diff options
Diffstat (limited to 'net/sunrpc/auth_gss/gss_krb5_unseal.c')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_krb5_unseal.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/gss_krb5_unseal.c b/net/sunrpc/auth_gss/gss_krb5_unseal.c new file mode 100644 index 00000000000..8767fc53183 --- /dev/null +++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c @@ -0,0 +1,202 @@ +/* + * linux/net/sunrpc/gss_krb5_unseal.c + * + * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c + * + * Copyright (c) 2000 The Regents of the University of Michigan. + * All rights reserved. + * + * Andy Adamson <andros@umich.edu> + */ + +/* + * Copyright 1993 by OpenVision Technologies, Inc. + * + * Permission to use, copy, modify, distribute, and sell this software + * and its documentation for any purpose is hereby granted without fee, + * provided that the above copyright notice appears in all copies and + * that both that copyright notice and this permission notice appear in + * supporting documentation, and that the name of OpenVision not be used + * in advertising or publicity pertaining to distribution of the software + * without specific, written prior permission. OpenVision makes no + * representations about the suitability of this software for any + * purpose. It is provided "as is" without express or implied warranty. + * + * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO + * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF + * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR + * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +/* + * Copyright (C) 1998 by the FundsXpress, INC. + * + * All rights reserved. + * + * Export of this software from the United States of America may require + * a specific license from the United States Government. It is the + * responsibility of any person or organization contemplating export to + * obtain such a license before exporting. + * + * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and + * distribute this software and its documentation for any purpose and + * without fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright notice and + * this permission notice appear in supporting documentation, and that + * the name of FundsXpress. not be used in advertising or publicity pertaining + * to distribution of the software without specific, written prior + * permission. FundsXpress makes no representations about the suitability of + * this software for any purpose. It is provided "as is" without express + * or implied warranty. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/jiffies.h> +#include <linux/sunrpc/gss_krb5.h> +#include <linux/crypto.h> + +#ifdef RPC_DEBUG +# define RPCDBG_FACILITY RPCDBG_AUTH +#endif + + +/* message_buffer is an input if toktype is MIC and an output if it is WRAP: + * If toktype is MIC: read_token is a mic token, and message_buffer is the + * data that the mic was supposedly taken over. + * If toktype is WRAP: read_token is a wrap token, and message_buffer is used + * to return the decrypted data. + */ + +/* XXX will need to change prototype and/or just split into a separate function + * when we add privacy (because read_token will be in pages too). */ +u32 +krb5_read_token(struct krb5_ctx *ctx, + struct xdr_netobj *read_token, + struct xdr_buf *message_buffer, + int *qop_state, int toktype) +{ + int signalg; + int sealalg; + s32 checksum_type; + struct xdr_netobj md5cksum = {.len = 0, .data = NULL}; + s32 now; + int direction; + s32 seqnum; + unsigned char *ptr = (unsigned char *)read_token->data; + int bodysize; + u32 ret = GSS_S_DEFECTIVE_TOKEN; + + dprintk("RPC: krb5_read_token\n"); + + if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr, + read_token->len)) + goto out; + + if ((*ptr++ != ((toktype>>8)&0xff)) || (*ptr++ != (toktype&0xff))) + goto out; + + /* XXX sanity-check bodysize?? */ + + if (toktype == KG_TOK_WRAP_MSG) { + /* XXX gone */ + goto out; + } + + /* get the sign and seal algorithms */ + + signalg = ptr[0] + (ptr[1] << 8); + sealalg = ptr[2] + (ptr[3] << 8); + + /* Sanity checks */ + + if ((ptr[4] != 0xff) || (ptr[5] != 0xff)) + goto out; + + if (((toktype != KG_TOK_WRAP_MSG) && (sealalg != 0xffff)) || + ((toktype == KG_TOK_WRAP_MSG) && (sealalg == 0xffff))) + goto out; + + /* in the current spec, there is only one valid seal algorithm per + key type, so a simple comparison is ok */ + + if ((toktype == KG_TOK_WRAP_MSG) && !(sealalg == ctx->sealalg)) + goto out; + + /* there are several mappings of seal algorithms to sign algorithms, + but few enough that we can try them all. */ + + if ((ctx->sealalg == SEAL_ALG_NONE && signalg > 1) || + (ctx->sealalg == SEAL_ALG_1 && signalg != SGN_ALG_3) || + (ctx->sealalg == SEAL_ALG_DES3KD && + signalg != SGN_ALG_HMAC_SHA1_DES3_KD)) + goto out; + + /* compute the checksum of the message */ + + /* initialize the the cksum */ + switch (signalg) { + case SGN_ALG_DES_MAC_MD5: + checksum_type = CKSUMTYPE_RSA_MD5; + break; + default: + ret = GSS_S_DEFECTIVE_TOKEN; + goto out; + } + + switch (signalg) { + case SGN_ALG_DES_MAC_MD5: + ret = make_checksum(checksum_type, ptr - 2, 8, + message_buffer, &md5cksum); + if (ret) + goto out; + + ret = krb5_encrypt(ctx->seq, NULL, md5cksum.data, + md5cksum.data, 16); + if (ret) + goto out; + + if (memcmp(md5cksum.data + 8, ptr + 14, 8)) { + ret = GSS_S_BAD_SIG; + goto out; + } + break; + default: + ret = GSS_S_DEFECTIVE_TOKEN; + goto out; + } + + /* it got through unscathed. Make sure the context is unexpired */ + + if (qop_state) + *qop_state = GSS_C_QOP_DEFAULT; + + now = get_seconds(); + + ret = GSS_S_CONTEXT_EXPIRED; + if (now > ctx->endtime) + goto out; + + /* do sequencing checks */ + + ret = GSS_S_BAD_SIG; + if ((ret = krb5_get_seq_num(ctx->seq, ptr + 14, ptr + 6, &direction, + &seqnum))) + goto out; + + if ((ctx->initiate && direction != 0xff) || + (!ctx->initiate && direction != 0)) + goto out; + + ret = GSS_S_COMPLETE; +out: + if (md5cksum.data) kfree(md5cksum.data); + return ret; +} |