summaryrefslogtreecommitdiff
path: root/utils/tuning/libtuning/libtuning.py
AgeCommit message (Expand)Author
2024-08-14utils: tuning: Change Tuner.add() to accept a list of modulesStefan Klug
2024-07-05libtuning: Only warn if processing returns NoneStefan Klug
2024-07-05libtuning: Migrate prints to python logging frameworkStefan Klug
2024-05-08libcamera: Drop file name from header comment blocksLaurent Pinchart
2022-11-25utils: tuning: libtuning: Implement the core of libtuningPaul Elder
1' href='#n61'>61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2020, Google Inc.
 *
 * pub_key.cpp - Public key signature verification
 */

#include "libcamera/internal/pub_key.h"

#if HAVE_CRYPTO
#include <openssl/evp.h>
#include <openssl/rsa.h>
#include <openssl/sha.h>
#include <openssl/x509.h>
#elif HAVE_GNUTLS
#include <gnutls/abstract.h>
#endif

/**
 * \file pub_key.h
 * \brief Public key signature verification
 */

namespace libcamera {

/**
 * \class PubKey
 * \brief Public key wrapper for signature verification
 *
 * The PubKey class wraps a public key and implements signature verification. It
 * only supports RSA keys and the RSA-SHA256 signature algorithm.
 */

/**
 * \brief Construct a PubKey from key data
 * \param[in] key Key data encoded in DER format
 */
PubKey::PubKey([[maybe_unused]] Span<const uint8_t> key)
	: valid_(false)
{
#if HAVE_CRYPTO
	const uint8_t *data = key.data();
	pubkey_ = d2i_PUBKEY(nullptr, &data, key.size());
	if (!pubkey_)
		return;

	valid_ = true;
#elif HAVE_GNUTLS
	int ret = gnutls_pubkey_init(&pubkey_);
	if (ret < 0)
		return;

	const gnutls_datum_t gnuTlsKey{
		const_cast<unsigned char *>(key.data()),
		static_cast<unsigned int>(key.size())
	};
	ret = gnutls_pubkey_import(pubkey_, &gnuTlsKey, GNUTLS_X509_FMT_DER);
	if (ret < 0)
		return;

	valid_ = true;
#endif
}

PubKey::~PubKey()
{
#if HAVE_CRYPTO
	EVP_PKEY_free(pubkey_);
#elif HAVE_GNUTLS
	gnutls_pubkey_deinit(pubkey_);
#endif
}

/**
 * \fn bool PubKey::isValid() const
 * \brief Check is the public key is valid
 * \return True if the public key is valid, false otherwise
 */

/**
 * \brief Verify signature on data
 * \param[in] data The signed data
 * \param[in] sig The signature
 *
 * Verify that the signature \a sig matches the signed \a data for the public
 * key. The signture algorithm is hardcoded to RSA-SHA256.
 *
 * \return True if the signature is valid, false otherwise
 */
bool PubKey::verify([[maybe_unused]] Span<const uint8_t> data,
		    [[maybe_unused]] Span<const uint8_t> sig) const
{
	if (!valid_)
		return false;

#if HAVE_CRYPTO
	/*
	 * Create and initialize a public key algorithm context for signature
	 * verification.
	 */
	EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new(pubkey_, nullptr);
	if (!ctx)
		return false;

	if (EVP_PKEY_verify_init(ctx) <= 0 ||
	    EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0 ||
	    EVP_PKEY_CTX_set_signature_md(ctx, EVP_sha256()) <= 0) {
		EVP_PKEY_CTX_free(ctx);
		return false;
	}

	/* Calculate the SHA256 digest of the data. */
	uint8_t digest[SHA256_DIGEST_LENGTH];
	SHA256(data.data(), data.size(), digest);

	/* Decrypt the signature and verify it matches the digest. */
	int ret = EVP_PKEY_verify(ctx, sig.data(), sig.size(), digest,
				  SHA256_DIGEST_LENGTH);
	EVP_PKEY_CTX_free(ctx);
	return ret == 1;
#elif HAVE_GNUTLS
	const gnutls_datum_t gnuTlsData{
		const_cast<unsigned char *>(data.data()),
		static_cast<unsigned int>(data.size())
	};

	const gnutls_datum_t gnuTlsSig{
		const_cast<unsigned char *>(sig.data()),
		static_cast<unsigned int>(sig.size())
	};

	int ret = gnutls_pubkey_verify_data2(pubkey_, GNUTLS_SIGN_RSA_SHA256, 0,
					     &gnuTlsData, &gnuTlsSig);
	return ret >= 0;
#else
	return false;
#endif
}

} /* namespace libcamera */