libradius: switch to HMAC_CTX on the heap

[Theo Buehler]

Another fairly mechanical conversion to prepare the switch to opaque
HMAC_CTX. It adds missing error checking for the HMAC API and uses
HMAC_Init_ex() instead of the deprecated HMAC_Init().

Index: radius_msgauth.c
===================================================================
RCS file: /cvs/src/lib/libradius/radius_msgauth.c,v
retrieving revision 1.1
diff -u -p -r1.1 radius_msgauth.c
--- radius_msgauth.c    20 Jul 2015 23:52:29 -0000      1.1
+++ radius_msgauth.c    15 Dec 2021 22:57:06 -0000
@@ -41,30 +41,38 @@
 
 #include "radius_local.h"
 
-static void
+static int
 radius_calc_message_authenticator(RADIUS_PACKET * packet, const char *secret,
     void *ma)
 {
        const RADIUS_ATTRIBUTE  *attr;
        const RADIUS_ATTRIBUTE  *end;
        u_char                   zero16[16];
-       HMAC_CTX                 ctx;
+       HMAC_CTX                *ctx;
        int                      mdlen;
+       int                      ret = -1;
 
        memset(zero16, 0, sizeof(zero16));
 
-       HMAC_Init(&ctx, secret, strlen(secret), EVP_md5());
+       if ((ctx = HMAC_CTX_new()) == NULL)
+               goto err;
+
+       if (!HMAC_Init_ex(ctx, secret, strlen(secret), EVP_md5(), NULL))
+               goto err;
 
        /*
         * Traverse the radius packet.
         */
        if (packet->request != NULL) {
-               HMAC_Update(&ctx, (const u_char *)packet->pdata, 4);
-               HMAC_Update(&ctx, (unsigned char *)packet->request->pdata
-                   ->authenticator, 16);
+               if (!HMAC_Update(ctx, (const u_char *)packet->pdata, 4))
+                       goto err;
+               if (!HMAC_Update(ctx, (unsigned char *)packet->request->pdata
+                   ->authenticator, 16))
+                       goto err;
        } else {
-               HMAC_Update(&ctx, (const u_char *)packet->pdata,
-                   sizeof(RADIUS_PACKET_DATA));
+               if (!HMAC_Update(ctx, (const u_char *)packet->pdata,
+                   sizeof(RADIUS_PACKET_DATA)))
+                       goto err;
        }
 
        attr = ATTRS_BEGIN(packet->pdata);
@@ -72,15 +80,26 @@ radius_calc_message_authenticator(RADIUS
 
        for (; attr < end; ATTRS_ADVANCE(attr)) {
                if (attr->type == RADIUS_TYPE_MESSAGE_AUTHENTICATOR) {
-                       HMAC_Update(&ctx, (u_char *)attr, 2);
-                       HMAC_Update(&ctx, (u_char *)zero16, sizeof(zero16));
-               } else
-                       HMAC_Update(&ctx, (u_char *)attr, (int) attr->length);
+                       if (!HMAC_Update(ctx, (u_char *)attr, 2))
+                               goto err;
+                       if (!HMAC_Update(ctx, (u_char *)zero16, sizeof(zero16)))
+                               goto err;
+               } else {
+                       if (!HMAC_Update(ctx, (u_char *)attr,
+                           (int)attr->length))
+                               goto err;
+               }
        }
 
-       HMAC_Final(&ctx, (u_char *)ma, &mdlen);
+       if (!HMAC_Final(ctx, (u_char *)ma, &mdlen))
+               goto err;
+
+       ret = 0;
+
+ err:
+       HMAC_CTX_free(ctx);
 
-       HMAC_cleanup(&ctx);
+       return (ret);
 }
 
 int
@@ -105,7 +124,8 @@ radius_set_message_authenticator(RADIUS_
 {
        u_char   ma[16];
 
-       radius_calc_message_authenticator(packet, secret, ma);
+       if (radius_calc_message_authenticator(packet, secret, ma) != 0)
+               return (-1);
 
        return (radius_set_raw_attr(packet, RADIUS_TYPE_MESSAGE_AUTHENTICATOR,
            ma, sizeof(ma)));
@@ -118,7 +138,8 @@ radius_check_message_authenticator(RADIU
        size_t   len;
        u_char   ma0[16], ma1[16];
 
-       radius_calc_message_authenticator(packet, secret, ma0);
+       if (radius_calc_message_authenticator(packet, secret, ma0) != 0)
+               return (-1);
 
        len = sizeof(ma1);
        if ((rval = radius_get_raw_attr(packet,