diff options
Diffstat (limited to 'net/sunrpc/auth_gss/gss_krb5_unseal.c')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_krb5_unseal.c | 126 |
1 files changed, 107 insertions, 19 deletions
diff --git a/net/sunrpc/auth_gss/gss_krb5_unseal.c b/net/sunrpc/auth_gss/gss_krb5_unseal.c index e30a993466b..6c981ddc19f 100644 --- a/net/sunrpc/auth_gss/gss_krb5_unseal.c +++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c @@ -3,7 +3,7 @@ * * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.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> @@ -58,7 +58,6 @@ */ #include <linux/types.h> -#include <linux/slab.h> #include <linux/jiffies.h> #include <linux/sunrpc/gss_krb5.h> #include <linux/crypto.h> @@ -71,20 +70,21 @@ /* read_token is a mic token, and message_buffer is the data that the mic was * supposedly taken over. */ -u32 -gss_verify_mic_kerberos(struct gss_ctx *gss_ctx, +static u32 +gss_verify_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *message_buffer, struct xdr_netobj *read_token) { - struct krb5_ctx *ctx = gss_ctx->internal_ctx_id; int signalg; int sealalg; - char cksumdata[16]; - struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata}; + char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; + struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), + .data = cksumdata}; s32 now; int direction; - s32 seqnum; + u32 seqnum; unsigned char *ptr = (unsigned char *)read_token->data; int bodysize; + u8 *cksumkey; dprintk("RPC: krb5_read_token\n"); @@ -92,30 +92,34 @@ gss_verify_mic_kerberos(struct gss_ctx *gss_ctx, read_token->len)) return GSS_S_DEFECTIVE_TOKEN; - if ((*ptr++ != ((KG_TOK_MIC_MSG>>8)&0xff)) || - (*ptr++ != ( KG_TOK_MIC_MSG &0xff)) ) + if ((ptr[0] != ((KG_TOK_MIC_MSG >> 8) & 0xff)) || + (ptr[1] != (KG_TOK_MIC_MSG & 0xff))) return GSS_S_DEFECTIVE_TOKEN; /* XXX sanity-check bodysize?? */ - signalg = ptr[0] + (ptr[1] << 8); - if (signalg != SGN_ALG_DES_MAC_MD5) + signalg = ptr[2] + (ptr[3] << 8); + if (signalg != ctx->gk5e->signalg) return GSS_S_DEFECTIVE_TOKEN; - sealalg = ptr[2] + (ptr[3] << 8); + sealalg = ptr[4] + (ptr[5] << 8); if (sealalg != SEAL_ALG_NONE) return GSS_S_DEFECTIVE_TOKEN; - if ((ptr[4] != 0xff) || (ptr[5] != 0xff)) + if ((ptr[6] != 0xff) || (ptr[7] != 0xff)) return GSS_S_DEFECTIVE_TOKEN; - if (make_checksum("md5", ptr - 2, 8, message_buffer, 0, &md5cksum)) - return GSS_S_FAILURE; + if (ctx->gk5e->keyed_cksum) + cksumkey = ctx->cksum; + else + cksumkey = NULL; - if (krb5_encrypt(ctx->seq, NULL, md5cksum.data, md5cksum.data, 16)) + if (make_checksum(ctx, ptr, 8, message_buffer, 0, + cksumkey, KG_USAGE_SIGN, &md5cksum)) return GSS_S_FAILURE; - if (memcmp(md5cksum.data + 8, ptr + 14, 8)) + if (memcmp(md5cksum.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 */ @@ -127,7 +131,8 @@ gss_verify_mic_kerberos(struct gss_ctx *gss_ctx, /* do sequencing checks */ - if (krb5_get_seq_num(ctx->seq, ptr + 14, ptr + 6, &direction, &seqnum)) + if (krb5_get_seq_num(ctx, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8, + &direction, &seqnum)) return GSS_S_FAILURE; if ((ctx->initiate && direction != 0xff) || @@ -136,3 +141,86 @@ gss_verify_mic_kerberos(struct gss_ctx *gss_ctx, 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; + u8 *ptr = read_token->data; + u8 *cksumkey; + u8 flags; + int i; + unsigned int cksum_usage; + + 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; + cksum_usage = KG_USAGE_ACCEPTOR_SIGN; + } else { + cksumkey = ctx->initiator_sign; + cksum_usage = KG_USAGE_INITIATOR_SIGN; + } + + if (make_checksum_v2(ctx, ptr, GSS_KRB5_TOK_HDR_LEN, message_buffer, 0, + cksumkey, cksum_usage, &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; + + /* + * NOTE: the sequence number at ptr + 8 is skipped, rpcsec_gss + * doesn't want it checked; see page 6 of rfc 2203. + */ + + return GSS_S_COMPLETE; +} + +u32 +gss_verify_mic_kerberos(struct gss_ctx *gss_ctx, + struct xdr_buf *message_buffer, + struct xdr_netobj *read_token) +{ + struct krb5_ctx *ctx = gss_ctx->internal_ctx_id; + + switch (ctx->enctype) { + default: + BUG(); + case ENCTYPE_DES_CBC_RAW: + case ENCTYPE_DES3_CBC_RAW: + case ENCTYPE_ARCFOUR_HMAC: + 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); + } +} + |