/* Maximum blocksize for the supported crypto algorithms */
#define GSS_KRB5_MAX_BLOCKSIZE (16)
+struct krb5_ctx;
+
struct gss_krb5_enctype {
const u32 etype; /* encryption (key) type */
const u32 ctype; /* checksum type */
u32 (*mk_key) (const struct gss_krb5_enctype *gk5e,
struct xdr_netobj *in,
struct xdr_netobj *out); /* complete key generation */
+ u32 (*encrypt_v2) (struct krb5_ctx *kctx, u32 offset,
+ struct xdr_buf *buf, int ec,
+ struct page **pages); /* v2 encryption function */
+ u32 (*decrypt_v2) (struct krb5_ctx *kctx, u32 offset,
+ struct xdr_buf *buf, u32 *headskip,
+ u32 *tailskip); /* v2 decryption function */
};
/* krb5_ctx flags definitions */
#define KG_TOK_MIC_MSG 0x0101
#define KG_TOK_WRAP_MSG 0x0201
+#define KG2_TOK_INITIAL 0x0101
+#define KG2_TOK_RESPONSE 0x0202
+#define KG2_TOK_MIC 0x0404
+#define KG2_TOK_WRAP 0x0504
+
+#define KG2_TOKEN_FLAG_SENTBYACCEPTOR 0x01
+#define KG2_TOKEN_FLAG_SEALED 0x02
+#define KG2_TOKEN_FLAG_ACCEPTORSUBKEY 0x04
+
+#define KG2_RESP_FLAG_ERROR 0x0001
+#define KG2_RESP_FLAG_DELEG_OK 0x0002
+
enum sgn_alg {
SGN_ALG_DES_MAC_MD5 = 0x0000,
SGN_ALG_MD2_5 = 0x0001,
#define CKSUMTYPE_RSA_MD5_DES 0x0008
#define CKSUMTYPE_NIST_SHA 0x0009
#define CKSUMTYPE_HMAC_SHA1_DES3 0x000c
+#define CKSUMTYPE_HMAC_SHA1_96_AES128 0x000f
+#define CKSUMTYPE_HMAC_SHA1_96_AES256 0x0010
+#define CKSUMTYPE_HMAC_MD5_ARCFOUR -138 /* Microsoft md5 hmac cksumtype */
/* from gssapi_err_krb5.h */
#define KG_CCACHE_NOMATCH (39756032L)
struct xdr_buf *body, int body_offset, u8 *cksumkey,
struct xdr_netobj *cksumout);
+u32
+make_checksum_v2(struct krb5_ctx *, char *header, int hdrlen,
+ struct xdr_buf *body, int body_offset, u8 *key,
+ struct xdr_netobj *cksum);
+
u32 gss_get_mic_kerberos(struct gss_ctx *, struct xdr_buf *,
struct xdr_netobj *);
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,
+ 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[GSS_KRB5_MAX_BLOCKSIZE];
struct blkcipher_desc desc;
return (char *)krb5_hdr;
}
+static void *
+setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token)
+{
+ __be16 *ptr, *krb5_hdr;
+ u8 *p, flags = 0x00;
+
+ if ((ctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
+ flags |= 0x01;
+ if (ctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY)
+ flags |= 0x04;
+
+ /* Per rfc 4121, sec 4.2.6.1, there is no header,
+ * just start the token */
+ krb5_hdr = ptr = (__be16 *)token->data;
+
+ *ptr++ = KG2_TOK_MIC;
+ p = (u8 *)ptr;
+ *p++ = flags;
+ *p++ = 0xff;
+ ptr = (__be16 *)p;
+ *ptr++ = 0xffff;
+ *ptr++ = 0xffff;
+
+ token->len = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength;
+ return krb5_hdr;
+}
+
static u32
gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
struct xdr_netobj *token)
}
u32
+gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
+ struct xdr_netobj *token)
+{
+ char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ struct xdr_netobj cksumobj = { .len = sizeof(cksumdata),
+ .data = cksumdata};
+ void *krb5_hdr;
+ s32 now;
+ u64 seq_send;
+ u8 *cksumkey;
+
+ dprintk("RPC: %s\n", __func__);
+
+ krb5_hdr = setup_token_v2(ctx, token);
+
+ /* Set up the sequence number. Now 64-bits in clear
+ * text and w/o direction indicator */
+ spin_lock(&krb5_seq_lock);
+ seq_send = ctx->seq_send64++;
+ spin_unlock(&krb5_seq_lock);
+ *((u64 *)(krb5_hdr + 8)) = cpu_to_be64(seq_send);
+
+ if (ctx->initiate)
+ cksumkey = ctx->initiator_sign;
+ else
+ cksumkey = ctx->acceptor_sign;
+
+ if (make_checksum_v2(ctx, krb5_hdr, GSS_KRB5_TOK_HDR_LEN,
+ text, 0, cksumkey, &cksumobj))
+ return GSS_S_FAILURE;
+
+ memcpy(krb5_hdr + GSS_KRB5_TOK_HDR_LEN, cksumobj.data, cksumobj.len);
+
+ now = get_seconds();
+
+ return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
+}
+
+u32
gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
struct xdr_netobj *token)
{
case ENCTYPE_DES_CBC_RAW:
case ENCTYPE_DES3_CBC_RAW:
return gss_get_mic_v1(ctx, text, token);
+ case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+ case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+ return gss_get_mic_v2(ctx, text, token);
}
}
return GSS_S_COMPLETE;
}
+static u32
+gss_verify_mic_v2(struct krb5_ctx *ctx,
+ struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
+{
+ char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ struct xdr_netobj cksumobj = {.len = sizeof(cksumdata),
+ .data = cksumdata};
+ s32 now;
+ u64 seqnum;
+ u8 *ptr = read_token->data;
+ u8 *cksumkey;
+ u8 flags;
+ int i;
+
+ dprintk("RPC: %s\n", __func__);
+
+ if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_MIC)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ flags = ptr[2];
+ if ((!ctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
+ (ctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
+ return GSS_S_BAD_SIG;
+
+ if (flags & KG2_TOKEN_FLAG_SEALED) {
+ dprintk("%s: token has unexpected sealed flag\n", __func__);
+ return GSS_S_FAILURE;
+ }
+
+ for (i = 3; i < 8; i++)
+ if (ptr[i] != 0xff)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ if (ctx->initiate)
+ cksumkey = ctx->acceptor_sign;
+ else
+ cksumkey = ctx->initiator_sign;
+
+ if (make_checksum_v2(ctx, ptr, GSS_KRB5_TOK_HDR_LEN, message_buffer, 0,
+ cksumkey, &cksumobj))
+ return GSS_S_FAILURE;
+
+ if (memcmp(cksumobj.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+ ctx->gk5e->cksumlength))
+ return GSS_S_BAD_SIG;
+
+ /* it got through unscathed. Make sure the context is unexpired */
+ now = get_seconds();
+ if (now > ctx->endtime)
+ return GSS_S_CONTEXT_EXPIRED;
+
+ /* do sequencing checks */
+
+ seqnum = be64_to_cpup((__be64 *)ptr + 8);
+
+ return GSS_S_COMPLETE;
+}
+
u32
gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
struct xdr_buf *message_buffer,
case ENCTYPE_DES_CBC_RAW:
case ENCTYPE_DES3_CBC_RAW:
return gss_verify_mic_v1(ctx, message_buffer, read_token);
+ case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+ case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+ return gss_verify_mic_v2(ctx, message_buffer, read_token);
}
}
return GSS_S_COMPLETE;
}
+/*
+ * We cannot currently handle tokens with rotated data. We need a
+ * generalized routine to rotate the data in place. It is anticipated
+ * that we won't encounter rotated data in the general case.
+ */
+static u32
+rotate_left(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf, u16 rrc)
+{
+ unsigned int realrrc = rrc % (buf->len - offset - GSS_KRB5_TOK_HDR_LEN);
+
+ if (realrrc == 0)
+ return 0;
+
+ dprintk("%s: cannot process token with rotated data: "
+ "rrc %u, realrrc %u\n", __func__, rrc, realrrc);
+ return 1;
+}
+
+static u32
+gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
+ struct xdr_buf *buf, struct page **pages)
+{
+ int blocksize;
+ u8 *ptr, *plainhdr;
+ s32 now;
+ u8 flags = 0x00;
+ __be16 *be16ptr, ec = 0;
+ __be64 *be64ptr;
+ u32 err;
+
+ dprintk("RPC: %s\n", __func__);
+
+ if (kctx->gk5e->encrypt_v2 == NULL)
+ return GSS_S_FAILURE;
+
+ /* make room for gss token header */
+ if (xdr_extend_head(buf, offset, GSS_KRB5_TOK_HDR_LEN))
+ return GSS_S_FAILURE;
+
+ /* construct gss token header */
+ ptr = plainhdr = buf->head[0].iov_base + offset;
+ *ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff);
+ *ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff);
+
+ if ((kctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
+ flags |= KG2_TOKEN_FLAG_SENTBYACCEPTOR;
+ if ((kctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) != 0)
+ flags |= KG2_TOKEN_FLAG_ACCEPTORSUBKEY;
+ /* We always do confidentiality in wrap tokens */
+ flags |= KG2_TOKEN_FLAG_SEALED;
+
+ *ptr++ = flags;
+ *ptr++ = 0xff;
+ be16ptr = (__be16 *)ptr;
+
+ blocksize = crypto_blkcipher_blocksize(kctx->acceptor_enc);
+ *be16ptr++ = cpu_to_be16(ec);
+ /* "inner" token header always uses 0 for RRC */
+ *be16ptr++ = cpu_to_be16(0);
+
+ be64ptr = (__be64 *)be16ptr;
+ spin_lock(&krb5_seq_lock);
+ *be64ptr = cpu_to_be64(kctx->seq_send64++);
+ spin_unlock(&krb5_seq_lock);
+
+ err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, ec, pages);
+ if (err)
+ return err;
+
+ now = get_seconds();
+ return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
+}
+
+static u32
+gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
+{
+ s32 now;
+ u64 seqnum;
+ u8 *ptr;
+ u8 flags = 0x00;
+ u16 ec, rrc;
+ int err;
+ u32 headskip, tailskip;
+ u8 decrypted_hdr[GSS_KRB5_TOK_HDR_LEN];
+ unsigned int movelen;
+
+
+ dprintk("RPC: %s\n", __func__);
+
+ if (kctx->gk5e->decrypt_v2 == NULL)
+ return GSS_S_FAILURE;
+
+ ptr = buf->head[0].iov_base + offset;
+
+ if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_WRAP)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ flags = ptr[2];
+ if ((!kctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
+ (kctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
+ return GSS_S_BAD_SIG;
+
+ if ((flags & KG2_TOKEN_FLAG_SEALED) == 0) {
+ dprintk("%s: token missing expected sealed flag\n", __func__);
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ if (ptr[3] != 0xff)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ ec = be16_to_cpup((__be16 *)(ptr + 4));
+ rrc = be16_to_cpup((__be16 *)(ptr + 6));
+
+ seqnum = be64_to_cpup((__be64 *)(ptr + 8));
+
+ if (rrc != 0) {
+ err = rotate_left(kctx, offset, buf, rrc);
+ if (err)
+ return GSS_S_FAILURE;
+ }
+
+ err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf,
+ &headskip, &tailskip);
+ if (err)
+ return GSS_S_FAILURE;
+
+ /*
+ * Retrieve the decrypted gss token header and verify
+ * it against the original
+ */
+ err = read_bytes_from_xdr_buf(buf,
+ buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip,
+ decrypted_hdr, GSS_KRB5_TOK_HDR_LEN);
+ if (err) {
+ dprintk("%s: error %u getting decrypted_hdr\n", __func__, err);
+ return GSS_S_FAILURE;
+ }
+ if (memcmp(ptr, decrypted_hdr, 6)
+ || memcmp(ptr + 8, decrypted_hdr + 8, 8)) {
+ dprintk("%s: token hdr, plaintext hdr mismatch!\n", __func__);
+ return GSS_S_FAILURE;
+ }
+
+ /* do sequencing checks */
+
+ /* it got through unscathed. Make sure the context is unexpired */
+ now = get_seconds();
+ if (now > kctx->endtime)
+ return GSS_S_CONTEXT_EXPIRED;
+
+ /*
+ * Move the head data back to the right position in xdr_buf.
+ * We ignore any "ec" data since it might be in the head or
+ * the tail, and we really don't need to deal with it.
+ * Note that buf->head[0].iov_len may indicate the available
+ * head buffer space rather than that actually occupied.
+ */
+ movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len);
+ movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip;
+ BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen >
+ buf->head[0].iov_len);
+ memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen);
+ buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+ buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+
+ return GSS_S_COMPLETE;
+}
+
u32
gss_wrap_kerberos(struct gss_ctx *gctx, int offset,
struct xdr_buf *buf, struct page **pages)
case ENCTYPE_DES_CBC_RAW:
case ENCTYPE_DES3_CBC_RAW:
return gss_wrap_kerberos_v1(kctx, offset, buf, pages);
+ case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+ case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+ return gss_wrap_kerberos_v2(kctx, offset, buf, pages);
}
}
case ENCTYPE_DES_CBC_RAW:
case ENCTYPE_DES3_CBC_RAW:
return gss_unwrap_kerberos_v1(kctx, offset, buf);
+ case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+ case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+ return gss_unwrap_kerberos_v2(kctx, offset, buf);
}
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff