diff options
author | Matt Caswell <matt@openssl.org> | 2021-12-10 17:17:27 +0000 |
---|---|---|
committer | Matt Caswell <matt@openssl.org> | 2022-01-13 11:45:45 +0000 |
commit | 93dd7ab35f6ccfb8bde7a7a6e38ea5817c5b54e2 (patch) | |
tree | 07a9123add74398ae68b4da813ccbcc7bfc10477 | |
parent | 5e7098e11581b6b3a4083a1c17889ed817e8ac22 (diff) |
Fix a leak in EVP_DigestInit_ex()
If an EVP_MD_CTX is reused then memory allocated and stored in md_data
can be leaked unless the EVP_MD's cleanup function is called.
Fixes #17149
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/17472)
-rw-r--r-- | crypto/evp/digest.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c index d1bfa274ca..41ecdd8e5a 100644 --- a/crypto/evp/digest.c +++ b/crypto/evp/digest.c @@ -15,6 +15,22 @@ #include "crypto/evp.h" #include "evp_local.h" + +static void cleanup_old_md_data(EVP_MD_CTX *ctx, int force) +{ + if (ctx->digest != NULL) { + if (ctx->digest->cleanup != NULL + && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_CLEANED)) + ctx->digest->cleanup(ctx); + if (ctx->md_data != NULL && ctx->digest->ctx_size > 0 + && (!EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_REUSE) + || force)) { + OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size); + ctx->md_data = NULL; + } + } +} + /* This call frees resources associated with the context */ int EVP_MD_CTX_reset(EVP_MD_CTX *ctx) { @@ -25,13 +41,8 @@ int EVP_MD_CTX_reset(EVP_MD_CTX *ctx) * Don't assume ctx->md_data was cleaned in EVP_Digest_Final, because * sometimes only copies of the context are ever finalised. */ - if (ctx->digest && ctx->digest->cleanup - && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_CLEANED)) - ctx->digest->cleanup(ctx); - if (ctx->digest && ctx->digest->ctx_size && ctx->md_data - && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_REUSE)) { - OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size); - } + cleanup_old_md_data(ctx, 0); + /* * pctx should be freed by the user of EVP_MD_CTX * if EVP_MD_CTX_FLAG_KEEP_PKEY_CTX is set @@ -76,6 +87,7 @@ int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl) if (ctx->engine && ctx->digest && (type == NULL || (type->type == ctx->digest->type))) goto skip_to_init; + if (type) { /* * Ensure an ENGINE left lying around from last time is cleared (the @@ -119,10 +131,8 @@ int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl) } #endif if (ctx->digest != type) { - if (ctx->digest && ctx->digest->ctx_size) { - OPENSSL_clear_free(ctx->md_data, ctx->digest->ctx_size); - ctx->md_data = NULL; - } + cleanup_old_md_data(ctx, 1); + ctx->digest = type; if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size) { ctx->update = type->update; |