ssize_t
do_read (int fd, void *buf, size_t sz, void *ivec)
{
if (do_encrypt) {
#ifdef KRB5
if(auth_method == AUTH_KRB5) {
krb5_error_code ret;
uint32_t len, outer_len;
int status;
krb5_data data;
void *edata;
ret = krb5_net_read (context, &fd, &len, 4);
if (ret <= 0)
return ret;
len = ntohl(len);
if (len > sz)
abort ();
/* ivec will be non null for protocol version 2 */
if(ivec != NULL)
outer_len = krb5_get_wrapped_length (context, crypto, len + 4);
else
outer_len = krb5_get_wrapped_length (context, crypto, len);
edata = malloc (outer_len);
if (edata == NULL)
errx (1, "malloc: cannot allocate %u bytes", outer_len);
ret = krb5_net_read (context, &fd, edata, outer_len);
if (ret <= 0) {
free(edata);
return ret;
}
status = krb5_decrypt_ivec(context, crypto, key_usage,
edata, outer_len, &data, ivec);
free (edata);
if (status)
krb5_err (context, 1, status, "decrypting data");
if(ivec != NULL) {
unsigned long l;
if(data.length < len + 4)
errx (1, "data received is too short");
_krb5_get_int(data.data, &l, 4);
if(l != len)
errx (1, "inconsistency in received data");
memcpy (buf, (unsigned char *)data.data+4, len);
} else
memcpy (buf, data.data, len);
krb5_data_free (&data);
return len;
} else
#endif /* KRB5 */
abort ();
} else
return read (fd, buf, sz);
}
static OM_uint32
verify_mic_des3
(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,
char *type
)
{
u_char *p;
u_char *seq;
uint32_t seq_number;
OM_uint32 ret;
krb5_crypto crypto;
krb5_data seq_data;
int cmp, docompat;
Checksum csum;
char *tmp;
char ivec[8];
p = token_buffer->value;
ret = _gsskrb5_verify_header (&p,
token_buffer->length,
type,
GSS_KRB5_MECHANISM);
if (ret)
return ret;
if (memcmp(p, "\x04\x00", 2) != 0) /* SGN_ALG = HMAC SHA1 DES3-KD */
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
return GSS_S_BAD_MIC;
p += 4;
ret = krb5_crypto_init(context, key,
ETYPE_DES3_CBC_NONE, &crypto);
if (ret){
*minor_status = ret;
return GSS_S_FAILURE;
}
/* verify sequence number */
docompat = 0;
retry:
if (docompat)
memset(ivec, 0, 8);
else
memcpy(ivec, p + 8, 8);
ret = krb5_decrypt_ivec (context,
crypto,
KRB5_KU_USAGE_SEQ,
p, 8, &seq_data, ivec);
if (ret) {
if (docompat++) {
krb5_crypto_destroy (context, crypto);
*minor_status = ret;
return GSS_S_FAILURE;
} else
goto retry;
}
if (seq_data.length != 8) {
krb5_data_free (&seq_data);
if (docompat++) {
krb5_crypto_destroy (context, crypto);
return GSS_S_BAD_MIC;
} else
goto retry;
}
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
seq = seq_data.data;
_gsskrb5_decode_om_uint32(seq, &seq_number);
if (context_handle->more_flags & LOCAL)
cmp = ct_memcmp(&seq[4], "\xff\xff\xff\xff", 4);
else
cmp = ct_memcmp(&seq[4], "\x00\x00\x00\x00", 4);
krb5_data_free (&seq_data);
if (cmp != 0) {
krb5_crypto_destroy (context, crypto);
*minor_status = 0;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_BAD_MIC;
}
ret = _gssapi_msg_order_check(context_handle->order, seq_number);
if (ret) {
krb5_crypto_destroy (context, crypto);
*minor_status = 0;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return ret;
}
/* verify checksum */
tmp = malloc (message_buffer->length + 8);
if (tmp == NULL) {
krb5_crypto_destroy (context, crypto);
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
memcpy (tmp, p - 8, 8);
memcpy (tmp + 8, message_buffer->value, message_buffer->length);
csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3;
csum.checksum.length = 20;
csum.checksum.data = p + 8;
ret = krb5_verify_checksum (context, crypto,
KRB5_KU_USAGE_SIGN,
tmp, message_buffer->length + 8,
&csum);
free (tmp);
if (ret) {
krb5_crypto_destroy (context, crypto);
*minor_status = ret;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_BAD_MIC;
}
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
krb5_crypto_destroy (context, crypto);
return GSS_S_COMPLETE;
}
static OM_uint32
unwrap_des3
(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 *p;
size_t len;
u_char *seq;
krb5_data seq_data;
u_char cksum[20];
uint32_t seq_number;
size_t padlength;
OM_uint32 ret;
int cstate;
krb5_crypto crypto;
Checksum csum;
int cmp;
p = input_message_buffer->value;
ret = _gsskrb5_verify_header (&p,
input_message_buffer->length,
"\x02\x01",
GSS_KRB5_MECHANISM);
if (ret)
return ret;
if (memcmp (p, "\x04\x00", 2) != 0) /* HMAC SHA1 DES3_KD */
return GSS_S_BAD_SIG;
p += 2;
if (memcmp (p, "\x02\x00", 2) == 0) {
cstate = 1;
} else if (memcmp (p, "\xff\xff", 2) == 0) {
cstate = 0;
} else
return GSS_S_BAD_MIC;
p += 2;
if(conf_state != NULL)
*conf_state = cstate;
if (memcmp (p, "\xff\xff", 2) != 0)
return GSS_S_DEFECTIVE_TOKEN;
p += 2;
p += 28;
len = p - (u_char *)input_message_buffer->value;
if(cstate) {
/* decrypt data */
krb5_data tmp;
ret = krb5_crypto_init(context, key,
ETYPE_DES3_CBC_NONE, &crypto);
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = krb5_decrypt(context, crypto, KRB5_KU_USAGE_SEAL,
p, input_message_buffer->length - len, &tmp);
krb5_crypto_destroy(context, crypto);
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
assert (tmp.length == input_message_buffer->length - len);
memcpy (p, tmp.data, tmp.length);
krb5_data_free(&tmp);
}
/* check pad */
ret = _gssapi_verify_pad(input_message_buffer,
input_message_buffer->length - len,
&padlength);
if (ret)
return ret;
/* verify sequence number */
HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
p -= 28;
ret = krb5_crypto_init(context, key,
ETYPE_DES3_CBC_NONE, &crypto);
if (ret) {
*minor_status = ret;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_FAILURE;
}
{
DES_cblock ivec;
memcpy(&ivec, p + 8, 8);
ret = krb5_decrypt_ivec (context,
crypto,
KRB5_KU_USAGE_SEQ,
p, 8, &seq_data,
&ivec);
}
krb5_crypto_destroy (context, crypto);
if (ret) {
*minor_status = ret;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_FAILURE;
}
if (seq_data.length != 8) {
krb5_data_free (&seq_data);
*minor_status = 0;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_BAD_MIC;
}
seq = seq_data.data;
_gsskrb5_decode_om_uint32(seq, &seq_number);
if (context_handle->more_flags & LOCAL)
cmp = memcmp(&seq[4], "\xff\xff\xff\xff", 4);
else
cmp = memcmp(&seq[4], "\x00\x00\x00\x00", 4);
krb5_data_free (&seq_data);
if (cmp != 0) {
*minor_status = 0;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return GSS_S_BAD_MIC;
}
ret = _gssapi_msg_order_check(context_handle->order, seq_number);
if (ret) {
*minor_status = 0;
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
return ret;
}
HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
/* verify checksum */
memcpy (cksum, p + 8, 20);
memcpy (p + 20, p - 8, 8);
csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3;
csum.checksum.length = 20;
csum.checksum.data = cksum;
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
ret = krb5_verify_checksum (context, crypto,
KRB5_KU_USAGE_SIGN,
p + 20,
input_message_buffer->length - len + 8,
&csum);
krb5_crypto_destroy (context, crypto);
if (ret) {
*minor_status = ret;
return GSS_S_FAILURE;
}
/* copy out data */
output_message_buffer->length = input_message_buffer->length
- len - padlength - 8;
output_message_buffer->value = malloc(output_message_buffer->length);
if(output_message_buffer->length != 0 && output_message_buffer->value == NULL)
return GSS_S_FAILURE;
memcpy (output_message_buffer->value,
p + 36,
output_message_buffer->length);
return GSS_S_COMPLETE;
}
