> -----Original Message-----
> From: Jamin Lin <jamin_lin@aspeedtech.com>
> Sent: Wednesday, July 15, 2026 11:33 AM
> To: Daniel P. Berrangé <berrange@redhat.com>; Cédric Le Goater
> <clg@kaod.org>; Peter Maydell <peter.maydell@linaro.org>; Steven Lee
> <steven_lee@aspeedtech.com>; Troy Lee <leetroy@gmail.com>; Kane Chen
> <kane_chen@aspeedtech.com>; Andrew Jeffery
> <andrew@codeconstruct.com.au>; Joel Stanley <joel@jms.id.au>; Eric Blake
> <eblake@redhat.com>; Markus Armbruster <armbru@redhat.com>; Fabiano
> Rosas <farosas@suse.de>; Laurent Vivier <lvivier@redhat.com>; Paolo Bonzini
> <pbonzini@redhat.com>; open list:All patches CC here
> <qemu-devel@nongnu.org>; open list:ASPEED BMCs
> <qemu-arm@nongnu.org>
> Cc: Jamin Lin <jamin_lin@aspeedtech.com>; Troy Lee
> <troy_lee@aspeedtech.com>
> Subject: [PATCH v2 08/17] crypto/cipher: Add setaad/gettag for AEAD modes
>
> AEAD modes such as GCM authenticate optional associated data (AAD) and
> produce an authentication tag, which the block-cipher encrypt/decrypt
> interface cannot express. Add qcrypto_cipher_setaad() and
> qcrypto_cipher_gettag() plus the matching backend driver hooks. The generic
> front-end reports an error when the selected mode's driver does not
> implement them, so calling them on a non-AEAD mode fails cleanly.
>
> Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
> crypto/cipherpriv.h | 8 ++++++++
> include/crypto/cipher.h | 36 ++++++++++++++++++++++++++++++++++++
> crypto/cipher.c | 31 +++++++++++++++++++++++++++++++
> 3 files changed, 75 insertions(+)
>
> diff --git a/crypto/cipherpriv.h b/crypto/cipherpriv.h index
> 64737ce961..c4f995f369 100644
> --- a/crypto/cipherpriv.h
> +++ b/crypto/cipherpriv.h
> @@ -34,6 +34,14 @@ struct QCryptoCipherDriver {
> const uint8_t *iv, size_t niv,
> Error **errp);
>
> + int (*cipher_setaad)(QCryptoCipher *cipher,
> + const uint8_t *aad, size_t len,
> + Error **errp);
> +
> + int (*cipher_gettag)(QCryptoCipher *cipher,
> + uint8_t *tag, size_t len,
> + Error **errp);
> +
> void (*cipher_free)(QCryptoCipher *cipher); };
>
> diff --git a/include/crypto/cipher.h b/include/crypto/cipher.h index
> 92939310ef..2e361411b9 100644
> --- a/include/crypto/cipher.h
> +++ b/include/crypto/cipher.h
> @@ -235,4 +235,40 @@ int qcrypto_cipher_setiv(QCryptoCipher *cipher,
> const uint8_t *iv, size_t niv,
> Error **errp);
>
> +/**
> + * qcrypto_cipher_setaad:
> + * @cipher: the cipher object
> + * @aad: the associated data to authenticate
> + * @len: the length of @aad
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * For AEAD modes such as GCM, feed the associated data (AAD) that is
> + * authenticated but not encrypted. It must be called after
> + * qcrypto_cipher_setiv() and before the first encrypt/decrypt call. It
> +is
> + * an error to call this on a mode that is not an AEAD mode.
> + *
> + * Returns: 0 on success, -1 on error
> + */
> +int qcrypto_cipher_setaad(QCryptoCipher *cipher,
> + const uint8_t *aad, size_t len,
> + Error **errp);
> +
> +/**
> + * qcrypto_cipher_gettag:
> + * @cipher: the cipher object
> + * @tag: buffer to receive the authentication tag
> + * @len: the length of @tag
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * For AEAD modes such as GCM, read back the authentication tag
> +computed
> + * over the associated data and the message. It must be called after
> +the
> + * encrypt/decrypt operation. It is an error to call this on a mode
> +that is
> + * not an AEAD mode.
> + *
> + * Returns: 0 on success, -1 on error
> + */
> +int qcrypto_cipher_gettag(QCryptoCipher *cipher,
> + uint8_t *tag, size_t len,
> + Error **errp);
> +
> #endif /* QCRYPTO_CIPHER_H */
> diff --git a/crypto/cipher.c b/crypto/cipher.c index 52d071a90c..67014aad6f
> 100644
> --- a/crypto/cipher.c
> +++ b/crypto/cipher.c
> @@ -205,6 +205,37 @@ int qcrypto_cipher_setiv(QCryptoCipher *cipher, }
>
>
> +int qcrypto_cipher_setaad(QCryptoCipher *cipher,
> + const uint8_t *aad, size_t len,
> + Error **errp) {
> + const QCryptoCipherDriver *drv = cipher->driver;
> +
> + if (!drv->cipher_setaad) {
> + error_setg(errp, "The cipher mode does not support associated
> data");
> + return -1;
> + }
> +
> + return drv->cipher_setaad(cipher, aad, len, errp); }
> +
> +
> +int qcrypto_cipher_gettag(QCryptoCipher *cipher,
> + uint8_t *tag, size_t len,
> + Error **errp) {
> + const QCryptoCipherDriver *drv = cipher->driver;
> +
> + if (!drv->cipher_gettag) {
> + error_setg(errp,
> + "The cipher mode does not produce an authentication
> tag");
> + return -1;
> + }
> +
> + return drv->cipher_gettag(cipher, tag, len, errp); }
> +
> +
> void qcrypto_cipher_free(QCryptoCipher *cipher) {
> if (cipher) {
> --
> 2.43.0
Reviewed-by: Kane Chen <kane_chen@aspeedtech.com>