[PATCH] bcrypt: Set pubkey_len and reallocate memory for pubkey.

[Santino Mazza]

This is needed because BCryptFinalizeKey doesn't change the
pubkey_len member based on the keylen member. Also it doesn't
reallocate the pubkey buffer. If we don't do this programs get
an error when trying to generate a key by setting the length
using BCryptSetProperty.

Signed-off-by: Santino Mazza <mazzasantino1206 at gmail.com>
---
 dlls/bcrypt/bcrypt_main.c  | 19 ++++++++++++++++++-
 dlls/bcrypt/tests/bcrypt.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/dlls/bcrypt/bcrypt_main.c b/dlls/bcrypt/bcrypt_main.c
index 5df4da009a4..2b3ceb803a0 100644
--- a/dlls/bcrypt/bcrypt_main.c
+++ b/dlls/bcrypt/bcrypt_main.c
@@ -704,7 +704,24 @@ static NTSTATUS set_key_property( struct key *key, const WCHAR *prop, UCHAR *val
     else if (!wcscmp( prop, BCRYPT_KEY_LENGTH ))
     {
         if (size < sizeof(DWORD)) return STATUS_INVALID_PARAMETER;
-        key->u.a.bitlen = *(DWORD*)value;
+        if (key->u.a.bitlen == *(DWORD *)value) return STATUS_SUCCESS;
+
+        key->u.a.bitlen = *(DWORD *)value;
+        switch (key->alg_id)
+        {
+        case ALG_ID_RSA:
+        case ALG_ID_RSA_SIGN:
+            key->u.a.pubkey_len = sizeof(BCRYPT_RSAKEY_BLOB) + 2 * key->u.a.bitlen / 8;
+            break;
+        case ALG_ID_DSA:
+            key->u.a.pubkey_len = sizeof(BCRYPT_DSA_KEY_BLOB) + 3 * key->u.a.bitlen / 8;
+            break;
+        default:
+            FIXME( "algorithm %u not supported\n", key->alg_id );
+            return STATUS_NOT_SUPPORTED;
+        }
+
+        key->u.a.pubkey = realloc( key->u.a.pubkey, key->u.a.pubkey_len );
         return STATUS_SUCCESS;
     }
 
diff --git a/dlls/bcrypt/tests/bcrypt.c b/dlls/bcrypt/tests/bcrypt.c
index efb5843fa4e..3b4fd3e31e7 100644
--- a/dlls/bcrypt/tests/bcrypt.c
+++ b/dlls/bcrypt/tests/bcrypt.c
@@ -2182,6 +2182,19 @@ static void test_RSA(void)
     HeapFree(GetProcessHeap(), 0, buf);
     BCryptDestroyKey(key);
 
+    /* generate rsa keys setting the key len by using properties */
+    key = NULL;
+    ret = BCryptGenerateKeyPair(alg, &key, 1024, 0);
+    ok(ret == STATUS_SUCCESS, "got %#lx\n", ret);
+    ok(key != NULL, "got null handle\n");
+
+    keylen = 2048;
+    BCryptSetProperty(key, BCRYPT_KEY_LENGTH, (UCHAR *)&keylen, sizeof(keylen), 0);
+
+    ret = BCryptFinalizeKeyPair(key, 0);
+    ok(ret == STATUS_SUCCESS, "got %#lx\n", ret);
+    if(key) BCryptDestroyKey(key);
+
     ret = BCryptCloseAlgorithmProvider(alg, 0);
     ok(!ret, "got %#lx\n", ret);
 }
@@ -2867,6 +2880,7 @@ static void test_DSA(void)
     BCRYPT_DSA_KEY_BLOB *dsablob;
     UCHAR sig[40], schemes;
     ULONG len, size;
+    DWORD keylen;
     NTSTATUS ret;
     BYTE *buf;
 
@@ -2945,6 +2959,21 @@ static void test_DSA(void)
     ret = BCryptDestroyKey(key);
     ok(!ret, "got %#lx\n", ret);
 
+    /* generate dsa key by setting the key length */
+    key = NULL;
+    ret = BCryptGenerateKeyPair(alg, &key, 512, 0);
+    ok(ret == STATUS_SUCCESS, "got %#lx\n", ret);
+
+    keylen = 1024;
+    ret = BCryptSetProperty(key, BCRYPT_KEY_LENGTH, (UCHAR *)&keylen, sizeof(keylen), 0);
+    ok(ret == STATUS_SUCCESS, "got %#lx\n", ret);
+
+    ret = BCryptFinalizeKeyPair(key, 0);
+    ok(ret == STATUS_SUCCESS, "got %#lx\n", ret);
+
+    ret = BCryptDestroyKey(key);
+    ok(ret == STATUS_SUCCESS, "got %#lx\n", ret);
+
     ret = BCryptCloseAlgorithmProvider(alg, 0);
     ok(!ret, "got %#lx\n", ret);
 }
-- 
2.32.0