Add encode/decode functions for ed25519 public keys

src/common/crypto_ed25519.h

@@ -69,8 +69,15 @@ int ed25519_checksig_batch(int *okay_out,
                            int n_checkable);
 #endif
 
+#define ED25519_BASE64_LEN 43
+
+int ed25519_public_from_base64(ed25519_public_key_t *pkey,
+                               const char *input);
+int ed25519_public_to_base64(char *output,
+                             const ed25519_public_key_t *pkey);
+
 /* XXXX write secret keys to disk, load secret keys from disk, read encrypted,
- * write encrypted. serialize public. parse public. */
+ * write encrypted. */
 
 #endif
 

src/common/crypto_format.c

@@ -9,6 +9,7 @@
 #endif
 #include "crypto.h"
 #include "crypto_curve25519.h"
+#include "crypto_ed25519.h"
 #include "util.h"
 #include "torlog.h"
 
@@ -43,3 +44,24 @@ curve25519_public_from_base64(curve25519_public_key_t *pkey,
   }
 }
 
+/** Try to decode the string <b>input</b> into an ed25519 public key. On
+ * success, store the value in <b>pkey</b> and return 0. Otherwise return
+ * -1. */
+int
+ed25519_public_from_base64(ed25519_public_key_t *pkey,
+                           const char *input)
+{
+  return digest256_from_base64((char*)pkey->pubkey, input);
+}
+
+/** Encode the public key <b>pkey</b> into the buffer at <b>output</b>,
+ * which must have space for ED25519_BASE64_LEN bytes of encoded key,
+ * plus one byte for a terminating NUL.  Return 0 on success, -1 on failure.
+ */
+int
+ed25519_public_to_base64(char *output,
+                         const ed25519_public_key_t *pkey)
+{
+  return digest256_to_base64(output, (const char *)pkey->pubkey);
+}
+