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34 #include <krb5_locl.h>
36 RCSID("$Id: rd_safe.c 19827 2007-01-11 02:54:59Z lha $");
38 static krb5_error_code
39 verify_checksum(krb5_context context,
40 krb5_auth_context auth_context,
52 safe->cksum.cksumtype = 0;
53 safe->cksum.checksum.data = NULL;
54 safe->cksum.checksum.length = 0;
56 ASN1_MALLOC_ENCODE(KRB_SAFE, buf, buf_size, safe, &len, ret);
60 krb5_abortx(context, "internal error in ASN.1 encoder");
62 if (auth_context->remote_subkey)
63 key = auth_context->remote_subkey;
64 else if (auth_context->local_subkey)
65 key = auth_context->local_subkey;
67 key = auth_context->keyblock;
69 ret = krb5_crypto_init(context, key, 0, &crypto);
72 ret = krb5_verify_checksum (context,
74 KRB5_KU_KRB_SAFE_CKSUM,
78 krb5_crypto_destroy(context, crypto);
85 krb5_error_code KRB5_LIB_FUNCTION
86 krb5_rd_safe(krb5_context context,
87 krb5_auth_context auth_context,
88 const krb5_data *inbuf,
90 krb5_replay_data *outdata)
97 krb5_data_zero(outbuf);
99 if ((auth_context->flags &
100 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
102 krb5_set_error_string(context, "rd_safe: need outdata to return data");
103 return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
106 ret = decode_KRB_SAFE (inbuf->data, inbuf->length, &safe, &len);
109 if (safe.pvno != 5) {
110 ret = KRB5KRB_AP_ERR_BADVERSION;
111 krb5_clear_error_string (context);
114 if (safe.msg_type != krb_safe) {
115 ret = KRB5KRB_AP_ERR_MSG_TYPE;
116 krb5_clear_error_string (context);
119 if (!krb5_checksum_is_keyed(context, safe.cksum.cksumtype)
120 || !krb5_checksum_is_collision_proof(context, safe.cksum.cksumtype)) {
121 ret = KRB5KRB_AP_ERR_INAPP_CKSUM;
122 krb5_clear_error_string (context);
126 /* check sender address */
128 if (safe.safe_body.s_address
129 && auth_context->remote_address
130 && !krb5_address_compare (context,
131 auth_context->remote_address,
132 safe.safe_body.s_address)) {
133 ret = KRB5KRB_AP_ERR_BADADDR;
134 krb5_clear_error_string (context);
138 /* check receiver address */
140 if (safe.safe_body.r_address
141 && auth_context->local_address
142 && !krb5_address_compare (context,
143 auth_context->local_address,
144 safe.safe_body.r_address)) {
145 ret = KRB5KRB_AP_ERR_BADADDR;
146 krb5_clear_error_string (context);
150 /* check timestamp */
151 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
154 krb5_timeofday (context, &sec);
156 if (safe.safe_body.timestamp == NULL ||
157 safe.safe_body.usec == NULL ||
158 abs(*safe.safe_body.timestamp - sec) > context->max_skew) {
159 ret = KRB5KRB_AP_ERR_SKEW;
160 krb5_clear_error_string (context);
164 /* XXX - check replay cache */
166 /* check sequence number. since MIT krb5 cannot generate a sequence
167 number of zero but instead generates no sequence number, we accept that
170 if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
171 if ((safe.safe_body.seq_number == NULL
172 && auth_context->remote_seqnumber != 0)
173 || (safe.safe_body.seq_number != NULL
174 && *safe.safe_body.seq_number !=
175 auth_context->remote_seqnumber)) {
176 ret = KRB5KRB_AP_ERR_BADORDER;
177 krb5_clear_error_string (context);
180 auth_context->remote_seqnumber++;
183 ret = verify_checksum (context, auth_context, &safe);
187 outbuf->length = safe.safe_body.user_data.length;
188 outbuf->data = malloc(outbuf->length);
189 if (outbuf->data == NULL && outbuf->length != 0) {
191 krb5_set_error_string (context, "malloc: out of memory");
192 krb5_data_zero(outbuf);
195 memcpy (outbuf->data, safe.safe_body.user_data.data, outbuf->length);
197 if ((auth_context->flags &
198 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) {
199 /* if these fields are not present in the safe-part, silently
201 memset(outdata, 0, sizeof(*outdata));
202 if(safe.safe_body.timestamp)
203 outdata->timestamp = *safe.safe_body.timestamp;
204 if(safe.safe_body.usec)
205 outdata->usec = *safe.safe_body.usec;
206 if(safe.safe_body.seq_number)
207 outdata->seq = *safe.safe_body.seq_number;
211 free_KRB_SAFE (&safe);