My knownhost work as of right now. It works at least partly. More tests and

tweaks will come.

src/misc.c

@@ -37,6 +37,8 @@
  */
 
 #include "libssh2_priv.h"
+#include "misc.h"
+
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
@@ -176,7 +178,7 @@ static const short base64_reverse_table[256] = {
  * Decode a base64 chunk and store it into a newly alloc'd buffer
  */
 LIBSSH2_API int
-libssh2_base64_decode(LIBSSH2_SESSION * session, char **data,
+libssh2_base64_decode(LIBSSH2_SESSION *session, char **data,
                       unsigned int *datalen, const char *src,
                       unsigned int src_len)
 {
@@ -222,6 +224,86 @@ libssh2_base64_decode(LIBSSH2_SESSION * session, char **data,
     return 0;
 }
 
+/* ---- Base64 Encoding/Decoding Table --- */
+static const char table64[]=
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+/*
+ * _libssh2_base64_encode()
+ *
+ * Returns the length of the newly created base64 string. The third argument
+ * is a pointer to an allocated area holding the base64 data. If something
+ * went wrong, 0 is returned.
+ *
+ */
+size_t _libssh2_base64_encode(LIBSSH2_SESSION *session,
+                              const char *inp, size_t insize, char **outptr)
+{
+  unsigned char ibuf[3];
+  unsigned char obuf[4];
+  int i;
+  int inputparts;
+  char *output;
+  char *base64data;
+  const char *indata = inp;
+
+  *outptr = NULL; /* set to NULL in case of failure before we reach the end */
+
+  if(0 == insize)
+    insize = strlen(indata);
+
+  base64data = output = LIBSSH2_ALLOC(session, insize*4/3+4);
+  if(NULL == output)
+    return 0;
+
+  while(insize > 0) {
+    for (i = inputparts = 0; i < 3; i++) {
+      if(insize > 0) {
+        inputparts++;
+        ibuf[i] = *indata;
+        indata++;
+        insize--;
+      }
+      else
+        ibuf[i] = 0;
+    }
+
+    obuf[0] = (unsigned char)  ((ibuf[0] & 0xFC) >> 2);
+    obuf[1] = (unsigned char) (((ibuf[0] & 0x03) << 4) | \
+                               ((ibuf[1] & 0xF0) >> 4));
+    obuf[2] = (unsigned char) (((ibuf[1] & 0x0F) << 2) | \
+                               ((ibuf[2] & 0xC0) >> 6));
+    obuf[3] = (unsigned char)   (ibuf[2] & 0x3F);
+
+    switch(inputparts) {
+    case 1: /* only one byte read */
+      snprintf(output, 5, "%c%c==",
+               table64[obuf[0]],
+               table64[obuf[1]]);
+      break;
+    case 2: /* two bytes read */
+      snprintf(output, 5, "%c%c%c=",
+               table64[obuf[0]],
+               table64[obuf[1]],
+               table64[obuf[2]]);
+      break;
+    default:
+      snprintf(output, 5, "%c%c%c%c",
+               table64[obuf[0]],
+               table64[obuf[1]],
+               table64[obuf[2]],
+               table64[obuf[3]] );
+      break;
+    }
+    output += 4;
+  }
+  *output=0;
+  *outptr = base64data; /* make it return the actual data memory */
+
+  return strlen(base64data); /* return the length of the new data */
+}
+/* ---- End of Base64 Encoding ---- */
+
 #ifdef LIBSSH2DEBUG
 LIBSSH2_API int
 libssh2_trace(LIBSSH2_SESSION * session, int bitmask)
@@ -283,3 +365,64 @@ libssh2_trace(LIBSSH2_SESSION * session, int bitmask)
     return 0;
 }
 #endif
+
+/* init the list head */
+void _libssh2_list_init(struct list_head *head)
+{
+    head->first = head->last = NULL;
+}
+
+/* add a node to the list */
+void _libssh2_list_add(struct list_head *head,
+                       struct list_node *entry)
+{
+    /* store a pointer to the head */
+    entry->head = head;
+
+    /* we add this entry at the "top" so it has no next */
+    entry->next = NULL;
+
+    /* make our prev point to what the head thinks is last */
+    entry->prev = head->last;
+
+    /* and make head's last be us now */
+    head->last = entry;
+
+    /* make sure our 'prev' node points to us next */
+    if(entry->prev)
+        entry->prev->next = entry;
+    else
+        head->first = entry;
+}
+
+/* return the "first" node in the list this head points to */
+void *_libssh2_list_first(struct list_head *head)
+{
+    return head->first;
+}
+
+/* return the next node in the list */
+void *_libssh2_list_next(struct list_node *node)
+{
+    return node->next;
+}
+
+/* return the prev node in the list */
+void *_libssh2_list_prev(struct list_node *node)
+{
+    return node->prev;
+}
+
+/* remove this node from the list */
+void _libssh2_list_remove(struct list_node *entry)
+{
+    if(entry->prev)
+        entry->prev->next = entry->next;
+    else
+        entry->head->first = entry->next;
+
+    if(entry->next)
+        entry->next->prev = entry->prev;
+    else
+        entry->head->last = entry->prev;
+}