Merge pull request #61 from matrix-org/dbkr/pk_private_export_import

Work with PkDecryption keys by their private keys

2 files changed, 36 insertions, 6 deletions

diff --git a/src/error.c b/src/error.c
index f541a93..5147b5c 100644
--- a/src/error.c
+++ b/src/error.c
@@ -31,6 +31,7 @@ static const char * ERRORS[] = {
     "UNKNOWN_MESSAGE_INDEX",
     "BAD_LEGACY_ACCOUNT_PICKLE",
     "BAD_SIGNATURE",
+    "OLM_INPUT_BUFFER_TOO_SMALL",
 };
 
 const char * _olm_error_to_string(enum OlmErrorCode error)
diff --git a/src/pk.cpp b/src/pk.cpp
index 4c5f50e..5cfcea2 100644
--- a/src/pk.cpp
+++ b/src/pk.cpp
@@ -187,31 +187,35 @@ size_t olm_clear_pk_decryption(
     return sizeof(OlmPkDecryption);
 }
 
-size_t olm_pk_generate_key_random_length(void) {
+size_t olm_pk_private_key_length(void) {
     return CURVE25519_KEY_LENGTH;
 }
 
+size_t olm_pk_generate_key_random_length(void) {
+    return olm_pk_private_key_length();
+}
+
 size_t olm_pk_key_length(void) {
     return olm::encode_base64_length(CURVE25519_KEY_LENGTH);
 }
 
-size_t olm_pk_generate_key(
+size_t olm_pk_key_from_private(
     OlmPkDecryption * decryption,
     void * pubkey, size_t pubkey_length,
-    void * random, size_t random_length
+    void * privkey, size_t privkey_length
 ) {
     if (pubkey_length < olm_pk_key_length()) {
         decryption->last_error =
             OlmErrorCode::OLM_OUTPUT_BUFFER_TOO_SMALL;
         return std::size_t(-1);
     }
-    if (random_length < olm_pk_generate_key_random_length()) {
+    if (privkey_length < olm_pk_private_key_length()) {
         decryption->last_error =
-            OlmErrorCode::OLM_NOT_ENOUGH_RANDOM;
+            OlmErrorCode::OLM_INPUT_BUFFER_TOO_SMALL;
         return std::size_t(-1);
     }
 
-    _olm_crypto_curve25519_generate_key((uint8_t *) random, &decryption->key_pair);
+    _olm_crypto_curve25519_generate_key((uint8_t *) privkey, &decryption->key_pair);
     olm::encode_base64(
         (const uint8_t *)decryption->key_pair.public_key.public_key,
         CURVE25519_KEY_LENGTH,
@@ -220,6 +224,14 @@ size_t olm_pk_generate_key(
     return 0;
 }
 
+size_t olm_pk_generate_key(
+    OlmPkDecryption * decryption,
+    void * pubkey, size_t pubkey_length,
+    void * privkey, size_t privkey_length
+) {
+    return olm_pk_key_from_private(decryption, pubkey, pubkey_length, privkey, privkey_length);
+}
+
 namespace {
     static const std::uint32_t PK_DECRYPTION_PICKLE_VERSION = 1;
 
@@ -380,4 +392,21 @@ size_t olm_pk_decrypt(
     }
 }
 
+size_t olm_pk_get_private_key(
+    OlmPkDecryption * decryption,
+    void *private_key, size_t private_key_length
+) {
+    if (private_key_length < olm_pk_private_key_length()) {
+        decryption->last_error =
+            OlmErrorCode::OLM_OUTPUT_BUFFER_TOO_SMALL;
+        return std::size_t(-1);
+    }
+    std::memcpy(
+        private_key,
+        decryption->key_pair.private_key.private_key,
+        olm_pk_private_key_length()
+    );
+    return olm_pk_private_key_length();
+}
+
 }