Create a ssh_get_hexa function.

This function converts a buffer into a colon separated hex string.


git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/libssh/trunk@308 7dcaeef0-15fb-0310-b436-a5af3365683c

include/libssh/libssh.h

@@ -231,7 +231,8 @@ void *string_data(STRING *str);
 void string_free(STRING *str);
 
 /* useful for debug */
-void ssh_print_hexa(char *descr, const unsigned char *what, int len);
+char *ssh_get_hexa(const unsigned char *what, size_t len);
+void ssh_print_hexa(const char *descr, const unsigned char *what, size_t len);
 int ssh_get_random(void *where,int len,int strong);
 
 /* this one can be called by the client to see the hash of the public key before accepting it */

libssh/dh.c

@@ -141,17 +141,54 @@ void ssh_print_bignum(char *which,bignum num){
     free(hex);	
 }
 
-void ssh_print_hexa(char *descr, const unsigned char *what, int len){
+/**
-    int i;
+ * @brief Convert a buffer into a colon separated hex string.
-    printf("%s : ",descr);
+ * The caller has to free the memory.
-    if(len>16)
+ *
-        printf ("\n        ");
+ * @param  what         What should be converted to a hex string.
-    for(i=0;i<len-1;i++){
+ *
-        printf("%.2hhx:",what[i]);
+ * @param  len          Length of the buffer to convert.
-        if((i+1) % 16 ==0)
+ *
-            printf("\n        ");
+ * @return              The hex string or NULL on error.
+ */
+char *ssh_get_hexa(const unsigned char *what, size_t len) {
+  char *hexa = NULL;
+  size_t i;
+
+  hexa = malloc(len * 3 + 1);
+  if (hexa == NULL) {
+    return NULL;
+  }
+
+  ZERO_STRUCTP(hexa);
+
+  for (i = 0; i < len; i++) {
+    char hex[4];
+    snprintf(hex, sizeof(hex), "%02x:", what[i]);
+    strcat(hexa, hex);
+  }
+
+  hexa[(len * 3) - 1] = '\0';
+
+  return hexa;
+}
+
+/**
+ * @brief Print a buffer as colon separated hex string.
+ *
+ * @param  descr        Description printed infront of the hex string.
+ *
+ * @param  what         What should be converted to a hex string.
+ *
+ * @param  len          Length of the buffer to convert.
+ */
+void ssh_print_hexa(const char *descr, const unsigned char *what, size_t len) {
+    char *hexa = ssh_get_hexa(what, len);
+
+    if (hexa == NULL) {
+      return;
     }
-    printf("%.2hhx\n",what[i]);
+    printf("%s: %s\n", descr, hexa);
 }
 
 void dh_generate_x(SSH_SESSION *session){

libssh/libssh.vers

@@ -8,7 +8,7 @@ SSH_0.3 {
     string_from_char; string_len; string_new; string_fill; string_to_char;
     string_copy; string_burn; string_data;
     ssh_crypto_init;
-    ssh_print_hexa; ssh_get_random;
+    ssh_get_hexa; ssh_print_hexa; ssh_get_random;
     ssh_get_pubkey_hash; ssh_get_pubkey;
     ssh_fd_poll; ssh_select; publickey_free;
     privatekey_from_file; publickey_to_string; publickey_from_privatekey;

sample.c

@@ -403,6 +403,7 @@ int main(int argc, char **argv){
     int auth=0;
     char *password;
     char *banner;
+    char *hexa;
     int state;
     char buf[10];
     unsigned char hash[MD5_DIGEST_LEN];
@@ -446,9 +447,11 @@ int main(int argc, char **argv){
 		    ssh_finalize();
             exit(-1);
         case SSH_SERVER_NOT_KNOWN:
+            ssh_get_pubkey_hash(session, hash);
+            hexa = ssh_get_hexa(hash, MD5_DIGEST_LEN);
             fprintf(stderr,"The server is unknown. Do you trust the host key ?\n");
-            ssh_get_pubkey_hash(session,hash);
+            fprintf(stderr, "Public key hash: %s\n", hexa);
-            ssh_print_hexa("Public key hash",hash,MD5_DIGEST_LEN);
+            free(hexa);
             fgets(buf,sizeof(buf),stdin);
             if(strncasecmp(buf,"yes",3)!=0){
                 ssh_disconnect(session);