[U-Boot] [PATCH v1 09/11] lib: crypto: add x509 parser

AKASHI Takahiro
2019-10-11T07:41:58Z

Imported from linux kernel v5.3.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
lib/Kconfig | 1 +
lib/Makefile | 1 +
lib/crypto/Kconfig | 10 +
lib/crypto/Makefile | 17 +
lib/crypto/x509.asn1 | 60 +++
lib/crypto/x509_akid.asn1 | 35 ++
lib/crypto/x509_cert_parser.c | 697 ++++++++++++++++++++++++++++++++++
lib/crypto/x509_parser.h | 57 +++
lib/crypto/x509_public_key.c | 292 ++++++++++++++
9 files changed, 1170 insertions(+)
create mode 100644 lib/crypto/x509.asn1
create mode 100644 lib/crypto/x509_akid.asn1
create mode 100644 lib/crypto/x509_cert_parser.c
create mode 100644 lib/crypto/x509_parser.h
create mode 100644 lib/crypto/x509_public_key.c

diff --git a/lib/Kconfig b/lib/Kconfig
index d2955c8feb0e..aa44f52d9181 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -253,6 +253,7 @@ config AES
present.

source lib/rsa/Kconfig
+source lib/crypto/Kconfig

config TPM
bool "Trusted Platform Module (TPM) Support"
diff --git a/lib/Makefile b/lib/Makefile
index 677ec33a1ce1..64ff105945b3 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_CMD_DHRYSTONE) += dhry/
obj-$(CONFIG_ARCH_AT91) += at91/
obj-$(CONFIG_OPTEE) += optee/
obj-$(CONFIG_BUILD_ASN1) += asn1_decoder.o
+obj-y += crypto/

obj-$(CONFIG_AES) += aes.o

diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index b8e8288d2f80..a87cf6107fc1 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -16,4 +16,14 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
appropriate hash algorithms (such as SHA-1) must be available.
ENOPKG will be reported if the requisite algorithm is unavailable.

+config X509_CERTIFICATE_PARSER
+ bool "X.509 certificate parser"
+ depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+ select ASN1
+ select OID_REGISTRY
+ help
+ This option provides support for parsing X.509 format blobs for key
+ data and provides the ability to instantiate a crypto key from a
+ public key packet found inside the certificate.
+
endif # ASYMMETRIC_KEY_TYPE
diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index a284de9e0411..2ec2d81a1f3c 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -8,3 +8,20 @@ obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += asymmetric_keys.o
asymmetric_keys-y := asymmetric_type.o

obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
+
+#
+# X.509 Certificate handling
+#
+obj-$(CONFIG_X509_CERTIFICATE_PARSER) += x509_key_parser.o
+x509_key_parser-y := \
+ x509.asn1.o \
+ x509_akid.asn1.o \
+ x509_cert_parser.o \
+ x509_public_key.o
+
+$(obj)/x509_cert_parser.o: \
+ $(obj)/x509.asn1.h \
+ $(obj)/x509_akid.asn1.h
+
+$(obj)/x509.asn1.o: $(obj)/x509.asn1.c $(obj)/x509.asn1.h
+$(obj)/x509_akid.asn1.o: $(obj)/x509_akid.asn1.c $(obj)/x509_akid.asn1.h
diff --git a/lib/crypto/x509.asn1 b/lib/crypto/x509.asn1
new file mode 100644
index 000000000000..5c9f4e4a5231
--- /dev/null
+++ b/lib/crypto/x509.asn1
@@ -0,0 +1,60 @@
+Certificate ::= SEQUENCE {
+ tbsCertificate TBSCertificate ({ x509_note_tbs_certificate }),
+ signatureAlgorithm AlgorithmIdentifier,
+ signature BIT STRING ({ x509_note_signature })
+ }
+
+TBSCertificate ::= SEQUENCE {
+ version [ 0 ] Version DEFAULT,
+ serialNumber CertificateSerialNumber ({ x509_note_serial }),
+ signature AlgorithmIdentifier ({ x509_note_pkey_algo }),
+ issuer Name ({ x509_note_issuer }),
+ validity Validity,
+ subject Name ({ x509_note_subject }),
+ subjectPublicKeyInfo SubjectPublicKeyInfo,
+ issuerUniqueID [ 1 ] IMPLICIT UniqueIdentifier OPTIONAL,
+ subjectUniqueID [ 2 ] IMPLICIT UniqueIdentifier OPTIONAL,
+ extensions [ 3 ] Extensions OPTIONAL
+ }
+
+Version ::= INTEGER
+CertificateSerialNumber ::= INTEGER
+
+AlgorithmIdentifier ::= SEQUENCE {
+ algorithm OBJECT IDENTIFIER ({ x509_note_OID }),
+ parameters ANY OPTIONAL ({ x509_note_params })
+}
+
+Name ::= SEQUENCE OF RelativeDistinguishedName
+
+RelativeDistinguishedName ::= SET OF AttributeValueAssertion
+
+AttributeValueAssertion ::= SEQUENCE {
+ attributeType OBJECT IDENTIFIER ({ x509_note_OID }),
+ attributeValue ANY ({ x509_extract_name_segment })
+ }
+
+Validity ::= SEQUENCE {
+ notBefore Time ({ x509_note_not_before }),
+ notAfter Time ({ x509_note_not_after })
+ }
+
+Time ::= CHOICE {
+ utcTime UTCTime,
+ generalTime GeneralizedTime
+ }
+
+SubjectPublicKeyInfo ::= SEQUENCE {
+ algorithm AlgorithmIdentifier,
+ subjectPublicKey BIT STRING ({ x509_extract_key_data })
+ }
+
+UniqueIdentifier ::= BIT STRING
+
+Extensions ::= SEQUENCE OF Extension
+
+Extension ::= SEQUENCE {
+ extnid OBJECT IDENTIFIER ({ x509_note_OID }),
+ critical BOOLEAN DEFAULT,
+ extnValue OCTET STRING ({ x509_process_extension })
+ }
diff --git a/lib/crypto/x509_akid.asn1 b/lib/crypto/x509_akid.asn1
new file mode 100644
index 000000000000..1a33231a75a8
--- /dev/null
+++ b/lib/crypto/x509_akid.asn1
@@ -0,0 +1,35 @@
+-- X.509 AuthorityKeyIdentifier
+-- rfc5280 section 4.2.1.1
+
+AuthorityKeyIdentifier ::= SEQUENCE {
+ keyIdentifier [0] IMPLICIT KeyIdentifier OPTIONAL,
+ authorityCertIssuer [1] IMPLICIT GeneralNames OPTIONAL,
+ authorityCertSerialNumber [2] IMPLICIT CertificateSerialNumber OPTIONAL
+ }
+
+KeyIdentifier ::= OCTET STRING ({ x509_akid_note_kid })
+
+CertificateSerialNumber ::= INTEGER ({ x509_akid_note_serial })
+
+GeneralNames ::= SEQUENCE OF GeneralName
+
+GeneralName ::= CHOICE {
+ otherName [0] ANY,
+ rfc822Name [1] IA5String,
+ dNSName [2] IA5String,
+ x400Address [3] ANY,
+ directoryName [4] Name ({ x509_akid_note_name }),
+ ediPartyName [5] ANY,
+ uniformResourceIdentifier [6] IA5String,
+ iPAddress [7] OCTET STRING,
+ registeredID [8] OBJECT IDENTIFIER
+ }
+
+Name ::= SEQUENCE OF RelativeDistinguishedName
+
+RelativeDistinguishedName ::= SET OF AttributeValueAssertion
+
+AttributeValueAssertion ::= SEQUENCE {
+ attributeType OBJECT IDENTIFIER ({ x509_note_OID }),
+ attributeValue ANY ({ x509_extract_name_segment })
+ }
diff --git a/lib/crypto/x509_cert_parser.c b/lib/crypto/x509_cert_parser.c
new file mode 100644
index 000000000000..e6d2a426a0bc
--- /dev/null
+++ b/lib/crypto/x509_cert_parser.c
@@ -0,0 +1,697 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* X.509 certificate parser
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells at redhat.com)
+ */
+
+#define pr_fmt(fmt) "X.509: "fmt
+#include <linux/kernel.h>
+#ifndef __UBOOT__
+#include <linux/export.h>
+#include <linux/slab.h>
+#endif
+#include <linux/err.h>
+#include <linux/oid_registry.h>
+#ifdef __UBOOT__
+#include <linux/string.h>
+#endif
+#include <crypto/public_key.h>
+#include "x509_parser.h"
+#include "x509.asn1.h"
+#include "x509_akid.asn1.h"
+
+struct x509_parse_context {
+ struct x509_certificate *cert; /* Certificate being constructed */
+ unsigned long data; /* Start of data */
+ const void *cert_start; /* Start of cert content */
+ const void *key; /* Key data */
+ size_t key_size; /* Size of key data */
+ const void *params; /* Key parameters */
+ size_t params_size; /* Size of key parameters */
+ enum OID key_algo; /* Public key algorithm */
+ enum OID last_oid; /* Last OID encountered */
+ enum OID algo_oid; /* Algorithm OID */
+ unsigned char nr_mpi; /* Number of MPIs stored */
+ u8 o_size; /* Size of organizationName (O) */
+ u8 cn_size; /* Size of commonName (CN) */
+ u8 email_size; /* Size of emailAddress */
+ u16 o_offset; /* Offset of organizationName (O) */
+ u16 cn_offset; /* Offset of commonName (CN) */
+ u16 email_offset; /* Offset of emailAddress */
+ unsigned raw_akid_size;
+ const void *raw_akid; /* Raw authorityKeyId in ASN.1 */
+ const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */
+ unsigned akid_raw_issuer_size;
+};
+
+/*
+ * Free an X.509 certificate
+ */
+void x509_free_certificate(struct x509_certificate *cert)
+{
+ if (cert) {
+ public_key_free(cert->pub);
+ public_key_signature_free(cert->sig);
+ kfree(cert->issuer);
+ kfree(cert->subject);
+ kfree(cert->id);
+ kfree(cert->skid);
+ kfree(cert);
+ }
+}
+EXPORT_SYMBOL_GPL(x509_free_certificate);
+
+/*
+ * Parse an X.509 certificate
+ */
+struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
+{
+ struct x509_certificate *cert;
+ struct x509_parse_context *ctx;
+ struct asymmetric_key_id *kid;
+ long ret;
+
+ ret = -ENOMEM;
+ cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
+ if (!cert)
+ goto error_no_cert;
+ cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
+ if (!cert->pub)
+ goto error_no_ctx;
+ cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
+ if (!cert->sig)
+ goto error_no_ctx;
+ ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
+ if (!ctx)
+ goto error_no_ctx;
+
+ ctx->cert = cert;
+ ctx->data = (unsigned long)data;
+
+ /* Attempt to decode the certificate */
+ ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
+ if (ret < 0)
+ goto error_decode;
+
+ /* Decode the AuthorityKeyIdentifier */
+ if (ctx->raw_akid) {
+ pr_devel("AKID: %u %*phN\n",
+ ctx->raw_akid_size, ctx->raw_akid_size, ctx->raw_akid);
+ ret = asn1_ber_decoder(&x509_akid_decoder, ctx,
+ ctx->raw_akid, ctx->raw_akid_size);
+ if (ret < 0) {
+ pr_warn("Couldn't decode AuthKeyIdentifier\n");
+ goto error_decode;
+ }
+ }
+
+ ret = -ENOMEM;
+ cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
+ if (!cert->pub->key)
+ goto error_decode;
+
+ cert->pub->keylen = ctx->key_size;
+
+ cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL);
+ if (!cert->pub->params)
+ goto error_decode;
+
+ cert->pub->paramlen = ctx->params_size;
+ cert->pub->algo = ctx->key_algo;
+
+ /* Grab the signature bits */
+ ret = x509_get_sig_params(cert);
+ if (ret < 0)
+ goto error_decode;
+
+ /* Generate cert issuer + serial number key ID */
+ kid = asymmetric_key_generate_id(cert->raw_serial,
+ cert->raw_serial_size,
+ cert->raw_issuer,
+ cert->raw_issuer_size);
+ if (IS_ERR(kid)) {
+ ret = PTR_ERR(kid);
+ goto error_decode;
+ }
+ cert->id = kid;
+
+#ifndef __UBOOT__
+ /* Detect self-signed certificates */
+ ret = x509_check_for_self_signed(cert);
+ if (ret < 0)
+ goto error_decode;
+#endif
+
+ kfree(ctx);
+ return cert;
+
+error_decode:
+ kfree(ctx);
+error_no_ctx:
+ x509_free_certificate(cert);
+error_no_cert:
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(x509_cert_parse);
+
+/*
+ * Note an OID when we find one for later processing when we know how
+ * to interpret it.
+ */
+int x509_note_OID(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ ctx->last_oid = look_up_OID(value, vlen);
+ if (ctx->last_oid == OID__NR) {
+ char buffer[50];
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_debug("Unknown OID: [%lu] %s\n",
+ (unsigned long)value - ctx->data, buffer);
+ }
+ return 0;
+}
+
+/*
+ * Save the position of the TBS data so that we can check the signature over it
+ * later.
+ */
+int x509_note_tbs_certificate(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
+ hdrlen, tag, (unsigned long)value - ctx->data, vlen);
+
+ ctx->cert->tbs = value - hdrlen;
+ ctx->cert->tbs_size = vlen + hdrlen;
+ return 0;
+}
+
+/*
+ * Record the public key algorithm
+ */
+int x509_note_pkey_algo(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ 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;
+
+ case OID_sha256WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha256";
+ goto rsa_pkcs1;
+
+ case OID_sha384WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha384";
+ goto rsa_pkcs1;
+
+ case OID_sha512WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha512";
+ goto rsa_pkcs1;
+
+ case OID_sha224WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha224";
+ goto rsa_pkcs1;
+
+ case OID_gost2012Signature256:
+ ctx->cert->sig->hash_algo = "streebog256";
+ goto ecrdsa;
+
+ case OID_gost2012Signature512:
+ ctx->cert->sig->hash_algo = "streebog512";
+ goto ecrdsa;
+ }
+
+rsa_pkcs1:
+ ctx->cert->sig->pkey_algo = "rsa";
+ ctx->cert->sig->encoding = "pkcs1";
+ ctx->algo_oid = ctx->last_oid;
+ return 0;
+ecrdsa:
+ ctx->cert->sig->pkey_algo = "ecrdsa";
+ ctx->cert->sig->encoding = "raw";
+ ctx->algo_oid = ctx->last_oid;
+ return 0;
+}
+
+/*
+ * Note the whereabouts and type of the signature.
+ */
+int x509_note_signature(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
+
+ if (ctx->last_oid != ctx->algo_oid) {
+ pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
+ ctx->algo_oid, ctx->last_oid);
+ return -EINVAL;
+ }
+
+ if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 ||
+ strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0) {
+ /* Discard the BIT STRING metadata */
+ if (vlen < 1 || *(const u8 *)value != 0)
+ return -EBADMSG;
+
+ value++;
+ vlen--;
+ }
+
+ ctx->cert->raw_sig = value;
+ ctx->cert->raw_sig_size = vlen;
+ return 0;
+}
+
+/*
+ * Note the certificate serial number
+ */
+int x509_note_serial(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ ctx->cert->raw_serial = value;
+ ctx->cert->raw_serial_size = vlen;
+ return 0;
+}
+
+/*
+ * Note some of the name segments from which we'll fabricate a name.
+ */
+int x509_extract_name_segment(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ switch (ctx->last_oid) {
+ case OID_commonName:
+ ctx->cn_size = vlen;
+ ctx->cn_offset = (unsigned long)value - ctx->data;
+ break;
+ case OID_organizationName:
+ ctx->o_size = vlen;
+ ctx->o_offset = (unsigned long)value - ctx->data;
+ break;
+ case OID_email_address:
+ ctx->email_size = vlen;
+ ctx->email_offset = (unsigned long)value - ctx->data;
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ * Fabricate and save the issuer and subject names
+ */
+static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
+ unsigned char tag,
+ char **_name, size_t vlen)
+{
+ const void *name, *data = (const void *)ctx->data;
+ size_t namesize;
+ char *buffer;
+
+ if (*_name)
+ return -EINVAL;
+
+ /* Empty name string if no material */
+ if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
+ buffer = kmalloc(1, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+ buffer[0] = 0;
+ goto done;
+ }
+
+ if (ctx->cn_size && ctx->o_size) {
+ /* Consider combining O and CN, but use only the CN if it is
+ * prefixed by the O, or a significant portion thereof.
+ */
+ namesize = ctx->cn_size;
+ name = data + ctx->cn_offset;
+ if (ctx->cn_size >= ctx->o_size &&
+ memcmp(data + ctx->cn_offset, data + ctx->o_offset,
+ ctx->o_size) == 0)
+ goto single_component;
+ if (ctx->cn_size >= 7 &&
+ ctx->o_size >= 7 &&
+ memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
+ goto single_component;
+
+ buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
+ GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ memcpy(buffer,
+ data + ctx->o_offset, ctx->o_size);
+ buffer[ctx->o_size + 0] = ':';
+ buffer[ctx->o_size + 1] = ' ';
+ memcpy(buffer + ctx->o_size + 2,
+ data + ctx->cn_offset, ctx->cn_size);
+ buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
+ goto done;
+
+ } else if (ctx->cn_size) {
+ namesize = ctx->cn_size;
+ name = data + ctx->cn_offset;
+ } else if (ctx->o_size) {
+ namesize = ctx->o_size;
+ name = data + ctx->o_offset;
+ } else {
+ namesize = ctx->email_size;
+ name = data + ctx->email_offset;
+ }
+
+single_component:
+ buffer = kmalloc(namesize + 1, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+ memcpy(buffer, name, namesize);
+ buffer[namesize] = 0;
+
+done:
+ *_name = buffer;
+ ctx->cn_size = 0;
+ ctx->o_size = 0;
+ ctx->email_size = 0;
+ return 0;
+}
+
+int x509_note_issuer(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ ctx->cert->raw_issuer = value;
+ ctx->cert->raw_issuer_size = vlen;
+ return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
+}
+
+int x509_note_subject(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ ctx->cert->raw_subject = value;
+ ctx->cert->raw_subject_size = vlen;
+ return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
+}
+
+/*
+ * Extract the parameters for the public key
+ */
+int x509_note_params(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ /*
+ * AlgorithmIdentifier is used three times in the x509, we should skip
+ * first and ignore third, using second one which is after subject and
+ * before subjectPublicKey.
+ */
+ if (!ctx->cert->raw_subject || ctx->key)
+ return 0;
+ ctx->params = value - hdrlen;
+ ctx->params_size = vlen + hdrlen;
+ return 0;
+}
+
+/*
+ * Extract the data for the public key algorithm
+ */
+int x509_extract_key_data(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ ctx->key_algo = ctx->last_oid;
+ if (ctx->last_oid == OID_rsaEncryption)
+ ctx->cert->pub->pkey_algo = "rsa";
+ else if (ctx->last_oid == OID_gost2012PKey256 ||
+ ctx->last_oid == OID_gost2012PKey512)
+ ctx->cert->pub->pkey_algo = "ecrdsa";
+ else
+ return -ENOPKG;
+
+ /* Discard the BIT STRING metadata */
+ if (vlen < 1 || *(const u8 *)value != 0)
+ return -EBADMSG;
+ ctx->key = value + 1;
+ ctx->key_size = vlen - 1;
+ return 0;
+}
+
+/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
+#define SEQ_TAG_KEYID (ASN1_CONT << 6)
+
+/*
+ * Process certificate extensions that are used to qualify the certificate.
+ */
+int x509_process_extension(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ struct asymmetric_key_id *kid;
+ const unsigned char *v = value;
+
+ pr_debug("Extension: %u\n", ctx->last_oid);
+
+ if (ctx->last_oid == OID_subjectKeyIdentifier) {
+ /* Get hold of the key fingerprint */
+ if (ctx->cert->skid || vlen < 3)
+ return -EBADMSG;
+ if (v[0] != ASN1_OTS || v[1] != vlen - 2)
+ return -EBADMSG;
+ v += 2;
+ vlen -= 2;
+
+ ctx->cert->raw_skid_size = vlen;
+ ctx->cert->raw_skid = v;
+ kid = asymmetric_key_generate_id(v, vlen, "", 0);
+ if (IS_ERR(kid))
+ return PTR_ERR(kid);
+ ctx->cert->skid = kid;
+ pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
+ return 0;
+ }
+
+ if (ctx->last_oid == OID_authorityKeyIdentifier) {
+ /* Get hold of the CA key fingerprint */
+ ctx->raw_akid = v;
+ ctx->raw_akid_size = vlen;
+ return 0;
+ }
+
+ return 0;
+}
+
+/**
+ * x509_decode_time - Decode an X.509 time ASN.1 object
+ * @_t: The time to fill in
+ * @hdrlen: The length of the object header
+ * @tag: The object tag
+ * @value: The object value
+ * @vlen: The size of the object value
+ *
+ * Decode an ASN.1 universal time or generalised time field into a struct the
+ * kernel can handle and check it for validity. The time is decoded thus:
+ *
+ * [RFC5280 ยง4.1.2.5]
+ * CAs conforming to this profile MUST always encode certificate validity
+ * dates through the year 2049 as UTCTime; certificate validity dates in
+ * 2050 or later MUST be encoded as GeneralizedTime. Conforming
+ * applications MUST be able to process validity dates that are encoded in
+ * either UTCTime or GeneralizedTime.
+ */
+int x509_decode_time(time64_t *_t, size_t hdrlen,
+ unsigned char tag,
+ const unsigned char *value, size_t vlen)
+{
+ static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
+ 31, 31, 30, 31, 30, 31 };
+ const unsigned char *p = value;
+ unsigned year, mon, day, hour, min, sec, mon_len;
+
+#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
+#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
+
+ if (tag == ASN1_UNITIM) {
+ /* UTCTime: YYMMDDHHMMSSZ */
+ if (vlen != 13)
+ goto unsupported_time;
+ year = DD2bin(p);
+ if (year >= 50)
+ year += 1900;
+ else
+ year += 2000;
+ } else if (tag == ASN1_GENTIM) {
+ /* GenTime: YYYYMMDDHHMMSSZ */
+ if (vlen != 15)
+ goto unsupported_time;
+ year = DD2bin(p) * 100 + DD2bin(p);
+ if (year >= 1950 && year <= 2049)
+ goto invalid_time;
+ } else {
+ goto unsupported_time;
+ }
+
+ mon = DD2bin(p);
+ day = DD2bin(p);
+ hour = DD2bin(p);
+ min = DD2bin(p);
+ sec = DD2bin(p);
+
+ if (*p != 'Z')
+ goto unsupported_time;
+
+ if (year < 1970 ||
+ mon < 1 || mon > 12)
+ goto invalid_time;
+
+ mon_len = month_lengths[mon - 1];
+ if (mon == 2) {
+ if (year % 4 == 0) {
+ mon_len = 29;
+ if (year % 100 == 0) {
+ mon_len = 28;
+ if (year % 400 == 0)
+ mon_len = 29;
+ }
+ }
+ }
+
+ if (day < 1 || day > mon_len ||
+ hour > 24 || /* ISO 8601 permits 24:00:00 as midnight tomorrow */
+ min > 59 ||
+ sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
+ goto invalid_time;
+
+ *_t = mktime64(year, mon, day, hour, min, sec);
+ return 0;
+
+unsupported_time:
+ pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
+ tag, (int)vlen, value);
+ return -EBADMSG;
+invalid_time:
+ pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
+ tag, (int)vlen, value);
+ return -EBADMSG;
+}
+EXPORT_SYMBOL_GPL(x509_decode_time);
+
+int x509_note_not_before(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
+}
+
+int x509_note_not_after(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
+}
+
+/*
+ * Note a key identifier-based AuthorityKeyIdentifier
+ */
+int x509_akid_note_kid(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ struct asymmetric_key_id *kid;
+
+ pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
+
+ if (ctx->cert->sig->auth_ids[1])
+ return 0;
+
+ kid = asymmetric_key_generate_id(value, vlen, "", 0);
+ if (IS_ERR(kid))
+ return PTR_ERR(kid);
+ pr_debug("authkeyid %*phN\n", kid->len, kid->data);
+ ctx->cert->sig->auth_ids[1] = kid;
+ return 0;
+}
+
+/*
+ * Note a directoryName in an AuthorityKeyIdentifier
+ */
+int x509_akid_note_name(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ pr_debug("AKID: name: %*phN\n", (int)vlen, value);
+
+ ctx->akid_raw_issuer = value;
+ ctx->akid_raw_issuer_size = vlen;
+ return 0;
+}
+
+/*
+ * Note a serial number in an AuthorityKeyIdentifier
+ */
+int x509_akid_note_serial(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ struct asymmetric_key_id *kid;
+
+ pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
+
+ if (!ctx->akid_raw_issuer || ctx->cert->sig->auth_ids[0])
+ return 0;
+
+ kid = asymmetric_key_generate_id(value,
+ vlen,
+ ctx->akid_raw_issuer,
+ ctx->akid_raw_issuer_size);
+ if (IS_ERR(kid))
+ return PTR_ERR(kid);
+
+ pr_debug("authkeyid %*phN\n", kid->len, kid->data);
+ ctx->cert->sig->auth_ids[0] = kid;
+ return 0;
+}
diff --git a/lib/crypto/x509_parser.h b/lib/crypto/x509_parser.h
new file mode 100644
index 000000000000..c233f136fb35
--- /dev/null
+++ b/lib/crypto/x509_parser.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* X.509 certificate parser internal definitions
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells at redhat.com)
+ */
+
+#include <linux/time.h>
+#include <crypto/public_key.h>
+#include <keys/asymmetric-type.h>
+
+struct x509_certificate {
+ struct x509_certificate *next;
+ struct x509_certificate *signer; /* Certificate that signed this one */
+ struct public_key *pub; /* Public key details */
+ struct public_key_signature *sig; /* Signature parameters */
+ char *issuer; /* Name of certificate issuer */
+ char *subject; /* Name of certificate subject */
+ struct asymmetric_key_id *id; /* Issuer + Serial number */
+ struct asymmetric_key_id *skid; /* Subject + subjectKeyId (optional) */
+ time64_t valid_from;
+ time64_t valid_to;
+ const void *tbs; /* Signed data */
+ unsigned tbs_size; /* Size of signed data */
+ unsigned raw_sig_size; /* Size of sigature */
+ const void *raw_sig; /* Signature data */
+ const void *raw_serial; /* Raw serial number in ASN.1 */
+ unsigned raw_serial_size;
+ unsigned raw_issuer_size;
+ const void *raw_issuer; /* Raw issuer name in ASN.1 */
+ const void *raw_subject; /* Raw subject name in ASN.1 */
+ unsigned raw_subject_size;
+ unsigned raw_skid_size;
+ const void *raw_skid; /* Raw subjectKeyId in ASN.1 */
+ unsigned index;
+ bool seen; /* Infinite recursion prevention */
+ bool verified;
+ bool self_signed; /* T if self-signed (check unsupported_sig too) */
+ bool unsupported_key; /* T if key uses unsupported crypto */
+ bool unsupported_sig; /* T if signature uses unsupported crypto */
+ bool blacklisted;
+};
+
+/*
+ * x509_cert_parser.c
+ */
+extern void x509_free_certificate(struct x509_certificate *cert);
+extern struct x509_certificate *x509_cert_parse(const void *data, size_t datalen);
+extern int x509_decode_time(time64_t *_t, size_t hdrlen,
+ unsigned char tag,
+ const unsigned char *value, size_t vlen);
+
+/*
+ * x509_public_key.c
+ */
+extern int x509_get_sig_params(struct x509_certificate *cert);
+extern int x509_check_for_self_signed(struct x509_certificate *cert);
diff --git a/lib/crypto/x509_public_key.c b/lib/crypto/x509_public_key.c
new file mode 100644
index 000000000000..04bdb672b496
--- /dev/null
+++ b/lib/crypto/x509_public_key.c
@@ -0,0 +1,292 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Instantiate a public key crypto key from an X.509 Certificate
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells at redhat.com)
+ */
+
+#define pr_fmt(fmt) "X.509: "fmt
+#ifdef __UBOOT__
+#include <common.h>
+#include <linux/compat.h>
+#include <linux/errno.h>
+#else
+#include <linux/module.h>
+#endif
+#include <linux/kernel.h>
+#ifndef __UBOOT__
+#include <linux/slab.h>
+#include <keys/asymmetric-subtype.h>
+#include <keys/asymmetric-parser.h>
+#include <keys/system_keyring.h>
+#include <crypto/hash.h>
+#include "asymmetric_keys.h"
+#endif
+#include "x509_parser.h"
+
+/*
+ * Set up the signature parameters in an X.509 certificate. This involves
+ * digesting the signed data and extracting the signature.
+ */
+int x509_get_sig_params(struct x509_certificate *cert)
+{
+ struct public_key_signature *sig = cert->sig;
+#ifndef __UBOOT__
+ struct crypto_shash *tfm;
+ struct shash_desc *desc;
+ size_t desc_size;
+#endif
+ int ret;
+
+ pr_devel("==>%s()\n", __func__);
+
+ if (!cert->pub->pkey_algo)
+ cert->unsupported_key = true;
+
+ if (!sig->pkey_algo)
+ cert->unsupported_sig = true;
+
+ /* We check the hash if we can - even if we can't then verify it */
+ if (!sig->hash_algo) {
+ cert->unsupported_sig = true;
+ return 0;
+ }
+
+ sig->s = kmemdup(cert->raw_sig, cert->raw_sig_size, GFP_KERNEL);
+ if (!sig->s)
+ return -ENOMEM;
+
+ sig->s_size = cert->raw_sig_size;
+
+#ifdef __UBOOT__
+ /*
+ * Note:
+ * This part (filling sig->digest) should be implemented if
+ * x509_check_for_self_signed() is enabled x509_cert_parse().
+ * Currently, this check won't affect UEFI secure boot.
+ */
+ ret = 0;
+#else
+ /* Allocate the hashing algorithm we're going to need and find out how
+ * big the hash operational data will be.
+ */
+ tfm = crypto_alloc_shash(sig->hash_algo, 0, 0);
+ if (IS_ERR(tfm)) {
+ if (PTR_ERR(tfm) == -ENOENT) {
+ cert->unsupported_sig = true;
+ return 0;
+ }
+ return PTR_ERR(tfm);
+ }
+
+ desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
+ sig->digest_size = crypto_shash_digestsize(tfm);
+
+ ret = -ENOMEM;
+ sig->digest = kmalloc(sig->digest_size, GFP_KERNEL);
+ if (!sig->digest)
+ goto error;
+
+ desc = kzalloc(desc_size, GFP_KERNEL);
+ if (!desc)
+ goto error;
+
+ desc->tfm = tfm;
+
+ ret = crypto_shash_digest(desc, cert->tbs, cert->tbs_size, sig->digest);
+ if (ret < 0)
+ goto error_2;
+
+ ret = is_hash_blacklisted(sig->digest, sig->digest_size, "tbs");
+ if (ret == -EKEYREJECTED) {
+ pr_err("Cert %*phN is blacklisted\n",
+ sig->digest_size, sig->digest);
+ cert->blacklisted = true;
+ ret = 0;
+ }
+
+error_2:
+ kfree(desc);
+error:
+ crypto_free_shash(tfm);
+#endif /* __UBOOT__ */
+ pr_devel("<==%s() = %d\n", __func__, ret);
+ return ret;
+}
+
+#ifndef __UBOOT__
+/*
+ * Check for self-signedness in an X.509 cert and if found, check the signature
+ * immediately if we can.
+ */
+int x509_check_for_self_signed(struct x509_certificate *cert)
+{
+ int ret = 0;
+
+ pr_devel("==>%s()\n", __func__);
+
+ if (cert->raw_subject_size != cert->raw_issuer_size ||
+ memcmp(cert->raw_subject, cert->raw_issuer,
+ cert->raw_issuer_size) != 0)
+ goto not_self_signed;
+
+ if (cert->sig->auth_ids[0] || cert->sig->auth_ids[1]) {
+ /* If the AKID is present it may have one or two parts. If
+ * both are supplied, both must match.
+ */
+ bool a = asymmetric_key_id_same(cert->skid, cert->sig->auth_ids[1]);
+ bool b = asymmetric_key_id_same(cert->id, cert->sig->auth_ids[0]);
+
+ if (!a && !b)
+ goto not_self_signed;
+
+ ret = -EKEYREJECTED;
+ if (((a && !b) || (b && !a)) &&
+ cert->sig->auth_ids[0] && cert->sig->auth_ids[1])
+ goto out;
+ }
+
+ ret = -EKEYREJECTED;
+ if (strcmp(cert->pub->pkey_algo, cert->sig->pkey_algo) != 0)
+ goto out;
+
+ ret = public_key_verify_signature(cert->pub, cert->sig);
+ if (ret < 0) {
+ if (ret == -ENOPKG) {
+ cert->unsupported_sig = true;
+ ret = 0;
+ }
+ goto out;
+ }
+
+ pr_devel("Cert Self-signature verified");
+ cert->self_signed = true;
+
+out:
+ pr_devel("<==%s() = %d\n", __func__, ret);
+ return ret;
+
+not_self_signed:
+ pr_devel("<==%s() = 0 [not]\n", __func__);
+ return 0;
+}
+
+/*
+ * Attempt to parse a data blob for a key as an X509 certificate.
+ */
+static int x509_key_preparse(struct key_preparsed_payload *prep)
+{
+ struct asymmetric_key_ids *kids;
+ struct x509_certificate *cert;
+ const char *q;
+ size_t srlen, sulen;
+ char *desc = NULL, *p;
+ int ret;
+
+ cert = x509_cert_parse(prep->data, prep->datalen);
+ if (IS_ERR(cert))
+ return PTR_ERR(cert);
+
+ pr_devel("Cert Issuer: %s\n", cert->issuer);
+ pr_devel("Cert Subject: %s\n", cert->subject);
+
+ if (cert->unsupported_key) {
+ ret = -ENOPKG;
+ goto error_free_cert;
+ }
+
+ pr_devel("Cert Key Algo: %s\n", cert->pub->pkey_algo);
+ pr_devel("Cert Valid period: %lld-%lld\n", cert->valid_from, cert->valid_to);
+
+ cert->pub->id_type = "X509";
+
+ if (cert->unsupported_sig) {
+ public_key_signature_free(cert->sig);
+ cert->sig = NULL;
+ } else {
+ pr_devel("Cert Signature: %s + %s\n",
+ cert->sig->pkey_algo, cert->sig->hash_algo);
+ }
+
+ /* Don't permit addition of blacklisted keys */
+ ret = -EKEYREJECTED;
+ if (cert->blacklisted)
+ goto error_free_cert;
+
+ /* Propose a description */
+ sulen = strlen(cert->subject);
+ if (cert->raw_skid) {
+ srlen = cert->raw_skid_size;
+ q = cert->raw_skid;
+ } else {
+ srlen = cert->raw_serial_size;
+ q = cert->raw_serial;
+ }
+
+ ret = -ENOMEM;
+ desc = kmalloc(sulen + 2 + srlen * 2 + 1, GFP_KERNEL);
+ if (!desc)
+ goto error_free_cert;
+ p = memcpy(desc, cert->subject, sulen);
+ p += sulen;
+ *p++ = ':';
+ *p++ = ' ';
+ p = bin2hex(p, q, srlen);
+ *p = 0;
+
+ kids = kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL);
+ if (!kids)
+ goto error_free_desc;
+ kids->id[0] = cert->id;
+ kids->id[1] = cert->skid;
+
+ /* We're pinning the module by being linked against it */
+ __module_get(public_key_subtype.owner);
+ prep->payload.data[asym_subtype] = &public_key_subtype;
+ prep->payload.data[asym_key_ids] = kids;
+ prep->payload.data[asym_crypto] = cert->pub;
+ prep->payload.data[asym_auth] = cert->sig;
+ prep->description = desc;
+ prep->quotalen = 100;
+
+ /* We've finished with the certificate */
+ cert->pub = NULL;
+ cert->id = NULL;
+ cert->skid = NULL;
+ cert->sig = NULL;
+ desc = NULL;
+ ret = 0;
+
+error_free_desc:
+ kfree(desc);
+error_free_cert:
+ x509_free_certificate(cert);
+ return ret;
+}
+
+static struct asymmetric_key_parser x509_key_parser = {
+ .owner = THIS_MODULE,
+ .name = "x509",
+ .parse = x509_key_preparse,
+};
+
+/*
+ * Module stuff
+ */
+static int __init x509_key_init(void)
+{
+ return register_asymmetric_key_parser(&x509_key_parser);
+}
+
+static void __exit x509_key_exit(void)
+{
+ unregister_asymmetric_key_parser(&x509_key_parser);
+}
+
+module_init(x509_key_init);
+module_exit(x509_key_exit);
+#endif /* !__UBOOT__ */
+
+MODULE_DESCRIPTION("X.509 certificate parser");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
--
2.21.0