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Diffstat (limited to 'src/libcamera/pub_key.cpp')
-rw-r--r-- | src/libcamera/pub_key.cpp | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/src/libcamera/pub_key.cpp b/src/libcamera/pub_key.cpp new file mode 100644 index 00000000..064d2dd2 --- /dev/null +++ b/src/libcamera/pub_key.cpp @@ -0,0 +1,97 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2020, Google Inc. + * + * pub_key.cpp - Public key signature verification + */ + +#include "pub_key.h" + +#if 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(Span<const uint8_t> key) + : valid_(false) +{ +#if 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_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(Span<const uint8_t> data, Span<const uint8_t> sig) const +{ +#if 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 */ |