fix the pbkdf2 implementation so output matches rfc 6070

diff --git a/ykpbkdf2.c b/ykpbkdf2.c
index 10510e8fe337fbd9c64531d96d8dd0a7a0dbbcf1..535b4147b484b26851822196fadabe3f53264dc6 100644 (file)
--- a/ykpbkdf2.c
+++ b/ykpbkdf2.c
@@ -62,10 +62,13 @@ int yk_pbkdf2(const char *passphrase,
 
        unsigned int block_count;
 
+       memset(dk, 0, dklen);
+
        for (block_count = 1; block_count <= l; block_count++) {
                unsigned char block[256]; /* A big chunk, that's 2048 bits */
                size_t block_len;
                unsigned int iteration;
+               int i;
 
                memcpy(block, salt, salt_len);
                block[salt_len + 0] = (block_count & 0xff000000) >> 24;
@@ -80,11 +83,13 @@ int yk_pbkdf2(const char *passphrase,
                                                block, sizeof(block)))
                                return 0;
                        block_len = prf_method->output_size;
+                       for(i = 0; i < dklen; i++) {
+                               dk[i] ^= block[i];
+                       }
                }
 
                if (block_len > dklen)
                        block_len = dklen; /* This happens in the last block */
-               memcpy(dk, block, block_len);
                dk += block_len;
                dklen -= block_len;
        }