pki: Add support to import ecdsa pubkeys.

include/libssh/pki_priv.h

@@ -34,6 +34,8 @@
 void _ssh_pki_log(const char *function,
                   const char *format, ...) PRINTF_ATTRIBUTE(2, 3);
 
+int pki_key_ecdsa_nid_from_name(const char *name);
+
 /* SSH Key Functions */
 ssh_key pki_key_dup(const ssh_key key, int demote);
 int pki_key_generate_rsa(ssh_key key, int parameter);
@@ -58,6 +60,7 @@ int pki_pubkey_build_dss(ssh_key key,
 int pki_pubkey_build_rsa(ssh_key key,
                          ssh_string e,
                          ssh_string n);
+int pki_pubkey_build_ecdsa(ssh_key key, int nid, ssh_string e);
 ssh_string pki_publickey_to_blob(const ssh_key key);
 int pki_export_pubkey_rsa1(const ssh_key key,
                            const char *host,

src/pki.c

@@ -625,6 +625,35 @@ static int pki_import_pubkey_buffer(ssh_buffer buffer,
             }
             break;
         case SSH_KEYTYPE_ECDSA:
+#ifdef HAVE_ECC
+            {
+                ssh_string e;
+                ssh_string i;
+                int nid;
+
+                i = buffer_get_ssh_string(buffer);
+                if (i == NULL) {
+                    goto fail;
+                }
+                nid = pki_key_ecdsa_nid_from_name(ssh_string_get_char(i));
+                ssh_string_free(i);
+                if (nid == -1) {
+                    goto fail;
+                }
+
+
+                e = buffer_get_ssh_string(buffer);
+                if (e == NULL) {
+                    goto fail;
+                }
+
+                rc = pki_pubkey_build_ecdsa(key, nid, e);
+
+                ssh_string_burn(e);
+                ssh_string_free(e);
+            }
+            break;
+#endif
         case SSH_KEYTYPE_UNKNOWN:
             ssh_pki_log("Unknown public key protocol %d", type);
             goto fail;
@@ -701,6 +730,7 @@ int ssh_pki_import_pubkey_blob(const ssh_string key_blob,
     ssh_buffer buffer;
     ssh_string type_s = NULL;
     enum ssh_keytypes_e type;
+    int nid;
     int rc;
 
     if (key_blob == NULL || pkey == NULL) {
@@ -727,11 +757,18 @@ int ssh_pki_import_pubkey_blob(const ssh_string key_blob,
     }
 
     type = ssh_key_type_from_name(ssh_string_get_char(type_s));
-    ssh_string_free(type_s);
     if (type == SSH_KEYTYPE_UNKNOWN) {
         ssh_pki_log("Unknown key type found!");
         goto fail;
     }
+    if (type == SSH_KEYTYPE_ECDSA) {
+        nid = pki_key_ecdsa_nid_from_name(ssh_string_get_char(type_s));
+        if (nid == -1) {
+            ssh_pki_log("Unknown nid found!");
+            goto fail;
+        }
+    }
+    ssh_string_free(type_s);
 
     rc = pki_import_pubkey_buffer(buffer, type, pkey);
 

src/pki_crypto.c

@@ -121,6 +121,19 @@ static const char *pki_key_ecdsa_nid_to_char(int nid)
     return "unknown";
 }
 
+int pki_key_ecdsa_nid_from_name(const char *name)
+{
+    if (strcmp(name, "nistp256") == 0) {
+        return NID_X9_62_prime256v1;
+    } else if (strcmp(name, "nistp384") == 0) {
+        return NID_secp384r1;
+    } else if (strcmp(name, "nistp521") == 0) {
+        return NID_secp521r1;
+    }
+
+    return -1;
+}
+
 static ssh_string make_ecpoint_string(const EC_GROUP *g,
                                       const EC_POINT *p)
 {
@@ -155,6 +168,45 @@ static ssh_string make_ecpoint_string(const EC_GROUP *g,
 
     return s;
 }
+
+int pki_pubkey_build_ecdsa(ssh_key key, int nid, ssh_string e)
+{
+    EC_POINT *p;
+    const EC_GROUP *g;
+    int ok;
+
+    key->ecdsa_nid = nid;
+    key->type_c = pki_key_ecdsa_nid_to_name(nid);
+
+    key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid);
+    if (key->ecdsa == NULL) {
+        return -1;
+    }
+
+    g = EC_KEY_get0_group(key->ecdsa);
+
+    p = EC_POINT_new(g);
+    if (p == NULL) {
+        return -1;
+    }
+
+    ok = EC_POINT_oct2point(g,
+                            p,
+                            ssh_string_data(e),
+                            ssh_string_len(e),
+                            NULL);
+    if (!ok) {
+        EC_POINT_free(p);
+        return -1;
+    }
+
+    ok = EC_KEY_set_public_key(key->ecdsa, p);
+    if (!ok) {
+        EC_POINT_free(p);
+    }
+
+    return 0;
+}
 #endif
 
 ssh_key pki_key_dup(const ssh_key key, int demote)