(u8 *sig, const u8 *sha256, const rsa_key *key);
+int rsa_verify(const u8 *sig, const size_t sig_length, const u8 *sha256, const rsa_public_key *pk);
+
+#endif

Assignment 7 - SGX Hands-on/lib/sha256.c

@@ -0,0 +1,223 @@
+#include "sha256.h"
+#include <stdio.h>
+#include <string.h>
+
+#define ROTL(x,n) ((x << n) | (x >> (32 - n)))
+#define ROTR(x,n) ((x >> n) | (x << (32 - n)))
+
+#define SHL(x,n) (x << n)
+#define SHR(x,n) (x >> n)
+
+#define Ch(x,y,z) ((x & y) ^ (~x&z))
+#define Maj(x,y,z) ((x & y) ^ (x & z) ^ (y & z))
+
+#define MSIZE 64
+
+static inline u32 Sigma0(u32 x) {
+    return ROTR(x,2) ^ ROTR(x,13) ^ ROTR(x,22);
+}
+
+static inline u32 Sigma1(u32 x) {
+    return ROTR(x,6) ^ ROTR(x,11) ^ ROTR(x,25);
+}
+
+static inline u32 sigma0(u32 x) {
+    return ROTR(x,7) ^ ROTR(x,18) ^ SHR(x,3);
+}
+
+static inline u32 sigma1(u32 x) {
+	return ROTR(x,17) ^ ROTR(x,19) ^ SHR(x,10);
+}
+
+const u32 K[64] = {
+	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+};
+
+static void initState(sha256State_t *state) {
+	state->H[0]=0x6a09e667;
+	state->H[1]=0xbb67ae85;
+	state->H[2]=0x3c6ef372;
+	state->H[3]=0xa54ff53a;
+	state->H[4]=0x510e527f;
+	state->H[5]=0x9b05688c;
+	state->H[6]=0x1f83d9ab;
+	state->H[7]=0x5be0cd19;
+	
+	state->length = 0;
+	state->finalised = 0;
+}
+
+static void sha256Round(sha256State_t *state);
+
+static void sha256Padding(sha256State_t *state) {
+	state->message[state->message_length / 4] |= 0x80 << (3 - (state->message_length % 4)) * 8;
+
+	if (state->message_length * 8 + 1 > 448) {
+		state->message_length = 64;
+		sha256Round(state);
+		memset(state->message, 0x00, 16*sizeof(u32));
+	}
+
+	state->finalised = 1;
+	state->length <<= 3;
+	state->message[14] = state->length >> 32;
+	state->message[15] = state->length & 0xffffffff;
+}
+
+static void sha256Round(sha256State_t *state) {
+	u32 T1, T2;
+	u32 a, b, c, d, e, f, g, h;
+
+	if (state->message_length != 64) {
+		sha256Padding(state);
+	}	
+	
+	int t = 0;
+	for (; t < 16; t++) 
+		state->W[t] = state->message[t];
+
+	for (; t < 64; t++) 
+		state->W[t] = sigma1(state->W[t-2]) + state->W[t-7] + sigma0(state->W[t-15]) + state->W[t-16];
+
+	a=state->H[0];
+    b=state->H[1];
+    c=state->H[2];
+    d=state->H[3];
+    e=state->H[4];
+   	f=state->H[5];
+   	g=state->H[6];
+    h=state->H[7];
+	
+	for (t = 0; t < 64; t++) {
+       	T1 = h + Sigma1(e) + Ch(e,f,g) + K[t] + state->W[t];
+       	T2 = Sigma0(a) + Maj(a,b,c);
+       	h = g;
+       	g = f;
+       	f = e;
+       	e = d + T1;
+       	d = c;
+       	c = b;
+       	b = a;
+       	a = T1 + T2;
+    }
+	
+	state->H[0] += a;
+    state->H[1] += b;
+    state->H[2] += c;
+    state->H[3] += d;
+    state->H[4] += e;
+    state->H[5] += f;
+    state->H[6] += g;
+    state->H[7] += h;
+}
+
+static void sha256Hash(sha256State_t *state, u8 *buffer, size_t b_len) {
+    if((buffer == NULL) || (state == NULL))
+        return;
+	
+    state->length += b_len;
+
+    size_t message_length = 0;
+    while(b_len > 0) {
+        message_length = (b_len < MSIZE) ? b_len : MSIZE;
+        memset(state->message, 0x00, MSIZE);
+        memcpy(state->message, buffer, message_length);
+
+		for(int i = 0; i < 16; i++)
+			state->message[i] = __builtin_bswap32(state->message[i]);
+
+        state->message_length = message_length;
+        sha256Round(state);
+
+        buffer += message_length;;
+        b_len -= message_length;;
+    }
+}
+
+static void sha256Finalise(u8 *hash, sha256State_t *state) {
+	if(!state->finalised) {
+		memset(state->message, 0x00, 16*sizeof(u32));
+        state->length <<= 3;
+		state->message[0] = 0x80000000;
+		state->message[14] = state->length >> 32;
+		state->message[15] = state->length & 0xffffffff;
+		state->message_length = 64;
+		state->finalised = 1;
+		sha256Round(state);
+	}
+
+	if(hash == NULL)
+		return;
+
+	for(int i = 0; i < 8; i++)
+		state->H[i] =  __builtin_bswap32(state->H[i]);
+	memcpy(hash, state->H, SIZE);
+}
+
+void sha256(u8 *hash, u8 *buffer, size_t buffer_length) {
+    sha256State_t state;
+
+    initState(&state);
+    sha256Hash(&state, buffer, buffer_length);
+    sha256Finalise(hash, &state);
+}
+
+#ifdef TEST
+int main(int argc, char **argv) {
+    unsigned char *tests[12] = {
+        "",
+        "\xe3\xb0\xc4\x42\x98\xfc\x1c\x14\x9a\xfb\xf4\xc8\x99\x6f\xb9\x24\x27\xae\x41\xe4\x64\x9b\x93\x4c\xa4\x95\x99\x1b\x78\x52\xb8\x55",
+
+        "abc",
+        "\xba\x78\x16\xbf\x8f\x01\xcf\xea\x41\x41\x40\xde\x5d\xae\x22\x23\xb0\x03\x61\xa3\x96\x17\x7a\x9c\xb4\x10\xff\x61\xf2\x00\x15\xad",
+
+        "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
+        "\x24\x8d\x6a\x61\xd2\x06\x38\xb8\xe5\xc0\x26\x93\x0c\x3e\x60\x39\xa3\x3c\xe4\x59\x64\xff\x21\x67\xf6\xec\xed\xd4\x19\xdb\x06\xc1",
+
+        "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
+        "\xcf\x5b\x16\xa7\x78\xaf\x83\x80\x03\x6c\xe5\x9e\x7b\x04\x92\x37\x0b\x24\x9b\x11\xe8\xf0\x7a\x51\xaf\xac\x45\x03\x7a\xfe\xe9\xd1",
+        
+        "\xbd",
+        "\x68\x32\x57\x20\xaa\xbd\x7c\x82\xf3\x0f\x55\x4b\x31\x3d\x05\x70\xc9\x5a\xcc\xbb\x7d\xc4\xb5\xaa\xe1\x12\x04\xc0\x8f\xfe\x73\x2b",
+
+        "\xc9\x8c\x8e\x55",
+        "\x7a\xbc\x22\xc0\xae\x5a\xf2\x6c\xe9\x3d\xbb\x94\x43\x3a\x0e\x0b\x2e\x11\x9d\x01\x4f\x8e\x7f\x65\xbd\x56\xc6\x1c\xcc\xcd\x95\x04"
+    };
+
+    for(int i = 0; i < 12; i += 2) {
+        u8 tmp[32];
+        sha256(tmp, tests[i], strlen(tests[i]));
+        for(int j = 0; j < 32; j++)
+            printf("%02x", tmp[j]);
+        printf(" ");
+        for(int j = 0; j < 32; j++)
+            printf("%02x", tests[i+1][j]);
+        printf("\n");
+    }
+
+    u8 tmp[32];
+    sha256State_t state;
+    initState(&state);
+    unsigned char *tvec = "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmno";
+    unsigned char *tres = "\x50\xe7\x2a\x0e\x26\x44\x2f\xe2\x55\x2d\xc3\x93\x8a\xc5\x86\x58\x22\x8c\x0c\xbf\xb1\xd2\xca\x87\x2a\xe4\x35\x26\x6f\xcd\x05\x5e";
+    for (size_t i = 0; i < 16777216; i++) {
+        sha256Hash(&state, tvec, 64);
+    }
+    sha256Finalise(tmp, &state);
+    for(int j = 0; j < 32; j++)
+        printf("%02x", tmp[j]);
+    printf(" ");
+    for(int j = 0; j < 32; j++)
+        printf("%02x", tres[j]);
+    printf("\n");
+
+    return 0;
+}
+#endif

Assignment 7 - SGX Hands-on/lib/sha256.h

@@ -0,0 +1,25 @@
+#ifndef SHA256_H
+#define SHA256_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+#define SIZE 32
+#define BUFFSIZE 4096
+
+typedef uint8_t u8;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef struct sha256State {
+	u32 W[64];
+	u32 message[16];
+    u32 H[8];
+    u32 message_length;
+    u64 length;
+    u8 finalised;
+} sha256State_t;
+
+void sha256(u8 *hash, u8 *buffer, size_t buffer_length);
+
+#endif