diff mbox series

[v10,5/9] x509: Detect sm2 keys by their parameters OID

Message ID 20210305005203.3547587-6-stefanb@linux.vnet.ibm.com (mailing list archive)
State Superseded
Delegated to: Herbert Xu
Headers show
Series Add support for x509 certs with NIST P384/256/192 keys | expand

Commit Message

Stefan Berger March 5, 2021, 12:51 a.m. UTC 
From: Stefan Berger <stefanb@linux.ibm.com>

Detect whether a key is an sm2 type of key by its OID in the parameters
array rather than assuming that everything under OID_id_ecPublicKey
is sm2, which is not the case.

Cc: David Howells <dhowells@redhat.com>
Cc: keyrings@vger.kernel.org
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
 crypto/asymmetric_keys/x509_cert_parser.c | 12 +++++++++++-
 include/linux/oid_registry.h              |  1 +
 lib/oid_registry.c                        | 13 +++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

Comments

tianjia.zhang March 5, 2021, 7:39 a.m. UTC | #1 
Hi,

On 3/5/21 8:51 AM, Stefan Berger wrote:
> From: Stefan Berger <stefanb@linux.ibm.com>
> 
> Detect whether a key is an sm2 type of key by its OID in the parameters
> array rather than assuming that everything under OID_id_ecPublicKey
> is sm2, which is not the case.
> 
> Cc: David Howells <dhowells@redhat.com>
> Cc: keyrings@vger.kernel.org
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
> ---
>   crypto/asymmetric_keys/x509_cert_parser.c | 12 +++++++++++-
>   include/linux/oid_registry.h              |  1 +
>   lib/oid_registry.c                        | 13 +++++++++++++
>   3 files changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
> index 52c9b455fc7d..1621ceaf5c95 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -459,6 +459,7 @@ int x509_extract_key_data(void *context, size_t hdrlen,
>   			  const void *value, size_t vlen)
>   {
>   	struct x509_parse_context *ctx = context;
> +	enum OID oid;
>   
>   	ctx->key_algo = ctx->last_oid;
>   	switch (ctx->last_oid) {
> @@ -470,7 +471,16 @@ int x509_extract_key_data(void *context, size_t hdrlen,
>   		ctx->cert->pub->pkey_algo = "ecrdsa";
>   		break;
>   	case OID_id_ecPublicKey:
> -		ctx->cert->pub->pkey_algo = "sm2";
> +		if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
> +			return -EBADMSG;
> +
> +		switch (oid) {
> +		case OID_sm2:
> +			ctx->cert->pub->pkey_algo = "sm2";
> +			break;
> +		default:
> +			return -ENOPKG;
> +		}
>   		break;
>   	default:
>   		return -ENOPKG;
> diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
> index b504e2f36b25..f32d91895e4d 100644
> --- a/include/linux/oid_registry.h
> +++ b/include/linux/oid_registry.h
> @@ -121,6 +121,7 @@ enum OID {
>   };
>   
>   extern enum OID look_up_OID(const void *data, size_t datasize);
> +extern int parse_OID(const void *data, size_t datasize, enum OID *oid);
>   extern int sprint_oid(const void *, size_t, char *, size_t);
>   extern int sprint_OID(enum OID, char *, size_t);
>   
> diff --git a/lib/oid_registry.c b/lib/oid_registry.c
> index f7ad43f28579..508e0b34b5f0 100644
> --- a/lib/oid_registry.c
> +++ b/lib/oid_registry.c
> @@ -11,6 +11,7 @@
>   #include <linux/kernel.h>
>   #include <linux/errno.h>
>   #include <linux/bug.h>
> +#include <linux/asn1.h>
>   #include "oid_registry_data.c"
>   
>   MODULE_DESCRIPTION("OID Registry");
> @@ -92,6 +93,18 @@ enum OID look_up_OID(const void *data, size_t datasize)
>   }
>   EXPORT_SYMBOL_GPL(look_up_OID);
>   
> +int parse_OID(const void *data, size_t datasize, enum OID *oid)
> +{
> +	const unsigned char *v = data;
> +
> +	if (datasize < 2 || v[0] != ASN1_OID || v[1] != datasize - 2)
> +		return -EBADMSG;
> +
> +	*oid = look_up_OID(data + 2, datasize - 2);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(parse_OID);
> +
>   /*
>    * sprint_OID - Print an Object Identifier into a buffer
>    * @data: The encoded OID to print
> 

Tested-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>

Best regards,
Tianjia
Jarkko Sakkinen March 5, 2021, 5:16 p.m. UTC | #2 
On Thu, Mar 04, 2021 at 07:51:59PM -0500, Stefan Berger wrote:
> From: Stefan Berger <stefanb@linux.ibm.com>
> 
> Detect whether a key is an sm2 type of key by its OID in the parameters
> array rather than assuming that everything under OID_id_ecPublicKey
> is sm2, which is not the case.
> 
> Cc: David Howells <dhowells@redhat.com>
> Cc: keyrings@vger.kernel.org
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
> ---
>  crypto/asymmetric_keys/x509_cert_parser.c | 12 +++++++++++-
>  include/linux/oid_registry.h              |  1 +
>  lib/oid_registry.c                        | 13 +++++++++++++
>  3 files changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
> index 52c9b455fc7d..1621ceaf5c95 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -459,6 +459,7 @@ int x509_extract_key_data(void *context, size_t hdrlen,
>  			  const void *value, size_t vlen)
>  {
>  	struct x509_parse_context *ctx = context;
> +	enum OID oid;

enum is not a real type, and it is hard to recall how much it allocates
from stack. I would replace this with plain int.

>  
>  	ctx->key_algo = ctx->last_oid;
>  	switch (ctx->last_oid) {
> @@ -470,7 +471,16 @@ int x509_extract_key_data(void *context, size_t hdrlen,
>  		ctx->cert->pub->pkey_algo = "ecrdsa";
>  		break;
>  	case OID_id_ecPublicKey:
> -		ctx->cert->pub->pkey_algo = "sm2";
> +		if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
> +			return -EBADMSG;
> +
> +		switch (oid) {
> +		case OID_sm2:
> +			ctx->cert->pub->pkey_algo = "sm2";
> +			break;
> +		default:
> +			return -ENOPKG;
> +		}
>  		break;
>  	default:
>  		return -ENOPKG;
> diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
> index b504e2f36b25..f32d91895e4d 100644
> --- a/include/linux/oid_registry.h
> +++ b/include/linux/oid_registry.h
> @@ -121,6 +121,7 @@ enum OID {
>  };
>  
>  extern enum OID look_up_OID(const void *data, size_t datasize);
> +extern int parse_OID(const void *data, size_t datasize, enum OID *oid);
>  extern int sprint_oid(const void *, size_t, char *, size_t);
>  extern int sprint_OID(enum OID, char *, size_t);
>  
> diff --git a/lib/oid_registry.c b/lib/oid_registry.c
> index f7ad43f28579..508e0b34b5f0 100644
> --- a/lib/oid_registry.c
> +++ b/lib/oid_registry.c
> @@ -11,6 +11,7 @@
>  #include <linux/kernel.h>
>  #include <linux/errno.h>
>  #include <linux/bug.h>
> +#include <linux/asn1.h>
>  #include "oid_registry_data.c"
>  
>  MODULE_DESCRIPTION("OID Registry");
> @@ -92,6 +93,18 @@ enum OID look_up_OID(const void *data, size_t datasize)
>  }
>  EXPORT_SYMBOL_GPL(look_up_OID);
>  
> +int parse_OID(const void *data, size_t datasize, enum OID *oid)

An exported function without kdoc.

> +{
> +	const unsigned char *v = data;
> +
> +	if (datasize < 2 || v[0] != ASN1_OID || v[1] != datasize - 2)
> +		return -EBADMSG;

'1' and '2' are magic numbers unless you either have constants defining
them, or at least an inline comment with explanation.

> +
> +	*oid = look_up_OID(data + 2, datasize - 2);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(parse_OID);
> +
>  /*
>   * sprint_OID - Print an Object Identifier into a buffer
>   * @data: The encoded OID to print
> -- 
> 2.29.2
> 
> 

/Jarkko
Stefan Berger March 5, 2021, 6:02 p.m. UTC | #3 
On 3/5/21 12:16 PM, Jarkko Sakkinen wrote:
> On Thu, Mar 04, 2021 at 07:51:59PM -0500, Stefan Berger wrote:
>> From: Stefan Berger <stefanb@linux.ibm.com>
>>
>> Detect whether a key is an sm2 type of key by its OID in the parameters
>> array rather than assuming that everything under OID_id_ecPublicKey
>> is sm2, which is not the case.
>>
>> Cc: David Howells <dhowells@redhat.com>
>> Cc: keyrings@vger.kernel.org
>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>> Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
>> ---
>>   crypto/asymmetric_keys/x509_cert_parser.c | 12 +++++++++++-
>>   include/linux/oid_registry.h              |  1 +
>>   lib/oid_registry.c                        | 13 +++++++++++++
>>   3 files changed, 25 insertions(+), 1 deletion(-)
>>
>> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
>> index 52c9b455fc7d..1621ceaf5c95 100644
>> --- a/crypto/asymmetric_keys/x509_cert_parser.c
>> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
>> @@ -459,6 +459,7 @@ int x509_extract_key_data(void *context, size_t hdrlen,
>>   			  const void *value, size_t vlen)
>>   {
>>   	struct x509_parse_context *ctx = context;
>> +	enum OID oid;
> enum is not a real type, and it is hard to recall how much it allocates
> from stack. I would replace this with plain int.


That would be worse considering existing code: 
https://elixir.bootlin.com/linux/latest/source/lib/oid_registry.c#L25


>
>>   
>>   	ctx->key_algo = ctx->last_oid;
>>   	switch (ctx->last_oid) {
>> @@ -470,7 +471,16 @@ int x509_extract_key_data(void *context, size_t hdrlen,
>>   		ctx->cert->pub->pkey_algo = "ecrdsa";
>>   		break;
>>   	case OID_id_ecPublicKey:
>> -		ctx->cert->pub->pkey_algo = "sm2";
>> +		if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
>> +			return -EBADMSG;
>> +
>> +		switch (oid) {
>> +		case OID_sm2:
>> +			ctx->cert->pub->pkey_algo = "sm2";
>> +			break;
>> +		default:
>> +			return -ENOPKG;
>> +		}
>>   		break;
>>   	default:
>>   		return -ENOPKG;
>> diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
>> index b504e2f36b25..f32d91895e4d 100644
>> --- a/include/linux/oid_registry.h
>> +++ b/include/linux/oid_registry.h
>> @@ -121,6 +121,7 @@ enum OID {
>>   };
>>   
>>   extern enum OID look_up_OID(const void *data, size_t datasize);
>> +extern int parse_OID(const void *data, size_t datasize, enum OID *oid);
>>   extern int sprint_oid(const void *, size_t, char *, size_t);
>>   extern int sprint_OID(enum OID, char *, size_t);
>>   
>> diff --git a/lib/oid_registry.c b/lib/oid_registry.c
>> index f7ad43f28579..508e0b34b5f0 100644
>> --- a/lib/oid_registry.c
>> +++ b/lib/oid_registry.c
>> @@ -11,6 +11,7 @@
>>   #include <linux/kernel.h>
>>   #include <linux/errno.h>
>>   #include <linux/bug.h>
>> +#include <linux/asn1.h>
>>   #include "oid_registry_data.c"
>>   
>>   MODULE_DESCRIPTION("OID Registry");
>> @@ -92,6 +93,18 @@ enum OID look_up_OID(const void *data, size_t datasize)
>>   }
>>   EXPORT_SYMBOL_GPL(look_up_OID);
>>   
>> +int parse_OID(const void *data, size_t datasize, enum OID *oid)
> An exported function without kdoc.
>
>> +{
>> +	const unsigned char *v = data;
>> +
>> +	if (datasize < 2 || v[0] != ASN1_OID || v[1] != datasize - 2)
>> +		return -EBADMSG;
> '1' and '2' are magic numbers unless you either have constants defining
> them, or at least an inline comment with explanation.


I can add those.
diff mbox series

Patch

diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 52c9b455fc7d..1621ceaf5c95 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -459,6 +459,7 @@  int x509_extract_key_data(void *context, size_t hdrlen,
 			  const void *value, size_t vlen)
 {
 	struct x509_parse_context *ctx = context;
+	enum OID oid;
 
 	ctx->key_algo = ctx->last_oid;
 	switch (ctx->last_oid) {
@@ -470,7 +471,16 @@  int x509_extract_key_data(void *context, size_t hdrlen,
 		ctx->cert->pub->pkey_algo = "ecrdsa";
 		break;
 	case OID_id_ecPublicKey:
-		ctx->cert->pub->pkey_algo = "sm2";
+		if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
+			return -EBADMSG;
+
+		switch (oid) {
+		case OID_sm2:
+			ctx->cert->pub->pkey_algo = "sm2";
+			break;
+		default:
+			return -ENOPKG;
+		}
 		break;
 	default:
 		return -ENOPKG;
diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index b504e2f36b25..f32d91895e4d 100644
--- a/include/linux/oid_registry.h
+++ b/include/linux/oid_registry.h
@@ -121,6 +121,7 @@  enum OID {
 };
 
 extern enum OID look_up_OID(const void *data, size_t datasize);
+extern int parse_OID(const void *data, size_t datasize, enum OID *oid);
 extern int sprint_oid(const void *, size_t, char *, size_t);
 extern int sprint_OID(enum OID, char *, size_t);
 
diff --git a/lib/oid_registry.c b/lib/oid_registry.c
index f7ad43f28579..508e0b34b5f0 100644
--- a/lib/oid_registry.c
+++ b/lib/oid_registry.c
@@ -11,6 +11,7 @@ 
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/bug.h>
+#include <linux/asn1.h>
 #include "oid_registry_data.c"
 
 MODULE_DESCRIPTION("OID Registry");
@@ -92,6 +93,18 @@  enum OID look_up_OID(const void *data, size_t datasize)
 }
 EXPORT_SYMBOL_GPL(look_up_OID);
 
+int parse_OID(const void *data, size_t datasize, enum OID *oid)
+{
+	const unsigned char *v = data;
+
+	if (datasize < 2 || v[0] != ASN1_OID || v[1] != datasize - 2)
+		return -EBADMSG;
+
+	*oid = look_up_OID(data + 2, datasize - 2);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(parse_OID);
+
 /*
  * sprint_OID - Print an Object Identifier into a buffer
  * @data: The encoded OID to print