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[Assignment-7] hardcoded public key/signatures sizes; cleaned up unused code

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This commit is contained in:
Sascha Tommasone 2024-07-06 13:28:46 +02:00 committed by saschato
parent 20529e2768
commit c1351d4853
3 changed files with 71 additions and 105 deletions
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157
7-SGX_Hands-on/src/enclave/enclave.c
View file

@ -41,6 +41,7 @@
#include <sgx_error.h>
#include <sgx_tcrypto.h>
#ifndef SK_SIZE
#define SK_SIZE SGX_ECP256_KEY_SIZE
#endif
@ -49,15 +50,14 @@
#define PK_SIZE 2*SK_SIZE
#endif
#ifndef SI_SIZE
#define SI_SIZE 2*SK_SIZE// + 8
#ifndef DG_SIZE
#define DG_SIZE SK_SIZE
#endif
#ifndef SI_SIZE
#define SI_SIZE 2*SK_SIZE
#endif
#define SWAP_UINT32(x) \
(((x) >> 24) & 0x000000FF) | \
(((x) >> 8) & 0x0000FF00) | \
(((x) << 8) & 0x00FF0000) | \
(((x) << 24) & 0xFF000000)
const sgx_ec256_public_t authorized[2] = {
{
@ -70,6 +70,11 @@ const sgx_ec256_public_t authorized[2] = {
}
};
int get_digest_size() {
return DG_SIZE;
}
int get_sealed_size() {
return sgx_calc_sealed_data_size(PK_SIZE, SK_SIZE);
}
@ -86,27 +91,7 @@ int get_private_key_size() {
return SK_SIZE;
}
static inline void pk_little_to_big(uint8_t *pk) {
uint32_t i, j;
for(i = 0, j = PK_SIZE / 2 - 1; i < j; i++, j--) {
uint8_t tmp = pk[i];
pk[i] = pk[j];
pk[j] = tmp;
}
for(i = PK_SIZE / 2, j = PK_SIZE - 1; i < j; i++, j--) {
uint8_t tmp = pk[i];
pk[i] = pk[j];
pk[j] = tmp;
}
}
static sgx_status_t seal_key_pair(sgx_ec256_private_t *private, sgx_ec256_public_t *public, uint8_t **sealed, uint32_t sealed_size) {
// invalid parameter handling
if((private == NULL) || (public == NULL))
return SGX_ERROR_INVALID_PARAMETER;
static sgx_status_t seal_key_pair(const sgx_ec256_private_t *private, const sgx_ec256_public_t *public, uint8_t **sealed) {
// allocate temporary buffers on stack
uint8_t pk[PK_SIZE] = {0};
uint8_t sk[SK_SIZE] = {0};
@ -115,14 +100,8 @@ static sgx_status_t seal_key_pair(sgx_ec256_private_t *private, sgx_ec256_public
memcpy(pk, public->gx, PK_SIZE);
memcpy(sk, private->r, SK_SIZE);
// calculate needed size
uint32_t size = get_sealed_size();
if(size > sealed_size) {
return SGX_ERROR_INVALID_PARAMETER;
}
// seal keypair
return sgx_seal_data(PK_SIZE, (const uint8_t *)pk, SK_SIZE, (const uint8_t *)sk, size, (sgx_sealed_data_t *) *sealed);
return sgx_seal_data(PK_SIZE, (const uint8_t *)pk, SK_SIZE, (const uint8_t *)sk, get_sealed_size(), (sgx_sealed_data_t *) *sealed);
}
static sgx_status_t unseal_key_pair(const uint8_t *sealed, sgx_ec256_private_t *private, sgx_ec256_public_t *public) {
@ -160,37 +139,54 @@ static sgx_status_t unseal_key_pair(const uint8_t *sealed, sgx_ec256_private_t *
return status;
}
sgx_status_t get_public_key(const uint8_t *sealed, uint32_t sealed_size, uint8_t *public_key, uint32_t public_key_size) {
sgx_status_t generate_key_pair(uint8_t *sealed, uint32_t sealed_size) {
// invalid parameter handling
if((sealed == NULL) || (sealed_size == 0)) {
if((sealed == NULL) || (sealed_size != get_sealed_size())) {
return SGX_ERROR_INVALID_PARAMETER;
}
// declare needed structs
sgx_ecc_state_handle_t ecc_handle;
sgx_ec256_private_t private;
sgx_ec256_public_t public;
sgx_status_t status;
// open ecc handle
if((status = sgx_ecc256_open_context(&ecc_handle)) != SGX_SUCCESS) {
return status;
}
// create ecc keypair
if((status = sgx_ecc256_create_key_pair(&private, &public, ecc_handle)) != SGX_SUCCESS) {
sgx_ecc256_close_context(ecc_handle);
return status;
}
// return status of sealing
return seal_key_pair(&private, &public, &sealed);
}
sgx_status_t get_public_key(const uint8_t *sealed, uint32_t sealed_size, uint8_t *public) {
// invalid parameter handling
if((sealed == NULL) || (sealed_size != get_sealed_size())) {
return SGX_ERROR_INVALID_PARAMETER;
} else if(public == NULL) {
return SGX_ERROR_INVALID_PARAMETER;
}
// unseal public key
sgx_status_t status;
sgx_ec256_public_t public;
if((status = unseal_key_pair(sealed, NULL, &public)) != SGX_SUCCESS) {
if((status = unseal_key_pair(sealed, NULL, (sgx_ec256_public_t *)public)) != SGX_SUCCESS) {
return status;
}
// copy public key into return buffer
// swap endianess
if((public_key != NULL) && (public_key != NULL) && (public_key_size == PK_SIZE)) {
memcpy(public_key, public.gx, SK_SIZE);
pk_little_to_big(public_key);
}
// return success
return status;
}
static sgx_status_t verify_signature(const uint8_t *data, const uint32_t data_size, const sgx_ec256_public_t *public, const sgx_ec256_signature_t* ecc_signature) {
static sgx_status_t verify_signature(const uint8_t *data, uint32_t data_size, const sgx_ec256_public_t *public, const sgx_ec256_signature_t* ecc_signature) {
// invalid parameter handling
if((data == NULL) || (data_size == 0)) {
return SGX_ERROR_INVALID_PARAMETER;
} else if(public == NULL) {
return SGX_ERROR_INVALID_PARAMETER;
} else if(ecc_signature == NULL) {
if((data == NULL) || (data_size == 0) || (public == NULL) || (ecc_signature == NULL)) {
return SGX_ERROR_INVALID_PARAMETER;
}
@ -205,7 +201,6 @@ static sgx_status_t verify_signature(const uint8_t *data, const uint32_t data_si
// verify signature
uint8_t result;
// sgx_ecdsa_verify_hash
sgx_status_t verification_status = sgx_ecdsa_verify(data, data_size, public, ecc_signature, &result, ecc_handle);
// handle failed verification process
@ -218,19 +213,17 @@ static sgx_status_t verify_signature(const uint8_t *data, const uint32_t data_si
return result;
}
sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, uint8_t *sealed, uint32_t sealed_size, uint8_t *public_key, uint32_t public_key_size, uint8_t *signature, uint32_t signature_size) {
sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, const uint8_t *sealed, uint32_t sealed_size, uint8_t *public_key, uint8_t *signature) {
// invalid parameter handling
if((data == NULL) || (data_size == 0)) {
if((data == NULL) || (data_size == 0) || (public_key == NULL) || (signature == NULL)) {
return SGX_ERROR_INVALID_PARAMETER;
} else if((sealed == NULL) || (sealed_size == 0)) {
return SGX_ERROR_INVALID_PARAMETER;
} else if((public_key == NULL) || (public_key_size != PK_SIZE)) {
} else if((sealed == NULL) || (sealed_size != get_sealed_size())) {
return SGX_ERROR_INVALID_PARAMETER;
}
// verify public key
for(size_t i = 0; i < sizeof(authorized)/sizeof(authorized[0]); i++) {
if(memcmp(public_key, authorized[i].gx, PK_SIZE) != 0) {
if(memcmp(public_key, authorized[i].gx, PK_SIZE) == 0) {
continue;
}
goto sign;
@ -243,7 +236,6 @@ sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, uint8_t *sea
sgx_ec256_signature_t ecc_signature;
sgx_ecc_state_handle_t ecc_handle;
sgx_ec256_private_t private;
sgx_ec256_public_t public;
// open ecc handle
sgx_status_t status;
@ -260,78 +252,51 @@ sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, uint8_t *sea
// try unseal keypair
sgx_status_t seal_status;
if(seal_status = unseal_key_pair(sealed, &private, NULL) != SGX_SUCCESS) {
if((status = sgx_ecc256_create_key_pair(&private, &public, ecc_handle)) != SGX_SUCCESS) {
sgx_ecc256_close_context(ecc_handle);
return status;
}
if(seal_status = unseal_key_pair(sealed, &private, (sgx_ec256_public_t *)public_key) != SGX_SUCCESS) {
sgx_ecc256_close_context(ecc_handle);
return seal_status;
}
// create signature
if((status = sgx_ecdsa_sign(data, data_size, &private, &ecc_signature, ecc_handle)) != SGX_SUCCESS) {
if((status = sgx_ecdsa_sign(data, DG_SIZE, &private, &ecc_signature, ecc_handle)) != SGX_SUCCESS) {
sgx_ecc256_close_context(ecc_handle);
return status;
}
// TODO: possible wrong endianess for other programms
// copy signature to return buffer
if((signature == NULL) || (signature_size != SI_SIZE)) {
if(signature == NULL) {
sgx_ecc256_close_context(ecc_handle);
return SGX_ERROR_INVALID_PARAMETER;
}
memcpy(signature, ecc_signature.x, SI_SIZE);
// seal the key
if((seal_status != SGX_SUCCESS) && (sealed != NULL)) {
seal_status = seal_key_pair(&private, &public, &sealed, sealed_size);
}
// export pk
memcpy(public_key, public.gx, PK_SIZE);
pk_little_to_big(public_key);
// close ecc handle and return success
sgx_ecc256_close_context(ecc_handle);
return seal_status;
return status;
}
sgx_status_t verify_firmware(const uint8_t *data, uint32_t data_size, const uint8_t *sealed, uint32_t sealed_size, const uint8_t *public_key, uint32_t public_key_size, const uint8_t *signature, uint32_t signature_size) {
sgx_status_t verify_firmware(const uint8_t *data, uint32_t data_size, const uint8_t *sealed, uint32_t sealed_size, const uint8_t *public_key, const uint8_t *signature) {
// invalid parameter handling
if((data == NULL) || (data_size == 0)) {
if((data == NULL) || (data_size == 0) || (signature == NULL)) {
return SGX_ERROR_INVALID_PARAMETER;
} else if(((sealed == NULL) || (sealed_size == 0)) && ((public_key == NULL) || (public_key_size == 0))) {
} else if((sealed == NULL) && (public_key == NULL)) {
return SGX_ERROR_INVALID_PARAMETER;
} else if((sealed != NULL) && (public_key != NULL)) {
return SGX_ERROR_INVALID_PARAMETER;
} else if((signature == NULL) || (signature_size == 0)) {
return SGX_ERROR_INVALID_PARAMETER;
}
// declare needed structures
sgx_ec256_public_t public;
sgx_status_t status;
// invalid signature
if(signature_size > SI_SIZE) {
return SGX_ERROR_INVALID_PARAMETER;
}
// verify signature from staff or enclave
if(public_key != NULL) {
// invalid public key
if(public_key_size != PK_SIZE) {
return SGX_ERROR_INVALID_PARAMETER;
}
// verification only with authorized public keys
for(size_t i = 0; i < sizeof(authorized)/sizeof(authorized[0]); i++) {
}
// public key little to big
pk_little_to_big(public_key);
// copy public key into struct
memcpy(public.gx, public_key, PK_SIZE);
} else {

8
7-SGX_Hands-on/src/enclave/enclave.edl
View file

@ -41,12 +41,14 @@ enclave {
trusted {
public int get_sealed_size();
public int get_digest_size();
public int get_signature_size();
public int get_public_key_size();
public int get_private_key_size();
public sgx_status_t get_public_key([in, size=sealed_size]const uint8_t *sealed, uint32_t sealed_size, [out, size=public_key_size]uint8_t *public_key, uint32_t public_key_size);
public sgx_status_t sign_firmware([in, size=data_size]const uint8_t *data, uint32_t data_size, [in, out, size=sealed_size]uint8_t *sealed, uint32_t sealed_size, [in, out, size=public_key_size]uint8_t *public_key, uint32_t public_key_size, [in, out, size=signature_size]uint8_t *signature, uint32_t signature_size);
public sgx_status_t verify_firmware([in, size=data_size]const uint8_t *data, uint32_t data_size, [in, size=sealed_size]const uint8_t *sealed, uint32_t sealed_size, [in, size=public_key_size]const uint8_t *public_key, uint32_t public_key_size, [in, size=signature_size]const uint8_t *signature, uint32_t signature_size);
public sgx_status_t generate_key_pair([out, size=sealed_size]uint8_t *sealed, uint32_t sealed_size);
public sgx_status_t get_public_key([in, size=sealed_size]const uint8_t *sealed, uint32_t sealed_size, [out, size=64]uint8_t *public_key);
public sgx_status_t sign_firmware([in, size=data_size]const uint8_t *data, uint32_t data_size, [in, size=sealed_size]const uint8_t *sealed, uint32_t sealed_size, [in, out, size=64]uint8_t *public_key, [in, out, size=64]uint8_t *signature);
public sgx_status_t verify_firmware([in, size=data_size]const uint8_t *data, uint32_t data_size, [in, size=sealed_size]const uint8_t *sealed, uint32_t sealed_size, [in, size=64]const uint8_t *public_key, [in, size=64]const uint8_t *signature);
};
/*

11
7-SGX_Hands-on/src/enclave/enclave.h
View file

@ -33,19 +33,18 @@
#ifndef _ENCLAVE_H_
#define _ENCLAVE_H_
#include <stdlib.h>
#include <stdint.h>
#include <assert.h>
#include <stdio.h>
#include <sgx_error.h>
int get_sealed_size();
int get_digest_size();
int get_signature_size();
int get_public_key_size();
int get_private_key_size();
sgx_status_t get_public_key(const uint8_t *sealed, const uint32_t sealed_size, uint8_t *public_key, uint32_t public_key_size);
sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, uint8_t *sealed, uint32_t sealed_size, uint8_t *public_key, uint32_t public_key_size, uint8_t *signature, uint32_t signature_size);
sgx_status_t verify_firmware(const uint8_t *data, uint32_t data_size, const uint8_t *sealed, uint32_t sealed_size, const uint8_t *public_key, uint32_t public_key_size, const uint8_t *signature, uint32_t signature_size);
sgx_status_t generate_key_pair(uint8_t *sealed, uint32_t sealed_size);
sgx_status_t get_public_key(const uint8_t *sealed, const uint32_t sealed_size, uint8_t *public_key);
sgx_status_t sign_firmware(const uint8_t *data, uint32_t data_size, const uint8_t *sealed, uint32_t sealed_size, uint8_t *public_key, uint8_t *signature);
sgx_status_t verify_firmware(const uint8_t *data, uint32_t data_size, const uint8_t *sealed, uint32_t sealed_size, const uint8_t *public_key, const uint8_t *signature);
#endif /* !_ENCLAVE_H_ */