Mirrors/u-boot
2
0
Fork 0
mirror of https://github.com/AsahiLinux/u-boot synced 2024-11-10 15:14:43 +00:00
Code Issues Projects Releases Packages Wiki Activity

lib: crypto: add x509 parser

Browse source 
Imported from linux kernel v5.3:
 x509.asn1 without changes
 x509_akid.asn1 without changes
 x509_parser.h without changes
 x509_cert_parser.c with changes marked as __UBOOT__
 x509_public_key.c with changes marked as __UBOOT__

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
This commit is contained in:
AKASHI Takahiro 2019-11-13 09:45:00 +09:00 committed by Tom Rini
parent 9b933bf6f4
commit b4adf627d5
9 changed files with 1172 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
lib/Kconfig
View file

@ -265,6 +265,7 @@ config AES
present.
source lib/rsa/Kconfig
source lib/crypto/Kconfig
config TPM
bool "Trusted Platform Module (TPM) Support"

1
lib/Makefile
View file

@ -18,6 +18,7 @@ obj-$(CONFIG_CMD_DHRYSTONE) += dhry/
obj-$(CONFIG_ARCH_AT91) += at91/
obj-$(CONFIG_OPTEE) += optee/
obj-$(CONFIG_ASN1_DECODER) += asn1_decoder.o
obj-y += crypto/
obj-$(CONFIG_AES) += aes.o

12
lib/crypto/Kconfig
View file

@ -27,4 +27,16 @@ config RSA_PUBLIC_KEY_PARSER
public key data and provides the ability to instantiate a public
key.
config X509_CERTIFICATE_PARSER
bool "X.509 certificate parser"
depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
select ASN1_DECODER
select ASN1_COMPILER
select OID_REGISTRY
select LIB_DATE
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

17
lib/crypto/Makefile
View file

@ -19,3 +19,20 @@ rsa_public_key-y := \
$(obj)/rsapubkey.asn1.o: $(obj)/rsapubkey.asn1.c $(obj)/rsapubkey.asn1.h
$(obj)/rsa_helper.o: $(obj)/rsapubkey.asn1.h
#
# X.509 Certificate handling
#
obj-$(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

60
lib/crypto/x509.asn1 Normal file
View file

@ -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 })
}

35
lib/crypto/x509_akid.asn1 Normal file
View file

@ -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 })
}

697
lib/crypto/x509_cert_parser.c Normal file
View file

@ -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@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 §4.1.2.5]
* 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;
}

57
lib/crypto/x509_parser.h Normal file
View file

@ -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@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);

292
lib/crypto/x509_public_key.c Normal file
View file

@ -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@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");