From: Kevin Coffman Date: Wed, 17 Mar 2010 17:02:51 +0000 (-0400) Subject: gss_krb5: introduce encryption type framework X-Git-Tag: firefly_0821_release~9833^2~2104^2~72 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=81d4a4333a1dfd6070f046265d928bb4c79aff88;p=firefly-linux-kernel-4.4.55.git gss_krb5: introduce encryption type framework Add enctype framework and change functions to use the generic values from it rather than the values hard-coded for des. Signed-off-by: Kevin Coffman Signed-off-by: Steve Dickson Signed-off-by: Trond Myklebust --- diff --git a/include/linux/sunrpc/gss_krb5.h b/include/linux/sunrpc/gss_krb5.h index 5378e455482c..f94935599d13 100644 --- a/include/linux/sunrpc/gss_krb5.h +++ b/include/linux/sunrpc/gss_krb5.h @@ -4,7 +4,7 @@ * Adapted from MIT Kerberos 5-1.2.1 lib/include/krb5.h, * lib/gssapi/krb5/gssapiP_krb5.h, and others * - * 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 @@ -36,6 +36,7 @@ * */ +#include #include #include #include @@ -46,9 +47,31 @@ /* Maximum blocksize for the supported crypto algorithms */ #define GSS_KRB5_MAX_BLOCKSIZE (16) +struct gss_krb5_enctype { + const u32 etype; /* encryption (key) type */ + const u32 ctype; /* checksum type */ + const char *name; /* "friendly" name */ + const char *encrypt_name; /* crypto encrypt name */ + const char *cksum_name; /* crypto checksum name */ + const u16 signalg; /* signing algorithm */ + const u16 sealalg; /* sealing algorithm */ + const u32 blocksize; /* encryption blocksize */ + const u32 cksumlength; /* checksum length */ + const u32 keyed_cksum; /* is it a keyed cksum? */ + const u32 keybytes; /* raw key len, in bytes */ + const u32 keylength; /* final key len, in bytes */ + u32 (*encrypt) (struct crypto_blkcipher *tfm, + void *iv, void *in, void *out, + int length); /* encryption function */ + u32 (*decrypt) (struct crypto_blkcipher *tfm, + void *iv, void *in, void *out, + int length); /* decryption function */ +}; + struct krb5_ctx { int initiate; /* 1 = initiating, 0 = accepting */ u32 enctype; + const struct gss_krb5_enctype *gk5e; /* enctype-specific info */ struct crypto_blkcipher *enc; struct crypto_blkcipher *seq; s32 endtime; diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c index 746b3e139aed..ccd5236953f7 100644 --- a/net/sunrpc/auth_gss/gss_krb5_crypto.c +++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c @@ -1,7 +1,7 @@ /* * 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 @@ -58,13 +58,13 @@ krb5_encrypt( { 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; @@ -92,13 +92,13 @@ krb5_decrypt( { 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; @@ -157,7 +157,7 @@ out: } 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; @@ -198,7 +198,7 @@ encryptor(struct scatterlist *sg, void *data) 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) @@ -256,7 +256,7 @@ gss_encrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *buf, } 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; @@ -278,7 +278,7 @@ decryptor(struct scatterlist *sg, void *data) 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) diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c index afe09108e1b0..a66eb706aeb7 100644 --- a/net/sunrpc/auth_gss/gss_krb5_mech.c +++ b/net/sunrpc/auth_gss/gss_krb5_mech.c @@ -1,7 +1,7 @@ /* * linux/net/sunrpc/gss_krb5_mech.c * - * Copyright (c) 2001 The Regents of the University of Michigan. + * Copyright (c) 2001-2008 The Regents of the University of Michigan. * All rights reserved. * * Andy Adamson @@ -48,6 +48,50 @@ # define RPCDBG_FACILITY RPCDBG_AUTH #endif +static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = { + /* + * DES (All DES enctypes are mapped to the same gss functionality) + */ + { + .etype = ENCTYPE_DES_CBC_RAW, + .ctype = CKSUMTYPE_RSA_MD5, + .name = "des-cbc-crc", + .encrypt_name = "cbc(des)", + .cksum_name = "md5", + .encrypt = krb5_encrypt, + .decrypt = krb5_decrypt, + .signalg = SGN_ALG_DES_MAC_MD5, + .sealalg = SEAL_ALG_DES, + .keybytes = 7, + .keylength = 8, + .blocksize = 8, + .cksumlength = 8, + }, +}; + +static const int num_supported_enctypes = + ARRAY_SIZE(supported_gss_krb5_enctypes); + +static int +supported_gss_krb5_enctype(int etype) +{ + int i; + for (i = 0; i < num_supported_enctypes; i++) + if (supported_gss_krb5_enctypes[i].etype == etype) + return 1; + return 0; +} + +static const struct gss_krb5_enctype * +get_gss_krb5_enctype(int etype) +{ + int i; + for (i = 0; i < num_supported_enctypes; i++) + if (supported_gss_krb5_enctypes[i].etype == etype) + return &supported_gss_krb5_enctypes[i]; + return NULL; +} + static const void * simple_get_bytes(const void *p, const void *end, void *res, int len) { @@ -78,35 +122,45 @@ simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res) } static inline const void * -get_key(const void *p, const void *end, struct crypto_blkcipher **res) +get_key(const void *p, const void *end, + struct krb5_ctx *ctx, struct crypto_blkcipher **res) { struct xdr_netobj key; int alg; - char *alg_name; p = simple_get_bytes(p, end, &alg, sizeof(alg)); if (IS_ERR(p)) goto out_err; + + switch (alg) { + case ENCTYPE_DES_CBC_CRC: + case ENCTYPE_DES_CBC_MD4: + case ENCTYPE_DES_CBC_MD5: + /* Map all these key types to ENCTYPE_DES_CBC_RAW */ + alg = ENCTYPE_DES_CBC_RAW; + break; + } + + if (!supported_gss_krb5_enctype(alg)) { + printk(KERN_WARNING "gss_kerberos_mech: unsupported " + "encryption key algorithm %d\n", alg); + goto out_err; + } p = simple_get_netobj(p, end, &key); if (IS_ERR(p)) goto out_err; - switch (alg) { - case ENCTYPE_DES_CBC_RAW: - alg_name = "cbc(des)"; - break; - default: - printk("gss_kerberos_mech: unsupported algorithm %d\n", alg); - goto out_err_free_key; - } - *res = crypto_alloc_blkcipher(alg_name, 0, CRYPTO_ALG_ASYNC); + *res = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0, + CRYPTO_ALG_ASYNC); if (IS_ERR(*res)) { - printk("gss_kerberos_mech: unable to initialize crypto algorithm %s\n", alg_name); + printk(KERN_WARNING "gss_kerberos_mech: unable to initialize " + "crypto algorithm %s\n", ctx->gk5e->encrypt_name); *res = NULL; goto out_err_free_key; } if (crypto_blkcipher_setkey(*res, key.data, key.len)) { - printk("gss_kerberos_mech: error setting key for crypto algorithm %s\n", alg_name); + printk(KERN_WARNING "gss_kerberos_mech: error setting key for " + "crypto algorithm %s\n", ctx->gk5e->encrypt_name); goto out_err_free_tfm; } @@ -134,6 +188,10 @@ gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx) /* Old format supports only DES! Any other enctype uses new format */ ctx->enctype = ENCTYPE_DES_CBC_RAW; + ctx->gk5e = get_gss_krb5_enctype(ctx->enctype); + if (ctx->gk5e == NULL) + goto out_err; + /* The downcall format was designed before we completely understood * the uses of the context fields; so it includes some stuff we * just give some minimal sanity-checking, and some we ignore @@ -164,10 +222,10 @@ gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx) p = simple_get_netobj(p, end, &ctx->mech_used); if (IS_ERR(p)) goto out_err; - p = get_key(p, end, &ctx->enc); + p = get_key(p, end, ctx, &ctx->enc); if (IS_ERR(p)) goto out_err_free_mech; - p = get_key(p, end, &ctx->seq); + p = get_key(p, end, ctx, &ctx->seq); if (IS_ERR(p)) goto out_err_free_key1; if (p != end) { diff --git a/net/sunrpc/auth_gss/gss_krb5_seal.c b/net/sunrpc/auth_gss/gss_krb5_seal.c index 71c2014e7ebf..46c6f44e5c3f 100644 --- a/net/sunrpc/auth_gss/gss_krb5_seal.c +++ b/net/sunrpc/auth_gss/gss_krb5_seal.c @@ -3,7 +3,7 @@ * * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5seal.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 @@ -70,36 +70,47 @@ DEFINE_SPINLOCK(krb5_seq_lock); +static char * +setup_token(struct krb5_ctx *ctx, struct xdr_netobj *token) +{ + __be16 *ptr, *krb5_hdr; + int body_size = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength; + + token->len = g_token_size(&ctx->mech_used, body_size); + + ptr = (__be16 *)token->data; + g_make_token_header(&ctx->mech_used, body_size, (unsigned char **)&ptr); + + /* ptr now at start of header described in rfc 1964, section 1.2.1: */ + krb5_hdr = ptr; + *ptr++ = KG_TOK_MIC_MSG; + *ptr++ = cpu_to_le16(ctx->gk5e->signalg); + *ptr++ = SEAL_ALG_NONE; + *ptr++ = 0xffff; + + return (char *)krb5_hdr; +} + static u32 gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text, struct xdr_netobj *token) { - char cksumdata[16]; - struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata}; - unsigned char *ptr, *msg_start; + char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; + struct xdr_netobj md5cksum = {.len = sizeof(cksumdata), + .data = cksumdata}; + void *ptr; s32 now; u32 seq_send; - dprintk("RPC: gss_krb5_seal\n"); + dprintk("RPC: %s\n", __func__); BUG_ON(ctx == NULL); now = get_seconds(); - token->len = g_token_size(&ctx->mech_used, GSS_KRB5_TOK_HDR_LEN + 8); - - ptr = token->data; - g_make_token_header(&ctx->mech_used, GSS_KRB5_TOK_HDR_LEN + 8, &ptr); - - /* ptr now at header described in rfc 1964, section 1.2.1: */ - ptr[0] = (unsigned char) ((KG_TOK_MIC_MSG >> 8) & 0xff); - ptr[1] = (unsigned char) (KG_TOK_MIC_MSG & 0xff); - - msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + 8; - - *(__be16 *)(ptr + 2) = htons(SGN_ALG_DES_MAC_MD5); - memset(ptr + 4, 0xff, 4); + ptr = setup_token(ctx, token); - if (make_checksum("md5", ptr, 8, text, 0, &md5cksum)) + if (make_checksum((char *)ctx->gk5e->cksum_name, ptr, 8, + text, 0, &md5cksum)) return GSS_S_FAILURE; if (krb5_encrypt(ctx->seq, NULL, md5cksum.data, diff --git a/net/sunrpc/auth_gss/gss_krb5_unseal.c b/net/sunrpc/auth_gss/gss_krb5_unseal.c index 069d4b59807a..10ee641a39d0 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 @@ -76,8 +76,9 @@ gss_verify_mic_v1(struct krb5_ctx *ctx, { 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; u32 seqnum; @@ -97,7 +98,7 @@ gss_verify_mic_v1(struct krb5_ctx *ctx, /* XXX sanity-check bodysize?? */ signalg = ptr[2] + (ptr[3] << 8); - if (signalg != SGN_ALG_DES_MAC_MD5) + if (signalg != ctx->gk5e->signalg) return GSS_S_DEFECTIVE_TOKEN; sealalg = ptr[4] + (ptr[5] << 8); @@ -107,13 +108,15 @@ gss_verify_mic_v1(struct krb5_ctx *ctx, if ((ptr[6] != 0xff) || (ptr[7] != 0xff)) return GSS_S_DEFECTIVE_TOKEN; - if (make_checksum("md5", ptr, 8, message_buffer, 0, &md5cksum)) + if (make_checksum((char *)ctx->gk5e->cksum_name, ptr, 8, + message_buffer, 0, &md5cksum)) return GSS_S_FAILURE; if (krb5_encrypt(ctx->seq, NULL, md5cksum.data, md5cksum.data, 16)) return GSS_S_FAILURE; - if (memcmp(md5cksum.data + 8, ptr + GSS_KRB5_TOK_HDR_LEN, 8)) + if (memcmp(md5cksum.data + 8, ptr + GSS_KRB5_TOK_HDR_LEN, + ctx->gk5e->cksumlength)) return GSS_S_BAD_SIG; /* it got through unscathed. Make sure the context is unexpired */ diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c index b45b59b17ae1..7188891bcc33 100644 --- a/net/sunrpc/auth_gss/gss_krb5_wrap.c +++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c @@ -1,3 +1,33 @@ +/* + * COPYRIGHT (c) 2008 + * The Regents of the University of Michigan + * ALL RIGHTS RESERVED + * + * Permission is granted to use, copy, create derivative works + * and redistribute this software and such derivative works + * for any purpose, so long as the name of The University of + * Michigan is not used in any advertising or publicity + * pertaining to the use of distribution of this software + * without specific, written prior authorization. If the + * above copyright notice or any other identification of the + * University of Michigan is included in any copy of any + * portion of this software, then the disclaimer below must + * also be included. + * + * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION + * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY + * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF + * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING + * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE + * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE + * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR + * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING + * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN + * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGES. + */ + #include #include #include @@ -128,8 +158,9 @@ static u32 gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf, struct page **pages) { - 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}; int blocksize = 0, plainlen; unsigned char *ptr, *msg_start; s32 now; @@ -137,7 +168,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct page **tmp_pages; u32 seq_send; - dprintk("RPC: gss_wrap_kerberos\n"); + dprintk("RPC: %s\n", __func__); now = get_seconds(); @@ -146,8 +177,9 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset, BUG_ON((buf->len - offset) % blocksize); plainlen = blocksize + buf->len - offset; - headlen = g_token_size(&kctx->mech_used, 24 + plainlen) - - (buf->len - offset); + headlen = g_token_size(&kctx->mech_used, + GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength + plainlen) - + (buf->len - offset); ptr = buf->head[0].iov_base + offset; /* shift data to make room for header. */ @@ -157,25 +189,26 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset, BUG_ON((buf->len - offset - headlen) % blocksize); g_make_token_header(&kctx->mech_used, - GSS_KRB5_TOK_HDR_LEN + 8 + plainlen, &ptr); + GSS_KRB5_TOK_HDR_LEN + + kctx->gk5e->cksumlength + plainlen, &ptr); /* ptr now at header described in rfc 1964, section 1.2.1: */ ptr[0] = (unsigned char) ((KG_TOK_WRAP_MSG >> 8) & 0xff); ptr[1] = (unsigned char) (KG_TOK_WRAP_MSG & 0xff); - msg_start = ptr + 24; + msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength; - *(__be16 *)(ptr + 2) = htons(SGN_ALG_DES_MAC_MD5); + *(__be16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg); memset(ptr + 4, 0xff, 4); - *(__be16 *)(ptr + 4) = htons(SEAL_ALG_DES); + *(__be16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg); make_confounder(msg_start, blocksize); /* XXXJBF: UGH!: */ tmp_pages = buf->pages; buf->pages = pages; - if (make_checksum("md5", ptr, 8, buf, + if (make_checksum((char *)kctx->gk5e->cksum_name, ptr, 8, buf, offset + headlen - blocksize, &md5cksum)) return GSS_S_FAILURE; buf->pages = tmp_pages; @@ -207,8 +240,9 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) { 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; @@ -217,6 +251,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) void *data_start, *orig_start; int data_len; int blocksize; + int crypt_offset; dprintk("RPC: gss_unwrap_kerberos\n"); @@ -234,22 +269,27 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) /* get the sign and seal algorithms */ signalg = ptr[2] + (ptr[3] << 8); - if (signalg != SGN_ALG_DES_MAC_MD5) + if (signalg != kctx->gk5e->signalg) return GSS_S_DEFECTIVE_TOKEN; sealalg = ptr[4] + (ptr[5] << 8); - if (sealalg != SEAL_ALG_DES) + if (sealalg != kctx->gk5e->sealalg) return GSS_S_DEFECTIVE_TOKEN; if ((ptr[6] != 0xff) || (ptr[7] != 0xff)) return GSS_S_DEFECTIVE_TOKEN; - if (gss_decrypt_xdr_buf(kctx->enc, buf, - ptr + GSS_KRB5_TOK_HDR_LEN + 8 - (unsigned char *)buf->head[0].iov_base)) + /* + * Data starts after token header and checksum. ptr points + * to the beginning of the token header + */ + crypt_offset = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) - + (unsigned char *)buf->head[0].iov_base; + if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset)) return GSS_S_DEFECTIVE_TOKEN; - if (make_checksum("md5", ptr, 8, buf, - ptr + GSS_KRB5_TOK_HDR_LEN + 8 - (unsigned char *)buf->head[0].iov_base, &md5cksum)) + if (make_checksum((char *)kctx->gk5e->cksum_name, ptr, 8, buf, + crypt_offset, &md5cksum)) return GSS_S_FAILURE; if (krb5_encrypt(kctx->seq, NULL, md5cksum.data, @@ -280,7 +320,8 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) * better to copy and encrypt at the same time. */ blocksize = crypto_blkcipher_blocksize(kctx->enc); - data_start = ptr + GSS_KRB5_TOK_HDR_LEN + 8 + blocksize; + data_start = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) + + blocksize; orig_start = buf->head[0].iov_base + offset; data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start; memmove(orig_start, data_start, data_len);