/*
* linux/net/sunrpc/gss_krb5_crypto.c
*
- * Copyright (c) 2000 The Regents of the University of Michigan.
+ * Copyright (c) 2000-2008 The Regents of the University of Michigan.
* All rights reserved.
*
* Andy Adamson <andros@umich.edu>
#include <linux/crypto.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
+#include <linux/random.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/sunrpc/xdr.h>
{
u32 ret = -EINVAL;
struct scatterlist sg[1];
- u8 local_iv[16] = {0};
+ u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };
if (length % crypto_blkcipher_blocksize(tfm) != 0)
goto out;
- if (crypto_blkcipher_ivsize(tfm) > 16) {
+ if (crypto_blkcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
dprintk("RPC: gss_k5encrypt: tfm iv size too large %d\n",
crypto_blkcipher_ivsize(tfm));
goto out;
{
u32 ret = -EINVAL;
struct scatterlist sg[1];
- u8 local_iv[16] = {0};
+ u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };
if (length % crypto_blkcipher_blocksize(tfm) != 0)
goto out;
- if (crypto_blkcipher_ivsize(tfm) > 16) {
+ if (crypto_blkcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
dprintk("RPC: gss_k5decrypt: tfm iv size too large %d\n",
crypto_blkcipher_ivsize(tfm));
goto out;
return crypto_hash_update(desc, sg, sg->length);
}
-/* checksum the plaintext data and hdrlen bytes of the token header */
-s32
-make_checksum(char *cksumname, char *header, int hdrlen, struct xdr_buf *body,
- int body_offset, struct xdr_netobj *cksum)
+static int
+arcfour_hmac_md5_usage_to_salt(unsigned int usage, u8 salt[4])
+{
+ unsigned int ms_usage;
+
+ switch (usage) {
+ case KG_USAGE_SIGN:
+ ms_usage = 15;
+ break;
+ case KG_USAGE_SEAL:
+ ms_usage = 13;
+ break;
+ default:
+ return EINVAL;;
+ }
+ salt[0] = (ms_usage >> 0) & 0xff;
+ salt[1] = (ms_usage >> 8) & 0xff;
+ salt[2] = (ms_usage >> 16) & 0xff;
+ salt[3] = (ms_usage >> 24) & 0xff;
+
+ return 0;
+}
+
+static u32
+make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen,
+ struct xdr_buf *body, int body_offset, u8 *cksumkey,
+ unsigned int usage, struct xdr_netobj *cksumout)
{
- struct hash_desc desc; /* XXX add to ctx? */
+ struct hash_desc desc;
struct scatterlist sg[1];
int err;
+ u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ u8 rc4salt[4];
+ struct crypto_hash *md5;
+ struct crypto_hash *hmac_md5;
+
+ if (cksumkey == NULL)
+ return GSS_S_FAILURE;
+
+ if (cksumout->len < kctx->gk5e->cksumlength) {
+ dprintk("%s: checksum buffer length, %u, too small for %s\n",
+ __func__, cksumout->len, kctx->gk5e->name);
+ return GSS_S_FAILURE;
+ }
+
+ if (arcfour_hmac_md5_usage_to_salt(usage, rc4salt)) {
+ dprintk("%s: invalid usage value %u\n", __func__, usage);
+ return GSS_S_FAILURE;
+ }
+
+ md5 = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(md5))
+ return GSS_S_FAILURE;
+
+ hmac_md5 = crypto_alloc_hash(kctx->gk5e->cksum_name, 0,
+ CRYPTO_ALG_ASYNC);
+ if (IS_ERR(hmac_md5)) {
+ crypto_free_hash(md5);
+ return GSS_S_FAILURE;
+ }
+
+ desc.tfm = md5;
+ desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ err = crypto_hash_init(&desc);
+ if (err)
+ goto out;
+ sg_init_one(sg, rc4salt, 4);
+ err = crypto_hash_update(&desc, sg, 4);
+ if (err)
+ goto out;
+
+ sg_init_one(sg, header, hdrlen);
+ err = crypto_hash_update(&desc, sg, hdrlen);
+ if (err)
+ goto out;
+ err = xdr_process_buf(body, body_offset, body->len - body_offset,
+ checksummer, &desc);
+ if (err)
+ goto out;
+ err = crypto_hash_final(&desc, checksumdata);
+ if (err)
+ goto out;
+
+ desc.tfm = hmac_md5;
+ desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ err = crypto_hash_init(&desc);
+ if (err)
+ goto out;
+ err = crypto_hash_setkey(hmac_md5, cksumkey, kctx->gk5e->keylength);
+ if (err)
+ goto out;
+
+ sg_init_one(sg, checksumdata, crypto_hash_digestsize(md5));
+ err = crypto_hash_digest(&desc, sg, crypto_hash_digestsize(md5),
+ checksumdata);
+ if (err)
+ goto out;
+
+ memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
+ cksumout->len = kctx->gk5e->cksumlength;
+out:
+ crypto_free_hash(md5);
+ crypto_free_hash(hmac_md5);
+ return err ? GSS_S_FAILURE : 0;
+}
+
+/*
+ * checksum the plaintext data and hdrlen bytes of the token header
+ * The checksum is performed over the first 8 bytes of the
+ * gss token header and then over the data body
+ */
+u32
+make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
+ struct xdr_buf *body, int body_offset, u8 *cksumkey,
+ unsigned int usage, struct xdr_netobj *cksumout)
+{
+ struct hash_desc desc;
+ struct scatterlist sg[1];
+ int err;
+ u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ unsigned int checksumlen;
+
+ if (kctx->gk5e->ctype == CKSUMTYPE_HMAC_MD5_ARCFOUR)
+ return make_checksum_hmac_md5(kctx, header, hdrlen,
+ body, body_offset,
+ cksumkey, usage, cksumout);
+
+ if (cksumout->len < kctx->gk5e->cksumlength) {
+ dprintk("%s: checksum buffer length, %u, too small for %s\n",
+ __func__, cksumout->len, kctx->gk5e->name);
+ return GSS_S_FAILURE;
+ }
- desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC);
+ desc.tfm = crypto_alloc_hash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(desc.tfm))
return GSS_S_FAILURE;
- cksum->len = crypto_hash_digestsize(desc.tfm);
desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+ checksumlen = crypto_hash_digestsize(desc.tfm);
+
+ if (cksumkey != NULL) {
+ err = crypto_hash_setkey(desc.tfm, cksumkey,
+ kctx->gk5e->keylength);
+ if (err)
+ goto out;
+ }
+
err = crypto_hash_init(&desc);
if (err)
goto out;
checksummer, &desc);
if (err)
goto out;
- err = crypto_hash_final(&desc, cksum->data);
+ err = crypto_hash_final(&desc, checksumdata);
+ if (err)
+ goto out;
+ switch (kctx->gk5e->ctype) {
+ case CKSUMTYPE_RSA_MD5:
+ err = kctx->gk5e->encrypt(kctx->seq, NULL, checksumdata,
+ checksumdata, checksumlen);
+ if (err)
+ goto out;
+ memcpy(cksumout->data,
+ checksumdata + checksumlen - kctx->gk5e->cksumlength,
+ kctx->gk5e->cksumlength);
+ break;
+ case CKSUMTYPE_HMAC_SHA1_DES3:
+ memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
+ break;
+ default:
+ BUG();
+ break;
+ }
+ cksumout->len = kctx->gk5e->cksumlength;
+out:
+ crypto_free_hash(desc.tfm);
+ return err ? GSS_S_FAILURE : 0;
+}
+
+/*
+ * checksum the plaintext data and hdrlen bytes of the token header
+ * Per rfc4121, sec. 4.2.4, the checksum is performed over the data
+ * body then over the first 16 octets of the MIC token
+ * Inclusion of the header data in the calculation of the
+ * checksum is optional.
+ */
+u32
+make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen,
+ struct xdr_buf *body, int body_offset, u8 *cksumkey,
+ unsigned int usage, struct xdr_netobj *cksumout)
+{
+ struct hash_desc desc;
+ struct scatterlist sg[1];
+ int err;
+ u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ unsigned int checksumlen;
+
+ if (kctx->gk5e->keyed_cksum == 0) {
+ dprintk("%s: expected keyed hash for %s\n",
+ __func__, kctx->gk5e->name);
+ return GSS_S_FAILURE;
+ }
+ if (cksumkey == NULL) {
+ dprintk("%s: no key supplied for %s\n",
+ __func__, kctx->gk5e->name);
+ return GSS_S_FAILURE;
+ }
+
+ desc.tfm = crypto_alloc_hash(kctx->gk5e->cksum_name, 0,
+ CRYPTO_ALG_ASYNC);
+ if (IS_ERR(desc.tfm))
+ return GSS_S_FAILURE;
+ checksumlen = crypto_hash_digestsize(desc.tfm);
+ desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ err = crypto_hash_setkey(desc.tfm, cksumkey, kctx->gk5e->keylength);
+ if (err)
+ goto out;
+
+ err = crypto_hash_init(&desc);
+ if (err)
+ goto out;
+ err = xdr_process_buf(body, body_offset, body->len - body_offset,
+ checksummer, &desc);
+ if (err)
+ goto out;
+ if (header != NULL) {
+ sg_init_one(sg, header, hdrlen);
+ err = crypto_hash_update(&desc, sg, hdrlen);
+ if (err)
+ goto out;
+ }
+ err = crypto_hash_final(&desc, checksumdata);
+ if (err)
+ goto out;
+
+ cksumout->len = kctx->gk5e->cksumlength;
+
+ switch (kctx->gk5e->ctype) {
+ case CKSUMTYPE_HMAC_SHA1_96_AES128:
+ case CKSUMTYPE_HMAC_SHA1_96_AES256:
+ /* note that this truncates the hash */
+ memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
+ break;
+ default:
+ BUG();
+ break;
+ }
out:
crypto_free_hash(desc.tfm);
return err ? GSS_S_FAILURE : 0;
}
struct encryptor_desc {
- u8 iv[8]; /* XXX hard-coded blocksize */
+ u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
struct blkcipher_desc desc;
int pos;
struct xdr_buf *outbuf;
desc->fraglen += sg->length;
desc->pos += sg->length;
- fraglen = thislen & 7; /* XXX hardcoded blocksize */
+ fraglen = thislen & (crypto_blkcipher_blocksize(desc->desc.tfm) - 1);
thislen -= fraglen;
if (thislen == 0)
}
struct decryptor_desc {
- u8 iv[8]; /* XXX hard-coded blocksize */
+ u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
struct blkcipher_desc desc;
struct scatterlist frags[4];
int fragno;
desc->fragno++;
desc->fraglen += sg->length;
- fraglen = thislen & 7; /* XXX hardcoded blocksize */
+ fraglen = thislen & (crypto_blkcipher_blocksize(desc->desc.tfm) - 1);
thislen -= fraglen;
if (thislen == 0)
return xdr_process_buf(buf, offset, buf->len - offset, decryptor, &desc);
}
+
+/*
+ * This function makes the assumption that it was ultimately called
+ * from gss_wrap().
+ *
+ * The client auth_gss code moves any existing tail data into a
+ * separate page before calling gss_wrap.
+ * The server svcauth_gss code ensures that both the head and the
+ * tail have slack space of RPC_MAX_AUTH_SIZE before calling gss_wrap.
+ *
+ * Even with that guarantee, this function may be called more than
+ * once in the processing of gss_wrap(). The best we can do is
+ * verify at compile-time (see GSS_KRB5_SLACK_CHECK) that the
+ * largest expected shift will fit within RPC_MAX_AUTH_SIZE.
+ * At run-time we can verify that a single invocation of this
+ * function doesn't attempt to use more the RPC_MAX_AUTH_SIZE.
+ */
+
+int
+xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen)
+{
+ u8 *p;
+
+ if (shiftlen == 0)
+ return 0;
+
+ BUILD_BUG_ON(GSS_KRB5_MAX_SLACK_NEEDED > RPC_MAX_AUTH_SIZE);
+ BUG_ON(shiftlen > RPC_MAX_AUTH_SIZE);
+
+ p = buf->head[0].iov_base + base;
+
+ memmove(p + shiftlen, p, buf->head[0].iov_len - base);
+
+ buf->head[0].iov_len += shiftlen;
+ buf->len += shiftlen;
+
+ return 0;
+}
+
+static u32
+gss_krb5_cts_crypt(struct crypto_blkcipher *cipher, struct xdr_buf *buf,
+ u32 offset, u8 *iv, struct page **pages, int encrypt)
+{
+ u32 ret;
+ struct scatterlist sg[1];
+ struct blkcipher_desc desc = { .tfm = cipher, .info = iv };
+ u8 data[crypto_blkcipher_blocksize(cipher) * 2];
+ struct page **save_pages;
+ u32 len = buf->len - offset;
+
+ BUG_ON(len > crypto_blkcipher_blocksize(cipher) * 2);
+
+ /*
+ * For encryption, we want to read from the cleartext
+ * page cache pages, and write the encrypted data to
+ * the supplied xdr_buf pages.
+ */
+ save_pages = buf->pages;
+ if (encrypt)
+ buf->pages = pages;
+
+ ret = read_bytes_from_xdr_buf(buf, offset, data, len);
+ buf->pages = save_pages;
+ if (ret)
+ goto out;
+
+ sg_init_one(sg, data, len);
+
+ if (encrypt)
+ ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, len);
+ else
+ ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, len);
+
+ if (ret)
+ goto out;
+
+ ret = write_bytes_to_xdr_buf(buf, offset, data, len);
+
+out:
+ return ret;
+}
+
+u32
+gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
+ struct xdr_buf *buf, int ec, struct page **pages)
+{
+ u32 err;
+ struct xdr_netobj hmac;
+ u8 *cksumkey;
+ u8 *ecptr;
+ struct crypto_blkcipher *cipher, *aux_cipher;
+ int blocksize;
+ struct page **save_pages;
+ int nblocks, nbytes;
+ struct encryptor_desc desc;
+ u32 cbcbytes;
+ unsigned int usage;
+
+ if (kctx->initiate) {
+ cipher = kctx->initiator_enc;
+ aux_cipher = kctx->initiator_enc_aux;
+ cksumkey = kctx->initiator_integ;
+ usage = KG_USAGE_INITIATOR_SEAL;
+ } else {
+ cipher = kctx->acceptor_enc;
+ aux_cipher = kctx->acceptor_enc_aux;
+ cksumkey = kctx->acceptor_integ;
+ usage = KG_USAGE_ACCEPTOR_SEAL;
+ }
+ blocksize = crypto_blkcipher_blocksize(cipher);
+
+ /* hide the gss token header and insert the confounder */
+ offset += GSS_KRB5_TOK_HDR_LEN;
+ if (xdr_extend_head(buf, offset, kctx->gk5e->conflen))
+ return GSS_S_FAILURE;
+ gss_krb5_make_confounder(buf->head[0].iov_base + offset, kctx->gk5e->conflen);
+ offset -= GSS_KRB5_TOK_HDR_LEN;
+
+ if (buf->tail[0].iov_base != NULL) {
+ ecptr = buf->tail[0].iov_base + buf->tail[0].iov_len;
+ } else {
+ buf->tail[0].iov_base = buf->head[0].iov_base
+ + buf->head[0].iov_len;
+ buf->tail[0].iov_len = 0;
+ ecptr = buf->tail[0].iov_base;
+ }
+
+ memset(ecptr, 'X', ec);
+ buf->tail[0].iov_len += ec;
+ buf->len += ec;
+
+ /* copy plaintext gss token header after filler (if any) */
+ memcpy(ecptr + ec, buf->head[0].iov_base + offset,
+ GSS_KRB5_TOK_HDR_LEN);
+ buf->tail[0].iov_len += GSS_KRB5_TOK_HDR_LEN;
+ buf->len += GSS_KRB5_TOK_HDR_LEN;
+
+ /* Do the HMAC */
+ hmac.len = GSS_KRB5_MAX_CKSUM_LEN;
+ hmac.data = buf->tail[0].iov_base + buf->tail[0].iov_len;
+
+ /*
+ * When we are called, pages points to the real page cache
+ * data -- which we can't go and encrypt! buf->pages points
+ * to scratch pages which we are going to send off to the
+ * client/server. Swap in the plaintext pages to calculate
+ * the hmac.
+ */
+ save_pages = buf->pages;
+ buf->pages = pages;
+
+ err = make_checksum_v2(kctx, NULL, 0, buf,
+ offset + GSS_KRB5_TOK_HDR_LEN,
+ cksumkey, usage, &hmac);
+ buf->pages = save_pages;
+ if (err)
+ return GSS_S_FAILURE;
+
+ nbytes = buf->len - offset - GSS_KRB5_TOK_HDR_LEN;
+ nblocks = (nbytes + blocksize - 1) / blocksize;
+ cbcbytes = 0;
+ if (nblocks > 2)
+ cbcbytes = (nblocks - 2) * blocksize;
+
+ memset(desc.iv, 0, sizeof(desc.iv));
+
+ if (cbcbytes) {
+ desc.pos = offset + GSS_KRB5_TOK_HDR_LEN;
+ desc.fragno = 0;
+ desc.fraglen = 0;
+ desc.pages = pages;
+ desc.outbuf = buf;
+ desc.desc.info = desc.iv;
+ desc.desc.flags = 0;
+ desc.desc.tfm = aux_cipher;
+
+ sg_init_table(desc.infrags, 4);
+ sg_init_table(desc.outfrags, 4);
+
+ err = xdr_process_buf(buf, offset + GSS_KRB5_TOK_HDR_LEN,
+ cbcbytes, encryptor, &desc);
+ if (err)
+ goto out_err;
+ }
+
+ /* Make sure IV carries forward from any CBC results. */
+ err = gss_krb5_cts_crypt(cipher, buf,
+ offset + GSS_KRB5_TOK_HDR_LEN + cbcbytes,
+ desc.iv, pages, 1);
+ if (err) {
+ err = GSS_S_FAILURE;
+ goto out_err;
+ }
+
+ /* Now update buf to account for HMAC */
+ buf->tail[0].iov_len += kctx->gk5e->cksumlength;
+ buf->len += kctx->gk5e->cksumlength;
+
+out_err:
+ if (err)
+ err = GSS_S_FAILURE;
+ return err;
+}
+
+u32
+gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
+ u32 *headskip, u32 *tailskip)
+{
+ struct xdr_buf subbuf;
+ u32 ret = 0;
+ u8 *cksum_key;
+ struct crypto_blkcipher *cipher, *aux_cipher;
+ struct xdr_netobj our_hmac_obj;
+ u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
+ u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
+ int nblocks, blocksize, cbcbytes;
+ struct decryptor_desc desc;
+ unsigned int usage;
+
+ if (kctx->initiate) {
+ cipher = kctx->acceptor_enc;
+ aux_cipher = kctx->acceptor_enc_aux;
+ cksum_key = kctx->acceptor_integ;
+ usage = KG_USAGE_ACCEPTOR_SEAL;
+ } else {
+ cipher = kctx->initiator_enc;
+ aux_cipher = kctx->initiator_enc_aux;
+ cksum_key = kctx->initiator_integ;
+ usage = KG_USAGE_INITIATOR_SEAL;
+ }
+ blocksize = crypto_blkcipher_blocksize(cipher);
+
+
+ /* create a segment skipping the header and leaving out the checksum */
+ xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
+ (buf->len - offset - GSS_KRB5_TOK_HDR_LEN -
+ kctx->gk5e->cksumlength));
+
+ nblocks = (subbuf.len + blocksize - 1) / blocksize;
+
+ cbcbytes = 0;
+ if (nblocks > 2)
+ cbcbytes = (nblocks - 2) * blocksize;
+
+ memset(desc.iv, 0, sizeof(desc.iv));
+
+ if (cbcbytes) {
+ desc.fragno = 0;
+ desc.fraglen = 0;
+ desc.desc.info = desc.iv;
+ desc.desc.flags = 0;
+ desc.desc.tfm = aux_cipher;
+
+ sg_init_table(desc.frags, 4);
+
+ ret = xdr_process_buf(&subbuf, 0, cbcbytes, decryptor, &desc);
+ if (ret)
+ goto out_err;
+ }
+
+ /* Make sure IV carries forward from any CBC results. */
+ ret = gss_krb5_cts_crypt(cipher, &subbuf, cbcbytes, desc.iv, NULL, 0);
+ if (ret)
+ goto out_err;
+
+
+ /* Calculate our hmac over the plaintext data */
+ our_hmac_obj.len = sizeof(our_hmac);
+ our_hmac_obj.data = our_hmac;
+
+ ret = make_checksum_v2(kctx, NULL, 0, &subbuf, 0,
+ cksum_key, usage, &our_hmac_obj);
+ if (ret)
+ goto out_err;
+
+ /* Get the packet's hmac value */
+ ret = read_bytes_from_xdr_buf(buf, buf->len - kctx->gk5e->cksumlength,
+ pkt_hmac, kctx->gk5e->cksumlength);
+ if (ret)
+ goto out_err;
+
+ if (memcmp(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
+ ret = GSS_S_BAD_SIG;
+ goto out_err;
+ }
+ *headskip = kctx->gk5e->conflen;
+ *tailskip = kctx->gk5e->cksumlength;
+out_err:
+ if (ret && ret != GSS_S_BAD_SIG)
+ ret = GSS_S_FAILURE;
+ return ret;
+}
+
+/*
+ * Compute Kseq given the initial session key and the checksum.
+ * Set the key of the given cipher.
+ */
+int
+krb5_rc4_setup_seq_key(struct krb5_ctx *kctx, struct crypto_blkcipher *cipher,
+ unsigned char *cksum)
+{
+ struct crypto_hash *hmac;
+ struct hash_desc desc;
+ struct scatterlist sg[1];
+ u8 Kseq[GSS_KRB5_MAX_KEYLEN];
+ u32 zeroconstant = 0;
+ int err;
+
+ dprintk("%s: entered\n", __func__);
+
+ hmac = crypto_alloc_hash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(hmac)) {
+ dprintk("%s: error %ld, allocating hash '%s'\n",
+ __func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
+ return PTR_ERR(hmac);
+ }
+
+ desc.tfm = hmac;
+ desc.flags = 0;
+
+ err = crypto_hash_init(&desc);
+ if (err)
+ goto out_err;
+
+ /* Compute intermediate Kseq from session key */
+ err = crypto_hash_setkey(hmac, kctx->Ksess, kctx->gk5e->keylength);
+ if (err)
+ goto out_err;
+
+ sg_init_table(sg, 1);
+ sg_set_buf(sg, &zeroconstant, 4);
+
+ err = crypto_hash_digest(&desc, sg, 4, Kseq);
+ if (err)
+ goto out_err;
+
+ /* Compute final Kseq from the checksum and intermediate Kseq */
+ err = crypto_hash_setkey(hmac, Kseq, kctx->gk5e->keylength);
+ if (err)
+ goto out_err;
+
+ sg_set_buf(sg, cksum, 8);
+
+ err = crypto_hash_digest(&desc, sg, 8, Kseq);
+ if (err)
+ goto out_err;
+
+ err = crypto_blkcipher_setkey(cipher, Kseq, kctx->gk5e->keylength);
+ if (err)
+ goto out_err;
+
+ err = 0;
+
+out_err:
+ crypto_free_hash(hmac);
+ dprintk("%s: returning %d\n", __func__, err);
+ return err;
+}
+
+/*
+ * Compute Kcrypt given the initial session key and the plaintext seqnum.
+ * Set the key of cipher kctx->enc.
+ */
+int
+krb5_rc4_setup_enc_key(struct krb5_ctx *kctx, struct crypto_blkcipher *cipher,
+ s32 seqnum)
+{
+ struct crypto_hash *hmac;
+ struct hash_desc desc;
+ struct scatterlist sg[1];
+ u8 Kcrypt[GSS_KRB5_MAX_KEYLEN];
+ u8 zeroconstant[4] = {0};
+ u8 seqnumarray[4];
+ int err, i;
+
+ dprintk("%s: entered, seqnum %u\n", __func__, seqnum);
+
+ hmac = crypto_alloc_hash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(hmac)) {
+ dprintk("%s: error %ld, allocating hash '%s'\n",
+ __func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
+ return PTR_ERR(hmac);
+ }
+
+ desc.tfm = hmac;
+ desc.flags = 0;
+
+ err = crypto_hash_init(&desc);
+ if (err)
+ goto out_err;
+
+ /* Compute intermediate Kcrypt from session key */
+ for (i = 0; i < kctx->gk5e->keylength; i++)
+ Kcrypt[i] = kctx->Ksess[i] ^ 0xf0;
+
+ err = crypto_hash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
+ if (err)
+ goto out_err;
+
+ sg_init_table(sg, 1);
+ sg_set_buf(sg, zeroconstant, 4);
+
+ err = crypto_hash_digest(&desc, sg, 4, Kcrypt);
+ if (err)
+ goto out_err;
+
+ /* Compute final Kcrypt from the seqnum and intermediate Kcrypt */
+ err = crypto_hash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
+ if (err)
+ goto out_err;
+
+ seqnumarray[0] = (unsigned char) ((seqnum >> 24) & 0xff);
+ seqnumarray[1] = (unsigned char) ((seqnum >> 16) & 0xff);
+ seqnumarray[2] = (unsigned char) ((seqnum >> 8) & 0xff);
+ seqnumarray[3] = (unsigned char) ((seqnum >> 0) & 0xff);
+
+ sg_set_buf(sg, seqnumarray, 4);
+
+ err = crypto_hash_digest(&desc, sg, 4, Kcrypt);
+ if (err)
+ goto out_err;
+
+ err = crypto_blkcipher_setkey(cipher, Kcrypt, kctx->gk5e->keylength);
+ if (err)
+ goto out_err;
+
+ err = 0;
+
+out_err:
+ crypto_free_hash(hmac);
+ dprintk("%s: returning %d\n", __func__, err);
+ return err;
+}
+
projects / linux-flexiantxendom0-3.2.10.git / blobdiff