From 83c96cbc76604daccbc31cea9411555aea96fd6d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi>
Date: Thu, 5 Feb 2015 09:16:51 +0200
Subject: [PATCH] crypto/hmac: support EVP_MD_CTX_FLAG_ONESHOT and set it
properly
Some engines (namely VIA C7 Padlock) work only if EVP_MD_CTX_FLAG_ONESHOT
is set before final update. This is because some crypto accelerators cannot
perform non-finalizing transform of the digest.
The usage of EVP_MD_CTX_FLAG_ONESHOT is used semantically slightly
differently here. It is set before the final EVP_DigestUpdate call, not
necessarily before EVP_DigestInit call. This will not cause any problems
though.
---
crypto/hmac/hmac.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/crypto/hmac/hmac.c b/crypto/hmac/hmac.c
index 1fc9e2c..6f16578 100644
--- a/crypto/hmac/hmac.c
+++ b/crypto/hmac/hmac.c
@@ -109,7 +109,8 @@ int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
j = EVP_MD_block_size(md);
OPENSSL_assert(j <= (int)sizeof(ctx->key));
if (j < len) {
- if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl))
+ EVP_MD_CTX_set_flags(&ctx->md_ctx, EVP_MD_CTX_FLAG_ONESHOT);
+ if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl))
goto err;
if (!EVP_DigestUpdate(&ctx->md_ctx, key, len))
goto err;
@@ -129,6 +130,7 @@ int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
if (reset) {
for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
pad[i] = 0x36 ^ ctx->key[i];
+ EVP_MD_CTX_clear_flags(&ctx->i_ctx, EVP_MD_CTX_FLAG_ONESHOT);
if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl))
goto err;
if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md)))
@@ -136,6 +138,7 @@ int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
pad[i] = 0x5c ^ ctx->key[i];
+ EVP_MD_CTX_clear_flags(&ctx->o_ctx, EVP_MD_CTX_FLAG_ONESHOT);
if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl))
goto err;
if (!EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md)))
@@ -143,6 +146,7 @@ int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
}
if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx))
goto err;
+ EVP_MD_CTX_clear_flags(&ctx->md_ctx, EVP_MD_CTX_FLAG_ONESHOT);
return 1;
err:
return 0;
@@ -177,6 +181,7 @@ int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
goto err;
if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx))
goto err;
+ EVP_MD_CTX_set_flags(&ctx->md_ctx,EVP_MD_CTX_FLAG_ONESHOT);
if (!EVP_DigestUpdate(&ctx->md_ctx, buf, i))
goto err;
if (!EVP_DigestFinal_ex(&ctx->md_ctx, md, len))
@@ -233,8 +238,9 @@ unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
if (md == NULL)
md = m;
HMAC_CTX_init(&c);
- if (!HMAC_Init(&c, key, key_len, evp_md))
+ if (!HMAC_Init_ex(&c, key, key_len, evp_md, NULL))
goto err;
+ HMAC_CTX_set_flags(&c,EVP_MD_CTX_FLAG_ONESHOT);
if (!HMAC_Update(&c, d, n))
goto err;
if (!HMAC_Final(&c, md, md_len))
@@ -247,7 +253,7 @@ unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
{
- EVP_MD_CTX_set_flags(&ctx->i_ctx, flags);
- EVP_MD_CTX_set_flags(&ctx->o_ctx, flags);
+ EVP_MD_CTX_set_flags(&ctx->i_ctx, flags & ~EVP_MD_CTX_FLAG_ONESHOT);
+ EVP_MD_CTX_set_flags(&ctx->o_ctx, flags & ~EVP_MD_CTX_FLAG_ONESHOT);
EVP_MD_CTX_set_flags(&ctx->md_ctx, flags);
}
--
2.2.2
