From: Eric Biggers Date: Thu, 19 Mar 2026 06:17:20 +0000 (-0700) Subject: lib/crypto: aesgcm: Use GHASH library API X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ea0c746ffa1e6e701d39a564f6286a3f5740826b;p=thirdparty%2Fkernel%2Fstable.git lib/crypto: aesgcm: Use GHASH library API Make the AES-GCM library use the GHASH library instead of directly calling gf128mul_lle(). This allows the architecture-optimized GHASH implementations to be used, or the improved generic implementation if no architecture-optimized implementation is usable. Note: this means that no longer needs to include . Remove that inclusion, and include explicitly from arch/x86/crypto/aesni-intel_glue.c which previously was relying on the transitive inclusion. Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20260319061723.1140720-20-ebiggers@kernel.org Signed-off-by: Eric Biggers --- diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index e6c38d1d8a92..f522fff9231e 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include diff --git a/include/crypto/gcm.h b/include/crypto/gcm.h index b524e47bd4d0..1d5f39ff1dc4 100644 --- a/include/crypto/gcm.h +++ b/include/crypto/gcm.h @@ -4,7 +4,7 @@ #include #include -#include +#include #define GCM_AES_IV_SIZE 12 #define GCM_RFC4106_IV_SIZE 8 @@ -65,7 +65,7 @@ static inline int crypto_ipsec_check_assoclen(unsigned int assoclen) } struct aesgcm_ctx { - be128 ghash_key; + struct ghash_key ghash_key; struct aes_enckey aes_key; unsigned int authsize; }; diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig index a39e7707e9ee..32fafe245f47 100644 --- a/lib/crypto/Kconfig +++ b/lib/crypto/Kconfig @@ -41,7 +41,7 @@ config CRYPTO_LIB_AES_CBC_MACS config CRYPTO_LIB_AESGCM tristate select CRYPTO_LIB_AES - select CRYPTO_LIB_GF128MUL + select CRYPTO_LIB_GF128HASH select CRYPTO_LIB_UTILS config CRYPTO_LIB_ARC4 diff --git a/lib/crypto/aesgcm.c b/lib/crypto/aesgcm.c index 02f5b5f32c76..8c7e74d2d147 100644 --- a/lib/crypto/aesgcm.c +++ b/lib/crypto/aesgcm.c @@ -5,9 +5,8 @@ * Copyright 2022 Google LLC */ -#include #include -#include +#include #include #include #include @@ -45,7 +44,7 @@ static void aesgcm_encrypt_block(const struct aes_enckey *key, void *dst, int aesgcm_expandkey(struct aesgcm_ctx *ctx, const u8 *key, unsigned int keysize, unsigned int authsize) { - u8 kin[AES_BLOCK_SIZE] = {}; + u8 h[AES_BLOCK_SIZE] = {}; int ret; ret = crypto_gcm_check_authsize(authsize) ?: @@ -54,24 +53,13 @@ int aesgcm_expandkey(struct aesgcm_ctx *ctx, const u8 *key, return ret; ctx->authsize = authsize; - aesgcm_encrypt_block(&ctx->aes_key, &ctx->ghash_key, kin); - + aesgcm_encrypt_block(&ctx->aes_key, h, h); + ghash_preparekey(&ctx->ghash_key, h); + memzero_explicit(h, sizeof(h)); return 0; } EXPORT_SYMBOL(aesgcm_expandkey); -static void aesgcm_ghash(be128 *ghash, const be128 *key, const void *src, - int len) -{ - while (len > 0) { - crypto_xor((u8 *)ghash, src, min(len, GHASH_BLOCK_SIZE)); - gf128mul_lle(ghash, key); - - src += GHASH_BLOCK_SIZE; - len -= GHASH_BLOCK_SIZE; - } -} - /** * aesgcm_mac - Generates the authentication tag using AES-GCM algorithm. * @ctx: The data structure that will hold the AES-GCM key schedule @@ -88,20 +76,33 @@ static void aesgcm_ghash(be128 *ghash, const be128 *key, const void *src, static void aesgcm_mac(const struct aesgcm_ctx *ctx, const u8 *src, int src_len, const u8 *assoc, int assoc_len, __be32 *ctr, u8 *authtag) { - be128 tail = { cpu_to_be64(assoc_len * 8), cpu_to_be64(src_len * 8) }; - u8 buf[AES_BLOCK_SIZE]; - be128 ghash = {}; + static const u8 zeroes[GHASH_BLOCK_SIZE]; + __be64 tail[2] = { + cpu_to_be64((u64)assoc_len * 8), + cpu_to_be64((u64)src_len * 8), + }; + struct ghash_ctx ghash; + u8 ghash_out[AES_BLOCK_SIZE]; + u8 enc_ctr[AES_BLOCK_SIZE]; + + ghash_init(&ghash, &ctx->ghash_key); + + ghash_update(&ghash, assoc, assoc_len); + ghash_update(&ghash, zeroes, -assoc_len & (GHASH_BLOCK_SIZE - 1)); - aesgcm_ghash(&ghash, &ctx->ghash_key, assoc, assoc_len); - aesgcm_ghash(&ghash, &ctx->ghash_key, src, src_len); - aesgcm_ghash(&ghash, &ctx->ghash_key, &tail, sizeof(tail)); + ghash_update(&ghash, src, src_len); + ghash_update(&ghash, zeroes, -src_len & (GHASH_BLOCK_SIZE - 1)); + + ghash_update(&ghash, (const u8 *)&tail, sizeof(tail)); + + ghash_final(&ghash, ghash_out); ctr[3] = cpu_to_be32(1); - aesgcm_encrypt_block(&ctx->aes_key, buf, ctr); - crypto_xor_cpy(authtag, buf, (u8 *)&ghash, ctx->authsize); + aesgcm_encrypt_block(&ctx->aes_key, enc_ctr, ctr); + crypto_xor_cpy(authtag, ghash_out, enc_ctr, ctx->authsize); - memzero_explicit(&ghash, sizeof(ghash)); - memzero_explicit(buf, sizeof(buf)); + memzero_explicit(ghash_out, sizeof(ghash_out)); + memzero_explicit(enc_ctr, sizeof(enc_ctr)); } static void aesgcm_crypt(const struct aesgcm_ctx *ctx, u8 *dst, const u8 *src,