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authorRuslan Ermilov <ru@FreeBSD.org>2004-04-27 15:00:29 +0000
committerRuslan Ermilov <ru@FreeBSD.org>2004-04-27 15:00:29 +0000
commitb4b831ef39a3e2f33a3acd094eac471c502ec259 (patch)
tree0dae619316439e29971df9d6d54b64a9b59363b9 /lib/libradius/radlib.c
parentd5ac36eda752e6ba04ae462709446fb085520b50 (diff)
downloadsrc-b4b831ef39a3e2f33a3acd094eac471c502ec259.tar.gz
src-b4b831ef39a3e2f33a3acd094eac471c502ec259.zip
- Added rad_demangle() for demangling user-passwords (needed for
MS-CHAPv1 MPPE-keys). - Added rad_demangle_mppe_key() for demangling mppe-keys (needed for MPPE-keys). - Added some typecasts for avoiding compiler warnings. - Fix: better handle wrong usage of the lib (if the programmer has not called rad_create_request() but rad_put_*(), then a weird error message was returned). - Added a new function for putting the Message-Authenticator. - Verify the Message-Authenticator, if it was found inside a response packet and silently drop the packet, if the validation failed. - Implicitly put the Message-Authenticator, if the EAP-Message attribute was added. - Added some missing defines. Submitted by: Michael Bretterklieber PR: 46555
Notes
Notes: svn path=/head/; revision=128684
Diffstat (limited to 'lib/libradius/radlib.c')
-rw-r--r--lib/libradius/radlib.c325
1 files changed, 305 insertions, 20 deletions
diff --git a/lib/libradius/radlib.c b/lib/libradius/radlib.c
index 702b06f12fe9..3460db5604b3 100644
--- a/lib/libradius/radlib.c
+++ b/lib/libradius/radlib.c
@@ -32,9 +32,21 @@ __FBSDID("$FreeBSD$");
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
+#ifdef WITH_SSL
+#include <openssl/hmac.h>
+#include <openssl/md5.h>
+#define MD5Init MD5_Init
+#define MD5Update MD5_Update
+#define MD5Final MD5_Final
+#else
+#define MD5_DIGEST_LENGTH 16
+#include <md5.h>
+#endif
+
+/* We need the MPPE_KEY_LEN define */
+#include <netgraph/ng_mppc.h>
#include <errno.h>
-#include <md5.h>
#include <netdb.h>
#include <stdarg.h>
#include <stddef.h>
@@ -50,6 +62,7 @@ static void generr(struct rad_handle *, const char *, ...)
__printflike(2, 3);
static void insert_scrambled_password(struct rad_handle *, int);
static void insert_request_authenticator(struct rad_handle *, int);
+static void insert_message_authenticator(struct rad_handle *, int);
static int is_valid_response(struct rad_handle *, int,
const struct sockaddr_in *);
static int put_password_attr(struct rad_handle *, int,
@@ -82,7 +95,7 @@ static void
insert_scrambled_password(struct rad_handle *h, int srv)
{
MD5_CTX ctx;
- unsigned char md5[16];
+ unsigned char md5[MD5_DIGEST_LENGTH];
const struct rad_server *srvp;
int padded_len;
int pos;
@@ -129,6 +142,31 @@ insert_request_authenticator(struct rad_handle *h, int srv)
MD5Final(&h->request[POS_AUTH], &ctx);
}
+static void
+insert_message_authenticator(struct rad_handle *h, int srv)
+{
+#ifdef WITH_SSL
+ u_char md[EVP_MAX_MD_SIZE];
+ u_int md_len;
+ const struct rad_server *srvp;
+ HMAC_CTX ctx;
+ srvp = &h->servers[srv];
+
+ if (h->authentic_pos != 0) {
+ HMAC_CTX_init(&ctx);
+ HMAC_Init(&ctx, srvp->secret, strlen(srvp->secret), EVP_md5());
+ HMAC_Update(&ctx, &h->request[POS_CODE], POS_AUTH - POS_CODE);
+ HMAC_Update(&ctx, &h->request[POS_AUTH], LEN_AUTH);
+ HMAC_Update(&ctx, &h->request[POS_ATTRS],
+ h->req_len - POS_ATTRS);
+ HMAC_Final(&ctx, md, &md_len);
+ HMAC_CTX_cleanup(&ctx);
+ HMAC_cleanup(&ctx);
+ memcpy(&h->request[h->authentic_pos + 2], md, md_len);
+ }
+#endif
+}
+
/*
* Return true if the current response is valid for a request to the
* specified server.
@@ -138,9 +176,14 @@ is_valid_response(struct rad_handle *h, int srv,
const struct sockaddr_in *from)
{
MD5_CTX ctx;
- unsigned char md5[16];
+ unsigned char md5[MD5_DIGEST_LENGTH];
const struct rad_server *srvp;
int len;
+#ifdef WITH_SSL
+ HMAC_CTX hctx;
+ u_char resp[MSGSIZE], md[EVP_MAX_MD_SIZE];
+ int pos, md_len;
+#endif
srvp = &h->servers[srv];
@@ -167,6 +210,44 @@ is_valid_response(struct rad_handle *h, int srv,
if (memcmp(&h->response[POS_AUTH], md5, sizeof md5) != 0)
return 0;
+#ifdef WITH_SSL
+ /*
+ * For non accounting responses check the message authenticator,
+ * if any.
+ */
+ if (h->response[POS_CODE] != RAD_ACCOUNTING_RESPONSE) {
+
+ memcpy(resp, h->response, MSGSIZE);
+ pos = POS_ATTRS;
+
+ /* Search and verify the Message-Authenticator */
+ while (pos < len - 2) {
+
+ if (h->response[pos] == RAD_MESSAGE_AUTHENTIC) {
+ /* zero fill the Message-Authenticator */
+ memset(&resp[pos + 2], 0, MD5_DIGEST_LENGTH);
+
+ HMAC_CTX_init(&hctx);
+ HMAC_Init(&hctx, srvp->secret,
+ strlen(srvp->secret), EVP_md5());
+ HMAC_Update(&hctx, &h->response[POS_CODE],
+ POS_AUTH - POS_CODE);
+ HMAC_Update(&hctx, &h->request[POS_AUTH],
+ LEN_AUTH);
+ HMAC_Update(&hctx, &resp[POS_ATTRS],
+ h->resp_len - POS_ATTRS);
+ HMAC_Final(&hctx, md, &md_len);
+ HMAC_CTX_cleanup(&hctx);
+ HMAC_cleanup(&hctx);
+ if (memcmp(md, &h->response[pos + 2],
+ MD5_DIGEST_LENGTH) != 0)
+ return 0;
+ break;
+ }
+ pos += h->response[pos + 1];
+ }
+ }
+#endif
return 1;
}
@@ -244,7 +325,7 @@ rad_add_server(struct rad_handle *h, const char *host, int port,
sizeof srvp->addr.sin_addr);
}
if (port != 0)
- srvp->addr.sin_port = htons(port);
+ srvp->addr.sin_port = htons((u_short)port);
else {
struct servent *sent;
@@ -482,6 +563,8 @@ rad_continue_send_request(struct rad_handle *h, int selected, int *fd,
if (h->pass_pos != 0)
insert_scrambled_password(h, h->srv);
+ insert_message_authenticator(h, h->srv);
+
/* Send the request */
n = sendto(h->fd, h->request, h->req_len, 0,
(const struct sockaddr *)&h->servers[h->srv].addr,
@@ -514,11 +597,12 @@ rad_create_request(struct rad_handle *h, int code)
for (i = 0; i < LEN_AUTH; i += 2) {
long r;
r = random();
- h->request[POS_AUTH+i] = r;
- h->request[POS_AUTH+i+1] = r >> 8;
+ h->request[POS_AUTH+i] = (u_char)r;
+ h->request[POS_AUTH+i+1] = (u_char)(r >> 8);
}
h->req_len = POS_ATTRS;
clear_password(h);
+ h->request_created = 1;
return 0;
}
@@ -570,7 +654,7 @@ rad_get_attr(struct rad_handle *h, const void **value, size_t *len)
}
type = h->response[h->resp_pos++];
*len = h->response[h->resp_pos++] - 2;
- if (h->resp_pos + *len > h->resp_len) {
+ if (h->resp_pos + (int)*len > h->resp_len) {
generr(h, "Malformed attribute in response");
return -1;
}
@@ -612,18 +696,23 @@ rad_init_send_request(struct rad_handle *h, int *fd, struct timeval *tv)
if (h->request[POS_CODE] == RAD_ACCOUNTING_REQUEST) {
/* Make sure no password given */
if (h->pass_pos || h->chap_pass) {
- generr(h, "User or Chap Password in accounting request");
+ generr(h, "User or Chap Password"
+ " in accounting request");
return -1;
}
} else {
- /* Make sure the user gave us a password */
- if (h->pass_pos == 0 && !h->chap_pass) {
- generr(h, "No User or Chap Password attributes given");
- return -1;
- }
- if (h->pass_pos != 0 && h->chap_pass) {
- generr(h, "Both User and Chap Password attributes given");
- return -1;
+ if (h->eap_msg == 0) {
+ /* Make sure the user gave us a password */
+ if (h->pass_pos == 0 && !h->chap_pass) {
+ generr(h, "No User or Chap Password"
+ " attributes given");
+ return -1;
+ }
+ if (h->pass_pos != 0 && h->chap_pass) {
+ generr(h, "Both User and Chap Password"
+ " attributes given");
+ return -1;
+ }
}
}
@@ -671,7 +760,10 @@ rad_auth_open(void)
h->pass_len = 0;
h->pass_pos = 0;
h->chap_pass = 0;
+ h->authentic_pos = 0;
h->type = RADIUS_AUTH;
+ h->request_created = 0;
+ h->eap_msg = 0;
}
return h;
}
@@ -704,12 +796,41 @@ rad_put_attr(struct rad_handle *h, int type, const void *value, size_t len)
{
int result;
- if (type == RAD_USER_PASSWORD)
+ if (!h->request_created) {
+ generr(h, "Please call rad_create_request()"
+ " before putting attributes");
+ return -1;
+ }
+
+ if (h->request[POS_CODE] == RAD_ACCOUNTING_REQUEST) {
+ if (type == RAD_EAP_MESSAGE) {
+ generr(h, "EAP-Message attribute is not valid"
+ " in accounting requests");
+ return -1;
+ }
+ }
+
+ /*
+ * When proxying EAP Messages, the Message Authenticator
+ * MUST be present; see RFC 3579.
+ */
+ if (type == RAD_EAP_MESSAGE) {
+ if (rad_put_message_authentic(h) == -1)
+ return -1;
+ }
+
+ if (type == RAD_USER_PASSWORD) {
result = put_password_attr(h, type, value, len);
- else {
+ } else if (type == RAD_MESSAGE_AUTHENTIC) {
+ result = rad_put_message_authentic(h);
+ } else {
result = put_raw_attr(h, type, value, len);
- if (result == 0 && type == RAD_CHAP_PASSWORD)
- h->chap_pass = 1;
+ if (result == 0) {
+ if (type == RAD_CHAP_PASSWORD)
+ h->chap_pass = 1;
+ else if (type == RAD_EAP_MESSAGE)
+ h->eap_msg = 1;
+ }
}
return result;
@@ -730,6 +851,32 @@ rad_put_string(struct rad_handle *h, int type, const char *str)
return rad_put_attr(h, type, str, strlen(str));
}
+int
+rad_put_message_authentic(struct rad_handle *h)
+{
+#ifdef WITH_SSL
+ u_char md_zero[MD5_DIGEST_LENGTH];
+
+ if (h->request[POS_CODE] == RAD_ACCOUNTING_REQUEST) {
+ generr(h, "Message-Authenticator is not valid"
+ " in accounting requests");
+ return -1;
+ }
+
+ if (h->authentic_pos == 0) {
+ h->authentic_pos = h->req_len;
+ memset(md_zero, 0, sizeof(md_zero));
+ return (put_raw_attr(h, RAD_MESSAGE_AUTHENTIC, md_zero,
+ sizeof(md_zero)));
+ }
+ return 0;
+#else
+ generr(h, "Message Authenticator not supported,"
+ " please recompile libradius with SSL support");
+ return -1;
+#endif
+}
+
/*
* Returns the response type code on success, or -1 on failure.
*/
@@ -893,6 +1040,12 @@ rad_put_vendor_attr(struct rad_handle *h, int vendor, int type,
struct vendor_attribute *attr;
int res;
+ if (!h->request_created) {
+ generr(h, "Please call rad_create_request()"
+ " before putting attributes");
+ return -1;
+ }
+
if ((attr = malloc(len + 6)) == NULL) {
generr(h, "malloc failure (%d bytes)", len + 6);
return -1;
@@ -940,6 +1093,138 @@ rad_request_authenticator(struct rad_handle *h, char *buf, size_t len)
return (LEN_AUTH);
}
+u_char *
+rad_demangle(struct rad_handle *h, const void *mangled, size_t mlen)
+{
+ char R[LEN_AUTH];
+ const char *S;
+ int i, Ppos;
+ MD5_CTX Context;
+ u_char b[MD5_DIGEST_LENGTH], *C, *demangled;
+
+ if ((mlen % 16 != 0) || mlen > 128) {
+ generr(h, "Cannot interpret mangled data of length %lu",
+ (u_long)mlen);
+ return NULL;
+ }
+
+ C = (u_char *)mangled;
+
+ /* We need the shared secret as Salt */
+ S = rad_server_secret(h);
+
+ /* We need the request authenticator */
+ if (rad_request_authenticator(h, R, sizeof R) != LEN_AUTH) {
+ generr(h, "Cannot obtain the RADIUS request authenticator");
+ return NULL;
+ }
+
+ demangled = malloc(mlen);
+ if (!demangled)
+ return NULL;
+
+ MD5Init(&Context);
+ MD5Update(&Context, S, strlen(S));
+ MD5Update(&Context, R, LEN_AUTH);
+ MD5Final(b, &Context);
+ Ppos = 0;
+ while (mlen) {
+
+ mlen -= 16;
+ for (i = 0; i < 16; i++)
+ demangled[Ppos++] = C[i] ^ b[i];
+
+ if (mlen) {
+ MD5Init(&Context);
+ MD5Update(&Context, S, strlen(S));
+ MD5Update(&Context, C, 16);
+ MD5Final(b, &Context);
+ }
+
+ C += 16;
+ }
+
+ return demangled;
+}
+
+u_char *
+rad_demangle_mppe_key(struct rad_handle *h, const void *mangled,
+ size_t mlen, size_t *len)
+{
+ char R[LEN_AUTH]; /* variable names as per rfc2548 */
+ const char *S;
+ u_char b[MD5_DIGEST_LENGTH], *demangled;
+ const u_char *A, *C;
+ MD5_CTX Context;
+ int Slen, i, Clen, Ppos;
+ u_char *P;
+
+ if (mlen % 16 != SALT_LEN) {
+ generr(h, "Cannot interpret mangled data of length %lu",
+ (u_long)mlen);
+ return NULL;
+ }
+
+ /* We need the RADIUS Request-Authenticator */
+ if (rad_request_authenticator(h, R, sizeof R) != LEN_AUTH) {
+ generr(h, "Cannot obtain the RADIUS request authenticator");
+ return NULL;
+ }
+
+ A = (const u_char *)mangled; /* Salt comes first */
+ C = (const u_char *)mangled + SALT_LEN; /* Then the ciphertext */
+ Clen = mlen - SALT_LEN;
+ S = rad_server_secret(h); /* We need the RADIUS secret */
+ Slen = strlen(S);
+ P = alloca(Clen); /* We derive our plaintext */
+
+ MD5Init(&Context);
+ MD5Update(&Context, S, Slen);
+ MD5Update(&Context, R, LEN_AUTH);
+ MD5Update(&Context, A, SALT_LEN);
+ MD5Final(b, &Context);
+ Ppos = 0;
+
+ while (Clen) {
+ Clen -= 16;
+
+ for (i = 0; i < 16; i++)
+ P[Ppos++] = C[i] ^ b[i];
+
+ if (Clen) {
+ MD5Init(&Context);
+ MD5Update(&Context, S, Slen);
+ MD5Update(&Context, C, 16);
+ MD5Final(b, &Context);
+ }
+
+ C += 16;
+ }
+
+ /*
+ * The resulting plain text consists of a one-byte length, the text and
+ * maybe some padding.
+ */
+ *len = *P;
+ if (*len > mlen - 1) {
+ generr(h, "Mangled data seems to be garbage %d %d",
+ *len, mlen-1);
+ return NULL;
+ }
+
+ if (*len > MPPE_KEY_LEN * 2) {
+ generr(h, "Key to long (%d) for me max. %d",
+ *len, MPPE_KEY_LEN * 2);
+ return NULL;
+ }
+ demangled = malloc(*len);
+ if (!demangled)
+ return NULL;
+
+ memcpy(demangled, P + 1, *len);
+ return demangled;
+}
+
const char *
rad_server_secret(struct rad_handle *h)
{