From 30e6c22e141d79fdb86e8f46fc66ce6c82cfd821 Mon Sep 17 00:00:00 2001
From: Andy Green <andy@warmcat.com>
Date: Thu, 11 Jun 2020 16:09:51 +0100
Subject: [PATCH] openssl3: migrate genhmac to EVP

The low level apis for HMAC (including those only introduced at 1.1.0...)
are all deprecated in OpenSSL v3.

Let's bite the bullet and migrate to EVP, it's already existing in modern
OpenSSL and we already use it for genhash.

EVP needs a PKEY, sort that out and keep it around until the hmac is
destroyed.
---
 cmake/lws_config.h.in               |  1 +
 include/libwebsockets/lws-genhash.h |  7 +++
 lib/tls/CMakeLists.txt              |  1 +
 lib/tls/openssl/lws-genhash.c       | 74 +++++++++++++++++++++++++++++
 4 files changed, 83 insertions(+)

diff --git a/cmake/lws_config.h.in b/cmake/lws_config.h.in
index 9136a8a04..a33f55dc0 100644
--- a/cmake/lws_config.h.in
+++ b/cmake/lws_config.h.in
@@ -46,6 +46,7 @@
 #cmakedefine LWS_HAVE_EVP_aes_256_cfb8
 #cmakedefine LWS_HAVE_EVP_aes_256_cfb128
 #cmakedefine LWS_HAVE_EVP_aes_128_xts
+#cmakedefine LWS_HAVE_EVP_PKEY_new_raw_private_key
 #cmakedefine LWS_HAVE_EXECVPE
 #cmakedefine LWS_HAVE_LIBCAP
 #cmakedefine LWS_HAVE_HMAC_CTX_new
diff --git a/include/libwebsockets/lws-genhash.h b/include/libwebsockets/lws-genhash.h
index 292a1ff62..8407d2f03 100644
--- a/include/libwebsockets/lws-genhash.h
+++ b/include/libwebsockets/lws-genhash.h
@@ -74,11 +74,18 @@ struct lws_genhmac_ctx {
 	mbedtls_md_context_t ctx;
 #else
 	const EVP_MD *evp_type;
+
+#if defined(LWS_HAVE_EVP_PKEY_new_raw_private_key)
+	EVP_MD_CTX *ctx;
+	EVP_PKEY *key;
+#else
 #if defined(LWS_HAVE_HMAC_CTX_new)
         HMAC_CTX *ctx;
 #else
         HMAC_CTX ctx;
 #endif
+#endif
+
 #endif
 };
 
diff --git a/lib/tls/CMakeLists.txt b/lib/tls/CMakeLists.txt
index 3a502d075..0c48f5d4c 100644
--- a/lib/tls/CMakeLists.txt
+++ b/lib/tls/CMakeLists.txt
@@ -298,6 +298,7 @@ CHECK_FUNCTION_EXISTS(${VARIA}EVP_aes_128_xts LWS_HAVE_EVP_aes_128_xts PARENT_SC
 CHECK_FUNCTION_EXISTS(${VARIA}RSA_verify_pss_mgf1 LWS_HAVE_RSA_verify_pss_mgf1 PARENT_SCOPE)
 CHECK_FUNCTION_EXISTS(${VARIA}HMAC_CTX_new LWS_HAVE_HMAC_CTX_new PARENT_SCOPE)
 CHECK_FUNCTION_EXISTS(${VARIA}SSL_CTX_set_ciphersuites LWS_HAVE_SSL_CTX_set_ciphersuites PARENT_SCOPE)
+CHECK_FUNCTION_EXISTS(${VARIA}EVP_PKEY_new_raw_private_key LWS_HAVE_EVP_PKEY_new_raw_private_key PARENT_SCOPE)
 
 if (LWS_WITH_SSL AND NOT LWS_WITH_MBEDTLS)
 	# we don't want to confuse what's in or out of the wrapper with
diff --git a/lib/tls/openssl/lws-genhash.c b/lib/tls/openssl/lws-genhash.c
index 04d881fdd..7ff52186d 100644
--- a/lib/tls/openssl/lws-genhash.c
+++ b/lib/tls/openssl/lws-genhash.c
@@ -93,6 +93,78 @@ lws_genhash_destroy(struct lws_genhash_ctx *ctx, void *result)
 	return ret;
 }
 
+#if defined(LWS_HAVE_EVP_PKEY_new_raw_private_key)
+
+int
+lws_genhmac_init(struct lws_genhmac_ctx *ctx, enum lws_genhmac_types type,
+		 const uint8_t *key, size_t key_len)
+{
+	ctx->ctx = EVP_MD_CTX_create();
+	if (!ctx->ctx)
+		return -1;
+
+	ctx->evp_type = 0;
+	ctx->type = type;
+
+	switch (type) {
+	case LWS_GENHMAC_TYPE_SHA256:
+		ctx->evp_type = EVP_sha256();
+		break;
+	case LWS_GENHMAC_TYPE_SHA384:
+		ctx->evp_type = EVP_sha384();
+		break;
+	case LWS_GENHMAC_TYPE_SHA512:
+		ctx->evp_type = EVP_sha512();
+		break;
+	default:
+		lwsl_err("%s: unknown HMAC type %d\n", __func__, type);
+		goto bail;
+	}
+
+	ctx->key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, key, key_len);
+	if (!ctx->key)
+		goto bail;
+
+	if (EVP_DigestSignInit(ctx->ctx, NULL, ctx->evp_type, NULL, ctx->key) != 1)
+		goto bail1;
+
+	return 0;
+
+bail1:
+	EVP_PKEY_free(ctx->key);
+bail:
+	EVP_MD_CTX_free(ctx->ctx);
+
+	return -1;
+}
+
+int
+lws_genhmac_update(struct lws_genhmac_ctx *ctx, const void *in, size_t len)
+{
+
+	if (EVP_DigestSignUpdate(ctx->ctx, in, len) != 1)
+		return -1;
+
+	return 0;
+}
+
+int
+lws_genhmac_destroy(struct lws_genhmac_ctx *ctx, void *result)
+{
+	size_t size = (size_t)lws_genhmac_size(ctx->type);
+	int n;
+
+	n = EVP_DigestSignFinal(ctx->ctx, result, &size);
+	EVP_MD_CTX_free(ctx->ctx);
+	EVP_PKEY_free(ctx->key);
+
+	if (n != 1)
+		return -1;
+
+	return 0;
+}
+
+#else
 
 int
 lws_genhmac_init(struct lws_genhmac_ctx *ctx, enum lws_genhmac_types type,
@@ -172,3 +244,5 @@ lws_genhmac_destroy(struct lws_genhmac_ctx *ctx, void *result)
 	return 0;
 }
 
+
+#endif