Return-Path: From: Lukasz Rymanowski To: linux-bluetooth@vger.kernel.org Cc: Lukasz Rymanowski Subject: [PATCH v2 2/3] shared/crypto: Add support to sign data with AES-CMAC Date: Thu, 15 May 2014 08:15:31 +0200 Message-Id: <1400134532-26574-2-git-send-email-lukasz.rymanowski@tieto.com> In-Reply-To: <1400134532-26574-1-git-send-email-lukasz.rymanowski@tieto.com> References: <1400134532-26574-1-git-send-email-lukasz.rymanowski@tieto.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: This patch adds support to generate hash using AES-CMAC algorithm --- src/shared/crypto.c | 36 ++++++++++++++++++++++++++++++++++++ src/shared/crypto.h | 3 +++ 2 files changed, 39 insertions(+) diff --git a/src/shared/crypto.c b/src/shared/crypto.c index f0b2979..0aec373 100644 --- a/src/shared/crypto.c +++ b/src/shared/crypto.c @@ -256,6 +256,42 @@ static inline void swap128(const uint8_t src[16], uint8_t dst[16]) dst[15 - i] = src[i]; } +bool bt_crypto_sign_att(struct bt_crypto *crypto, const uint8_t key[16], + const uint8_t *m, uint16_t m_len, + uint8_t signature[12]) +{ + int fd; + int len; + uint8_t tmp[16], out[16]; + + if (!crypto) + return false; + + /* The most significant octet of key corresponds to key[0] */ + swap128(key, tmp); + + fd = alg_new(crypto->cmac_aes, tmp, 16); + if (fd < 0) + return false; + + len = send(fd, m, m_len, 0); + if (len < 0) + return false; + + len = read(fd, out, 16); + if (len < 0) + return false; + + /* + * The most significant octet of hash corresponds to out[0] - swap it. + * Then truncate in most significant bit first order to a length of + * 12 octets + */ + swap128(out, tmp); + memcpy(signature, tmp + 4, 12); + + return true; +} /* * Security function e * diff --git a/src/shared/crypto.h b/src/shared/crypto.h index cae8daa..64faed2 100644 --- a/src/shared/crypto.h +++ b/src/shared/crypto.h @@ -46,3 +46,6 @@ bool bt_crypto_c1(struct bt_crypto *crypto, const uint8_t k[16], bool bt_crypto_s1(struct bt_crypto *crypto, const uint8_t k[16], const uint8_t r1[16], const uint8_t r2[16], uint8_t res[16]); +bool bt_crypto_sign_att(struct bt_crypto *crypto, const uint8_t key[16], + const uint8_t *m, uint16_t m_len, + uint8_t signature[12]); -- 1.8.4