Re: [PATCH] crypto: pkcs7: remove md4 md5 x.509 support

["Jarkko Sakkinen" <jarkko@kernel.org>]

On Mon Oct 2, 2023 at 2:57 AM EEST, Dimitri John Ledkov wrote:
> Remove support for md4 md5 hash and signatures in x.509 certificate
> parsers, pkcs7 signature parser, authenticode parser.
>
> All of these are insecure or broken, and everyone has long time ago
> migrated to alternative hash implementations.
>
> Also remove md2 & md3 oids which have already didn't have support.
>
> This is also likely the last user of md4 in the kernel, and thus
> crypto/md4.c and related tests in tcrypt & testmgr can likely be
> removed. Other users such as cifs smbfs ext modpost sumversions have
> their own internal implementation as needed.
>
> Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
> ---
>  crypto/asymmetric_keys/mscode_parser.c    | 6 ------
>  crypto/asymmetric_keys/pkcs7_parser.c     | 6 ------
>  crypto/asymmetric_keys/x509_cert_parser.c | 6 ------
>  include/linux/oid_registry.h              | 8 --------
>  4 files changed, 26 deletions(-)
>
> diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c
> index 839591ad21..690405ebe7 100644
> --- a/crypto/asymmetric_keys/mscode_parser.c
> +++ b/crypto/asymmetric_keys/mscode_parser.c
> @@ -75,12 +75,6 @@ int mscode_note_digest_algo(void *context, size_t hdrlen,
>  
>  	oid = look_up_OID(value, vlen);
>  	switch (oid) {
> -	case OID_md4:
> -		ctx->digest_algo = "md4";
> -		break;
> -	case OID_md5:
> -		ctx->digest_algo = "md5";
> -		break;
>  	case OID_sha1:
>  		ctx->digest_algo = "sha1";
>  		break;
> diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
> index 277482bb17..cf4caab962 100644
> --- a/crypto/asymmetric_keys/pkcs7_parser.c
> +++ b/crypto/asymmetric_keys/pkcs7_parser.c
> @@ -227,12 +227,6 @@ int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
>  	struct pkcs7_parse_context *ctx = context;
>  
>  	switch (ctx->last_oid) {
> -	case OID_md4:
> -		ctx->sinfo->sig->hash_algo = "md4";
> -		break;
> -	case OID_md5:
> -		ctx->sinfo->sig->hash_algo = "md5";
> -		break;
>  	case OID_sha1:
>  		ctx->sinfo->sig->hash_algo = "sha1";
>  		break;
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
> index 7a9b084e20..8d23a69890 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -195,15 +195,9 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
>  	pr_debug("PubKey Algo: %u\n", ctx->last_oid);
>  
>  	switch (ctx->last_oid) {
> -	case OID_md2WithRSAEncryption:
> -	case OID_md3WithRSAEncryption:
>  	default:
>  		return -ENOPKG; /* Unsupported combination */
>  
> -	case OID_md4WithRSAEncryption:
> -		ctx->cert->sig->hash_algo = "md4";
> -		goto rsa_pkcs1;
> -
>  	case OID_sha1WithRSAEncryption:
>  		ctx->cert->sig->hash_algo = "sha1";
>  		goto rsa_pkcs1;
> diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
> index 0f4a890392..89fb4612b2 100644
> --- a/include/linux/oid_registry.h
> +++ b/include/linux/oid_registry.h
> @@ -30,9 +30,6 @@ enum OID {
>  
>  	/* PKCS#1 {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1)} */
>  	OID_rsaEncryption,		/* 1.2.840.113549.1.1.1 */
> -	OID_md2WithRSAEncryption,	/* 1.2.840.113549.1.1.2 */
> -	OID_md3WithRSAEncryption,	/* 1.2.840.113549.1.1.3 */
> -	OID_md4WithRSAEncryption,	/* 1.2.840.113549.1.1.4 */
>  	OID_sha1WithRSAEncryption,	/* 1.2.840.113549.1.1.5 */
>  	OID_sha256WithRSAEncryption,	/* 1.2.840.113549.1.1.11 */
>  	OID_sha384WithRSAEncryption,	/* 1.2.840.113549.1.1.12 */
> @@ -49,11 +46,6 @@ enum OID {
>  	OID_smimeCapabilites,		/* 1.2.840.113549.1.9.15 */
>  	OID_smimeAuthenticatedAttrs,	/* 1.2.840.113549.1.9.16.2.11 */
>  
> -	/* {iso(1) member-body(2) us(840) rsadsi(113549) digestAlgorithm(2)} */
> -	OID_md2,			/* 1.2.840.113549.2.2 */
> -	OID_md4,			/* 1.2.840.113549.2.4 */
> -	OID_md5,			/* 1.2.840.113549.2.5 */
> -
>  	OID_mskrb5,			/* 1.2.840.48018.1.2.2 */
>  	OID_krb5,			/* 1.2.840.113554.1.2.2 */
>  	OID_krb5u2u,			/* 1.2.840.113554.1.2.2.3 */
> -- 
> 2.34.1

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko