Arduino/pico-fido
1
0
Fork 1
mirror of https://github.com/polhenarejos/pico-fido.git synced 2025-12-19 02:48:04 +08:00
Code Issues Packages Projects Releases Wiki Activity

More fixes

Browse Source 
Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
This commit is contained in:
Pol Henarejos
2022-09-21 16:30:49 +02:00
parent 99fc76a385
commit 4ab898378a
4 changed files with 125 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

142
src/fido/cbor_get_assertion.c
View File

@@ -42,7 +42,7 @@ uint8_t numberOfCredentialsx = 0;
int cbor_get_assertion(const uint8_t *data, size_t len) {
size_t resp_size = 0;
uint64_t pinUvAuthProtocol = 0;
uint64_t pinUvAuthProtocol = 0, hmacSecretPinUvAuthProtocol = 1;
CredOptions options = {0};
CredExtensions extensions = {0};
CborParser parser;
@@ -56,6 +56,8 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
size_t allowList_len = 0, creds_len = 0;
uint8_t *aut_data = NULL;
bool asserted = false;
int64_t kty = 0, alg = 0, crv = 0;
CborByteString kax = {0}, kay = {0}, salt_enc = {0}, salt_auth = {0};
CBOR_CHECK(cbor_parser_init(data, len, 0, &parser, &map));
uint64_t val_c = 1;
@@ -94,9 +96,52 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
CBOR_PARSE_ARRAY_END(_f1, 2);
}
else if (val_u == 0x04) { // extensions
extensions.present = true;
CBOR_PARSE_MAP_START(_f1, 2) {
CBOR_FIELD_GET_KEY_TEXT(2);
CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "hmac-secret", extensions.hmac_secret);
if (strcmp(_fd2, "hmac-secret") == 0) {
extensions.hmac_secret = ptrue;
uint64_t ukey = 0;
CBOR_PARSE_MAP_START(_f2, 3) {
CBOR_FIELD_GET_UINT(ukey, 3);
if (ukey == 0x01) {
int64_t kkey = 0;
CBOR_PARSE_MAP_START(_f3, 4) {
CBOR_FIELD_GET_INT(kkey, 4);
if (kkey == 1) {
CBOR_FIELD_GET_INT(kty, 4);
}
else if (kkey == 3) {
CBOR_FIELD_GET_INT(alg, 4);
}
else if (kkey == -1) {
CBOR_FIELD_GET_INT(crv, 4);
}
else if (kkey == -2) {
CBOR_FIELD_GET_BYTES(kax, 4);
}
else if (kkey == -3) {
CBOR_FIELD_GET_BYTES(kay, 4);
}
else
CBOR_ADVANCE(4);
}
CBOR_PARSE_MAP_END(_f3, 4);
}
else if (ukey == 0x02) {
CBOR_FIELD_GET_BYTES(salt_enc, 3);
}
else if (ukey == 0x03) {
CBOR_FIELD_GET_BYTES(salt_auth, 3);
}
else if (ukey == 0x04) {
CBOR_FIELD_GET_UINT(hmacSecretPinUvAuthProtocol, 3);
}
else
CBOR_ADVANCE(3);
}
CBOR_PARSE_MAP_END(_f2, 3);
}
CBOR_FIELD_KEY_TEXT_VAL_UINT(2, "credProtect", extensions.credProtect);
CBOR_ADVANCE(2);
}
@@ -122,7 +167,7 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
}
CBOR_PARSE_MAP_END(map, 1);
uint8_t flags = FIDO2_AUT_FLAG_AT;
uint8_t flags = 0;
uint8_t rp_id_hash[32];
mbedtls_sha256((uint8_t *)rpId.data, rpId.len, rp_id_hash, 0);
@@ -262,9 +307,12 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
size_t ext_len = 0;
uint8_t ext [512];
/*
if (extensions.present == true) {
cbor_encoder_init(&encoder, ext, sizeof(ext), 0);
int l = 0;
if (options.up == pfalse)
extensions.hmac_secret = NULL;
if (extensions.hmac_secret != NULL)
l++;
if (extensions.credProtect != 0)
@@ -277,39 +325,65 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
if (extensions.hmac_secret != NULL) {
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "hmac-secret"));
CBOR_CHECK(cbor_encode_boolean(&mapEncoder, *extensions.hmac_secret));
uint8_t sharedSecret[64];
mbedtls_ecp_point Qp;
mbedtls_ecp_point_init(&Qp);
mbedtls_mpi_lset(&Qp.Z, 1);
if (mbedtls_mpi_read_binary(&Qp.X, kax.data, kax.len) != 0) {
mbedtls_ecp_point_free(&Qp);
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
}
if (mbedtls_mpi_read_binary(&Qp.Y, kay.data, kay.len) != 0) {
mbedtls_ecp_point_free(&Qp);
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
}
int ret = ecdh(hmacSecretPinUvAuthProtocol, &Qp, sharedSecret);
mbedtls_ecp_point_free(&Qp);
if (ret != 0) {
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
}
if (verify(hmacSecretPinUvAuthProtocol, sharedSecret, salt_enc.data, salt_enc.len, salt_auth.data) != 0) {
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
CBOR_ERROR(CTAP2_ERR_PIN_AUTH_INVALID);
}
if (salt_enc.len != 32 || salt_enc.len != 64) {
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
}
uint8_t salt_dec[64];
ret = decrypt(hmacSecretPinUvAuthProtocol, sharedSecret, salt_enc.data, salt_enc.len, salt_dec);
if (ret != 0) {
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
}
uint8_t cred_random[64], *crd = NULL;
ret = credential_derive_hmac_key(cred_id, cred_id_len, cred_random);
if (ret != 0) {
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
}
if (flags & FIDO2_AUT_FLAG_UV)
crd = cred_random + 32;
else
crd = cred_random;
uint8_t out1[64], hmac_res[64];
mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), crd, 32, salt_dec, 32, out1);
if (salt_enc.len == 64)
mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), crd, 32, salt_dec+32, 32, out1+32);
encrypt(hmacSecretPinUvAuthProtocol, sharedSecret, out1, salt_enc.len, hmac_res);
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, hmac_res, salt_enc.len));
}
CBOR_CHECK(cbor_encoder_close_container(&encoder, &mapEncoder));
ext_len = cbor_encoder_get_buffer_size(&encoder, ext);
flags |= FIDO2_AUT_FLAG_ED;
}
uint8_t pkey[66];
const mbedtls_ecp_curve_info *cinfo = mbedtls_ecp_curve_info_from_grp_id(ekey.grp.id);
if (cinfo == NULL)
CBOR_ERROR(CTAP1_ERR_OTHER);
size_t olen = 0, pkey_len = ceil((float)cinfo->bit_size/8);
*/
uint32_t ctr = *(uint32_t *)file_get_data(ef_counter);
uint8_t cbor_buf[1024];
cbor_encoder_init(&encoder, cbor_buf, sizeof(cbor_buf), 0);
CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, 5));
CBOR_CHECK(cbor_encode_uint(&mapEncoder, 1));
CBOR_CHECK(cbor_encode_uint(&mapEncoder, 2));
CBOR_CHECK(cbor_encode_uint(&mapEncoder, 3));
CBOR_CHECK(cbor_encode_negative_int(&mapEncoder, -selcred->alg));
CBOR_CHECK(cbor_encode_negative_int(&mapEncoder, 1));
CBOR_CHECK(cbor_encode_uint(&mapEncoder, selcred->curve));
CBOR_CHECK(cbor_encode_negative_int(&mapEncoder, 2));
mbedtls_mpi_write_binary(&ekey.Q.X, pkey, pkey_len);
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, pkey, pkey_len));
CBOR_CHECK(cbor_encode_negative_int(&mapEncoder, 3));
mbedtls_mpi_write_binary(&ekey.Q.Y, pkey, pkey_len);
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, pkey, pkey_len));
CBOR_CHECK(cbor_encoder_close_container(&encoder, &mapEncoder));
size_t rs = cbor_encoder_get_buffer_size(&encoder, cbor_buf);
size_t aut_data_len = 32 + 1 + 4 + (16 + 2 + cred_id_len + rs) + ext_len;
size_t aut_data_len = 32 + 1 + 4 + ext_len;
aut_data = (uint8_t *)calloc(1, aut_data_len + clientDataHash.len);
uint8_t *pa = aut_data;
memcpy(pa, rp_id_hash, 32); pa += 32;
@@ -318,11 +392,6 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
*pa++ = ctr >> 16;
*pa++ = ctr >> 8;
*pa++ = ctr & 0xff;
memcpy(pa, aaguid, 16); pa += 16;
*pa++ = cred_id_len >> 8;
*pa++ = cred_id_len & 0xff;
memcpy(pa, cred_id, cred_id_len); pa += cred_id_len;
memcpy(pa, cbor_buf, rs); pa += rs;
memcpy(pa, ext, ext_len); pa += ext_len;
if (pa-aut_data != aut_data_len)
CBOR_ERROR(CTAP1_ERR_OTHER);
@@ -330,6 +399,7 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
memcpy(pa, clientDataHash.data, clientDataHash.len);
uint8_t hash[32], sig[MBEDTLS_ECDSA_MAX_LEN];
ret = mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), aut_data, aut_data_len+clientDataHash.len, hash);
size_t olen = 0;
ret = mbedtls_ecdsa_write_signature(&ekey, MBEDTLS_MD_SHA256, hash, 32, sig, sizeof(sig), &olen, random_gen, NULL);
mbedtls_ecdsa_free(&ekey);
@@ -343,10 +413,10 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x01));
CBOR_CHECK(cbor_encoder_create_map(&mapEncoder, &mapEncoder2, 2));
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "type"));
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "public-key"));
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "id"));
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder2, cred_id, cred_id_len));
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "type"));
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder2, "public-key"));
CBOR_CHECK(cbor_encoder_close_container(&mapEncoder, &mapEncoder2));
CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x02));
@@ -366,7 +436,7 @@ int cbor_get_assertion(const uint8_t *data, size_t len) {
CBOR_CHECK(cbor_encode_uint(&mapEncoder, numberOfCredentials));
}
CBOR_CHECK(cbor_encoder_close_container(&encoder, &mapEncoder));
res_APDU_size = cbor_encoder_get_buffer_size(&encoder, ctap_resp->init.data + 1);
resp_size = cbor_encoder_get_buffer_size(&encoder, ctap_resp->init.data + 1);
err:
if (asserted == false) {
CBOR_FREE_BYTE_STRING(clientDataHash);

14
src/fido/credential.c
View File

@@ -214,3 +214,17 @@ int credential_store(const uint8_t *cred_id, size_t cred_id_len, const uint8_t *
low_flash_available();
return 0;
}
int credential_derive_hmac_key(const uint8_t *cred_id, size_t cred_id_len, uint8_t *outk) {
memset(outk, 0, 64);
int r = 0;
if ((r = load_keydev(outk)) != 0)
return r;
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA512);
mbedtls_md_hmac(md_info, outk, 32, (uint8_t *)"SLIP-0022", 9, outk);
mbedtls_md_hmac(md_info, outk, 32, (uint8_t *)"\xf1\xd0\x02\x00", 4, outk);
mbedtls_md_hmac(md_info, outk, 32, (uint8_t *)"hmac-secret", 11, outk);
mbedtls_md_hmac(md_info, outk, 32, cred_id, cred_id_len, outk);
return 0;
}

1
src/fido/credential.h
View File

@@ -57,5 +57,6 @@ extern void credential_free(Credential *cred);
extern int credential_store(const uint8_t *cred_id, size_t cred_id_len, const uint8_t *rp_id_hash);
extern int credential_load(const uint8_t *cred_id, size_t cred_id_len, const uint8_t *rp_id_hash, Credential *cred);
extern int credential_create_cred(Credential *cred, uint8_t *cred_id, size_t *cred_id_len);
extern int credential_derive_hmac_key(const uint8_t *cred_id, size_t cred_id_len, uint8_t *outk);
#endif // _CREDENTIAL_H_

4
src/fido/fido.h
View File

@@ -37,6 +37,10 @@ extern CTAPHID_FRAME *ctap_req, *ctap_resp;
extern void init_fido();
extern mbedtls_ecp_group_id fido_curve_to_mbedtls(int curve);
extern int fido_load_key(int curve, const uint8_t *cred_id, mbedtls_ecdsa_context *key);
extern int load_keydev(uint8_t *key);
extern int encrypt(uint8_t protocol, const uint8_t *key, const uint8_t *in, size_t in_len, uint8_t *out);
extern int decrypt(uint8_t protocol, const uint8_t *key, const uint8_t *in, size_t in_len, uint8_t *out);
extern int ecdh(uint8_t protocol, const mbedtls_ecp_point *Q, uint8_t *sharedSecret);
#define FIDO2_ALG_ES256 -7 //ECDSA-SHA256 P256
#define FIDO2_ALG_EDDSA -8 //EdDSA