// // Copyright (C) 2014 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 UPDATE_ENGINE_PAYLOAD_CONSUMER_PAYLOAD_VERIFIER_H_ #define UPDATE_ENGINE_PAYLOAD_CONSUMER_PAYLOAD_VERIFIER_H_ #include #include #include #include #include #include #include "update_engine/update_metadata.pb.h" // This class holds the public keys and implements methods used for payload // signature verification. See payload_generator/payload_signer.h for payload // signing. namespace chromeos_update_engine { class PayloadVerifier { public: // Pads a SHA256 hash so that it may be encrypted/signed with RSA2048 or // RSA4096 using the PKCS#1 v1.5 scheme. // hash should be a pointer to vector of exactly 256 bits. |rsa_size| must be // one of 256 or 512 bytes. The vector will be modified in place and will // result in having a length of 2048 or 4096 bits, depending on the rsa size. // Returns true on success, false otherwise. static bool PadRSASHA256Hash(brillo::Blob* hash, size_t rsa_size); // Parses the input as a PEM encoded public string. And creates a // PayloadVerifier with that public key for signature verification. static std::unique_ptr CreateInstance( const std::string& pem_public_key); // Extracts the public keys from the certificates contained in the input // zip file. And creates a PayloadVerifier with these public keys. static std::unique_ptr CreateInstanceFromZipPath( const std::string& certificate_zip_path); // Interprets |signature_proto| as a protocol buffer containing the // |Signatures| message and decrypts each signature data using the stored // public key. Pads the 32 bytes |sha256_hash_data| to 256 or 512 bytes // according to the PKCS#1 v1.5 standard; and returns whether *any* of the // decrypted hashes matches the padded hash data. In case of any error parsing // the signatures, returns false. bool VerifySignature(const std::string& signature_proto, const brillo::Blob& sha256_hash_data) const; // Verifies if |sig_data| is a raw signature of the hash |sha256_hash_data|. // If PayloadVerifier is using RSA as the public key, further puts the // decrypted data of |sig_data| into |decrypted_sig_data|. bool VerifyRawSignature(const brillo::Blob& sig_data, const brillo::Blob& sha256_hash_data, brillo::Blob* decrypted_sig_data) const; private: explicit PayloadVerifier( std::vector>&& public_keys) : public_keys_(std::move(public_keys)) {} // Decrypts |sig_data| with the given |public_key| and populates // |out_hash_data| with the decoded raw hash. Returns true if successful, // false otherwise. bool GetRawHashFromSignature(const brillo::Blob& sig_data, const EVP_PKEY* public_key, brillo::Blob* out_hash_data) const; std::vector> public_keys_; }; } // namespace chromeos_update_engine #endif // UPDATE_ENGINE_PAYLOAD_CONSUMER_PAYLOAD_VERIFIER_H_