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Do not return extensions if they are not requested OR are false.

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Fixes #136

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
This commit is contained in:
Pol Henarejos
2025-03-30 19:32:25 +02:00
parent 64f371e6e5
commit c3ea413592
3 changed files with 98 additions and 94 deletions
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144
src/fido/cbor_get_assertion.c
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@@ -469,91 +469,93 @@ int cbor_get_assertion(const uint8_t *data, size_t len, bool next) {
if (options.up == pfalse) {
extensions.hmac_secret = NULL;
}
if (extensions.hmac_secret != NULL) {
if (extensions.hmac_secret == ptrue) {
l++;
}
if (credBlob == ptrue) {
l++;
}
if (extensions.thirdPartyPayment != NULL) {
if (extensions.thirdPartyPayment == ptrue) {
l++;
}
CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, l));
if (credBlob == ptrue) {
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "credBlob"));
if (selcred->extensions.credBlob.present == true) {
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, selcred->extensions.credBlob.data,
selcred->extensions.credBlob.len));
if (l > 0) {
CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, l));
if (credBlob == ptrue) {
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "credBlob"));
if (selcred->extensions.credBlob.present == true) {
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, selcred->extensions.credBlob.data,
selcred->extensions.credBlob.len));
}
else {
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, NULL, 0));
}
}
else {
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, NULL, 0));
}
}
if (extensions.hmac_secret != NULL) {
if (extensions.hmac_secret == ptrue) {
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "hmac-secret"));
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "hmac-secret"));
uint8_t sharedSecret[64] = {0};
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) {
uint8_t sharedSecret[64] = {0};
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);
}
ret = ecdh((uint8_t)hmacSecretPinUvAuthProtocol, &Qp, sharedSecret);
mbedtls_ecp_point_free(&Qp);
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
if (ret != 0) {
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
}
if (verify((uint8_t)hmacSecretPinUvAuthProtocol, sharedSecret, salt_enc.data, (uint16_t)salt_enc.len, salt_auth.data) != 0) {
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
CBOR_ERROR(CTAP2_ERR_EXTENSION_FIRST);
}
uint8_t salt_dec[64] = {0}, poff = ((uint8_t)hmacSecretPinUvAuthProtocol - 1) * IV_SIZE;
ret = decrypt((uint8_t)hmacSecretPinUvAuthProtocol, sharedSecret, salt_enc.data, (uint16_t)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] = {0}, *crd = NULL;
ret = credential_derive_hmac_key(selcred->id.data, selcred->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] = {0}, hmac_res[80] = {0};
mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), crd, 32, salt_dec, 32, out1);
if ((uint8_t)salt_enc.len == 64 + poff) {
mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), crd, 32, salt_dec + 32, 32, out1 + 32);
}
encrypt((uint8_t)hmacSecretPinUvAuthProtocol, sharedSecret, out1, (uint16_t)(salt_enc.len - poff), hmac_res);
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, hmac_res, salt_enc.len));
}
if (mbedtls_mpi_read_binary(&Qp.Y, kay.data, kay.len) != 0) {
mbedtls_ecp_point_free(&Qp);
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
if (extensions.thirdPartyPayment == ptrue) {
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "thirdPartyPayment"));
if (selcred->extensions.thirdPartyPayment == ptrue) {
CBOR_CHECK(cbor_encode_boolean(&mapEncoder, true));
}
else {
CBOR_CHECK(cbor_encode_boolean(&mapEncoder, false));
}
}
ret = ecdh((uint8_t)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((uint8_t)hmacSecretPinUvAuthProtocol, sharedSecret, salt_enc.data, (uint16_t)salt_enc.len, salt_auth.data) != 0) {
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
CBOR_ERROR(CTAP2_ERR_EXTENSION_FIRST);
}
uint8_t salt_dec[64] = {0}, poff = ((uint8_t)hmacSecretPinUvAuthProtocol - 1) * IV_SIZE;
ret = decrypt((uint8_t)hmacSecretPinUvAuthProtocol, sharedSecret, salt_enc.data, (uint16_t)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] = {0}, *crd = NULL;
ret = credential_derive_hmac_key(selcred->id.data, selcred->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] = {0}, hmac_res[80] = {0};
mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), crd, 32, salt_dec, 32, out1);
if ((uint8_t)salt_enc.len == 64 + poff) {
mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), crd, 32, salt_dec + 32, 32, out1 + 32);
}
encrypt((uint8_t)hmacSecretPinUvAuthProtocol, sharedSecret, out1, (uint16_t)(salt_enc.len - poff), hmac_res);
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, hmac_res, salt_enc.len));
}
if (extensions.thirdPartyPayment != NULL) {
CBOR_CHECK(cbor_encode_text_stringz(&mapEncoder, "thirdPartyPayment"));
if (selcred->extensions.thirdPartyPayment == ptrue) {
CBOR_CHECK(cbor_encode_boolean(&mapEncoder, true));
}
else {
CBOR_CHECK(cbor_encode_boolean(&mapEncoder, false));
}
}
CBOR_CHECK(cbor_encoder_close_container(&encoder, &mapEncoder));
ext_len = cbor_encoder_get_buffer_size(&encoder, ext);
flags |= FIDO2_AUT_FLAG_ED;
CBOR_CHECK(cbor_encoder_close_container(&encoder, &mapEncoder));
ext_len = cbor_encoder_get_buffer_size(&encoder, ext);
flags |= FIDO2_AUT_FLAG_ED;
}
}
uint32_t ctr = get_sign_counter();