From patchwork Wed Oct 16 10:20:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 13838139 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5FF21D1AD42 for ; Wed, 16 Oct 2024 10:21:51 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t118o-0000Lc-Hv; Wed, 16 Oct 2024 06:20:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t118m-0000Kv-Nw for qemu-devel@nongnu.org; Wed, 16 Oct 2024 06:20:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t118l-0002pI-69 for qemu-devel@nongnu.org; Wed, 16 Oct 2024 06:20:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1729074022; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/77uZabxQYbI+7iElg+IwhYCsa5tCIzuO6b18O5VOLc=; b=gz2a4VKnbCBk31HqH/rA7sF4pcp8UyhfUJgdMIaMeaNfMa/8xDHizNR36W9Kj3W+UrYcx8 ZPLJUcOKixIbTDCohXgbP8aRYwDAjeDl1KQ32W7lC1sQ6uM4LU8DE/3jIPZa0qZwXKBVqx mcPnB/J3Ged9QvdRkN9Kx2wuhvksh/Q= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-510-VbpXEhBwNMG7mvogCtXhDA-1; Wed, 16 Oct 2024 06:20:20 -0400 X-MC-Unique: VbpXEhBwNMG7mvogCtXhDA-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 599361954B18; Wed, 16 Oct 2024 10:20:17 +0000 (UTC) Received: from toolbox.redhat.com (unknown [10.42.28.95]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id F1C461956056; Wed, 16 Oct 2024 10:20:15 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Dorjoy Chowdhury Subject: [PATCH v2 3/3] include/crypto: clarify @result/@result_len for hash/hmac APIs Date: Wed, 16 Oct 2024 11:20:06 +0100 Message-ID: <20241016102006.480218-4-berrange@redhat.com> In-Reply-To: <20241016102006.480218-1-berrange@redhat.com> References: <20241016102006.480218-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.063, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org The @result parameter passed to hash/hmac APIs may either contain a pre-allocated buffer, or a buffer can be allocated on the fly. Clarify these two different usage models in the API docs. Signed-off-by: Daniel P. Berrangé --- include/crypto/hash.h | 30 +++++++++++++++++++++++------- include/crypto/hmac.h | 17 ++++++++++++----- 2 files changed, 35 insertions(+), 12 deletions(-) diff --git a/include/crypto/hash.h b/include/crypto/hash.h index b791ca92a4..317bf9ecde 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -98,11 +98,18 @@ int qcrypto_hash_bytesv(QCryptoHashAlgo alg, * @errp: pointer to a NULL-initialized error object * * Computes the hash across all the memory region - * @buf of length @len. The @result pointer will be - * filled with raw bytes representing the computed - * hash, which will have length @resultlen. The - * memory pointer in @result must be released - * with a call to g_free() when no longer required. + * @buf of length @len. + * + * If @result_len is set to a non-zero value by the caller, then + * @result must hold a pointer that is @result_len in size, and + * @result_len match the size of the hash output. The digest will + * be written into @result. + * + * If @result_len is set to zero, then this function will allocate + * a buffer to hold the hash output digest, storing a pointer to + * the buffer in @result, and setting @result_len to its size. + * The memory referenced in @result must be released with a call + * to g_free() when no longer required by the caller. * * Returns: 0 on success, -1 on error */ @@ -215,8 +222,17 @@ int qcrypto_hash_finalize_base64(QCryptoHash *hash, * * Computes the hash from the given hash object. Hash object * is expected to have it's data updated from the qcrypto_hash_update function. - * The memory pointer in @result must be released with a call to g_free() - * when no longer required. + * + * If @result_len is set to a non-zero value by the caller, then + * @result must hold a pointer that is @result_len in size, and + * @result_len match the size of the hash output. The digest will + * be written into @result. + * + * If @result_len is set to zero, then this function will allocate + * a buffer to hold the hash output digest, storing a pointer to + * the buffer in @result, and setting @result_len to its size. + * The memory referenced in @result must be released with a call + * to g_free() when no longer required by the caller. * * Returns: 0 on success, -1 on error */ diff --git a/include/crypto/hmac.h b/include/crypto/hmac.h index c69a0dfab3..aaff95f7db 100644 --- a/include/crypto/hmac.h +++ b/include/crypto/hmac.h @@ -103,11 +103,18 @@ int qcrypto_hmac_bytesv(QCryptoHmac *hmac, * @errp: pointer to a NULL-initialized error object * * Computes the hmac across all the memory region - * @buf of length @len. The @result pointer will be - * filled with raw bytes representing the computed - * hmac, which will have length @resultlen. The - * memory pointer in @result must be released - * with a call to g_free() when no longer required. + * @buf of length @len. + * + * If @result_len is set to a non-zero value by the caller, then + * @result must hold a pointer that is @result_len in size, and + * @result_len match the size of the hash output. The digest will + * be written into @result. + * + * If @result_len is set to zero, then this function will allocate + * a buffer to hold the hash output digest, storing a pointer to + * the buffer in @result, and setting @result_len to its size. + * The memory referenced in @result must be released with a call + * to g_free() when no longer required by the caller. * * Returns: * 0 on success, -1 on error