vendor/krb5/1.15.1

1 files changed, 782 insertions, 0 deletions

diff --git a/src/lib/gssapi/krb5/util_crypt.c b/src/lib/gssapi/krb5/util_crypt.c
new file mode 100644
index 000000000000..0cebde12a85c
--- /dev/null
+++ b/src/lib/gssapi/krb5/util_crypt.c
@@ -0,0 +1,782 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+ * Copyright 2001, 2008 by the Massachusetts Institute of Technology.
+ * 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 "k5-int.h"
+#include "gssapiP_krb5.h"
+#ifdef HAVE_MEMORY_H
+#include <memory.h>
+#endif
+
+static krb5_error_code
+kg_copy_keys(krb5_context context, krb5_gss_ctx_id_rec *ctx, krb5_key subkey)
+{
+    krb5_error_code code;
+
+    krb5_k_free_key(context, ctx->enc);
+    ctx->enc = NULL;
+    code = krb5_k_create_key(context, &subkey->keyblock, &ctx->enc);
+    if (code != 0)
+        return code;
+
+    krb5_k_free_key(context, ctx->seq);
+    ctx->seq = NULL;
+    code = krb5_k_create_key(context, &subkey->keyblock, &ctx->seq);
+    if (code != 0)
+        return code;
+
+    return 0;
+}
+
+static krb5_error_code
+kg_derive_des_enc_key(krb5_context context, krb5_key subkey, krb5_key *out)
+{
+    krb5_error_code code;
+    krb5_keyblock *keyblock;
+    unsigned int i;
+
+    *out = NULL;
+
+    code = krb5_k_key_keyblock(context, subkey, &keyblock);
+    if (code != 0)
+        return code;
+
+    for (i = 0; i < keyblock->length; i++)
+        keyblock->contents[i] ^= 0xF0;
+
+    code = krb5_k_create_key(context, keyblock, out);
+    krb5_free_keyblock(context, keyblock);
+    return code;
+}
+
+krb5_error_code
+kg_setup_keys(krb5_context context, krb5_gss_ctx_id_rec *ctx, krb5_key subkey,
+              krb5_cksumtype *cksumtype)
+{
+    krb5_error_code code;
+
+    assert(ctx != NULL);
+    assert(subkey != NULL);
+
+    *cksumtype = 0;
+    ctx->proto = 0;
+
+    if (ctx->enc == NULL) {
+        ctx->signalg = -1;
+        ctx->sealalg = -1;
+    }
+
+    code = krb5int_c_mandatory_cksumtype(context, subkey->keyblock.enctype,
+                                         cksumtype);
+    if (code != 0)
+        return code;
+
+    switch (subkey->keyblock.enctype) {
+    case ENCTYPE_DES_CBC_MD5:
+    case ENCTYPE_DES_CBC_MD4:
+    case ENCTYPE_DES_CBC_CRC:
+        krb5_k_free_key(context, ctx->seq);
+        code = krb5_k_create_key(context, &subkey->keyblock, &ctx->seq);
+        if (code != 0)
+            return code;
+
+        krb5_k_free_key(context, ctx->enc);
+        code = kg_derive_des_enc_key(context, subkey, &ctx->enc);
+        if (code != 0)
+            return code;
+
+        ctx->enc->keyblock.enctype = ENCTYPE_DES_CBC_RAW;
+        ctx->seq->keyblock.enctype = ENCTYPE_DES_CBC_RAW;
+        ctx->signalg = SGN_ALG_DES_MAC_MD5;
+        ctx->cksum_size = 8;
+        ctx->sealalg = SEAL_ALG_DES;
+
+        break;
+    case ENCTYPE_DES3_CBC_SHA1:
+        code = kg_copy_keys(context, ctx, subkey);
+        if (code != 0)
+            return code;
+
+        ctx->enc->keyblock.enctype = ENCTYPE_DES3_CBC_RAW;
+        ctx->seq->keyblock.enctype = ENCTYPE_DES3_CBC_RAW;
+        ctx->signalg = SGN_ALG_HMAC_SHA1_DES3_KD;
+        ctx->cksum_size = 20;
+        ctx->sealalg = SEAL_ALG_DES3KD;
+        break;
+    case ENCTYPE_ARCFOUR_HMAC:
+    case ENCTYPE_ARCFOUR_HMAC_EXP:
+        /* RFC 4121 accidentally omits RC4-HMAC-EXP as a "not-newer" enctype,
+         * even though RFC 4757 treats it as one. */
+        code = kg_copy_keys(context, ctx, subkey);
+        if (code != 0)
+            return code;
+
+        ctx->signalg = SGN_ALG_HMAC_MD5;
+        ctx->cksum_size = 8;
+        ctx->sealalg = SEAL_ALG_MICROSOFT_RC4;
+        break;
+    default:
+        ctx->proto = 1;
+        break;
+    }
+
+    return 0;
+}
+
+int
+kg_confounder_size(krb5_context context, krb5_enctype enctype)
+{
+    krb5_error_code code;
+    size_t blocksize;
+    /* We special case rc4*/
+    if (enctype == ENCTYPE_ARCFOUR_HMAC || enctype == ENCTYPE_ARCFOUR_HMAC_EXP)
+        return 8;
+    code = krb5_c_block_size(context, enctype, &blocksize);
+    if (code)
+        return(-1); /* XXX */
+
+    return(blocksize);
+}
+
+krb5_error_code
+kg_make_confounder(krb5_context context, krb5_enctype enctype,
+                   unsigned char *buf)
+{
+    int confsize;
+    krb5_data lrandom;
+
+    confsize = kg_confounder_size(context, enctype);
+    if (confsize < 0)
+        return KRB5_BAD_MSIZE;
+
+    lrandom.length = confsize;
+    lrandom.data = (char *)buf;
+
+    return(krb5_c_random_make_octets(context, &lrandom));
+}
+
+/* Set *data_out to a krb5_data structure containing iv, or to NULL if iv is
+ * NULL. */
+static krb5_error_code
+iv_to_state(krb5_context context, krb5_key key, krb5_pointer iv,
+            krb5_data **data_out)
+{
+    krb5_error_code code;
+    krb5_data *data;
+    size_t blocksize;
+
+    *data_out = NULL;
+    if (iv == NULL)
+        return 0;
+
+    code = krb5_c_block_size(context, key->keyblock.enctype, &blocksize);
+    if (code)
+        return code;
+
+    data = k5alloc(sizeof(*data), &code);
+    if (data == NULL)
+        return code;
+    code = alloc_data(data, blocksize);
+    if (code) {
+        free(data);
+        return code;
+    }
+    memcpy(data->data, iv, blocksize);
+    *data_out = data;
+    return 0;
+}
+
+krb5_error_code
+kg_encrypt(krb5_context context, krb5_key key, int usage, krb5_pointer iv,
+           krb5_const_pointer in, krb5_pointer out, unsigned int length)
+{
+    krb5_error_code code;
+    krb5_data *state, inputd;
+    krb5_enc_data outputd;
+
+    code = iv_to_state(context, key, iv, &state);
+    if (code)
+        return code;
+
+    inputd.length = length;
+    inputd.data = (char *)in;
+
+    outputd.ciphertext.length = length;
+    outputd.ciphertext.data = out;
+
+    code = krb5_k_encrypt(context, key, usage, state, &inputd, &outputd);
+    krb5_free_data(context, state);
+    return code;
+}
+
+krb5_error_code
+kg_encrypt_inplace(krb5_context context, krb5_key key, int usage,
+                   krb5_pointer iv, krb5_pointer ptr, unsigned int length)
+{
+    krb5_error_code code;
+    krb5_crypto_iov iov;
+    krb5_data *state;
+
+    code = iv_to_state(context, key, iv, &state);
+    if (code)
+        return code;
+
+    iov.flags = KRB5_CRYPTO_TYPE_DATA;
+    iov.data = make_data((void *)ptr, length);
+    code = krb5_k_encrypt_iov(context, key, usage, state, &iov, 1);
+    krb5_free_data(context, state);
+    return code;
+}
+
+/* length is the length of the cleartext. */
+
+krb5_error_code
+kg_decrypt(krb5_context context, krb5_key key, int usage, krb5_pointer iv,
+           krb5_const_pointer in, krb5_pointer out, unsigned int length)
+{
+    krb5_error_code code;
+    krb5_data *state, outputd;
+    krb5_enc_data inputd;
+
+    code = iv_to_state(context, key, iv, &state);
+    if (code)
+        return code;
+
+    inputd.enctype = ENCTYPE_UNKNOWN;
+    inputd.ciphertext.length = length;
+    inputd.ciphertext.data = (char *)in;
+
+    outputd.length = length;
+    outputd.data = out;
+
+    code = krb5_k_decrypt(context, key, usage, state, &inputd, &outputd);
+    krb5_free_data(context, state);
+    return code;
+}
+
+krb5_error_code
+kg_arcfour_docrypt(const krb5_keyblock *keyblock, int usage,
+                   const unsigned char *kd_data, size_t kd_data_len,
+                   const unsigned char *input_buf, size_t input_len,
+                   unsigned char *output_buf)
+{
+    krb5_data kd = make_data((char *) kd_data, kd_data_len);
+    krb5_crypto_iov kiov;
+
+    memcpy(output_buf, input_buf, input_len);
+    kiov.flags = KRB5_CRYPTO_TYPE_DATA;
+    kiov.data = make_data(output_buf, input_len);
+    return krb5int_arcfour_gsscrypt(keyblock, usage, &kd, &kiov, 1);
+}
+
+/* AEAD */
+static krb5_error_code
+kg_translate_iov_v1(krb5_context context, krb5_enctype enctype,
+                    gss_iov_buffer_desc *iov, int iov_count,
+                    krb5_crypto_iov **pkiov, size_t *pkiov_count)
+{
+    gss_iov_buffer_desc *header;
+    gss_iov_buffer_desc *trailer;
+    int i = 0, j;
+    size_t kiov_count;
+    krb5_crypto_iov *kiov;
+    size_t conf_len;
+
+    *pkiov = NULL;
+    *pkiov_count = 0;
+
+    conf_len = kg_confounder_size(context, enctype);
+
+    header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
+    assert(header != NULL);
+
+    if (header->buffer.length < conf_len)
+        return KRB5_BAD_MSIZE;
+
+    trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
+    assert(trailer == NULL || trailer->buffer.length == 0);
+
+    kiov_count = 3 + iov_count;
+    kiov = (krb5_crypto_iov *)malloc(kiov_count * sizeof(krb5_crypto_iov));
+    if (kiov == NULL)
+        return ENOMEM;
+
+    /* For pre-CFX (raw enctypes) there is no krb5 header */
+    kiov[i].flags = KRB5_CRYPTO_TYPE_HEADER;
+    kiov[i].data.length = 0;
+    kiov[i].data.data = NULL;
+    i++;
+
+    /* For pre-CFX, the confounder is at the end of the GSS header */
+    kiov[i].flags = KRB5_CRYPTO_TYPE_DATA;
+    kiov[i].data.length = conf_len;
+    kiov[i].data.data = (char *)header->buffer.value + header->buffer.length - conf_len;
+    i++;
+
+    for (j = 0; j < iov_count; j++) {
+        kiov[i].flags = kg_translate_flag_iov(iov[j].type);
+        if (kiov[i].flags == KRB5_CRYPTO_TYPE_EMPTY)
+            continue;
+
+        kiov[i].data.length = iov[j].buffer.length;
+        kiov[i].data.data = (char *)iov[j].buffer.value;
+        i++;
+    }
+
+    kiov[i].flags = KRB5_CRYPTO_TYPE_TRAILER;
+    kiov[i].data.length = 0;
+    kiov[i].data.data = NULL;
+    i++;
+
+    *pkiov = kiov;
+    *pkiov_count = i;
+
+    return 0;
+}
+
+/*
+ * DCE_STYLE indicates actual RRC is EC + RRC
+ * EC is extra rotate count for DCE_STYLE, pad length otherwise
+ * RRC is rotate count.
+ */
+static krb5_error_code
+kg_translate_iov_v3(krb5_context context, int dce_style, size_t ec, size_t rrc,
+                    krb5_enctype enctype, gss_iov_buffer_desc *iov,
+                    int iov_count, krb5_crypto_iov **pkiov,
+                    size_t *pkiov_count)
+{
+    gss_iov_buffer_t header;
+    gss_iov_buffer_t trailer;
+    int i = 0, j;
+    size_t kiov_count;
+    krb5_crypto_iov *kiov;
+    unsigned int k5_headerlen = 0, k5_trailerlen = 0;
+    size_t gss_headerlen, gss_trailerlen;
+    krb5_error_code code;
+
+    *pkiov = NULL;
+    *pkiov_count = 0;
+
+    header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
+    assert(header != NULL);
+
+    trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
+    assert(trailer == NULL || rrc == 0);
+
+    code = krb5_c_crypto_length(context, enctype, KRB5_CRYPTO_TYPE_HEADER,
+                                &k5_headerlen);
+    if (code != 0)
+        return code;
+
+    code = krb5_c_crypto_length(context, enctype, KRB5_CRYPTO_TYPE_TRAILER,
+                                &k5_trailerlen);
+    if (code != 0)
+        return code;
+
+    /* Check header and trailer sizes */
+    gss_headerlen = 16 /* GSS-Header */ + k5_headerlen; /* Kerb-Header */
+    gss_trailerlen = ec + 16 /* E(GSS-Header) */ + k5_trailerlen; /* Kerb-Trailer */
+
+    /* If we're caller without a trailer, we must rotate by trailer length */
+    if (trailer == NULL) {
+        size_t actual_rrc = rrc;
+
+        if (dce_style)
+            actual_rrc += ec; /* compensate for Windows bug */
+
+        if (actual_rrc != gss_trailerlen)
+            return KRB5_BAD_MSIZE;
+
+        gss_headerlen += gss_trailerlen;
+        gss_trailerlen = 0;
+    } else {
+        if (trailer->buffer.length != gss_trailerlen)
+            return KRB5_BAD_MSIZE;
+    }
+
+    if (header->buffer.length != gss_headerlen)
+        return KRB5_BAD_MSIZE;
+
+    kiov_count = 3 + iov_count;
+    kiov = (krb5_crypto_iov *)malloc(kiov_count * sizeof(krb5_crypto_iov));
+    if (kiov == NULL)
+        return ENOMEM;
+
+    /*
+     * The krb5 header is located at the end of the GSS header.
+     */
+    kiov[i].flags = KRB5_CRYPTO_TYPE_HEADER;
+    kiov[i].data.length = k5_headerlen;
+    kiov[i].data.data = (char *)header->buffer.value + header->buffer.length - k5_headerlen;
+    i++;
+
+    for (j = 0; j < iov_count; j++) {
+        kiov[i].flags = kg_translate_flag_iov(iov[j].type);
+        if (kiov[i].flags == KRB5_CRYPTO_TYPE_EMPTY)
+            continue;
+
+        kiov[i].data.length = iov[j].buffer.length;
+        kiov[i].data.data = (char *)iov[j].buffer.value;
+        i++;
+    }
+
+    /*
+     * The EC and encrypted GSS header are placed in the trailer, which may
+     * be rotated directly after the plaintext header if no trailer buffer
+     * is provided.
+     */
+    kiov[i].flags = KRB5_CRYPTO_TYPE_DATA;
+    kiov[i].data.length = ec + 16; /* E(Header) */
+    if (trailer == NULL)
+        kiov[i].data.data = (char *)header->buffer.value + 16;
+    else
+        kiov[i].data.data = (char *)trailer->buffer.value;
+    i++;
+
+    /*
+     * The krb5 trailer is placed after the encrypted copy of the
+     * krb5 header (which may be in the GSS header or trailer).
+     */
+    kiov[i].flags = KRB5_CRYPTO_TYPE_TRAILER;
+    kiov[i].data.length = k5_trailerlen;
+    kiov[i].data.data = kiov[i - 1].data.data + ec + 16; /* E(Header) */
+    i++;
+
+    *pkiov = kiov;
+    *pkiov_count = i;
+
+    return 0;
+}
+
+/* PROTO is 1 if CFX, 0 if pre-CFX */
+static krb5_error_code
+kg_translate_iov(krb5_context context, int proto, int dce_style, size_t ec,
+                 size_t rrc, krb5_enctype enctype, gss_iov_buffer_desc *iov,
+                 int iov_count, krb5_crypto_iov **pkiov, size_t *pkiov_count)
+{
+    return proto ?
+        kg_translate_iov_v3(context, dce_style, ec, rrc, enctype,
+                            iov, iov_count, pkiov, pkiov_count) :
+        kg_translate_iov_v1(context, enctype, iov, iov_count,
+                            pkiov, pkiov_count);
+}
+
+krb5_error_code
+kg_encrypt_iov(krb5_context context, int proto, int dce_style, size_t ec,
+               size_t rrc, krb5_key key, int usage, krb5_pointer iv,
+               gss_iov_buffer_desc *iov, int iov_count)
+{
+    krb5_error_code code;
+    krb5_data *state;
+    size_t kiov_len;
+    krb5_crypto_iov *kiov;
+
+    code = iv_to_state(context, key, iv, &state);
+    if (code)
+        return code;
+
+    code = kg_translate_iov(context, proto, dce_style, ec, rrc,
+                            key->keyblock.enctype, iov, iov_count,
+                            &kiov, &kiov_len);
+    if (code == 0) {
+        code = krb5_k_encrypt_iov(context, key, usage, state, kiov, kiov_len);
+        free(kiov);
+    }
+
+    krb5_free_data(context, state);
+    return code;
+}
+
+/* length is the length of the cleartext. */
+
+krb5_error_code
+kg_decrypt_iov(krb5_context context, int proto, int dce_style, size_t ec,
+               size_t rrc, krb5_key key, int usage, krb5_pointer iv,
+               gss_iov_buffer_desc *iov, int iov_count)
+{
+    krb5_error_code code;
+    krb5_data *state;
+    size_t kiov_len;
+    krb5_crypto_iov *kiov;
+
+    code = iv_to_state(context, key, iv, &state);
+    if (code)
+        return code;
+
+    code = kg_translate_iov(context, proto, dce_style, ec, rrc,
+                            key->keyblock.enctype, iov, iov_count,
+                            &kiov, &kiov_len);
+    if (code == 0) {
+        code = krb5_k_decrypt_iov(context, key, usage, state, kiov, kiov_len);
+        free(kiov);
+    }
+
+    krb5_free_data(context, state);
+    return code;
+}
+
+krb5_error_code
+kg_arcfour_docrypt_iov(krb5_context context, const krb5_keyblock *keyblock,
+                       int usage, const unsigned char *kd_data,
+                       size_t kd_data_len, gss_iov_buffer_desc *iov,
+                       int iov_count)
+{
+    krb5_error_code code;
+    krb5_data kd = make_data((char *) kd_data, kd_data_len);
+    krb5_crypto_iov *kiov = NULL;
+    size_t kiov_len = 0;
+
+    code = kg_translate_iov(context, 0 /* proto */, 0 /* dce_style */,
+                            0 /* ec */, 0 /* rrc */, keyblock->enctype,
+                            iov, iov_count, &kiov, &kiov_len);
+    if (code)
+        return code;
+    code = krb5int_arcfour_gsscrypt(keyblock, usage, &kd, kiov, kiov_len);
+    free(kiov);
+    return code;
+}
+
+krb5_cryptotype
+kg_translate_flag_iov(OM_uint32 type)
+{
+    krb5_cryptotype ktype;
+
+    switch (GSS_IOV_BUFFER_TYPE(type)) {
+    case GSS_IOV_BUFFER_TYPE_DATA:
+    case GSS_IOV_BUFFER_TYPE_PADDING:
+        ktype = KRB5_CRYPTO_TYPE_DATA;
+        break;
+    case GSS_IOV_BUFFER_TYPE_SIGN_ONLY:
+        ktype = KRB5_CRYPTO_TYPE_SIGN_ONLY;
+        break;
+    default:
+        ktype = KRB5_CRYPTO_TYPE_EMPTY;
+        break;
+    }
+
+    return ktype;
+}
+
+gss_iov_buffer_t
+kg_locate_iov(gss_iov_buffer_desc *iov, int iov_count, OM_uint32 type)
+{
+    int i;
+    gss_iov_buffer_t p = GSS_C_NO_IOV_BUFFER;
+
+    if (iov == GSS_C_NO_IOV_BUFFER)
+        return GSS_C_NO_IOV_BUFFER;
+
+    for (i = iov_count - 1; i >= 0; i--) {
+        if (GSS_IOV_BUFFER_TYPE(iov[i].type) == type) {
+            if (p == GSS_C_NO_IOV_BUFFER)
+                p = &iov[i];
+            else
+                return GSS_C_NO_IOV_BUFFER;
+        }
+    }
+
+    return p;
+}
+
+/* Return the IOV where the GSSAPI token header should be placed (and possibly
+ * the checksum as well, depending on the token type). */
+gss_iov_buffer_t
+kg_locate_header_iov(gss_iov_buffer_desc *iov, int iov_count, int toktype)
+{
+    if (toktype == KG_TOK_MIC_MSG)
+        return kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_MIC_TOKEN);
+    else
+        return kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
+}
+
+void
+kg_iov_msglen(gss_iov_buffer_desc *iov, int iov_count, size_t *data_length_p,
+              size_t *assoc_data_length_p)
+{
+    int i;
+    size_t data_length = 0, assoc_data_length = 0;
+
+    assert(iov != GSS_C_NO_IOV_BUFFER);
+
+    *data_length_p = *assoc_data_length_p = 0;
+
+    for (i = 0; i < iov_count; i++) {
+        OM_uint32 type = GSS_IOV_BUFFER_TYPE(iov[i].type);
+
+        if (type == GSS_IOV_BUFFER_TYPE_SIGN_ONLY)
+            assoc_data_length += iov[i].buffer.length;
+
+        if (type == GSS_IOV_BUFFER_TYPE_DATA ||
+            type == GSS_IOV_BUFFER_TYPE_SIGN_ONLY)
+            data_length += iov[i].buffer.length;
+    }
+
+    *data_length_p = data_length;
+    *assoc_data_length_p = assoc_data_length;
+}
+
+void
+kg_release_iov(gss_iov_buffer_desc *iov, int iov_count)
+{
+    int i;
+
+    assert(iov != GSS_C_NO_IOV_BUFFER);
+
+    for (i = 0; i < iov_count; i++) {
+        if (iov[i].type & GSS_IOV_BUFFER_FLAG_ALLOCATED) {
+            gssalloc_free(iov[i].buffer.value);
+            iov[i].buffer.length = 0;
+            iov[i].buffer.value = NULL;
+            iov[i].type &= ~(GSS_IOV_BUFFER_FLAG_ALLOCATED);
+        }
+    }
+}
+
+OM_uint32
+kg_fixup_padding_iov(OM_uint32 *minor_status, gss_iov_buffer_desc *iov,
+                     int iov_count)
+{
+    gss_iov_buffer_t padding = NULL;
+    gss_iov_buffer_t data = NULL;
+    size_t padlength, relative_padlength;
+    unsigned char *p;
+
+    data = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_DATA);
+    padding = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
+
+    if (data == NULL) {
+        *minor_status = 0;
+        return GSS_S_COMPLETE;
+    }
+
+    if (padding == NULL || padding->buffer.length == 0) {
+        *minor_status = EINVAL;
+        return GSS_S_FAILURE;
+    }
+
+    p = (unsigned char *)padding->buffer.value;
+    padlength = p[padding->buffer.length - 1];
+
+    if (data->buffer.length + padding->buffer.length < padlength ||
+        padlength == 0) {
+        *minor_status = (OM_uint32)KRB5_BAD_MSIZE;
+        return GSS_S_DEFECTIVE_TOKEN;
+    }
+
+    /*
+     * kg_unseal_stream_iov() will place one byte of padding in the
+     * padding buffer; its true value is unknown until after decryption.
+     *
+     * relative_padlength contains the number of bytes to compensate the
+     * padding and data buffers by; it will be zero if the caller manages
+     * the padding length.
+     *
+     * If the caller manages the padding length, then relative_padlength
+     * wil be zero.
+     *
+     * eg. if the buffers are structured as follows:
+     *
+     *      +---DATA---+-PAD-+
+     *      | ABCDE444 | 4   |
+     *      +----------+-----+
+     *
+     * after compensation they would look like:
+     *
+     *      +-DATA--+-PAD--+
+     *      | ABCDE | NULL |
+     *      +-------+------+
+     */
+    relative_padlength = padlength - padding->buffer.length;
+
+    assert(data->buffer.length >= relative_padlength);
+
+    data->buffer.length -= relative_padlength;
+
+    kg_release_iov(padding, 1);
+    padding->buffer.length = 0;
+    padding->buffer.value = NULL;
+
+    return GSS_S_COMPLETE;
+}
+
+krb5_boolean
+kg_integ_only_iov(gss_iov_buffer_desc *iov, int iov_count)
+{
+    int i;
+    krb5_boolean has_conf_data = FALSE;
+
+    assert(iov != GSS_C_NO_IOV_BUFFER);
+
+    for (i = 0; i < iov_count; i++) {
+        if (GSS_IOV_BUFFER_TYPE(iov[i].type) == GSS_IOV_BUFFER_TYPE_DATA) {
+            has_conf_data = TRUE;
+            break;
+        }
+    }
+
+    return (has_conf_data == FALSE);
+}
+
+krb5_error_code
+kg_allocate_iov(gss_iov_buffer_t iov, size_t size)
+{
+    assert(iov != GSS_C_NO_IOV_BUFFER);
+    assert(iov->type & GSS_IOV_BUFFER_FLAG_ALLOCATE);
+
+    iov->buffer.length = size;
+    iov->buffer.value = gssalloc_malloc(size);
+    if (iov->buffer.value == NULL) {
+        iov->buffer.length = 0;
+        return ENOMEM;
+    }
+
+    iov->type |= GSS_IOV_BUFFER_FLAG_ALLOCATED;
+
+    return 0;
+}