/*
* Split a STREAM | SIGN_DATA | DATA into
* HEADER | SIGN_DATA | DATA | PADDING | TRAILER
*/
static OM_uint32
kg_unseal_stream_iov(OM_uint32 *minor_status,
krb5_gss_ctx_id_rec *ctx,
int *conf_state,
gss_qop_t *qop_state,
gss_iov_buffer_desc *iov,
int iov_count,
int toktype)
{
unsigned char *ptr;
unsigned int bodysize;
OM_uint32 code = 0, major_status = GSS_S_FAILURE;
krb5_context context = ctx->k5_context;
int conf_req_flag, toktype2;
int i = 0, j;
gss_iov_buffer_desc *tiov = NULL;
gss_iov_buffer_t stream, data = NULL;
gss_iov_buffer_t theader, tdata = NULL, tpadding, ttrailer;
assert(toktype == KG_TOK_WRAP_MSG);
if (toktype != KG_TOK_WRAP_MSG || (ctx->gss_flags & GSS_C_DCE_STYLE)) {
code = EINVAL;
goto cleanup;
}
stream = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_STREAM);
assert(stream != NULL);
ptr = (unsigned char *)stream->buffer.value;
code = g_verify_token_header(ctx->mech_used,
&bodysize, &ptr, -1,
stream->buffer.length, 0);
if (code != 0) {
major_status = GSS_S_DEFECTIVE_TOKEN;
goto cleanup;
}
if (bodysize < 2) {
*minor_status = (OM_uint32)G_BAD_TOK_HEADER;
return GSS_S_DEFECTIVE_TOKEN;
}
toktype2 = load_16_be(ptr);
ptr += 2;
bodysize -= 2;
tiov = (gss_iov_buffer_desc *)calloc((size_t)iov_count + 2, sizeof(gss_iov_buffer_desc));
if (tiov == NULL) {
code = ENOMEM;
goto cleanup;
}
/* HEADER */
theader = &tiov[i++];
theader->type = GSS_IOV_BUFFER_TYPE_HEADER;
theader->buffer.value = stream->buffer.value;
theader->buffer.length = ptr - (unsigned char *)stream->buffer.value;
if (bodysize < 14 ||
stream->buffer.length != theader->buffer.length + bodysize) {
major_status = GSS_S_DEFECTIVE_TOKEN;
goto cleanup;
}
theader->buffer.length += 14;
/* n[SIGN_DATA] | DATA | m[SIGN_DATA] */
for (j = 0; j < iov_count; j++) {
OM_uint32 type = GSS_IOV_BUFFER_TYPE(iov[j].type);
if (type == GSS_IOV_BUFFER_TYPE_DATA) {
if (data != NULL) {
/* only a single DATA buffer can appear */
code = EINVAL;
goto cleanup;
}
data = &iov[j];
tdata = &tiov[i];
}
if (type == GSS_IOV_BUFFER_TYPE_DATA ||
type == GSS_IOV_BUFFER_TYPE_SIGN_ONLY)
tiov[i++] = iov[j];
}
if (data == NULL) {
/* a single DATA buffer must be present */
code = EINVAL;
goto cleanup;
}
/* PADDING | TRAILER */
tpadding = &tiov[i++];
tpadding->type = GSS_IOV_BUFFER_TYPE_PADDING;
tpadding->buffer.length = 0;
tpadding->buffer.value = NULL;
ttrailer = &tiov[i++];
ttrailer->type = GSS_IOV_BUFFER_TYPE_TRAILER;
switch (toktype2) {
case KG2_TOK_MIC_MSG:
case KG2_TOK_WRAP_MSG:
case KG2_TOK_DEL_CTX: {
size_t ec, rrc;
krb5_enctype enctype;
unsigned int k5_headerlen = 0;
unsigned int k5_trailerlen = 0;
if (ctx->have_acceptor_subkey)
enctype = ctx->acceptor_subkey->keyblock.enctype;
else
enctype = ctx->subkey->keyblock.enctype;
conf_req_flag = ((ptr[0] & FLAG_WRAP_CONFIDENTIAL) != 0);
ec = conf_req_flag ? load_16_be(ptr + 2) : 0;
rrc = load_16_be(ptr + 4);
if (rrc != 0) {
if (!gss_krb5int_rotate_left((unsigned char *)stream->buffer.value + 16,
stream->buffer.length - 16, rrc)) {
code = ENOMEM;
goto cleanup;
}
store_16_be(0, ptr + 4); /* set RRC to zero */
}
if (conf_req_flag) {
code = krb5_c_crypto_length(context, enctype, KRB5_CRYPTO_TYPE_HEADER, &k5_headerlen);
if (code != 0)
goto cleanup;
theader->buffer.length += k5_headerlen; /* length validated later */
}
/* no PADDING for CFX, EC is used instead */
code = krb5_c_crypto_length(context, enctype,
conf_req_flag ? KRB5_CRYPTO_TYPE_TRAILER : KRB5_CRYPTO_TYPE_CHECKSUM,
&k5_trailerlen);
if (code != 0)
goto cleanup;
ttrailer->buffer.length = ec + (conf_req_flag ? 16 : 0 /* E(Header) */) + k5_trailerlen;
ttrailer->buffer.value = (unsigned char *)stream->buffer.value +
stream->buffer.length - ttrailer->buffer.length;
break;
}
case KG_TOK_MIC_MSG:
case KG_TOK_WRAP_MSG:
case KG_TOK_DEL_CTX:
theader->buffer.length += ctx->cksum_size +
kg_confounder_size(context, ctx->enc->keyblock.enctype);
/*
* we can't set the padding accurately until decryption;
* kg_fixup_padding_iov() will take care of this
*/
tpadding->buffer.length = 1;
tpadding->buffer.value = (unsigned char *)stream->buffer.value + stream->buffer.length - 1;
/* no TRAILER for pre-CFX */
ttrailer->buffer.length = 0;
ttrailer->buffer.value = NULL;
break;
default:
code = (OM_uint32)G_BAD_TOK_HEADER;
major_status = GSS_S_DEFECTIVE_TOKEN;
goto cleanup;
break;
}
/* IOV: -----------0-------------+---1---+--2--+----------------3--------------*/
/* Old: GSS-Header | Conf | Data | Pad | */
/* CFX: GSS-Header | Kerb-Header | Data | | EC | E(Header) | Kerb-Trailer */
/* GSS: -------GSS-HEADER--------+-DATA--+-PAD-+----------GSS-TRAILER----------*/
/* validate lengths */
if (stream->buffer.length < theader->buffer.length +
tpadding->buffer.length +
ttrailer->buffer.length)
{
code = (OM_uint32)KRB5_BAD_MSIZE;
major_status = GSS_S_DEFECTIVE_TOKEN;
goto cleanup;
}
/* setup data */
tdata->buffer.length = stream->buffer.length - ttrailer->buffer.length -
tpadding->buffer.length - theader->buffer.length;
assert(data != NULL);
if (data->type & GSS_IOV_BUFFER_FLAG_ALLOCATE) {
code = kg_allocate_iov(tdata, tdata->buffer.length);
if (code != 0)
goto cleanup;
memcpy(tdata->buffer.value,
(unsigned char *)stream->buffer.value + theader->buffer.length, tdata->buffer.length);
} else
tdata->buffer.value = (unsigned char *)stream->buffer.value + theader->buffer.length;
assert(i <= iov_count + 2);
major_status = kg_unseal_iov_token(&code, ctx, conf_state, qop_state,
tiov, i, toktype);
if (major_status == GSS_S_COMPLETE)
*data = *tdata;
else
kg_release_iov(tdata, 1);
cleanup:
if (tiov != NULL)
free(tiov);
*minor_status = code;
return major_status;
}
static krb5_error_code
make_seal_token_v1_iov(krb5_context context,
krb5_gss_ctx_id_rec *ctx,
int conf_req_flag,
int *conf_state,
gss_iov_buffer_desc *iov,
int iov_count,
int toktype)
{
krb5_error_code code = 0;
gss_iov_buffer_t header;
gss_iov_buffer_t padding;
gss_iov_buffer_t trailer;
krb5_checksum md5cksum;
krb5_checksum cksum;
size_t k5_headerlen = 0, k5_trailerlen = 0;
size_t data_length = 0, assoc_data_length = 0;
size_t tmsglen = 0, tlen;
unsigned char *ptr;
krb5_keyusage sign_usage = KG_USAGE_SIGN;
assert(toktype == KG_TOK_WRAP_MSG);
md5cksum.length = cksum.length = 0;
md5cksum.contents = cksum.contents = NULL;
header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
if (header == NULL)
return EINVAL;
padding = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
if (padding == NULL && (ctx->gss_flags & GSS_C_DCE_STYLE) == 0)
return EINVAL;
trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
if (trailer != NULL)
trailer->buffer.length = 0;
/* Determine confounder length */
if (toktype == KG_TOK_WRAP_MSG || conf_req_flag)
k5_headerlen = kg_confounder_size(context, ctx->enc);
/* Check padding length */
if (toktype == KG_TOK_WRAP_MSG) {
size_t k5_padlen = (ctx->sealalg == SEAL_ALG_MICROSOFT_RC4) ? 1 : 8;
size_t gss_padlen;
size_t conf_data_length;
kg_iov_msglen(iov, iov_count, &data_length, &assoc_data_length);
conf_data_length = k5_headerlen + data_length - assoc_data_length;
if (k5_padlen == 1)
gss_padlen = 1; /* one byte to indicate one byte of padding */
else
gss_padlen = k5_padlen - (conf_data_length % k5_padlen);
if (ctx->gss_flags & GSS_C_DCE_STYLE) {
/* DCE will pad the actual data itself; padding buffer optional and will be zeroed */
gss_padlen = 0;
if (conf_data_length % k5_padlen)
code = KRB5_BAD_MSIZE;
} else if (padding->type & GSS_IOV_BUFFER_FLAG_ALLOCATE) {
code = kg_allocate_iov(padding, gss_padlen);
} else if (padding->buffer.length < gss_padlen) {
code = KRB5_BAD_MSIZE;
}
if (code != 0)
goto cleanup;
/* Initialize padding buffer to pad itself */
if (padding != NULL) {
padding->buffer.length = gss_padlen;
memset(padding->buffer.value, (int)gss_padlen, gss_padlen);
}
if (ctx->gss_flags & GSS_C_DCE_STYLE)
tmsglen = k5_headerlen; /* confounder length */
else
tmsglen = conf_data_length + padding->buffer.length + assoc_data_length;
}
/* Determine token size */
tlen = g_token_size(ctx->mech_used, 14 + ctx->cksum_size + tmsglen);
k5_headerlen += tlen - tmsglen;
if (header->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
code = kg_allocate_iov(header, k5_headerlen);
else if (header->buffer.length < k5_headerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
header->buffer.length = k5_headerlen;
ptr = (unsigned char *)header->buffer.value;
g_make_token_header(ctx->mech_used, 14 + ctx->cksum_size + tmsglen, &ptr, toktype);
/* 0..1 SIGN_ALG */
store_16_le(ctx->signalg, &ptr[0]);
/* 2..3 SEAL_ALG or Filler */
if (toktype == KG_TOK_WRAP_MSG && conf_req_flag) {
store_16_le(ctx->sealalg, &ptr[2]);
} else {
/* No seal */
ptr[2] = 0xFF;
ptr[3] = 0xFF;
}
/* 4..5 Filler */
ptr[4] = 0xFF;
ptr[5] = 0xFF;
/* pad the plaintext, encrypt if needed, and stick it in the token */
/* initialize the checksum */
switch (ctx->signalg) {
case SGN_ALG_DES_MAC_MD5:
case SGN_ALG_MD2_5:
md5cksum.checksum_type = CKSUMTYPE_RSA_MD5;
break;
case SGN_ALG_HMAC_SHA1_DES3_KD:
md5cksum.checksum_type = CKSUMTYPE_HMAC_SHA1_DES3;
break;
case SGN_ALG_HMAC_MD5:
md5cksum.checksum_type = CKSUMTYPE_HMAC_MD5_ARCFOUR;
if (toktype != KG_TOK_WRAP_MSG)
sign_usage = 15;
break;
default:
case SGN_ALG_DES_MAC:
abort ();
}
code = krb5_c_checksum_length(context, md5cksum.checksum_type, &k5_trailerlen);
if (code != 0)
goto cleanup;
md5cksum.length = k5_trailerlen;
if (k5_headerlen != 0) {
code = kg_make_confounder(context, ctx->enc, ptr + 14 + ctx->cksum_size);
if (code != 0)
goto cleanup;
}
/* compute the checksum */
code = kg_make_checksum_iov_v1(context, md5cksum.checksum_type,
ctx->cksum_size, ctx->seq, ctx->enc,
sign_usage, iov, iov_count, toktype,
&md5cksum);
if (code != 0)
goto cleanup;
switch (ctx->signalg) {
case SGN_ALG_DES_MAC_MD5:
case SGN_ALG_3:
code = kg_encrypt(context, ctx->seq, KG_USAGE_SEAL,
(g_OID_equal(ctx->mech_used, gss_mech_krb5_old) ?
ctx->seq->contents : NULL),
md5cksum.contents, md5cksum.contents, 16);
if (code != 0)
goto cleanup;
cksum.length = ctx->cksum_size;
cksum.contents = md5cksum.contents + 16 - cksum.length;
memcpy(ptr + 14, cksum.contents, cksum.length);
break;
case SGN_ALG_HMAC_SHA1_DES3_KD:
assert(md5cksum.length == ctx->cksum_size);
memcpy(ptr + 14, md5cksum.contents, md5cksum.length);
break;
case SGN_ALG_HMAC_MD5:
memcpy(ptr + 14, md5cksum.contents, ctx->cksum_size);
break;
}
/* create the seq_num */
code = kg_make_seq_num(context, ctx->seq, ctx->initiate ? 0 : 0xFF,
(OM_uint32)ctx->seq_send, ptr + 14, ptr + 6);
if (code != 0)
goto cleanup;
if (conf_req_flag) {
if (ctx->sealalg == SEAL_ALG_MICROSOFT_RC4) {
unsigned char bigend_seqnum[4];
krb5_keyblock *enc_key;
size_t i;
store_32_be(ctx->seq_send, bigend_seqnum);
code = krb5_copy_keyblock(context, ctx->enc, &enc_key);
if (code != 0)
goto cleanup;
assert(enc_key->length == 16);
for (i = 0; i < enc_key->length; i++)
((char *)enc_key->contents)[i] ^= 0xF0;
code = kg_arcfour_docrypt_iov(context, enc_key, 0,
bigend_seqnum, 4,
iov, iov_count);
krb5_free_keyblock(context, enc_key);
} else {
code = kg_encrypt_iov(context, ctx->proto,
((ctx->gss_flags & GSS_C_DCE_STYLE) != 0),
0 /*EC*/, 0 /*RRC*/,
ctx->enc, KG_USAGE_SEAL, NULL,
iov, iov_count);
}
if (code != 0)
goto cleanup;
}
ctx->seq_send++;
ctx->seq_send &= 0xFFFFFFFFL;
code = 0;
if (conf_state != NULL)
*conf_state = conf_req_flag;
cleanup:
if (code != 0)
kg_release_iov(iov, iov_count);
krb5_free_checksum_contents(context, &md5cksum);
return code;
}
krb5_error_code
gss_krb5int_make_seal_token_v3_iov(krb5_context context,
krb5_gss_ctx_id_rec *ctx,
int conf_req_flag,
int *conf_state,
gss_iov_buffer_desc *iov,
int iov_count,
int toktype)
{
krb5_error_code code = 0;
gss_iov_buffer_t header;
gss_iov_buffer_t padding;
gss_iov_buffer_t trailer;
unsigned char acceptor_flag;
unsigned short tok_id;
unsigned char *outbuf = NULL;
unsigned char *tbuf = NULL;
int key_usage;
size_t rrc = 0;
unsigned int gss_headerlen, gss_trailerlen;
krb5_key key;
krb5_cksumtype cksumtype;
size_t data_length, assoc_data_length;
assert(ctx->big_endian == 0);
assert(ctx->proto == 1);
acceptor_flag = ctx->initiate ? 0 : FLAG_SENDER_IS_ACCEPTOR;
key_usage = (toktype == KG_TOK_WRAP_MSG
? (ctx->initiate
? KG_USAGE_INITIATOR_SEAL
: KG_USAGE_ACCEPTOR_SEAL)
: (ctx->initiate
? KG_USAGE_INITIATOR_SIGN
: KG_USAGE_ACCEPTOR_SIGN));
if (ctx->have_acceptor_subkey) {
key = ctx->acceptor_subkey;
cksumtype = ctx->acceptor_subkey_cksumtype;
} else {
key = ctx->subkey;
cksumtype = ctx->cksumtype;
}
assert(key != NULL);
assert(cksumtype != 0);
kg_iov_msglen(iov, iov_count, &data_length, &assoc_data_length);
header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
if (header == NULL)
return EINVAL;
padding = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
if (padding != NULL)
padding->buffer.length = 0;
trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
if (toktype == KG_TOK_WRAP_MSG && conf_req_flag) {
unsigned int k5_headerlen, k5_trailerlen, k5_padlen;
size_t ec = 0;
size_t conf_data_length = data_length - assoc_data_length;
code = krb5_c_crypto_length(context, key->keyblock.enctype,
KRB5_CRYPTO_TYPE_HEADER, &k5_headerlen);
if (code != 0)
goto cleanup;
code = krb5_c_padding_length(context, key->keyblock.enctype,
conf_data_length + 16 /* E(Header) */, &k5_padlen);
if (code != 0)
goto cleanup;
if (k5_padlen == 0 && (ctx->gss_flags & GSS_C_DCE_STYLE)) {
/* Windows rejects AEAD tokens with non-zero EC */
code = krb5_c_block_size(context, key->keyblock.enctype, &ec);
if (code != 0)
goto cleanup;
} else
ec = k5_padlen;
code = krb5_c_crypto_length(context, key->keyblock.enctype,
KRB5_CRYPTO_TYPE_TRAILER, &k5_trailerlen);
if (code != 0)
goto cleanup;
gss_headerlen = 16 /* Header */ + k5_headerlen;
gss_trailerlen = ec + 16 /* E(Header) */ + k5_trailerlen;
if (trailer == NULL) {
rrc = gss_trailerlen;
/* Workaround for Windows bug where it rotates by EC + RRC */
if (ctx->gss_flags & GSS_C_DCE_STYLE)
rrc -= ec;
gss_headerlen += gss_trailerlen;
}
if (header->type & GSS_IOV_BUFFER_FLAG_ALLOCATE) {
code = kg_allocate_iov(header, (size_t) gss_headerlen);
} else if (header->buffer.length < gss_headerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
outbuf = (unsigned char *)header->buffer.value;
header->buffer.length = (size_t) gss_headerlen;
if (trailer != NULL) {
if (trailer->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
code = kg_allocate_iov(trailer, (size_t) gss_trailerlen);
else if (trailer->buffer.length < gss_trailerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
trailer->buffer.length = (size_t) gss_trailerlen;
}
/* TOK_ID */
store_16_be(KG2_TOK_WRAP_MSG, outbuf);
/* flags */
outbuf[2] = (acceptor_flag
| (conf_req_flag ? FLAG_WRAP_CONFIDENTIAL : 0)
| (ctx->have_acceptor_subkey ? FLAG_ACCEPTOR_SUBKEY : 0));
/* filler */
outbuf[3] = 0xFF;
/* EC */
store_16_be(ec, outbuf + 4);
/* RRC */
store_16_be(0, outbuf + 6);
store_64_be(ctx->seq_send, outbuf + 8);
/* EC | copy of header to be encrypted, located in (possibly rotated) trailer */
if (trailer == NULL)
tbuf = (unsigned char *)header->buffer.value + 16; /* Header */
else
tbuf = (unsigned char *)trailer->buffer.value;
memset(tbuf, 0xFF, ec);
memcpy(tbuf + ec, header->buffer.value, 16);
code = kg_encrypt_iov(context, ctx->proto,
((ctx->gss_flags & GSS_C_DCE_STYLE) != 0),
ec, rrc, key, key_usage, 0, iov, iov_count);
if (code != 0)
goto cleanup;
/* RRC */
store_16_be(rrc, outbuf + 6);
ctx->seq_send++;
} else if (toktype == KG_TOK_WRAP_MSG && !conf_req_flag) {
tok_id = KG2_TOK_WRAP_MSG;
wrap_with_checksum:
gss_headerlen = 16;
code = krb5_c_crypto_length(context, key->keyblock.enctype,
KRB5_CRYPTO_TYPE_CHECKSUM,
&gss_trailerlen);
if (code != 0)
goto cleanup;
assert(gss_trailerlen <= 0xFFFF);
if (trailer == NULL) {
rrc = gss_trailerlen;
gss_headerlen += gss_trailerlen;
}
if (header->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
code = kg_allocate_iov(header, (size_t) gss_headerlen);
else if (header->buffer.length < gss_headerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
outbuf = (unsigned char *)header->buffer.value;
header->buffer.length = (size_t) gss_headerlen;
if (trailer != NULL) {
if (trailer->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
code = kg_allocate_iov(trailer, (size_t) gss_trailerlen);
else if (trailer->buffer.length < gss_trailerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
trailer->buffer.length = (size_t) gss_trailerlen;
}
/* TOK_ID */
store_16_be(tok_id, outbuf);
/* flags */
outbuf[2] = (acceptor_flag
| (ctx->have_acceptor_subkey ? FLAG_ACCEPTOR_SUBKEY : 0));
/* filler */
outbuf[3] = 0xFF;
if (toktype == KG_TOK_WRAP_MSG) {
/* Use 0 for checksum calculation, substitute
* checksum length later.
*/
/* EC */
store_16_be(0, outbuf + 4);
/* RRC */
store_16_be(0, outbuf + 6);
} else {
/* MIC and DEL store 0xFF in EC and RRC */
store_16_be(0xFFFF, outbuf + 4);
store_16_be(0xFFFF, outbuf + 6);
}
store_64_be(ctx->seq_send, outbuf + 8);
code = kg_make_checksum_iov_v3(context, cksumtype,
rrc, key, key_usage,
iov, iov_count);
if (code != 0)
goto cleanup;
ctx->seq_send++;
if (toktype == KG_TOK_WRAP_MSG) {
/* Fix up EC field */
store_16_be(gss_trailerlen, outbuf + 4);
/* Fix up RRC field */
store_16_be(rrc, outbuf + 6);
}
} else if (toktype == KG_TOK_MIC_MSG) {
tok_id = KG2_TOK_MIC_MSG;
trailer = NULL;
goto wrap_with_checksum;
} else if (toktype == KG_TOK_DEL_CTX) {
tok_id = KG2_TOK_DEL_CTX;
goto wrap_with_checksum;
} else {
abort();
}
code = 0;
if (conf_state != NULL)
*conf_state = conf_req_flag;
cleanup:
if (code != 0)
kg_release_iov(iov, iov_count);
return code;
}
