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hcrypto: Make more buffers persist across HMAC operations

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If we don't change MD algorithm across two calls to HMAC_Init_ex
using the same context, don't bother reallocating all of our buffers.
This commit is contained in:
Simon Wilkinson
2018-05-14 14:21:50 +01:00
committed by Jeffrey Altman
parent b9b8e76376
commit 2d84fc65bb
1 changed files with 12 additions and 22 deletions
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34
lib/hcrypto/hmac.c
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@@ -93,49 +93,39 @@ HMAC_Init_ex(HMAC_CTX *ctx,
ENGINE *engine)
{
unsigned char *p;
size_t i;
size_t i, blockSize;
blockSize = EVP_MD_block_size(md);
if (ctx->md != md) {
if (ctx->md != NULL)
HMAC_CTX_cleanup(ctx);
ctx->md = md;
if (ctx->buf) {
memset(ctx->buf, 0, ctx->key_length);
free (ctx->buf);
}
ctx->key_length = EVP_MD_size(ctx->md);
ctx->buf = malloc(ctx->key_length);
ctx->opad = malloc(blockSize);
ctx->ipad = malloc(blockSize);
ctx->ctx = EVP_MD_CTX_create();
}
#if 0
ctx->engine = engine;
#endif
if (keylen > EVP_MD_block_size(ctx->md)) {
if (keylen > blockSize) {
EVP_Digest(key, keylen, ctx->buf, NULL, ctx->md, engine);
key = ctx->buf;
keylen = EVP_MD_size(ctx->md);
}
if (ctx->opad) {
memset(ctx->opad, 0, ctx->key_length);
free(ctx->opad);
}
if (ctx->ipad) {
memset(ctx->ipad, 0, ctx->key_length);
free(ctx->ipad);
}
ctx->opad = malloc(EVP_MD_block_size(ctx->md));
ctx->ipad = malloc(EVP_MD_block_size(ctx->md));
memset(ctx->ipad, 0x36, EVP_MD_block_size(ctx->md));
memset(ctx->opad, 0x5c, EVP_MD_block_size(ctx->md));
memset(ctx->ipad, 0x36, blockSize);
memset(ctx->opad, 0x5c, blockSize);
for (i = 0, p = ctx->ipad; i < keylen; i++)
p[i] ^= ((const unsigned char *)key)[i];
for (i = 0, p = ctx->opad; i < keylen; i++)
p[i] ^= ((const unsigned char *)key)[i];
if (ctx->ctx == NULL)
ctx->ctx = EVP_MD_CTX_create();
EVP_DigestInit_ex(ctx->ctx, ctx->md, ctx->engine);
EVP_DigestUpdate(ctx->ctx, ctx->ipad, EVP_MD_block_size(ctx->md));
}