PBKDF2 should be efficient. Contributed by Christian Heimes
authorBen Laurie <ben@links.org>
Sun, 3 Nov 2013 17:23:50 +0000 (17:23 +0000)
committerBen Laurie <ben@links.org>
Sun, 3 Nov 2013 17:23:50 +0000 (17:23 +0000)
<christian@python.org>.

crypto/evp/p5_crpt2.c

index 975d004..9409a82 100644 (file)
@@ -85,7 +85,7 @@ int PKCS5_PBKDF2_HMAC(const char *pass, int passlen,
        unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];
        int cplen, j, k, tkeylen, mdlen;
        unsigned long i = 1;
-       HMAC_CTX hctx;
+       HMAC_CTX hctx_tpl, hctx;
 
        mdlen = EVP_MD_size(digest);
        if (mdlen < 0)
@@ -98,6 +98,11 @@ int PKCS5_PBKDF2_HMAC(const char *pass, int passlen,
                passlen = 0;
        else if(passlen == -1)
                passlen = strlen(pass);
+       if (!HMAC_Init_ex(&hctx_tpl, pass, passlen, digest, NULL))
+               {
+               HMAC_CTX_cleanup(&hctx_tpl);
+               return 0;
+               }
        while(tkeylen)
                {
                if(tkeylen > mdlen)
@@ -111,19 +116,35 @@ int PKCS5_PBKDF2_HMAC(const char *pass, int passlen,
                itmp[1] = (unsigned char)((i >> 16) & 0xff);
                itmp[2] = (unsigned char)((i >> 8) & 0xff);
                itmp[3] = (unsigned char)(i & 0xff);
-               if (!HMAC_Init_ex(&hctx, pass, passlen, digest, NULL)
-                       || !HMAC_Update(&hctx, salt, saltlen)
-                       || !HMAC_Update(&hctx, itmp, 4)
-                       || !HMAC_Final(&hctx, digtmp, NULL))
+               if (!HMAC_CTX_copy(&hctx, &hctx_tpl))
                        {
+                       HMAC_CTX_cleanup(&hctx_tpl);
+                       return 0;
+                       }
+               if (!HMAC_Update(&hctx, salt, saltlen)
+                   || !HMAC_Update(&hctx, itmp, 4)
+                   || !HMAC_Final(&hctx, digtmp, NULL))
+                       {
+                       HMAC_CTX_cleanup(&hctx_tpl);
                        HMAC_CTX_cleanup(&hctx);
                        return 0;
                        }
                memcpy(p, digtmp, cplen);
                for(j = 1; j < iter; j++)
                        {
-                       HMAC(digest, pass, passlen,
-                                digtmp, mdlen, digtmp, NULL);
+                       if (!HMAC_CTX_copy(&hctx, &hctx_tpl))
+                               {
+                               HMAC_CTX_cleanup(&hctx_tpl);
+                               return 0;
+                               }
+                       if (!HMAC_Update(&hctx, digtmp, mdlen)
+                           || !HMAC_Final(&hctx, digtmp, NULL))
+                               {
+                               HMAC_CTX_cleanup(&hctx_tpl);
+                               HMAC_CTX_cleanup(&hctx);
+                               return 0;
+                               }
+                       HMAC_CTX_cleanup(&hctx);
                        for(k = 0; k < cplen; k++)
                                p[k] ^= digtmp[k];
                        }
@@ -131,7 +152,7 @@ int PKCS5_PBKDF2_HMAC(const char *pass, int passlen,
                i++;
                p+= cplen;
                }
-       HMAC_CTX_cleanup(&hctx);
+       HMAC_CTX_cleanup(&hctx_tpl);
 #ifdef DEBUG_PKCS5V2
        fprintf(stderr, "Password:\n");
        h__dump (pass, passlen);