platform_hardware_interfaces/identity/aidl/default/EicOpsImpl.cc
Seth Moore be32113307 Revert "Add remote key provisioning to the IC HAL"
Revert "Add dependency on keymint cpp lib"

Revert "Allow default identity service to call keymint"

Revert submission 1956689-add rkp to identity-default

Reason for revert: Broke git-master. Will resubmit later.
Reverted Changes:
I96dcf3027:Add remote key provisioning to the IC HAL
Id686ac33a:Add dependency on keymint cpp lib
Ib368a2a00:Log to logd in the default identity service
I7d2906de0:Refactor IC support for RKP
Iae0f14f1c:Fix formatting of identity credential aidl
I01d086a4b:Allow default identity service to call keymint

Change-Id: I76a898c04090c5befe5fb5a5d07ec2e397fdd8b3
2022-01-25 22:44:24 +00:00

543 lines
20 KiB
C++

/*
* Copyright 2020, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "EicOpsImpl"
#include <optional>
#include <tuple>
#include <vector>
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <string.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <android/hardware/identity/support/IdentityCredentialSupport.h>
#include <openssl/sha.h>
#include <openssl/aes.h>
#include <openssl/bn.h>
#include <openssl/crypto.h>
#include <openssl/ec.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/hkdf.h>
#include <openssl/hmac.h>
#include <openssl/objects.h>
#include <openssl/pem.h>
#include <openssl/pkcs12.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#include <openssl/x509_vfy.h>
#include "EicOps.h"
using ::std::map;
using ::std::optional;
using ::std::string;
using ::std::tuple;
using ::std::vector;
void* eicMemSet(void* s, int c, size_t n) {
return memset(s, c, n);
}
void* eicMemCpy(void* dest, const void* src, size_t n) {
return memcpy(dest, src, n);
}
size_t eicStrLen(const char* s) {
return strlen(s);
}
void* eicMemMem(const uint8_t* haystack, size_t haystackLen, const uint8_t* needle,
size_t needleLen) {
return memmem(haystack, haystackLen, needle, needleLen);
}
int eicCryptoMemCmp(const void* s1, const void* s2, size_t n) {
return CRYPTO_memcmp(s1, s2, n);
}
void eicOpsHmacSha256Init(EicHmacSha256Ctx* ctx, const uint8_t* key, size_t keySize) {
HMAC_CTX* realCtx = (HMAC_CTX*)ctx;
HMAC_CTX_init(realCtx);
if (HMAC_Init_ex(realCtx, key, keySize, EVP_sha256(), nullptr /* impl */) != 1) {
LOG(ERROR) << "Error initializing HMAC_CTX";
}
}
void eicOpsHmacSha256Update(EicHmacSha256Ctx* ctx, const uint8_t* data, size_t len) {
HMAC_CTX* realCtx = (HMAC_CTX*)ctx;
if (HMAC_Update(realCtx, data, len) != 1) {
LOG(ERROR) << "Error updating HMAC_CTX";
}
}
void eicOpsHmacSha256Final(EicHmacSha256Ctx* ctx, uint8_t digest[EIC_SHA256_DIGEST_SIZE]) {
HMAC_CTX* realCtx = (HMAC_CTX*)ctx;
unsigned int size = 0;
if (HMAC_Final(realCtx, digest, &size) != 1) {
LOG(ERROR) << "Error finalizing HMAC_CTX";
}
if (size != EIC_SHA256_DIGEST_SIZE) {
LOG(ERROR) << "Expected 32 bytes from HMAC_Final, got " << size;
}
}
void eicOpsSha256Init(EicSha256Ctx* ctx) {
SHA256_CTX* realCtx = (SHA256_CTX*)ctx;
SHA256_Init(realCtx);
}
void eicOpsSha256Update(EicSha256Ctx* ctx, const uint8_t* data, size_t len) {
SHA256_CTX* realCtx = (SHA256_CTX*)ctx;
SHA256_Update(realCtx, data, len);
}
void eicOpsSha256Final(EicSha256Ctx* ctx, uint8_t digest[EIC_SHA256_DIGEST_SIZE]) {
SHA256_CTX* realCtx = (SHA256_CTX*)ctx;
SHA256_Final(digest, realCtx);
}
bool eicOpsRandom(uint8_t* buf, size_t numBytes) {
optional<vector<uint8_t>> bytes = ::android::hardware::identity::support::getRandom(numBytes);
if (!bytes.has_value()) {
return false;
}
memcpy(buf, bytes.value().data(), numBytes);
return true;
}
bool eicNextId(uint32_t* id) {
uint32_t oldId = *id;
uint32_t newId = 0;
do {
union {
uint8_t value8;
uint32_t value32;
} value;
if (!eicOpsRandom(&value.value8, sizeof(value))) {
return false;
}
newId = value.value32;
} while (newId == oldId && newId == 0);
*id = newId;
return true;
}
bool eicOpsEncryptAes128Gcm(
const uint8_t* key, // Must be 16 bytes
const uint8_t* nonce, // Must be 12 bytes
const uint8_t* data, // May be NULL if size is 0
size_t dataSize,
const uint8_t* additionalAuthenticationData, // May be NULL if size is 0
size_t additionalAuthenticationDataSize, uint8_t* encryptedData) {
vector<uint8_t> cppKey;
cppKey.resize(16);
memcpy(cppKey.data(), key, 16);
vector<uint8_t> cppData;
cppData.resize(dataSize);
if (dataSize > 0) {
memcpy(cppData.data(), data, dataSize);
}
vector<uint8_t> cppAAD;
cppAAD.resize(additionalAuthenticationDataSize);
if (additionalAuthenticationDataSize > 0) {
memcpy(cppAAD.data(), additionalAuthenticationData, additionalAuthenticationDataSize);
}
vector<uint8_t> cppNonce;
cppNonce.resize(12);
memcpy(cppNonce.data(), nonce, 12);
optional<vector<uint8_t>> cppEncryptedData =
android::hardware::identity::support::encryptAes128Gcm(cppKey, cppNonce, cppData,
cppAAD);
if (!cppEncryptedData.has_value()) {
return false;
}
memcpy(encryptedData, cppEncryptedData.value().data(), cppEncryptedData.value().size());
return true;
}
// Decrypts |encryptedData| using |key| and |additionalAuthenticatedData|,
// returns resulting plaintext in |data| must be of size |encryptedDataSize| - 28.
//
// The format of |encryptedData| must be as specified in the
// encryptAes128Gcm() function.
bool eicOpsDecryptAes128Gcm(const uint8_t* key, // Must be 16 bytes
const uint8_t* encryptedData, size_t encryptedDataSize,
const uint8_t* additionalAuthenticationData,
size_t additionalAuthenticationDataSize, uint8_t* data) {
vector<uint8_t> keyVec;
keyVec.resize(16);
memcpy(keyVec.data(), key, 16);
vector<uint8_t> encryptedDataVec;
encryptedDataVec.resize(encryptedDataSize);
if (encryptedDataSize > 0) {
memcpy(encryptedDataVec.data(), encryptedData, encryptedDataSize);
}
vector<uint8_t> aadVec;
aadVec.resize(additionalAuthenticationDataSize);
if (additionalAuthenticationDataSize > 0) {
memcpy(aadVec.data(), additionalAuthenticationData, additionalAuthenticationDataSize);
}
optional<vector<uint8_t>> decryptedDataVec =
android::hardware::identity::support::decryptAes128Gcm(keyVec, encryptedDataVec,
aadVec);
if (!decryptedDataVec.has_value()) {
eicDebug("Error decrypting data");
return false;
}
if (decryptedDataVec.value().size() != encryptedDataSize - 28) {
eicDebug("Decrypted data is size %zd, expected %zd", decryptedDataVec.value().size(),
encryptedDataSize - 28);
return false;
}
if (decryptedDataVec.value().size() > 0) {
memcpy(data, decryptedDataVec.value().data(), decryptedDataVec.value().size());
}
return true;
}
bool eicOpsCreateEcKey(uint8_t privateKey[EIC_P256_PRIV_KEY_SIZE],
uint8_t publicKey[EIC_P256_PUB_KEY_SIZE]) {
optional<vector<uint8_t>> keyPair = android::hardware::identity::support::createEcKeyPair();
if (!keyPair) {
eicDebug("Error creating EC keypair");
return false;
}
optional<vector<uint8_t>> privKey =
android::hardware::identity::support::ecKeyPairGetPrivateKey(keyPair.value());
if (!privKey) {
eicDebug("Error extracting private key");
return false;
}
if (privKey.value().size() != EIC_P256_PRIV_KEY_SIZE) {
eicDebug("Private key is %zd bytes, expected %zd", privKey.value().size(),
(size_t)EIC_P256_PRIV_KEY_SIZE);
return false;
}
optional<vector<uint8_t>> pubKey =
android::hardware::identity::support::ecKeyPairGetPublicKey(keyPair.value());
if (!pubKey) {
eicDebug("Error extracting public key");
return false;
}
// ecKeyPairGetPublicKey() returns 0x04 | x | y, we don't want the leading 0x04.
if (pubKey.value().size() != EIC_P256_PUB_KEY_SIZE + 1) {
eicDebug("Public key is %zd bytes long, expected %zd", pubKey.value().size(),
(size_t)EIC_P256_PRIV_KEY_SIZE + 1);
return false;
}
memcpy(privateKey, privKey.value().data(), EIC_P256_PRIV_KEY_SIZE);
memcpy(publicKey, pubKey.value().data() + 1, EIC_P256_PUB_KEY_SIZE);
return true;
}
bool eicOpsCreateCredentialKey(uint8_t privateKey[EIC_P256_PRIV_KEY_SIZE], const uint8_t* challenge,
size_t challengeSize, const uint8_t* applicationId,
size_t applicationIdSize, bool testCredential, uint8_t* cert,
size_t* certSize) {
vector<uint8_t> challengeVec(challengeSize);
memcpy(challengeVec.data(), challenge, challengeSize);
vector<uint8_t> applicationIdVec(applicationIdSize);
memcpy(applicationIdVec.data(), applicationId, applicationIdSize);
optional<std::pair<vector<uint8_t>, vector<vector<uint8_t>>>> ret =
android::hardware::identity::support::createEcKeyPairAndAttestation(
challengeVec, applicationIdVec, testCredential);
if (!ret) {
eicDebug("Error generating CredentialKey and attestation");
return false;
}
// Extract certificate chain.
vector<uint8_t> flatChain =
android::hardware::identity::support::certificateChainJoin(ret.value().second);
if (*certSize < flatChain.size()) {
eicDebug("Buffer for certificate is only %zd bytes long, need %zd bytes", *certSize,
flatChain.size());
return false;
}
memcpy(cert, flatChain.data(), flatChain.size());
*certSize = flatChain.size();
// Extract private key.
optional<vector<uint8_t>> privKey =
android::hardware::identity::support::ecKeyPairGetPrivateKey(ret.value().first);
if (!privKey) {
eicDebug("Error extracting private key");
return false;
}
if (privKey.value().size() != EIC_P256_PRIV_KEY_SIZE) {
eicDebug("Private key is %zd bytes, expected %zd", privKey.value().size(),
(size_t)EIC_P256_PRIV_KEY_SIZE);
return false;
}
memcpy(privateKey, privKey.value().data(), EIC_P256_PRIV_KEY_SIZE);
return true;
}
bool eicOpsSignEcKey(const uint8_t publicKey[EIC_P256_PUB_KEY_SIZE],
const uint8_t signingKey[EIC_P256_PRIV_KEY_SIZE], unsigned int serial,
const char* issuerName, const char* subjectName, time_t validityNotBefore,
time_t validityNotAfter, const uint8_t* proofOfBinding,
size_t proofOfBindingSize, uint8_t* cert, size_t* certSize) { // inout
vector<uint8_t> signingKeyVec(EIC_P256_PRIV_KEY_SIZE);
memcpy(signingKeyVec.data(), signingKey, EIC_P256_PRIV_KEY_SIZE);
vector<uint8_t> pubKeyVec(EIC_P256_PUB_KEY_SIZE + 1);
pubKeyVec[0] = 0x04;
memcpy(pubKeyVec.data() + 1, publicKey, EIC_P256_PUB_KEY_SIZE);
string serialDecimal = android::base::StringPrintf("%d", serial);
map<string, vector<uint8_t>> extensions;
if (proofOfBinding != nullptr) {
vector<uint8_t> proofOfBindingVec(proofOfBinding, proofOfBinding + proofOfBindingSize);
extensions["1.3.6.1.4.1.11129.2.1.26"] = proofOfBindingVec;
}
optional<vector<uint8_t>> certVec =
android::hardware::identity::support::ecPublicKeyGenerateCertificate(
pubKeyVec, signingKeyVec, serialDecimal, issuerName, subjectName,
validityNotBefore, validityNotAfter, extensions);
if (!certVec) {
eicDebug("Error generating certificate");
return false;
}
if (*certSize < certVec.value().size()) {
eicDebug("Buffer for certificate is only %zd bytes long, need %zd bytes", *certSize,
certVec.value().size());
return false;
}
memcpy(cert, certVec.value().data(), certVec.value().size());
*certSize = certVec.value().size();
return true;
}
bool eicOpsEcDsa(const uint8_t privateKey[EIC_P256_PRIV_KEY_SIZE],
const uint8_t digestOfData[EIC_SHA256_DIGEST_SIZE],
uint8_t signature[EIC_ECDSA_P256_SIGNATURE_SIZE]) {
vector<uint8_t> privKeyVec(EIC_P256_PRIV_KEY_SIZE);
memcpy(privKeyVec.data(), privateKey, EIC_P256_PRIV_KEY_SIZE);
vector<uint8_t> digestVec(EIC_SHA256_DIGEST_SIZE);
memcpy(digestVec.data(), digestOfData, EIC_SHA256_DIGEST_SIZE);
optional<vector<uint8_t>> derSignature =
android::hardware::identity::support::signEcDsaDigest(privKeyVec, digestVec);
if (!derSignature) {
eicDebug("Error signing data");
return false;
}
ECDSA_SIG* sig;
const unsigned char* p = derSignature.value().data();
sig = d2i_ECDSA_SIG(nullptr, &p, derSignature.value().size());
if (sig == nullptr) {
eicDebug("Error decoding DER signature");
return false;
}
if (BN_bn2binpad(sig->r, signature, 32) != 32) {
eicDebug("Error encoding r");
return false;
}
if (BN_bn2binpad(sig->s, signature + 32, 32) != 32) {
eicDebug("Error encoding s");
return false;
}
return true;
}
static const uint8_t hbkTest[16] = {0};
static const uint8_t hbkReal[16] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
const uint8_t* eicOpsGetHardwareBoundKey(bool testCredential) {
if (testCredential) {
return hbkTest;
}
return hbkReal;
}
bool eicOpsValidateAuthToken(uint64_t /* challenge */, uint64_t /* secureUserId */,
uint64_t /* authenticatorId */, int /* hardwareAuthenticatorType */,
uint64_t /* timeStamp */, const uint8_t* /* mac */,
size_t /* macSize */, uint64_t /* verificationTokenChallenge */,
uint64_t /* verificationTokenTimeStamp */,
int /* verificationTokenSecurityLevel */,
const uint8_t* /* verificationTokenMac */,
size_t /* verificationTokenMacSize */) {
// Here's where we would validate the passed-in |authToken| to assure ourselves
// that it comes from the e.g. biometric hardware and wasn't made up by an attacker.
//
// However this involves calculating the MAC which requires access to the to
// a pre-shared key which we don't have...
//
return true;
}
bool eicOpsX509GetPublicKey(const uint8_t* x509Cert, size_t x509CertSize, uint8_t* publicKey,
size_t* publicKeySize) {
vector<uint8_t> chain;
chain.resize(x509CertSize);
memcpy(chain.data(), x509Cert, x509CertSize);
optional<vector<uint8_t>> res =
android::hardware::identity::support::certificateChainGetTopMostKey(chain);
if (!res) {
return false;
}
if (res.value().size() > *publicKeySize) {
eicDebug("Public key size is %zd but buffer only has room for %zd bytes",
res.value().size(), *publicKeySize);
return false;
}
*publicKeySize = res.value().size();
memcpy(publicKey, res.value().data(), *publicKeySize);
eicDebug("Extracted %zd bytes public key from %zd bytes X.509 cert", *publicKeySize,
x509CertSize);
return true;
}
bool eicOpsX509CertSignedByPublicKey(const uint8_t* x509Cert, size_t x509CertSize,
const uint8_t* publicKey, size_t publicKeySize) {
vector<uint8_t> certVec(x509Cert, x509Cert + x509CertSize);
vector<uint8_t> publicKeyVec(publicKey, publicKey + publicKeySize);
return android::hardware::identity::support::certificateSignedByPublicKey(certVec,
publicKeyVec);
}
bool eicOpsEcDsaVerifyWithPublicKey(const uint8_t* digest, size_t digestSize,
const uint8_t* signature, size_t signatureSize,
const uint8_t* publicKey, size_t publicKeySize) {
vector<uint8_t> digestVec(digest, digest + digestSize);
vector<uint8_t> signatureVec(signature, signature + signatureSize);
vector<uint8_t> publicKeyVec(publicKey, publicKey + publicKeySize);
vector<uint8_t> derSignature;
if (!android::hardware::identity::support::ecdsaSignatureCoseToDer(signatureVec,
derSignature)) {
LOG(ERROR) << "Error convering signature to DER format";
return false;
}
if (!android::hardware::identity::support::checkEcDsaSignature(digestVec, derSignature,
publicKeyVec)) {
LOG(ERROR) << "Signature check failed";
return false;
}
return true;
}
bool eicOpsEcdh(const uint8_t publicKey[EIC_P256_PUB_KEY_SIZE],
const uint8_t privateKey[EIC_P256_PUB_KEY_SIZE],
uint8_t sharedSecret[EIC_P256_COORDINATE_SIZE]) {
vector<uint8_t> pubKeyVec(EIC_P256_PUB_KEY_SIZE + 1);
pubKeyVec[0] = 0x04;
memcpy(pubKeyVec.data() + 1, publicKey, EIC_P256_PUB_KEY_SIZE);
vector<uint8_t> privKeyVec(EIC_P256_PRIV_KEY_SIZE);
memcpy(privKeyVec.data(), privateKey, EIC_P256_PRIV_KEY_SIZE);
optional<vector<uint8_t>> shared =
android::hardware::identity::support::ecdh(pubKeyVec, privKeyVec);
if (!shared) {
LOG(ERROR) << "Error performing ECDH";
return false;
}
if (shared.value().size() != EIC_P256_COORDINATE_SIZE) {
LOG(ERROR) << "Unexpected size of shared secret " << shared.value().size() << " expected "
<< EIC_P256_COORDINATE_SIZE << " bytes";
return false;
}
memcpy(sharedSecret, shared.value().data(), EIC_P256_COORDINATE_SIZE);
return true;
}
bool eicOpsHkdf(const uint8_t* sharedSecret, size_t sharedSecretSize, const uint8_t* salt,
size_t saltSize, const uint8_t* info, size_t infoSize, uint8_t* output,
size_t outputSize) {
vector<uint8_t> sharedSecretVec(sharedSecretSize);
memcpy(sharedSecretVec.data(), sharedSecret, sharedSecretSize);
vector<uint8_t> saltVec(saltSize);
memcpy(saltVec.data(), salt, saltSize);
vector<uint8_t> infoVec(infoSize);
memcpy(infoVec.data(), info, infoSize);
optional<vector<uint8_t>> result = android::hardware::identity::support::hkdf(
sharedSecretVec, saltVec, infoVec, outputSize);
if (!result) {
LOG(ERROR) << "Error performing HKDF";
return false;
}
if (result.value().size() != outputSize) {
LOG(ERROR) << "Unexpected size of HKDF " << result.value().size() << " expected "
<< outputSize;
return false;
}
memcpy(output, result.value().data(), outputSize);
return true;
}
#ifdef EIC_DEBUG
void eicPrint(const char* format, ...) {
va_list args;
va_start(args, format);
vfprintf(stderr, format, args);
va_end(args);
}
void eicHexdump(const char* message, const uint8_t* data, size_t dataSize) {
vector<uint8_t> dataVec(dataSize);
memcpy(dataVec.data(), data, dataSize);
android::hardware::identity::support::hexdump(message, dataVec);
}
void eicCborPrettyPrint(const uint8_t* cborData, size_t cborDataSize, size_t maxBStrSize) {
vector<uint8_t> cborDataVec(cborDataSize);
memcpy(cborDataVec.data(), cborData, cborDataSize);
string str =
android::hardware::identity::support::cborPrettyPrint(cborDataVec, maxBStrSize, {});
fprintf(stderr, "%s\n", str.c_str());
}
#endif // EIC_DEBUG