#include "gsskrb5_locl.h"
#define GSS_ARCFOUR_WRAP_TOKEN_SIZE 32
#define GSS_ARCFOUR_WRAP_TOKEN_DCE_DER_HEADER_SIZE 13
static krb5_error_code
arcfour_mic_key(krb5_context context, krb5_keyblock *key,
void *cksum_data, size_t cksum_size,
void *key6_data, size_t key6_size)
{
krb5_error_code ret;
Checksum cksum_k5;
krb5_keyblock key5;
char k5_data[16];
Checksum cksum_k6;
char T[4];
memset(T, 0, 4);
cksum_k5.checksum.data = k5_data;
cksum_k5.checksum.length = sizeof(k5_data);
if (key->keytype == KRB5_ENCTYPE_ARCFOUR_HMAC_MD5_56) {
char L40[14] = "fortybits";
memcpy(L40 + 10, T, sizeof(T));
ret = krb5_hmac(context, CKSUMTYPE_RSA_MD5,
L40, 14, 0, key, &cksum_k5);
memset(&k5_data[7], 0xAB, 9);
} else {
ret = krb5_hmac(context, CKSUMTYPE_RSA_MD5,
T, 4, 0, key, &cksum_k5);
}
if (ret)
return ret;
key5.keytype = KRB5_ENCTYPE_ARCFOUR_HMAC_MD5;
key5.keyvalue = cksum_k5.checksum;
cksum_k6.checksum.data = key6_data;
cksum_k6.checksum.length = key6_size;
return krb5_hmac(context, CKSUMTYPE_RSA_MD5,
cksum_data, cksum_size, 0, &key5, &cksum_k6);
}
static krb5_error_code
arcfour_mic_cksum(krb5_context context,
krb5_keyblock *key, unsigned usage,
u_char *sgn_cksum, size_t sgn_cksum_sz,
const u_char *v1, size_t l1,
const void *v2, size_t l2,
const void *v3, size_t l3)
{
Checksum CKSUM;
u_char *ptr;
size_t len;
krb5_crypto crypto;
krb5_error_code ret;
assert(sgn_cksum_sz == 8);
len = l1 + l2 + l3;
ptr = malloc(len);
if (ptr == NULL)
return ENOMEM;
memcpy(ptr, v1, l1);
memcpy(ptr + l1, v2, l2);
memcpy(ptr + l1 + l2, v3, l3);
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret) {
free(ptr);
return ret;
}
ret = krb5_create_checksum(context,
crypto,
usage,
0,
ptr, len,
&CKSUM);
free(ptr);
if (ret == 0) {
memcpy(sgn_cksum, CKSUM.checksum.data, sgn_cksum_sz);
free_Checksum(&CKSUM);
}
krb5_crypto_destroy(context, crypto);
return ret;
}
OM_uint32
_gssapi_get_mic_arcfour(OM_uint32 * minor_status,
const gsskrb5_ctx context_handle,
krb5_context context,
gss_qop_t qop_req,
const gss_buffer_t message_buffer,
gss_buffer_t message_token,
krb5_keyblock *key)
{
krb5_error_code ret;
int32_t seq_number;
size_t len, total_len;
u_char k6_data[16], *p0, *p;
EVP_CIPHER_CTX rc4_key;
_gsskrb5_encap_length (22, &len, &total_len, GSS_KRB5_MECHANISM);
message_token->length = total_len;
message_token->value = malloc (total_len);
if (message_token->value == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
p0 = _gssapi_make_mech_header(message_token->value,
len,
GSS_KRB5_MECHANISM);
p = p0;
*p++ = 0x01;
*p++ = 0x01;
*p++ = 0x11;
*p++ = 0x00;
*p++ = 0xff;
*p++ = 0xff;
*p++ = 0xff;
*p++ = 0xff;
p = NULL;
ret = arcfour_mic_cksum(context,
key, KRB5_KU_USAGE_SIGN,
p0 + 16, 8,
p0, 8,
message_buffer->value, message_buffer->length,
NULL, 0);
if (ret) {
_gsskrb5_release_buffer(minor_status, message_token);
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = arcfour_mic_key(context, key,
p0 + 16, 8,
k6_data, sizeof(k6_data));
if (ret) {
_gsskrb5_release_buffer(minor_status, message_token);
*minor_status = ret;
return GSS_S_FAILURE;
}
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
krb5_auth_con_getlocalseqnumber (context,
context_handle->auth_context,
&seq_number);
p = p0 + 8;
_gss_mg_encode_be_uint32(seq_number, p);
krb5_auth_con_setlocalseqnumber (context,
context_handle->auth_context,
++seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
memset (p + 4, (context_handle->more_flags & LOCAL) ? 0 : 0xff, 4);
EVP_CIPHER_CTX_init(&rc4_key);
EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
EVP_Cipher(&rc4_key, p, p, 8);
EVP_CIPHER_CTX_cleanup(&rc4_key);
memset(k6_data, 0, sizeof(k6_data));
*minor_status = 0;
return GSS_S_COMPLETE;
}
OM_uint32
_gssapi_verify_mic_arcfour(OM_uint32 * minor_status,
const gsskrb5_ctx context_handle,
krb5_context context,
const gss_buffer_t message_buffer,
const gss_buffer_t token_buffer,
gss_qop_t * qop_state,
krb5_keyblock *key,
const char *type)
{
krb5_error_code ret;
uint32_t seq_number;
OM_uint32 omret;
u_char SND_SEQ[8], cksum_data[8], *p;
char k6_data[16];
int cmp;
if (qop_state)
*qop_state = 0;
p = token_buffer->value;
omret = _gsskrb5_verify_header (&p,
token_buffer->length,
type,
GSS_KRB5_MECHANISM);
if (omret)
return omret;
if (memcmp(p, "\x11\x00", 2) != 0)
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
return GSS_S_BAD_MIC;
p += 4;
ret = arcfour_mic_cksum(context,
key, KRB5_KU_USAGE_SIGN,
cksum_data, sizeof(cksum_data),
p - 8, 8,
message_buffer->value, message_buffer->length,
NULL, 0);
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = arcfour_mic_key(context, key,
cksum_data, sizeof(cksum_data),
k6_data, sizeof(k6_data));
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
cmp = ct_memcmp(cksum_data, p + 8, 8);
if (cmp) {
*minor_status = 0;
return GSS_S_BAD_MIC;
}
{
EVP_CIPHER_CTX rc4_key;
EVP_CIPHER_CTX_init(&rc4_key);
EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, (void *)k6_data, NULL, 0);
EVP_Cipher(&rc4_key, SND_SEQ, p, 8);
EVP_CIPHER_CTX_cleanup(&rc4_key);
memset(k6_data, 0, sizeof(k6_data));
}
_gss_mg_decode_be_uint32(SND_SEQ, &seq_number);
if (context_handle->more_flags & LOCAL)
cmp = memcmp(&SND_SEQ[4], "\xff\xff\xff\xff", 4);
else
cmp = memcmp(&SND_SEQ[4], "\x00\x00\x00\x00", 4);
memset(SND_SEQ, 0, sizeof(SND_SEQ));
if (cmp != 0) {
*minor_status = 0;
return GSS_S_BAD_MIC;
}
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
omret = _gssapi_msg_order_check(context_handle->gk5c.order, seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
if (omret)
return omret;
*minor_status = 0;
return GSS_S_COMPLETE;
}
OM_uint32
_gssapi_wrap_arcfour(OM_uint32 * minor_status,
const gsskrb5_ctx context_handle,
krb5_context context,
int conf_req_flag,
gss_qop_t qop_req,
const gss_buffer_t input_message_buffer,
int * conf_state,
gss_buffer_t output_message_buffer,
krb5_keyblock *key)
{
u_char Klocaldata[16], k6_data[16], *p, *p0;
size_t len, total_len, datalen;
krb5_keyblock Klocal;
krb5_error_code ret;
int32_t seq_number;
if (conf_state)
*conf_state = 0;
datalen = input_message_buffer->length;
if (IS_DCE_STYLE(context_handle)) {
len = GSS_ARCFOUR_WRAP_TOKEN_SIZE;
_gssapi_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
total_len += datalen;
} else {
datalen += 1;
len = datalen + GSS_ARCFOUR_WRAP_TOKEN_SIZE;
_gssapi_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
}
output_message_buffer->length = total_len;
output_message_buffer->value = malloc (total_len);
if (output_message_buffer->value == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
p0 = _gssapi_make_mech_header(output_message_buffer->value,
len,
GSS_KRB5_MECHANISM);
p = p0;
*p++ = 0x02;
*p++ = 0x01;
*p++ = 0x11;
*p++ = 0x00;
if (conf_req_flag) {
*p++ = 0x10;
*p++ = 0x00;
} else {
*p++ = 0xff;
*p++ = 0xff;
}
*p++ = 0xff;
*p++ = 0xff;
p = NULL;
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
krb5_auth_con_getlocalseqnumber (context,
context_handle->auth_context,
&seq_number);
_gss_mg_encode_be_uint32(seq_number, p0 + 8);
krb5_auth_con_setlocalseqnumber (context,
context_handle->auth_context,
++seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
memset (p0 + 8 + 4,
(context_handle->more_flags & LOCAL) ? 0 : 0xff,
4);
krb5_generate_random_block(p0 + 24, 8);
p = p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE;
memcpy(p, input_message_buffer->value, input_message_buffer->length);
if (!IS_DCE_STYLE(context_handle))
p[input_message_buffer->length] = 1;
ret = arcfour_mic_cksum(context,
key, KRB5_KU_USAGE_SEAL,
p0 + 16, 8,
p0, 8,
p0 + 24, 8,
p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE,
datalen);
if (ret) {
*minor_status = ret;
_gsskrb5_release_buffer(minor_status, output_message_buffer);
return GSS_S_FAILURE;
}
{
int i;
Klocal.keytype = key->keytype;
Klocal.keyvalue.data = Klocaldata;
Klocal.keyvalue.length = sizeof(Klocaldata);
for (i = 0; i < 16; i++)
Klocaldata[i] = ((u_char *)key->keyvalue.data)[i] ^ 0xF0;
}
ret = arcfour_mic_key(context, &Klocal,
p0 + 8, 4,
k6_data, sizeof(k6_data));
memset(Klocaldata, 0, sizeof(Klocaldata));
if (ret) {
_gsskrb5_release_buffer(minor_status, output_message_buffer);
*minor_status = ret;
return GSS_S_FAILURE;
}
if(conf_req_flag) {
EVP_CIPHER_CTX rc4_key;
EVP_CIPHER_CTX_init(&rc4_key);
EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
EVP_Cipher(&rc4_key, p0 + 24, p0 + 24, 8 + datalen);
EVP_CIPHER_CTX_cleanup(&rc4_key);
}
memset(k6_data, 0, sizeof(k6_data));
ret = arcfour_mic_key(context, key,
p0 + 16, 8,
k6_data, sizeof(k6_data));
if (ret) {
_gsskrb5_release_buffer(minor_status, output_message_buffer);
*minor_status = ret;
return GSS_S_FAILURE;
}
{
EVP_CIPHER_CTX rc4_key;
EVP_CIPHER_CTX_init(&rc4_key);
EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
EVP_Cipher(&rc4_key, p0 + 8, p0 + 8 , 8);
EVP_CIPHER_CTX_cleanup(&rc4_key);
memset(k6_data, 0, sizeof(k6_data));
}
if (conf_state)
*conf_state = conf_req_flag;
*minor_status = 0;
return GSS_S_COMPLETE;
}
OM_uint32 _gssapi_unwrap_arcfour(OM_uint32 *minor_status,
const gsskrb5_ctx context_handle,
krb5_context context,
const gss_buffer_t input_message_buffer,
gss_buffer_t output_message_buffer,
int *conf_state,
gss_qop_t *qop_state,
krb5_keyblock *key)
{
u_char Klocaldata[16];
krb5_keyblock Klocal;
krb5_error_code ret;
uint32_t seq_number;
size_t datalen;
OM_uint32 omret;
u_char k6_data[16], SND_SEQ[8], Confounder[8];
u_char cksum_data[8];
u_char *p, *p0;
int cmp;
int conf_flag;
size_t padlen = 0, len;
if (conf_state)
*conf_state = 0;
if (qop_state)
*qop_state = 0;
p0 = input_message_buffer->value;
if (IS_DCE_STYLE(context_handle)) {
len = GSS_ARCFOUR_WRAP_TOKEN_SIZE +
GSS_ARCFOUR_WRAP_TOKEN_DCE_DER_HEADER_SIZE;
if (input_message_buffer->length < len)
return GSS_S_BAD_MECH;
} else {
len = input_message_buffer->length;
}
omret = _gssapi_verify_mech_header(&p0,
len,
GSS_KRB5_MECHANISM);
if (omret)
return omret;
len = (p0 - (u_char *)input_message_buffer->value) +
GSS_ARCFOUR_WRAP_TOKEN_SIZE;
if (len > input_message_buffer->length)
return GSS_S_BAD_MECH;
datalen = input_message_buffer->length - len;
p = p0;
if (memcmp(p, "\x02\x01", 2) != 0)
return GSS_S_BAD_SIG;
p += 2;
if (memcmp(p, "\x11\x00", 2) != 0)
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\x10\x00", 2) == 0)
conf_flag = 1;
else if (memcmp (p, "\xff\xff", 2) == 0)
conf_flag = 0;
else
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\xff\xff", 2) != 0)
return GSS_S_BAD_MIC;
p = NULL;
ret = arcfour_mic_key(context, key,
p0 + 16, 8,
k6_data, sizeof(k6_data));
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
{
EVP_CIPHER_CTX rc4_key;
EVP_CIPHER_CTX_init(&rc4_key);
EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
EVP_Cipher(&rc4_key, SND_SEQ, p0 + 8, 8);
EVP_CIPHER_CTX_cleanup(&rc4_key);
memset(k6_data, 0, sizeof(k6_data));
}
_gss_mg_decode_be_uint32(SND_SEQ, &seq_number);
if (context_handle->more_flags & LOCAL)
cmp = memcmp(&SND_SEQ[4], "\xff\xff\xff\xff", 4);
else
cmp = memcmp(&SND_SEQ[4], "\x00\x00\x00\x00", 4);
if (cmp != 0) {
*minor_status = 0;
return GSS_S_BAD_MIC;
}
{
int i;
Klocal.keytype = key->keytype;
Klocal.keyvalue.data = Klocaldata;
Klocal.keyvalue.length = sizeof(Klocaldata);
for (i = 0; i < 16; i++)
Klocaldata[i] = ((u_char *)key->keyvalue.data)[i] ^ 0xF0;
}
ret = arcfour_mic_key(context, &Klocal,
SND_SEQ, 4,
k6_data, sizeof(k6_data));
memset(Klocaldata, 0, sizeof(Klocaldata));
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
output_message_buffer->value = malloc(datalen);
if (output_message_buffer->value == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
output_message_buffer->length = datalen;
if(conf_flag) {
EVP_CIPHER_CTX rc4_key;
EVP_CIPHER_CTX_init(&rc4_key);
EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
EVP_Cipher(&rc4_key, Confounder, p0 + 24, 8);
EVP_Cipher(&rc4_key, output_message_buffer->value, p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE, datalen);
EVP_CIPHER_CTX_cleanup(&rc4_key);
} else {
memcpy(Confounder, p0 + 24, 8);
memcpy(output_message_buffer->value,
p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE,
datalen);
}
memset(k6_data, 0, sizeof(k6_data));
if (!IS_DCE_STYLE(context_handle)) {
ret = _gssapi_verify_pad(output_message_buffer, datalen, &padlen);
if (ret) {
_gsskrb5_release_buffer(minor_status, output_message_buffer);
*minor_status = 0;
return ret;
}
output_message_buffer->length -= padlen;
}
ret = arcfour_mic_cksum(context,
key, KRB5_KU_USAGE_SEAL,
cksum_data, sizeof(cksum_data),
p0, 8,
Confounder, sizeof(Confounder),
output_message_buffer->value,
output_message_buffer->length + padlen);
if (ret) {
_gsskrb5_release_buffer(minor_status, output_message_buffer);
*minor_status = ret;
return GSS_S_FAILURE;
}
cmp = ct_memcmp(cksum_data, p0 + 16, 8);
if (cmp) {
_gsskrb5_release_buffer(minor_status, output_message_buffer);
*minor_status = 0;
return GSS_S_BAD_MIC;
}
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
omret = _gssapi_msg_order_check(context_handle->gk5c.order, seq_number);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
if (omret)
return omret;
if (conf_state)
*conf_state = conf_flag;
*minor_status = 0;
return GSS_S_COMPLETE;
}
static OM_uint32
max_wrap_length_arcfour(const gsskrb5_ctx ctx,
krb5_crypto crypto,
size_t input_length,
OM_uint32 *max_input_size)
{
if (IS_DCE_STYLE(ctx)) {
size_t len, total_len;
len = GSS_ARCFOUR_WRAP_TOKEN_SIZE;
_gssapi_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
if (input_length < len)
*max_input_size = 0;
else
*max_input_size = (OM_uint32)(input_length - len);
} else {
size_t extrasize = GSS_ARCFOUR_WRAP_TOKEN_SIZE;
size_t blocksize = 8;
size_t len, total_len;
len = 8 + input_length + blocksize + extrasize;
_gsskrb5_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
total_len -= input_length;
if (total_len < input_length) {
*max_input_size = (OM_uint32)(input_length - total_len);
(*max_input_size) &= (~(OM_uint32)(blocksize - 1));
} else {
*max_input_size = 0;
}
}
return GSS_S_COMPLETE;
}
OM_uint32
_gssapi_wrap_size_arcfour(OM_uint32 *minor_status,
const gsskrb5_ctx ctx,
krb5_context context,
int conf_req_flag,
gss_qop_t qop_req,
OM_uint32 req_output_size,
OM_uint32 *max_input_size,
krb5_keyblock *key)
{
krb5_error_code ret;
krb5_crypto crypto;
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret != 0) {
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = max_wrap_length_arcfour(ctx, crypto,
req_output_size, max_input_size);
if (ret != 0) {
*minor_status = ret;
krb5_crypto_destroy(context, crypto);
return GSS_S_FAILURE;
}
krb5_crypto_destroy(context, crypto);
return GSS_S_COMPLETE;
}