[PATCH v2 18/19] crypto: make RSA a visible option

[Ahmad Fatoum]

On 01.08.24 07:57, Sascha Hauer wrote:
> With upcoming ECDSA support RSA won't be the only option for FIT image
> verification anymore. Make CONFIG_CRYPTO_RSA visible so that the user
> can choose. CONFIG_CRYPTO_RSA defaults to yes when FITIMAGE_SIGNATURE
> is selected so that existing configs continue to work.
> 
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>

Reviewed-by: Ahmad Fatoum <a.fatoum at pengutronix.de>

> ---
>  common/Kconfig     | 1 -
>  common/image-fit.c | 5 +++++
>  crypto/Kconfig     | 3 ++-
>  3 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/common/Kconfig b/common/Kconfig
> index 31360892ae..65850f68bd 100644
> --- a/common/Kconfig
> +++ b/common/Kconfig
> @@ -59,7 +59,6 @@ config FITIMAGE
>  	select DIGEST
>  
>  config FITIMAGE_SIGNATURE
> -	select CRYPTO_RSA
>  	bool
>  
>  config LOGBUF
> diff --git a/common/image-fit.c b/common/image-fit.c
> index 4a69049abc..6002440e7e 100644
> --- a/common/image-fit.c
> +++ b/common/image-fit.c
> @@ -262,6 +262,11 @@ static int fit_check_rsa_signature(struct device_node *sig_node,
>  	const char *sig_value;
>  	int ret;
>  
> +	if (!IS_ENABLED(CONFIG_CRYPTO_RSA)) {
> +		pr_err("RSA support is disabled, Cannot verify image\n");
> +		return -EOPNOTSUPP;
> +	}
> +
>  	sig_value = of_get_property(sig_node, "value", &sig_len);
>  	if (!sig_value) {
>  		pr_err("signature value not found in %pOF\n", sig_node);
> diff --git a/crypto/Kconfig b/crypto/Kconfig
> index eeacd9ffb7..22faff5100 100644
> --- a/crypto/Kconfig
> +++ b/crypto/Kconfig
> @@ -116,7 +116,8 @@ config CRYPTO_PBKDF2
>  	bool
>  
>  config CRYPTO_RSA
> -	bool
> +	bool "RSA support"
> +	default y if FITIMAGE_SIGNATURE
>  
>  config CRYPTO_RSA_BUILTIN_KEYS
>  	bool

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