return crypto_hash_update(desc, sg, sg->length);
}
+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;
+ 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
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);
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;
+}
+
git.openpandora.org / pandora-kernel.git / blobdiff