diff options
Diffstat (limited to 'sys/kgssapi/krb5/kcrypto_aes.c')
| -rw-r--r-- | sys/kgssapi/krb5/kcrypto_aes.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/sys/kgssapi/krb5/kcrypto_aes.c b/sys/kgssapi/krb5/kcrypto_aes.c new file mode 100644 index 0000000..d2dac21 --- /dev/null +++ b/sys/kgssapi/krb5/kcrypto_aes.c @@ -0,0 +1,384 @@ +/*- + * Copyright (c) 2008 Isilon Inc http://www.isilon.com/ + * Authors: Doug Rabson <dfr@rabson.org> + * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/mutex.h> +#include <sys/kobj.h> +#include <sys/mbuf.h> +#include <opencrypto/cryptodev.h> + +#include <kgssapi/gssapi.h> +#include <kgssapi/gssapi_impl.h> + +#include "kcrypto.h" + +struct aes_state { + struct mtx as_lock; + uint64_t as_session; +}; + +static void +aes_init(struct krb5_key_state *ks) +{ + struct aes_state *as; + + as = malloc(sizeof(struct aes_state), M_GSSAPI, M_WAITOK|M_ZERO); + mtx_init(&as->as_lock, "gss aes lock", NULL, MTX_DEF); + ks->ks_priv = as; +} + +static void +aes_destroy(struct krb5_key_state *ks) +{ + struct aes_state *as = ks->ks_priv; + + if (as->as_session) + crypto_freesession(as->as_session); + mtx_destroy(&as->as_lock); + free(ks->ks_priv, M_GSSAPI); +} + +static void +aes_set_key(struct krb5_key_state *ks, const void *in) +{ + void *kp = ks->ks_key; + struct aes_state *as = ks->ks_priv; + struct cryptoini cri[2]; + + if (kp != in) + bcopy(in, kp, ks->ks_class->ec_keylen); + + if (as->as_session) + crypto_freesession(as->as_session); + + bzero(cri, sizeof(cri)); + + /* + * We only want the first 96 bits of the HMAC. + */ + cri[0].cri_alg = CRYPTO_SHA1_HMAC; + cri[0].cri_klen = ks->ks_class->ec_keybits; + cri[0].cri_mlen = 12; + cri[0].cri_key = ks->ks_key; + cri[0].cri_next = &cri[1]; + + cri[1].cri_alg = CRYPTO_AES_CBC; + cri[1].cri_klen = ks->ks_class->ec_keybits; + cri[1].cri_mlen = 0; + cri[1].cri_key = ks->ks_key; + cri[1].cri_next = NULL; + + crypto_newsession(&as->as_session, cri, + CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE); +} + +static void +aes_random_to_key(struct krb5_key_state *ks, const void *in) +{ + + aes_set_key(ks, in); +} + +static int +aes_crypto_cb(struct cryptop *crp) +{ + int error; + struct aes_state *as = (struct aes_state *) crp->crp_opaque; + + if (CRYPTO_SESID2CAPS(as->as_session) & CRYPTOCAP_F_SYNC) + return (0); + + error = crp->crp_etype; + if (error == EAGAIN) + error = crypto_dispatch(crp); + mtx_lock(&as->as_lock); + if (error || (crp->crp_flags & CRYPTO_F_DONE)) + wakeup(crp); + mtx_unlock(&as->as_lock); + + return (0); +} + +static void +aes_encrypt_1(const struct krb5_key_state *ks, int buftype, void *buf, + size_t skip, size_t len, void *ivec, int encdec) +{ + struct aes_state *as = ks->ks_priv; + struct cryptop *crp; + struct cryptodesc *crd; + int error; + + crp = crypto_getreq(1); + crd = crp->crp_desc; + + crd->crd_skip = skip; + crd->crd_len = len; + crd->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT | encdec; + if (ivec) { + bcopy(ivec, crd->crd_iv, 16); + } else { + bzero(crd->crd_iv, 16); + } + crd->crd_next = NULL; + crd->crd_alg = CRYPTO_AES_CBC; + + crp->crp_sid = as->as_session; + crp->crp_flags = buftype | CRYPTO_F_CBIFSYNC; + crp->crp_buf = buf; + crp->crp_opaque = (void *) as; + crp->crp_callback = aes_crypto_cb; + + error = crypto_dispatch(crp); + + if ((CRYPTO_SESID2CAPS(as->as_session) & CRYPTOCAP_F_SYNC) == 0) { + mtx_lock(&as->as_lock); + if (!error && !(crp->crp_flags & CRYPTO_F_DONE)) + error = msleep(crp, &as->as_lock, 0, "gssaes", 0); + mtx_unlock(&as->as_lock); + } + + crypto_freereq(crp); +} + +static void +aes_encrypt(const struct krb5_key_state *ks, struct mbuf *inout, + size_t skip, size_t len, void *ivec, size_t ivlen) +{ + size_t blocklen = 16, plen; + struct { + uint8_t cn_1[16], cn[16]; + } last2; + int i, off; + + /* + * AES encryption with cyphertext stealing: + * + * CTSencrypt(P[0], ..., P[n], IV, K): + * len = length(P[n]) + * (C[0], ..., C[n-2], E[n-1]) = + * CBCencrypt(P[0], ..., P[n-1], IV, K) + * P = pad(P[n], 0, blocksize) + * E[n] = CBCencrypt(P, E[n-1], K); + * C[n-1] = E[n] + * C[n] = E[n-1]{0..len-1} + */ + plen = len % blocklen; + if (len == blocklen) { + /* + * Note: caller will ensure len >= blocklen. + */ + aes_encrypt_1(ks, CRYPTO_F_IMBUF, inout, skip, len, ivec, + CRD_F_ENCRYPT); + } else if (plen == 0) { + /* + * This is equivalent to CBC mode followed by swapping + * the last two blocks. We assume that neither of the + * last two blocks cross iov boundaries. + */ + aes_encrypt_1(ks, CRYPTO_F_IMBUF, inout, skip, len, ivec, + CRD_F_ENCRYPT); + off = skip + len - 2 * blocklen; + m_copydata(inout, off, 2 * blocklen, (void*) &last2); + m_copyback(inout, off, blocklen, last2.cn); + m_copyback(inout, off + blocklen, blocklen, last2.cn_1); + } else { + /* + * This is the difficult case. We encrypt all but the + * last partial block first. We then create a padded + * copy of the last block and encrypt that using the + * second to last encrypted block as IV. Once we have + * the encrypted versions of the last two blocks, we + * reshuffle to create the final result. + */ + aes_encrypt_1(ks, CRYPTO_F_IMBUF, inout, skip, len - plen, + ivec, CRD_F_ENCRYPT); + + /* + * Copy out the last two blocks, pad the last block + * and encrypt it. Rearrange to get the final + * result. The cyphertext for cn_1 is in cn. The + * cyphertext for cn is the first plen bytes of what + * is in cn_1 now. + */ + off = skip + len - blocklen - plen; + m_copydata(inout, off, blocklen + plen, (void*) &last2); + for (i = plen; i < blocklen; i++) + last2.cn[i] = 0; + aes_encrypt_1(ks, 0, last2.cn, 0, blocklen, last2.cn_1, + CRD_F_ENCRYPT); + m_copyback(inout, off, blocklen, last2.cn); + m_copyback(inout, off + blocklen, plen, last2.cn_1); + } +} + +static void +aes_decrypt(const struct krb5_key_state *ks, struct mbuf *inout, + size_t skip, size_t len, void *ivec, size_t ivlen) +{ + size_t blocklen = 16, plen; + struct { + uint8_t cn_1[16], cn[16]; + } last2; + int i, off, t; + + /* + * AES decryption with cyphertext stealing: + * + * CTSencrypt(C[0], ..., C[n], IV, K): + * len = length(C[n]) + * E[n] = C[n-1] + * X = decrypt(E[n], K) + * P[n] = (X ^ C[n]){0..len-1} + * E[n-1] = {C[n,0],...,C[n,len-1],X[len],...,X[blocksize-1]} + * (P[0],...,P[n-1]) = CBCdecrypt(C[0],...,C[n-2],E[n-1], IV, K) + */ + plen = len % blocklen; + if (len == blocklen) { + /* + * Note: caller will ensure len >= blocklen. + */ + aes_encrypt_1(ks, CRYPTO_F_IMBUF, inout, skip, len, ivec, 0); + } else if (plen == 0) { + /* + * This is equivalent to CBC mode followed by swapping + * the last two blocks. + */ + off = skip + len - 2 * blocklen; + m_copydata(inout, off, 2 * blocklen, (void*) &last2); + m_copyback(inout, off, blocklen, last2.cn); + m_copyback(inout, off + blocklen, blocklen, last2.cn_1); + aes_encrypt_1(ks, CRYPTO_F_IMBUF, inout, skip, len, ivec, 0); + } else { + /* + * This is the difficult case. We first decrypt the + * second to last block with a zero IV to make X. The + * plaintext for the last block is the XOR of X and + * the last cyphertext block. + * + * We derive a new cypher text for the second to last + * block by mixing the unused bytes of X with the last + * cyphertext block. The result of that can be + * decrypted with the rest in CBC mode. + */ + off = skip + len - plen - blocklen; + aes_encrypt_1(ks, CRYPTO_F_IMBUF, inout, off, blocklen, + NULL, 0); + m_copydata(inout, off, blocklen + plen, (void*) &last2); + + for (i = 0; i < plen; i++) { + t = last2.cn[i]; + last2.cn[i] ^= last2.cn_1[i]; + last2.cn_1[i] = t; + } + + m_copyback(inout, off, blocklen + plen, (void*) &last2); + aes_encrypt_1(ks, CRYPTO_F_IMBUF, inout, skip, len - plen, + ivec, 0); + } + +} + +static void +aes_checksum(const struct krb5_key_state *ks, int usage, + struct mbuf *inout, size_t skip, size_t inlen, size_t outlen) +{ + struct aes_state *as = ks->ks_priv; + struct cryptop *crp; + struct cryptodesc *crd; + int error; + + crp = crypto_getreq(1); + crd = crp->crp_desc; + + crd->crd_skip = skip; + crd->crd_len = inlen; + crd->crd_inject = skip + inlen; + crd->crd_flags = 0; + crd->crd_next = NULL; + crd->crd_alg = CRYPTO_SHA1_HMAC; + + crp->crp_sid = as->as_session; + crp->crp_ilen = inlen; + crp->crp_olen = 12; + crp->crp_etype = 0; + crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; + crp->crp_buf = (void *) inout; + crp->crp_opaque = (void *) as; + crp->crp_callback = aes_crypto_cb; + + error = crypto_dispatch(crp); + + if ((CRYPTO_SESID2CAPS(as->as_session) & CRYPTOCAP_F_SYNC) == 0) { + mtx_lock(&as->as_lock); + if (!error && !(crp->crp_flags & CRYPTO_F_DONE)) + error = msleep(crp, &as->as_lock, 0, "gssaes", 0); + mtx_unlock(&as->as_lock); + } + + crypto_freereq(crp); +} + +struct krb5_encryption_class krb5_aes128_encryption_class = { + "aes128-cts-hmac-sha1-96", /* name */ + ETYPE_AES128_CTS_HMAC_SHA1_96, /* etype */ + EC_DERIVED_KEYS, /* flags */ + 16, /* blocklen */ + 1, /* msgblocklen */ + 12, /* checksumlen */ + 128, /* keybits */ + 16, /* keylen */ + aes_init, + aes_destroy, + aes_set_key, + aes_random_to_key, + aes_encrypt, + aes_decrypt, + aes_checksum +}; + +struct krb5_encryption_class krb5_aes256_encryption_class = { + "aes256-cts-hmac-sha1-96", /* name */ + ETYPE_AES256_CTS_HMAC_SHA1_96, /* etype */ + EC_DERIVED_KEYS, /* flags */ + 16, /* blocklen */ + 1, /* msgblocklen */ + 12, /* checksumlen */ + 256, /* keybits */ + 32, /* keylen */ + aes_init, + aes_destroy, + aes_set_key, + aes_random_to_key, + aes_encrypt, + aes_decrypt, + aes_checksum +}; |
