From: Frederic Lecaille Date: Thu, 28 May 2026 12:49:07 +0000 (+0200) Subject: MEDIUM: quic: optimize HKDF operations by reusing per-thread contexts X-Git-Tag: v3.4.0~64 X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=4e0af590e8384ec5ede80ae725d25bc7178927f2;p=thirdparty%2Fhaproxy.git MEDIUM: quic: optimize HKDF operations by reusing per-thread contexts Allocating and freeing an OpenSSL EVP_PKEY_CTX context via EVP_PKEY_CTX_new_id() and EVP_PKEY_CTX_free() on every HKDF cryptographic operation (such as during stateless reset token generation) induces unnecessary memory allocation overhead. Optimize this by introducing a global per-thread context array 'quic_tls_hkdf_ctxs'. These contexts are allocated and initialized once at startup via a POST_CHECK hook (quic_tls_alloc_hkdf_ctxs) and are properly freed at exit via a POST_DEINIT hook (quic_tls_dealloc_hkdf_ctxs). The functions quic_hkdf_extract(), quic_hkdf_expand(), and quic_hkdf_extract_and_expand() now reuse the pre-allocated context corresponding to the current thread ID ('tid'), removing dynamic allocations from these frequent execution paths. As a cleanup, quic_hkdf_expand() is now static and unexported from the header file. Should be easily backported to all versions for optimization purposes. --- diff --git a/include/haproxy/quic_tls.h b/include/haproxy/quic_tls.h index 0e053a71e..a2dc9b31e 100644 --- a/include/haproxy/quic_tls.h +++ b/include/haproxy/quic_tls.h @@ -97,11 +97,6 @@ int quic_tls_derive_token_secret(const EVP_MD *md, const unsigned char *salt, size_t saltlen, const unsigned char *secret, size_t secretlen); -int quic_hkdf_expand(const EVP_MD *md, - unsigned char *buf, size_t buflen, - const unsigned char *key, size_t keylen, - const unsigned char *label, size_t labellen); - int quic_hkdf_expand_label(const EVP_MD *md, unsigned char *buf, size_t buflen, const unsigned char *key, size_t keylen, diff --git a/src/quic_tls.c b/src/quic_tls.c index 04d6b6b88..24388c274 100644 --- a/src/quic_tls.c +++ b/src/quic_tls.c @@ -6,6 +6,7 @@ #include #include +#include #include #include #include @@ -25,6 +26,8 @@ DECLARE_POOL(pool_head_quic_tls_key, "quic_tls_key", QUIC_TLS_KEY_LEN); DECLARE_TYPED_POOL(pool_head_quic_crypto_buf, "quic_crypto_buf", struct quic_crypto_buf); DECLARE_STATIC_TYPED_POOL(pool_head_quic_cstream, "quic_cstream", struct quic_cstream); +EVP_PKEY_CTX **quic_tls_hkdf_ctxs; + /* Initial salt depending on QUIC version to derive client/server initial secrets. * This one is for draft-29 QUIC version. */ @@ -314,16 +317,12 @@ void qc_enc_level_free(struct quic_conn *qc, struct quic_enc_level **qel) *qel = NULL; } -int quic_hkdf_extract(const EVP_MD *md, - unsigned char *buf, size_t buflen, - const unsigned char *key, size_t keylen, - const unsigned char *salt, size_t saltlen) +static int quic_hkdf_extract(const EVP_MD *md, + unsigned char *buf, size_t buflen, + const unsigned char *key, size_t keylen, + const unsigned char *salt, size_t saltlen) { - EVP_PKEY_CTX *ctx; - - ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); - if (!ctx) - return 0; + EVP_PKEY_CTX *ctx = quic_tls_hkdf_ctxs[tid]; if (EVP_PKEY_derive_init(ctx) <= 0 || EVP_PKEY_CTX_hkdf_mode(ctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) <= 0 || @@ -331,26 +330,17 @@ int quic_hkdf_extract(const EVP_MD *md, EVP_PKEY_CTX_set1_hkdf_salt(ctx, salt, saltlen) <= 0 || EVP_PKEY_CTX_set1_hkdf_key(ctx, key, keylen) <= 0 || EVP_PKEY_derive(ctx, buf, &buflen) <= 0) - goto err; + return 0; - EVP_PKEY_CTX_free(ctx); return 1; - - err: - EVP_PKEY_CTX_free(ctx); - return 0; } -int quic_hkdf_expand(const EVP_MD *md, - unsigned char *buf, size_t buflen, - const unsigned char *key, size_t keylen, - const unsigned char *label, size_t labellen) +static int quic_hkdf_expand(const EVP_MD *md, + unsigned char *buf, size_t buflen, + const unsigned char *key, size_t keylen, + const unsigned char *label, size_t labellen) { - EVP_PKEY_CTX *ctx; - - ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); - if (!ctx) - return 0; + EVP_PKEY_CTX *ctx = quic_tls_hkdf_ctxs[tid]; if (EVP_PKEY_derive_init(ctx) <= 0 || EVP_PKEY_CTX_hkdf_mode(ctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) <= 0 || @@ -358,14 +348,9 @@ int quic_hkdf_expand(const EVP_MD *md, EVP_PKEY_CTX_set1_hkdf_key(ctx, key, keylen) <= 0 || EVP_PKEY_CTX_add1_hkdf_info(ctx, label, labellen) <= 0 || EVP_PKEY_derive(ctx, buf, &buflen) <= 0) - goto err; + return 0; - EVP_PKEY_CTX_free(ctx); return 1; - - err: - EVP_PKEY_CTX_free(ctx); - return 0; } /* Extracts a peudo-random secret key from which is eventually not @@ -382,11 +367,7 @@ int quic_hkdf_extract_and_expand(const EVP_MD *md, const unsigned char *salt, size_t saltlen, const unsigned char *label, size_t labellen) { - EVP_PKEY_CTX *ctx; - - ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); - if (!ctx) - return 0; + EVP_PKEY_CTX *ctx = quic_tls_hkdf_ctxs[tid]; if (EVP_PKEY_derive_init(ctx) <= 0 || EVP_PKEY_CTX_hkdf_mode(ctx, EVP_PKEY_HKDEF_MODE_EXTRACT_AND_EXPAND) <= 0 || @@ -395,14 +376,9 @@ int quic_hkdf_extract_and_expand(const EVP_MD *md, EVP_PKEY_CTX_set1_hkdf_key(ctx, key, keylen) <= 0 || EVP_PKEY_CTX_add1_hkdf_info(ctx, label, labellen) <= 0 || EVP_PKEY_derive(ctx, buf, &buflen) <= 0) - goto err; + return 0; - EVP_PKEY_CTX_free(ctx); return 1; - - err: - EVP_PKEY_CTX_free(ctx); - return 0; } /* https://quicwg.org/base-drafts/draft-ietf-quic-tls.html#protection-keys @@ -1240,3 +1216,45 @@ int quic_tls_finalize(struct quic_conn *qc, int server) quic_tls_ctx_free(&qc->nictx); goto out; } + +/* Cryptographic context allocator for HKDF operations */ +static int quic_tls_dealloc_hkdf_ctxs(void) +{ + int i; + + if (!quic_tls_hkdf_ctxs) + return 1; + + for (i = 0; i < global.nbthread; i++) + EVP_PKEY_CTX_free(quic_tls_hkdf_ctxs[i]); + + free(quic_tls_hkdf_ctxs); + return 1; +} +REGISTER_POST_DEINIT(quic_tls_dealloc_hkdf_ctxs); + +/* Cryptographic context for HKDF operations deallocator*/ +static int quic_tls_alloc_hkdf_ctxs(void) +{ + int i, ret = -1; + + quic_tls_hkdf_ctxs = calloc(global.nbthread, sizeof(*quic_tls_hkdf_ctxs)); + if (!quic_tls_hkdf_ctxs) + goto err; + + for (i = 0; i < global.nbthread; i++) { + quic_tls_hkdf_ctxs[i] = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); + if (!quic_tls_hkdf_ctxs[i]) + goto err; + } + + ret = 0; + leave: + return ret; + + err: + ha_alert("failed to alloc the QUIC HKDF contexts.\n"); + quic_tls_dealloc_hkdf_ctxs(); + goto leave; +} +REGISTER_POST_CHECK(quic_tls_alloc_hkdf_ctxs);