/*
* Copyright (C) 2008 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.
*/
#ifndef _RECOVERY_VERIFIER_H
#define _RECOVERY_VERIFIER_H
#include <stdint.h>
#include <functional>
#include <memory>
#include <vector>
#include <openssl/ec_key.h>
#include <openssl/rsa.h>
#include <openssl/sha.h>
constexpr size_t MiB = 1024 * 1024;
using HasherUpdateCallback = std::function<void(const uint8_t* addr, uint64_t size)>;
struct RSADeleter {
void operator()(RSA* rsa) const {
RSA_free(rsa);
}
};
struct ECKEYDeleter {
void operator()(EC_KEY* ec_key) const {
EC_KEY_free(ec_key);
}
};
struct Certificate {
typedef enum {
KEY_TYPE_RSA,
KEY_TYPE_EC,
} KeyType;
Certificate(int hash_len_,
KeyType key_type_,
std::unique_ptr<RSA, RSADeleter>&& rsa_,
std::unique_ptr<EC_KEY, ECKEYDeleter>&& ec_)
: hash_len(hash_len_),
key_type(key_type_),
rsa(std::move(rsa_)),
ec(std::move(ec_)) {}
// SHA_DIGEST_LENGTH (SHA-1) or SHA256_DIGEST_LENGTH (SHA-256)
int hash_len;
KeyType key_type;
std::unique_ptr<RSA, RSADeleter> rsa;
std::unique_ptr<EC_KEY, ECKEYDeleter> ec;
};
class VerifierInterface {
public:
virtual ~VerifierInterface() = default;
// Returns the package size in bytes.
virtual uint64_t GetPackageSize() const = 0;
// Reads |byte_count| data starting from |offset|, and puts the result in |buffer|.
virtual bool ReadFullyAtOffset(uint8_t* buffer, uint64_t byte_count, uint64_t offset) = 0;
// Updates the hash contexts for |length| bytes data starting from |start|.
virtual bool UpdateHashAtOffset(const std::vector<HasherUpdateCallback>& hashers, uint64_t start,
uint64_t length) = 0;
// Updates the progress in fraction during package verification.
virtual void SetProgress(float progress) = 0;
};
// Looks for an RSA signature embedded in the .ZIP file comment given the path to the zip.
// Verifies that it matches one of the given public keys. Returns VERIFY_SUCCESS or
// VERIFY_FAILURE (if any error is encountered or no key matches the signature).
int verify_file(VerifierInterface* package, const std::vector<Certificate>& keys);
// Checks that the RSA key has a modulus of 2048 or 4096 bits long, and public exponent is 3 or
// 65537.
bool CheckRSAKey(const std::unique_ptr<RSA, RSADeleter>& rsa);
// Checks that the field size of the curve for the EC key is 256 bits.
bool CheckECKey(const std::unique_ptr<EC_KEY, ECKEYDeleter>& ec_key);
// Parses a PEM-encoded x509 certificate from the given buffer and saves it into |cert|. Returns
// false if there is a parsing failure or the signature's encryption algorithm is not supported.
bool LoadCertificateFromBuffer(const std::vector<uint8_t>& pem_content, Certificate* cert);
// Iterates over the zip entries with the suffix "x509.pem" and returns a list of recognized
// certificates. Returns an empty list if we fail to parse any of the entries.
std::vector<Certificate> LoadKeysFromZipfile(const std::string& zip_name);
#define VERIFY_SUCCESS 0
#define VERIFY_FAILURE 1
#endif /* _RECOVERY_VERIFIER_H */
