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doc/share/security/patches/SA-15:07/ntp.patch
Xin LI 4f5662b555 Add 3 new advisories and patches.
2015-04-07 20:36:34 +00:00

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Index: contrib/ntp/ntpd/ntp_crypto.c
===================================================================
--- contrib/ntp/ntpd/ntp_crypto.c (revision 280717)
+++ contrib/ntp/ntpd/ntp_crypto.c (working copy)
@@ -93,6 +93,7 @@
#define TAI_1972 10 /* initial TAI offset (s) */
#define MAX_LEAP 100 /* max UTC leapseconds (s) */
#define VALUE_LEN (6 * 4) /* min response field length */
+#define MAX_VALLEN (65535 - VALUE_LEN)
#define YEAR (60 * 60 * 24 * 365) /* seconds in year */
/*
@@ -137,8 +138,8 @@ static u_int ident_scheme = 0; /* server identity
*/
static int crypto_verify P((struct exten *, struct value *,
struct peer *));
-static int crypto_encrypt P((struct exten *, struct value *,
- keyid_t *));
+static int crypto_encrypt P((const u_char *, u_int, keyid_t *,
+ struct value *));
static int crypto_alice P((struct peer *, struct value *));
static int crypto_alice2 P((struct peer *, struct value *));
static int crypto_alice3 P((struct peer *, struct value *));
@@ -446,6 +447,12 @@ crypto_recv(
tstamp = ntohl(ep->tstamp);
fstamp = ntohl(ep->fstamp);
vallen = ntohl(ep->vallen);
+ /*
+ * Bug 2761: I hope this isn't too early...
+ */
+ if ( vallen == 0
+ || len - VALUE_LEN < vallen)
+ return XEVNT_LEN;
}
switch (code) {
@@ -488,7 +495,7 @@ crypto_recv(
break;
if (vallen == 0 || vallen > MAXHOSTNAME ||
- len < VALUE_LEN + vallen) {
+ len - VALUE_LEN < vallen) {
rval = XEVNT_LEN;
break;
}
@@ -1250,7 +1257,8 @@ crypto_xmit(
vallen = ntohl(ep->vallen);
if (vallen == 8) {
strcpy(certname, sys_hostname);
- } else if (vallen == 0 || vallen > MAXHOSTNAME) {
+ } else if (vallen == 0 || vallen > MAXHOSTNAME ||
+ len - VALUE_LEN < vallen) {
rval = XEVNT_LEN;
break;
@@ -1407,7 +1415,10 @@ crypto_xmit(
* anything goes wrong.
*/
case CRYPTO_COOK | CRYPTO_RESP:
- if ((opcode & 0xffff) < VALUE_LEN) {
+ vallen = ntohl(ep->vallen); /* Must be <64k */
+ if ( vallen == 0
+ || (vallen >= MAX_VALLEN)
+ || (opcode & 0x0000ffff) < VALUE_LEN + vallen) {
rval = XEVNT_LEN;
break;
}
@@ -1420,10 +1431,11 @@ crypto_xmit(
}
tcookie = peer->pcookie;
}
- if ((rval = crypto_encrypt(ep, &vtemp, &tcookie)) ==
- XEVNT_OK)
+ if ((rval = crypto_encrypt((const u_char *)ep->pkt, vallen, &tcookie, &vtemp))
+ == XEVNT_OK) {
len += crypto_send(fp, &vtemp);
- value_free(&vtemp);
+ value_free(&vtemp);
+ }
break;
/*
@@ -1558,10 +1570,15 @@ crypto_verify(
* are rounded up to the next word.
*/
vallen = ntohl(ep->vallen);
+ if ( vallen == 0
+ || vallen > MAX_VALLEN)
+ return (XEVNT_LEN);
i = (vallen + 3) / 4;
siglen = ntohl(ep->pkt[i++]);
- if (len < VALUE_LEN + ((vallen + 3) / 4) * 4 + ((siglen + 3) /
- 4) * 4)
+ if ( siglen > MAX_VALLEN
+ || len - VALUE_LEN < ((vallen + 3) / 4) * 4
+ || len - VALUE_LEN - ((vallen + 3) / 4) * 4
+ < ((siglen + 3) / 4) * 4)
return (XEVNT_LEN);
/*
@@ -1627,6 +1644,7 @@ crypto_verify(
* avoid doing the sign exchange.
*/
EVP_VerifyInit(&ctx, peer->digest);
+ /* XXX: the "+ 12" needs to be at least documented... */
EVP_VerifyUpdate(&ctx, (u_char *)&ep->tstamp, vallen + 12);
if (EVP_VerifyFinal(&ctx, (u_char *)&ep->pkt[i], siglen, pkey) <= 0)
return (XEVNT_SIG);
@@ -1641,10 +1659,10 @@ crypto_verify(
/*
- * crypto_encrypt - construct encrypted cookie and signature from
- * extension field and cookie
+ * crypto_encrypt - construct vp (encrypted cookie and signature) from
+ * the public key and cookie.
*
- * Returns
+ * Returns:
* XEVNT_OK success
* XEVNT_PUB bad or missing public key
* XEVNT_CKY bad or missing cookie
@@ -1652,9 +1670,10 @@ crypto_verify(
*/
static int
crypto_encrypt(
- struct exten *ep, /* extension pointer */
- struct value *vp, /* value pointer */
- keyid_t *cookie /* server cookie */
+ const u_char *ptr, /* Public Key */
+ u_int vallen, /* Length of Public Key */
+ keyid_t *cookie, /* server cookie */
+ struct value *vp /* value pointer */
)
{
EVP_PKEY *pkey; /* public key */
@@ -1661,15 +1680,11 @@ crypto_encrypt(
EVP_MD_CTX ctx; /* signature context */
tstamp_t tstamp; /* NTP timestamp */
u_int32 temp32;
- u_int len;
- u_char *ptr;
/*
* Extract the public key from the request.
*/
- len = ntohl(ep->vallen);
- ptr = (u_char *)ep->pkt;
- pkey = d2i_PublicKey(EVP_PKEY_RSA, NULL, &ptr, len);
+ pkey = d2i_PublicKey(EVP_PKEY_RSA, NULL, &ptr, vallen);
if (pkey == NULL) {
msyslog(LOG_ERR, "crypto_encrypt %s\n",
ERR_error_string(ERR_get_error(), NULL));
@@ -1683,9 +1698,9 @@ crypto_encrypt(
memset(vp, 0, sizeof(struct value));
vp->tstamp = htonl(tstamp);
vp->fstamp = hostval.tstamp;
- len = EVP_PKEY_size(pkey);
- vp->vallen = htonl(len);
- vp->ptr = emalloc(len);
+ vallen = EVP_PKEY_size(pkey);
+ vp->vallen = htonl(vallen);
+ vp->ptr = emalloc(vallen);
temp32 = htonl(*cookie);
if (!RSA_public_encrypt(4, (u_char *)&temp32, vp->ptr,
pkey->pkey.rsa, RSA_PKCS1_OAEP_PADDING)) {
@@ -1705,9 +1720,9 @@ crypto_encrypt(
vp->sig = emalloc(sign_siglen);
EVP_SignInit(&ctx, sign_digest);
EVP_SignUpdate(&ctx, (u_char *)&vp->tstamp, 12);
- EVP_SignUpdate(&ctx, vp->ptr, len);
- if (EVP_SignFinal(&ctx, vp->sig, &len, sign_pkey))
- vp->siglen = htonl(len);
+ EVP_SignUpdate(&ctx, vp->ptr, vallen);
+ if (EVP_SignFinal(&ctx, vp->sig, &vallen, sign_pkey))
+ vp->siglen = htonl(sign_siglen);
return (XEVNT_OK);
}
@@ -1794,6 +1809,9 @@ crypto_ident(
* call in the protocol module.
*
* Returns extension field pointer (no errors).
+ *
+ * XXX: opcode and len should really be 32-bit quantities and
+ * we should make sure that str is not too big.
*/
struct exten *
crypto_args(
@@ -1805,11 +1823,14 @@ crypto_args(
tstamp_t tstamp; /* NTP timestamp */
struct exten *ep; /* extension field pointer */
u_int len; /* extension field length */
+ size_t slen;
tstamp = crypto_time();
len = sizeof(struct exten);
- if (str != NULL)
- len += strlen(str);
+ if (str != NULL) {
+ slen = strlen(str);
+ len += slen;
+ }
ep = emalloc(len);
memset(ep, 0, len);
if (opcode == 0)
@@ -1829,8 +1850,8 @@ crypto_args(
ep->fstamp = hostval.tstamp;
ep->vallen = 0;
if (str != NULL) {
- ep->vallen = htonl(strlen(str));
- memcpy((char *)ep->pkt, str, strlen(str));
+ ep->vallen = htonl(slen);
+ memcpy((char *)ep->pkt, str, slen);
} else {
ep->pkt[0] = peer->associd;
}
@@ -1844,6 +1865,8 @@ crypto_args(
* Returns extension field length. Note: it is not polite to send a
* nonempty signature with zero timestamp or a nonzero timestamp with
* empty signature, but these rules are not enforced here.
+ *
+ * XXX This code won't work on a box with 16-bit ints.
*/
u_int
crypto_send(
@@ -2212,7 +2235,8 @@ crypto_bob(
tstamp_t tstamp; /* NTP timestamp */
BIGNUM *bn, *bk, *r;
u_char *ptr;
- u_int len;
+ u_int len; /* extension field length */
+ u_int vallen = 0; /* value length */
/*
* If the IFF parameters are not valid, something awful
@@ -2227,8 +2251,11 @@ crypto_bob(
/*
* Extract r from the challenge.
*/
- len = ntohl(ep->vallen);
- if ((r = BN_bin2bn((u_char *)ep->pkt, len, NULL)) == NULL) {
+ vallen = ntohl(ep->vallen);
+ len = ntohl(ep->opcode) & 0x0000ffff;
+ if (vallen == 0 || len < VALUE_LEN || len - VALUE_LEN < vallen)
+ return XEVNT_LEN;
+ if ((r = BN_bin2bn((u_char *)ep->pkt, vallen, NULL)) == NULL) {
msyslog(LOG_ERR, "crypto_bob %s\n",
ERR_error_string(ERR_get_error(), NULL));
return (XEVNT_ERR);
@@ -2240,7 +2267,7 @@ crypto_bob(
*/
bctx = BN_CTX_new(); bk = BN_new(); bn = BN_new();
sdsa = DSA_SIG_new();
- BN_rand(bk, len * 8, -1, 1); /* k */
+ BN_rand(bk, vallen * 8, -1, 1); /* k */
BN_mod_mul(bn, dsa->priv_key, r, dsa->q, bctx); /* b r mod q */
BN_add(bn, bn, bk);
BN_mod(bn, bn, dsa->q, bctx); /* k + b r mod q */
@@ -2254,19 +2281,25 @@ crypto_bob(
/*
* Encode the values in ASN.1 and sign.
*/
- tstamp = crypto_time();
- memset(vp, 0, sizeof(struct value));
- vp->tstamp = htonl(tstamp);
- vp->fstamp = htonl(if_fstamp);
- len = i2d_DSA_SIG(sdsa, NULL);
- if (len <= 0) {
+ vallen = i2d_DSA_SIG(sdsa, NULL);
+ if (vallen == 0) {
msyslog(LOG_ERR, "crypto_bob %s\n",
ERR_error_string(ERR_get_error(), NULL));
DSA_SIG_free(sdsa);
return (XEVNT_ERR);
}
- vp->vallen = htonl(len);
- ptr = emalloc(len);
+ if (vallen > MAX_VALLEN) {
+ msyslog(LOG_ERR, "crypto_bob: signature is too big: %d",
+ vallen);
+ DSA_SIG_free(sdsa);
+ return (XEVNT_LEN);
+ }
+ memset(vp, 0, sizeof(struct value));
+ tstamp = crypto_time();
+ vp->tstamp = htonl(tstamp);
+ vp->fstamp = htonl(if_fstamp);
+ vp->vallen = htonl(vallen);
+ ptr = emalloc(vallen);
vp->ptr = ptr;
i2d_DSA_SIG(sdsa, &ptr);
DSA_SIG_free(sdsa);
@@ -2277,11 +2310,12 @@ crypto_bob(
if (tstamp < cinfo->first || tstamp > cinfo->last)
return (XEVNT_PER);
+ /* XXX: more validation to make sure the sign fits... */
vp->sig = emalloc(sign_siglen);
EVP_SignInit(&ctx, sign_digest);
EVP_SignUpdate(&ctx, (u_char *)&vp->tstamp, 12);
- EVP_SignUpdate(&ctx, vp->ptr, len);
- if (EVP_SignFinal(&ctx, vp->sig, &len, sign_pkey))
+ EVP_SignUpdate(&ctx, vp->ptr, vallen);
+ if (EVP_SignFinal(&ctx, vp->sig, &vallen, sign_pkey))
vp->siglen = htonl(len);
return (XEVNT_OK);
}
Index: contrib/ntp/ntpd/ntp_proto.c
===================================================================
--- contrib/ntp/ntpd/ntp_proto.c (revision 280717)
+++ contrib/ntp/ntpd/ntp_proto.c (working copy)
@@ -459,7 +459,7 @@ receive(
while (has_mac > 0) {
int temp;
- if (has_mac % 4 != 0 || has_mac < 0) {
+ if (has_mac % 4 != 0 || has_mac < MIN_MAC_LEN) {
sys_badlength++;
return; /* bad MAC length */
}
@@ -483,6 +483,13 @@ receive(
return; /* bad MAC length */
}
}
+ /*
+ * If has_mac is < 0 we had a malformed packet.
+ */
+ if (has_mac < 0) {
+ sys_badlength++;
+ return; /* bad length */
+ }
#ifdef OPENSSL
pkeyid = tkeyid = 0;
#endif /* OPENSSL */
@@ -942,12 +949,9 @@ receive(
}
/*
- * Update the origin and destination timestamps. If
- * unsynchronized or bogus abandon ship. If the crypto machine
+ * If unsynchronized or bogus abandon ship. If the crypto machine
* breaks, light the crypto bit and plaint the log.
*/
- peer->org = p_xmt;
- peer->rec = rbufp->recv_time;
if (peer->flash & PKT_TEST_MASK) {
#ifdef OPENSSL
if (crypto_flags && (peer->flags & FLAG_SKEY)) {
@@ -978,10 +982,11 @@ receive(
* versions. If symmetric modes, return a crypto-NAK. The peer
* should restart the protocol.
*/
- } else if (!AUTH(peer->keyid || (restrict_mask & RES_DONTTRUST),
- is_authentic)) {
+ } else if (!AUTH(peer->keyid || has_mac ||
+ (restrict_mask & RES_DONTTRUST), is_authentic)) {
peer->flash |= TEST5;
- if (hismode == MODE_ACTIVE || hismode == MODE_PASSIVE)
+ if (has_mac &&
+ (hismode == MODE_ACTIVE || hismode == MODE_PASSIVE))
fast_xmit(rbufp, MODE_ACTIVE, 0, restrict_mask);
return; /* bad auth */
}
@@ -989,7 +994,12 @@ receive(
/*
* That was hard and I am sweaty, but the packet is squeaky
* clean. Get on with real work.
+ *
+ * Update the origin and destination timestamps.
*/
+ peer->org = p_xmt;
+ peer->rec = rbufp->recv_time;
+
peer->received++;
peer->timereceived = current_time;
if (is_authentic == AUTH_OK)
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