Commit fffcf87a authored by Matt Caswell's avatar Matt Caswell
Browse files

Fix ABI break with HMAC 



Recent HMAC changes broke ABI compatibility due to a new field in HMAC_CTX.
This backs that change out, and does it a different way.

Thanks to Timo Teras for the concept.

Conflicts:
	crypto/hmac/hmac.c

Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
parent 3adca975

crypto/hmac/hmac.c

+7 −12
Original line number Diff line number Diff line
@@ -87,6 +87,9 @@ int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, 
            return FIPS_hmac_init_ex(ctx, key, len, md, NULL);

    }

#endif

    /* If we are changing MD then we must have a key */

    if (md != NULL && md != ctx->md && (key == NULL || len < 0))

        return 0;



    if (md != NULL) {

        reset = 1;
@@ -97,9 +100,6 @@ int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, 
        return 0;

    }



    if (!ctx->key_init && key == NULL)

        return 0;



    if (key != NULL) {

        reset = 1;

        j = EVP_MD_block_size(md);
@@ -121,7 +121,6 @@ int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, 
        if (ctx->key_length != HMAC_MAX_MD_CBLOCK)

            memset(&ctx->key[ctx->key_length], 0,

                   HMAC_MAX_MD_CBLOCK - ctx->key_length);

        ctx->key_init = 1;

    }



    if (reset) {
@@ -159,7 +158,7 @@ int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len) 
    if (FIPS_mode() && !ctx->i_ctx.engine)

        return FIPS_hmac_update(ctx, data, len);

#endif

    if (!ctx->key_init)

    if (!ctx->md)

        return 0;



    return EVP_DigestUpdate(&ctx->md_ctx, data, len);
@@ -174,7 +173,7 @@ int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len) 
        return FIPS_hmac_final(ctx, md, len);

#endif



    if (!ctx->key_init)

    if (!ctx->md)

        goto err;



    if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i))
@@ -195,7 +194,6 @@ void HMAC_CTX_init(HMAC_CTX *ctx) 
    EVP_MD_CTX_init(&ctx->i_ctx);

    EVP_MD_CTX_init(&ctx->o_ctx);

    EVP_MD_CTX_init(&ctx->md_ctx);

    ctx->key_init = 0;

    ctx->md = NULL;

}
@@ -207,11 +205,8 @@ int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx) 
        goto err;

    if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx))

        goto err;

    dctx->key_init = sctx->key_init;

    if (sctx->key_init) {

    memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK);

    dctx->key_length = sctx->key_length;

    }

    dctx->md = sctx->md;

    return 1;

 err:

crypto/hmac/hmac.h

+0 −1
Original line number Diff line number Diff line
@@ -79,7 +79,6 @@ typedef struct hmac_ctx_st { 
    EVP_MD_CTX o_ctx;

    unsigned int key_length;

    unsigned char key[HMAC_MAX_MD_CBLOCK];

    int key_init;

} HMAC_CTX;



# define HMAC_size(e)    (EVP_MD_size((e)->md))

crypto/hmac/hmactest.c

+6 −1
Original line number Diff line number Diff line
@@ -233,7 +233,12 @@ test5: 
        err++;

        goto test6;

    }

    if (!HMAC_Init_ex(&ctx, NULL, 0, EVP_sha256(), NULL)) {

    if (HMAC_Init_ex(&ctx, NULL, 0, EVP_sha256(), NULL)) {

        printf("Should disallow changing MD without a new key (test 5)\n");

        err++;

        goto test6;

    }

    if (!HMAC_Init_ex(&ctx, test[4].key, test[4].key_len, EVP_sha256(), NULL)) {

        printf("Failed to reinitialise HMAC (test 5)\n");

        err++;

        goto test6;