1 files changed, 45 insertions, 0 deletions
diff --git a/private_key.go b/private_key.go
index 06534ef..ae5b90a 100644
--- a/private_key.go
+++ b/private_key.go
@@ -10,6 +10,7 @@ import (
   "flag"
   "fmt"
   "io"
+  "io/ioutil"
   "os"
 )
 
@@ -96,4 +97,48 @@ func parse_create_flags() CreateFlags {
   return flags
 }
 
+// load the private key stored at `path`
+func load_private_key(path string) PrivateKey {
+  if path == "" {
+    crash_with_help(2, "No path to private key supplied!")
+  }
 
+  file, err := os.Open(path)
+  if err != nil {
+    crash_with_help(3, fmt.Sprintf("Error when opening private key: %s", err))
+  }
+  defer file.Close()
+
+  data, err := ioutil.ReadAll(file)
+  if err != nil {
+    crash_with_help(3, fmt.Sprintf("Error when reading private key: %s", err))
+  }
+
+  block, _ := pem.Decode(data)
+  if block.Type == TypeLabelRSA {
+    return load_private_key_rsa(block)
+  } else if block.Type == TypeLabelECDSA {
+    return load_private_key_ecdsa(block)
+  } else {
+    crash_with_help(2, "No valid private key file! Only RSA and ECDSA keys are allowed!")
+    return nil
+  }
+}
+
+// parse rsa private key
+func load_private_key_rsa(block *pem.Block) PrivateKey {
+  key, err := x509.ParsePKCS1PrivateKey(block.Bytes)
+  if err != nil {
+    crash_with_help(3, fmt.Sprintf("Error parsing private key: %s", err))
+  }
+  return key
+}
+
+// parse ecdsa private key
+func load_private_key_ecdsa(block *pem.Block) PrivateKey {
+  key, err := x509.ParseECPrivateKey(block.Bytes)
+  if err != nil {
+    crash_with_help(3, fmt.Sprintf("Error parsing private key: %s", err))
+  }
+  return key
+}