diff mbox series

[2/8] lib: crypto: add public_key_verify_signature()

Message ID 20200609051401.18192-3-takahiro.akashi@linaro.org
State Superseded, archived
Delegated to: Heinrich Schuchardt
Headers show
Series efi_loader: secure boot: support intermediate certificates in signature | expand

Commit Message

AKASHI Takahiro June 9, 2020, 5:13 a.m. UTC
This function will be called from x509_check_for_self_signed() and
pkcs7_verify_one(), which will be imported from linux in a later patch.

While it does exist in linux code and has a similar functionality of
rsa_verify(), it calls further linux-specific interfaces inside.
That could lead to more files being imported from linux.

So simply re-implement it here instead of re-using the code.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
 include/crypto/public_key.h |  2 +-
 lib/crypto/public_key.c     | 56 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 2 deletions(-)

Comments

Heinrich Schuchardt June 9, 2020, 10:26 a.m. UTC | #1
On 09.06.20 07:13, AKASHI Takahiro wrote:
> This function will be called from x509_check_for_self_signed() and
> pkcs7_verify_one(), which will be imported from linux in a later patch.
>
> While it does exist in linux code and has a similar functionality of
> rsa_verify(), it calls further linux-specific interfaces inside.
> That could lead to more files being imported from linux.
>
> So simply re-implement it here instead of re-using the code.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> ---
>  include/crypto/public_key.h |  2 +-
>  lib/crypto/public_key.c     | 56 ++++++++++++++++++++++++++++++++++++-
>  2 files changed, 56 insertions(+), 2 deletions(-)
>
> diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
> index 436a1ee1ee64..3ba90fcc3483 100644
> --- a/include/crypto/public_key.h
> +++ b/include/crypto/public_key.h
> @@ -82,9 +82,9 @@ extern int decrypt_blob(struct kernel_pkey_params *, const void *, void *);
>  extern int create_signature(struct kernel_pkey_params *, const void *, void *);
>  extern int verify_signature(const struct key *,
>  			    const struct public_key_signature *);
> +#endif /* __UBOOT__ */
>
>  int public_key_verify_signature(const struct public_key *pkey,
>  				const struct public_key_signature *sig);
> -#endif /* !__UBOOT__ */
>
>  #endif /* _LINUX_PUBLIC_KEY_H */
> diff --git a/lib/crypto/public_key.c b/lib/crypto/public_key.c
> index e12ebbb3d0c5..232e79d086ae 100644
> --- a/lib/crypto/public_key.c
> +++ b/lib/crypto/public_key.c
> @@ -25,7 +25,10 @@
>  #include <keys/asymmetric-subtype.h>
>  #endif
>  #include <crypto/public_key.h>
> -#ifndef __UBOOT__
> +#ifdef __UBOOT__
> +#include <image.h>
> +#include <u-boot/rsa.h>
> +#else
>  #include <crypto/akcipher.h>
>  #endif
>
> @@ -80,6 +83,57 @@ void public_key_signature_free(struct public_key_signature *sig)
>  }
>  EXPORT_SYMBOL_GPL(public_key_signature_free);
>
> +/*
> + * Verify a signature using a public key.

Please, supply a function description according to
https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-documentation

Best regards

Heinrich

> + */
> +int public_key_verify_signature(const struct public_key *pkey,
> +				const struct public_key_signature *sig)
> +{
> +	struct image_sign_info info;
> +	struct image_region region;
> +	int ret;
> +
> +	pr_devel("==>%s()\n", __func__);
> +
> +	if (!pkey || !sig)
> +		return -EINVAL;
> +
> +	if (pkey->key_is_private)
> +		return -EINVAL;
> +
> +	memset(&info, '\0', sizeof(info));
> +	info.padding = image_get_padding_algo("pkcs-1.5");
> +	/*
> +	 * Note: image_get_[checksum|crypto]_algo takes an string
> +	 * argument like "<checksum>,<crypto>"
> +	 * TODO: support other hash algorithms
> +	 */
> +	if (!strcmp(sig->hash_algo, "sha1")) {
> +		info.checksum = image_get_checksum_algo("sha1,rsa2048");
> +		info.name = "sha1,rsa2048";
> +	} else if (!strcmp(sig->hash_algo, "sha256")) {
> +		info.checksum = image_get_checksum_algo("sha256,rsa2048");
> +		info.name = "sha256,rsa2048";
> +	} else {
> +		pr_warn("unknown msg digest algo: %s\n", sig->hash_algo);
> +		return -ENOPKG;
> +	}
> +	info.crypto = image_get_crypto_algo(info.name);
> +
> +	info.key = pkey->key;
> +	info.keylen = pkey->keylen;
> +
> +	region.data = sig->digest;
> +	region.size = sig->digest_size;
> +
> +	if (rsa_verify_with_pkey(&info, sig->digest, sig->s, sig->s_size))
> +		ret = -EKEYREJECTED;
> +	else
> +		ret = 0;
> +
> +	pr_devel("<==%s() = %d\n", __func__, ret);
> +	return ret;
> +}
>  #else
>  /*
>   * Destroy a public key algorithm key.
>
diff mbox series

Patch

diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 436a1ee1ee64..3ba90fcc3483 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -82,9 +82,9 @@  extern int decrypt_blob(struct kernel_pkey_params *, const void *, void *);
 extern int create_signature(struct kernel_pkey_params *, const void *, void *);
 extern int verify_signature(const struct key *,
 			    const struct public_key_signature *);
+#endif /* __UBOOT__ */
 
 int public_key_verify_signature(const struct public_key *pkey,
 				const struct public_key_signature *sig);
-#endif /* !__UBOOT__ */
 
 #endif /* _LINUX_PUBLIC_KEY_H */
diff --git a/lib/crypto/public_key.c b/lib/crypto/public_key.c
index e12ebbb3d0c5..232e79d086ae 100644
--- a/lib/crypto/public_key.c
+++ b/lib/crypto/public_key.c
@@ -25,7 +25,10 @@ 
 #include <keys/asymmetric-subtype.h>
 #endif
 #include <crypto/public_key.h>
-#ifndef __UBOOT__
+#ifdef __UBOOT__
+#include <image.h>
+#include <u-boot/rsa.h>
+#else
 #include <crypto/akcipher.h>
 #endif
 
@@ -80,6 +83,57 @@  void public_key_signature_free(struct public_key_signature *sig)
 }
 EXPORT_SYMBOL_GPL(public_key_signature_free);
 
+/*
+ * Verify a signature using a public key.
+ */
+int public_key_verify_signature(const struct public_key *pkey,
+				const struct public_key_signature *sig)
+{
+	struct image_sign_info info;
+	struct image_region region;
+	int ret;
+
+	pr_devel("==>%s()\n", __func__);
+
+	if (!pkey || !sig)
+		return -EINVAL;
+
+	if (pkey->key_is_private)
+		return -EINVAL;
+
+	memset(&info, '\0', sizeof(info));
+	info.padding = image_get_padding_algo("pkcs-1.5");
+	/*
+	 * Note: image_get_[checksum|crypto]_algo takes an string
+	 * argument like "<checksum>,<crypto>"
+	 * TODO: support other hash algorithms
+	 */
+	if (!strcmp(sig->hash_algo, "sha1")) {
+		info.checksum = image_get_checksum_algo("sha1,rsa2048");
+		info.name = "sha1,rsa2048";
+	} else if (!strcmp(sig->hash_algo, "sha256")) {
+		info.checksum = image_get_checksum_algo("sha256,rsa2048");
+		info.name = "sha256,rsa2048";
+	} else {
+		pr_warn("unknown msg digest algo: %s\n", sig->hash_algo);
+		return -ENOPKG;
+	}
+	info.crypto = image_get_crypto_algo(info.name);
+
+	info.key = pkey->key;
+	info.keylen = pkey->keylen;
+
+	region.data = sig->digest;
+	region.size = sig->digest_size;
+
+	if (rsa_verify_with_pkey(&info, sig->digest, sig->s, sig->s_size))
+		ret = -EKEYREJECTED;
+	else
+		ret = 0;
+
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
 #else
 /*
  * Destroy a public key algorithm key.