This patch provides support for the openssl 1.0.
It was written by Tomas Mraz from Red Hat, so all credits go to him.

diff -up Pound-2.5/config.c.openssl Pound-2.5/config.c
--- Pound-2.5/config.c.openssl	2010-02-10 12:23:09.000000000 +0100
+++ Pound-2.5/config.c	2010-02-10 12:23:07.000000000 +0100
@@ -431,14 +431,22 @@ t_hash(const TABNODE *e)
         res = (res ^ *k++) * 16777619;
     return res;
 }
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+static IMPLEMENT_LHASH_HASH_FN(t, TABNODE)
+#else
 static IMPLEMENT_LHASH_HASH_FN(t_hash, const TABNODE *)
+#endif
 
 static int
 t_cmp(const TABNODE *d1, const TABNODE *d2)
 {
     return strcmp(d1->key, d2->key);
 }
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+static IMPLEMENT_LHASH_COMP_FN(t, TABNODE)
+#else
 static IMPLEMENT_LHASH_COMP_FN(t_cmp, const TABNODE *)
+#endif
 
 /*
  * parse a service
@@ -460,7 +468,11 @@ parse_service(const char *svc_name)
     pthread_mutex_init(&res->mut, NULL);
     if(svc_name)
         strncpy(res->name, svc_name, KEY_SIZE);
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+    if((res->sessions = LHM_lh_new(TABNODE, t)) == NULL)
+#else
     if((res->sessions = lh_new(LHASH_HASH_FN(t_hash), LHASH_COMP_FN(t_cmp))) == NULL)
+#endif
         conf_err("lh_new failed - aborted");
     ign_case = ignore_case;
     while(conf_fgets(lin, MAXBUF)) {
diff -up Pound-2.5/pound.h.openssl Pound-2.5/pound.h
--- Pound-2.5/pound.h.openssl	2010-02-02 12:49:02.000000000 +0100
+++ Pound-2.5/pound.h	2010-02-10 12:15:18.000000000 +0100
@@ -322,6 +322,10 @@ typedef struct _tn {
 /* maximal session key size */
 #define KEY_SIZE    127
 
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+DECLARE_LHASH_OF(TABNODE);
+#endif
+
 /* service definition */
 typedef struct _service {
     char                name[KEY_SIZE + 1]; /* symbolic name */
@@ -337,7 +341,11 @@ typedef struct _service {
     int                 sess_ttl;   /* session time-to-live */
     regex_t             sess_start; /* pattern to identify the session data */
     regex_t             sess_pat;   /* pattern to match the session data */
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+    LHASH_OF(TABNODE)   *sessions;  /* currently active sessions */
+#else
     LHASH               *sessions;  /* currently active sessions */
+#endif
     int                 dynscale;   /* true if the back-ends should be dynamically rescaled */
     int                 disabled;   /* true if the service is disabled */
     struct _service     *next;
diff -up Pound-2.5/svc.c.openssl Pound-2.5/svc.c
--- Pound-2.5/svc.c.openssl	2010-02-02 12:49:02.000000000 +0100
+++ Pound-2.5/svc.c	2010-02-10 12:13:29.000000000 +0100
@@ -27,12 +27,17 @@
 
 #include    "pound.h"
 
+#ifndef LHASH_OF
+#define LHASH_OF(x) LHASH
+#define CHECKED_LHASH_OF(type, h) h
+#endif
+
 /*
  * Add a new key/content pair to a hash table
  * the table should be already locked
  */
 static void
-t_add(LHASH *const tab, const char *key, const void *content, const size_t cont_len)
+t_add(LHASH_OF(TABNODE) *const tab, const char *key, const void *content, const size_t cont_len)
 {
     TABNODE *t, *old;
 
@@ -53,7 +58,11 @@ t_add(LHASH *const tab, const char *key,
     }
     memcpy(t->content, content, cont_len);
     t->last_acc = time(NULL);
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+    if((old = LHM_lh_insert(TABNODE, tab, t)) != NULL) {
+#else
     if((old = (TABNODE *)lh_insert(tab, t)) != NULL) {
+#endif
         free(old->key);
         free(old->content);
         free(old);
@@ -68,12 +77,16 @@ t_add(LHASH *const tab, const char *key,
  * side-effect: update the time of last access
  */
 static void *
-t_find(LHASH *const tab, char *const key)
+t_find(LHASH_OF(TABNODE) *const tab, char *const key)
 {
     TABNODE t, *res;
 
     t.key = key;
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+    if((res = LHM_lh_retrieve(TABNODE, tab, &t)) != NULL) {
+#else
     if((res = (TABNODE *)lh_retrieve(tab, &t)) != NULL) {
+#endif
         res->last_acc = time(NULL);
         return res->content;
     }
@@ -84,12 +97,16 @@ t_find(LHASH *const tab, char *const key
  * Delete a key
  */
 static void
-t_remove(LHASH *const tab, char *const key)
+t_remove(LHASH_OF(TABNODE) *const tab, char *const key)
 {
     TABNODE t, *res;
 
     t.key = key;
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+    if((res = LHM_lh_delete(TABNODE, tab, &t)) != NULL) {
+#else
     if((res = (TABNODE *)lh_delete(tab, &t)) != NULL) {
+#endif
         free(res->key);
         free(res->content);
         free(res);
@@ -98,59 +115,75 @@ t_remove(LHASH *const tab, char *const k
 }
 
 typedef struct  {
-    LHASH   *tab;
+    LHASH_OF(TABNODE) *tab;
     time_t  lim;
     void    *content;
     int     cont_len;
 }   ALL_ARG;
 
 static void
-t_old(TABNODE *t, void *arg)
+t_old_doall_arg(TABNODE *t, ALL_ARG *a)
 {
-    ALL_ARG *a;
-
-    a = (ALL_ARG *)arg;
     if(t->last_acc < a->lim)
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+        LHM_lh_delete(TABNODE, a->tab, t);
+#else
         lh_delete(a->tab, t);
+#endif
     return;
 }
-IMPLEMENT_LHASH_DOALL_ARG_FN(t_old, TABNODE *, void *)
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+IMPLEMENT_LHASH_DOALL_ARG_FN(t_old, TABNODE, ALL_ARG)
+#else
+#define t_old t_old_doall_arg
+IMPLEMENT_LHASH_DOALL_ARG_FN(t_old, TABNODE *, ALL_ARG *)
+#endif
 
 /*
  * Expire all old nodes
  */
 static void
-t_expire(LHASH *const tab, const time_t lim)
+t_expire(LHASH_OF(TABNODE) *const tab, const time_t lim)
 {
     ALL_ARG a;
     int down_load;
 
     a.tab = tab;
     a.lim = lim;
-    down_load = tab->down_load;
-    tab->down_load = 0;
+    down_load = CHECKED_LHASH_OF(TABNODE, tab)->down_load;
+    CHECKED_LHASH_OF(TABNODE, tab)->down_load = 0;
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+    LHM_lh_doall_arg(TABNODE, tab, LHASH_DOALL_ARG_FN(t_old), ALL_ARG, &a);
+#else
     lh_doall_arg(tab, LHASH_DOALL_ARG_FN(t_old), &a);
-    tab->down_load = down_load;
+#endif
+    CHECKED_LHASH_OF(TABNODE, tab)->down_load = down_load;
     return;
 }
 
 static void
-t_cont(TABNODE *t, void *arg)
+t_cont_doall_arg(TABNODE *t, ALL_ARG *a)
 {
-    ALL_ARG *a;
-
-    a = (ALL_ARG *)arg;
     if(memcmp(t->content, a->content, a->cont_len) == 0)
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+        LHM_lh_delete(TABNODE, a->tab, t);
+#else
         lh_delete(a->tab, t);
+#endif
     return;
 }
-IMPLEMENT_LHASH_DOALL_ARG_FN(t_cont, TABNODE *, void *)
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+IMPLEMENT_LHASH_DOALL_ARG_FN(t_cont, TABNODE, ALL_ARG)
+#else
+#define t_cont t_cont_doall_arg
+IMPLEMENT_LHASH_DOALL_ARG_FN(t_cont, TABNODE *, ALL_ARG *)
+#endif
 
 /*
  * Remove all nodes with the given content
  */
 static void
-t_clean(LHASH *const tab, void *const content, const size_t cont_len)
+t_clean(LHASH_OF(TABNODE) *const tab, void *const content, const size_t cont_len)
 {
     ALL_ARG a;
     int down_load;
@@ -158,10 +191,14 @@ t_clean(LHASH *const tab, void *const co
     a.tab = tab;
     a.content = content;
     a.cont_len = cont_len;
-    down_load = tab->down_load;
-    tab->down_load = 0;
+    down_load = CHECKED_LHASH_OF(TABNODE, tab)->down_load;
+    CHECKED_LHASH_OF(TABNODE, tab)->down_load = 0;
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+    LHM_lh_doall_arg(TABNODE, tab, LHASH_DOALL_ARG_FN(t_cont), ALL_ARG, &a);
+#else
     lh_doall_arg(tab, LHASH_DOALL_ARG_FN(t_cont), &a);
-    tab->down_load = down_load;
+#endif
+    CHECKED_LHASH_OF(TABNODE, tab)->down_load = down_load;
     return;
 }
 
@@ -1410,13 +1447,11 @@ typedef struct  {
 }   DUMP_ARG;
 
 static void
-t_dump(TABNODE *t, void *arg)
+t_dump_doall_arg(TABNODE *t, DUMP_ARG *a)
 {
-    DUMP_ARG    *a;
     BACKEND     *be, *bep;
     int         n_be, sz;
 
-    a = (DUMP_ARG *)arg;
     memcpy(&bep, t->content, sizeof(bep));
     for(n_be = 0, be = a->backends; be; be = be->next, n_be++)
         if(be == bep)
@@ -1432,19 +1467,28 @@ t_dump(TABNODE *t, void *arg)
     return;
 }
 
-IMPLEMENT_LHASH_DOALL_ARG_FN(t_dump, TABNODE *, void *)
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+IMPLEMENT_LHASH_DOALL_ARG_FN(t_dump, TABNODE, DUMP_ARG)
+#else
+#define t_dump t_dump_doall_arg
+IMPLEMENT_LHASH_DOALL_ARG_FN(t_dump, TABNODE *, DUMP_ARG *)
+#endif
 
 /*
  * write sessions to the control socket
  */
 static void
-dump_sess(const int control_sock, LHASH *const sess, BACKEND *const backends)
+dump_sess(const int control_sock, LHASH_OF(TABNODE) *const sess, BACKEND *const backends)
 {
     DUMP_ARG a;
 
     a.control_sock = control_sock;
     a.backends = backends;
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+    LHM_lh_doall_arg(TABNODE, sess, LHASH_DOALL_ARG_FN(t_dump), DUMP_ARG, &a);
+#else
     lh_doall_arg(sess, LHASH_DOALL_ARG_FN(t_dump), &a);
+#endif
     return;
 }