Re: [PATCH 02/18] asymmetric keys: implement EMSA_PKCS1-v1_5-ENCODE in rsa

[Pavel Machek <pavel-+ZI9xUNit7I@public.gmane.org>]

On Thu 2013-08-22 19:01:41, Lee, Chun-Yi wrote:
> Implement EMSA_PKCS1-v1_5-ENCODE [RFC3447 sec 9.2] in rsa.c. It's the
> first step of signature generation operation
> (RSASSA-PKCS1-v1_5-SIGN).

Is this your own code, or did you copy it from somewhere?

> +	if (!T)
> +		goto error_T;
> +
> +	memcpy(T, RSA_ASN1_templates[hash_algo].data, RSA_ASN1_templates[hash_algo].size);
> +	memcpy(T + RSA_ASN1_templates[hash_algo].size, pks->digest, pks->digest_size);
> +
> +	/* 3) check If emLen < tLen + 11, output "intended encoded message length too short" */
> +	if (emLen < tLen + 11) {
> +		ret = EINVAL;
> +		goto error_emLen;
> +	}

Normal kernel calling convention is 0 / -EINVAL.

> +	memcpy(EM + 2, PS, emLen - tLen - 3);
> +	EM[2 + emLen - tLen - 3] = 0x00;
> +	memcpy(EM + 2 + emLen - tLen - 3 + 1, T, tLen);

ThisDoesNotLookLikeKernelCode, NoCamelCase, please.

> +	*_EM = EM;

And we don't usually use _ prefix like this.


> --- a/include/crypto/public_key.h
> +++ b/include/crypto/public_key.h
> @@ -110,6 +110,8 @@ extern void public_key_destroy(void *payload);
>  struct public_key_signature {
>  	u8 *digest;
>  	u8 digest_size;			/* Number of bytes in digest */
> +	u8 *S;				/* signature S of length k octets */

u8 *signature?

> +	size_t k;			/* length k of signature S */

u8 *signature_length.

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