Files
external_libcamera/src/libcamera/pub_key.cpp
Laurent Pinchart 626172a16b libcamera: Drop file name from header comment blocks
Source files in libcamera start by a comment block header, which
includes the file name and a one-line description of the file contents.
While the latter is useful to get a quick overview of the file contents
at a glance, the former is mostly a source of inconvenience. The name in
the comments can easily get out of sync with the file name when files
are renamed, and copy & paste during development have often lead to
incorrect names being used to start with.

Readers of the source code are expected to know which file they're
looking it. Drop the file name from the header comment block.

The change was generated with the following script:

----------------------------------------

dirs="include/libcamera src test utils"

declare -rA patterns=(
	['c']=' \* '
	['cpp']=' \* '
	['h']=' \* '
	['py']='# '
	['sh']='# '
)

for ext in ${!patterns[@]} ; do
	files=$(for dir in $dirs ; do find $dir -name "*.${ext}" ; done)
	pattern=${patterns[${ext}]}

	for file in $files ; do
		name=$(basename ${file})
		sed -i "s/^\(${pattern}\)${name} - /\1/" "$file"
	done
done
----------------------------------------

This misses several files that are out of sync with the comment block
header. Those will be addressed separately and manually.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
2024-05-08 22:39:50 +03:00

141 lines
3.2 KiB
C++

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2020, Google Inc.
*
* 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 */