Mitigate cache-timing attack in CBC mode. This is done by implementing

[openssl.git] / crypto / evp / p5_crpt.c

diff --git a/crypto/evp/p5_crpt.c b/crypto/evp/p5_crpt.c
index 56cec480d561c1b7e5e320f7a96829cc844ceb6a..c0dfb7de373037148fb233020fee72bc2978e598 100644 (file)
--- a/crypto/evp/p5_crpt.c
+++ b/crypto/evp/p5_crpt.c
@@ -58,9 +58,9 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include "cryptlib.h"
 #include <openssl/x509.h>
 #include <openssl/evp.h>
-#include "cryptlib.h"
 
 /* PKCS#5 v1.5 compatible PBE functions: see PKCS#5 v2.0 for more info.
  */
@@ -110,7 +110,8 @@ int PKCS5_PBE_keyivgen(EVP_CIPHER_CTX *cctx, const char *pass, int passlen,
        int i;
        PBEPARAM *pbe;
        int saltlen, iter;
-       unsigned char *salt, *pbuf;
+       unsigned char *salt;
+       const unsigned char *pbuf;
 
        /* Extract useful info from parameter */
        pbuf = param->value.sequence->data;
@@ -128,22 +129,26 @@ int PKCS5_PBE_keyivgen(EVP_CIPHER_CTX *cctx, const char *pass, int passlen,
        if(!pass) passlen = 0;
        else if(passlen == -1) passlen = strlen(pass);
 
-       EVP_DigestInit (&ctx, md);
-       EVP_DigestUpdate (&ctx, pass, passlen);
-       EVP_DigestUpdate (&ctx, salt, saltlen);
+       EVP_MD_CTX_init(&ctx);
+       EVP_DigestInit_ex(&ctx, md, NULL);
+       EVP_DigestUpdate(&ctx, pass, passlen);
+       EVP_DigestUpdate(&ctx, salt, saltlen);
        PBEPARAM_free(pbe);
-       EVP_DigestFinal (&ctx, md_tmp, NULL);
+       EVP_DigestFinal_ex(&ctx, md_tmp, NULL);
        for (i = 1; i < iter; i++) {
-               EVP_DigestInit(&ctx, md);
+               EVP_DigestInit_ex(&ctx, md, NULL);
                EVP_DigestUpdate(&ctx, md_tmp, EVP_MD_size(md));
-               EVP_DigestFinal (&ctx, md_tmp, NULL);
+               EVP_DigestFinal_ex (&ctx, md_tmp, NULL);
        }
-       memcpy (key, md_tmp, EVP_CIPHER_key_length(cipher));
-       memcpy (iv, md_tmp + (16 - EVP_CIPHER_iv_length(cipher)),
+       EVP_MD_CTX_cleanup(&ctx);
+       OPENSSL_assert(EVP_CIPHER_key_length(cipher) <= (int)sizeof(md_tmp));
+       memcpy(key, md_tmp, EVP_CIPHER_key_length(cipher));
+       OPENSSL_assert(EVP_CIPHER_iv_length(cipher) <= 16);
+       memcpy(iv, md_tmp + (16 - EVP_CIPHER_iv_length(cipher)),
                                                 EVP_CIPHER_iv_length(cipher));
-       EVP_CipherInit(cctx, cipher, key, iv, en_de);
-       memset(md_tmp, 0, EVP_MAX_MD_SIZE);
-       memset(key, 0, EVP_MAX_KEY_LENGTH);
-       memset(iv, 0, EVP_MAX_IV_LENGTH);
+       EVP_CipherInit_ex(cctx, cipher, NULL, key, iv, en_de);
+       OPENSSL_cleanse(md_tmp, EVP_MAX_MD_SIZE);
+       OPENSSL_cleanse(key, EVP_MAX_KEY_LENGTH);
+       OPENSSL_cleanse(iv, EVP_MAX_IV_LENGTH);
        return 1;
 }