[deliverable/linux.git] / crypto / asymmetric_keys / x509_cert_parser.c

/* X.509 certificate parser
 *
 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#define pr_fmt(fmt) "X.509: "fmt
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/oid_registry.h>
#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 */
	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;
		}
	}

	cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
	if (!cert->pub->key)
		goto error_decode;

	cert->pub->keylen = ctx->key_size;

	/* 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;

	/* Detect self-signed certificates */
	ret = x509_check_for_self_signed(cert);
	if (ret < 0)
		goto error_decode;

	kfree(ctx);
	return cert;

error_decode:
	kfree(cert->pub->key);
	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;
	}

rsa_pkcs1:
	ctx->cert->sig->pkey_algo = "rsa";
	ctx->cert->sig->encoding = "pkcs1";
	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;
	}

	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 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;

	if (ctx->last_oid != OID_rsaEncryption)
		return -ENOPKG;

	ctx->cert->pub->pkey_algo = "rsa";

	/* Discard the BIT STRING metadata */
	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;
}
Commit	Line	Data
c26fd69f DH	1	/* X.509 certificate parser
	2	*
	3	* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public Licence
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the Licence, or (at your option) any later version.
	10	*/
	11
	12	#define pr_fmt(fmt) "X.509: "fmt
	13	#include <linux/kernel.h>
ace0107a	14	#include <linux/export.h>
c26fd69f DH	15	#include <linux/slab.h>
	16	#include <linux/err.h>
	17	#include <linux/oid_registry.h>
db6c43bd	18	#include <crypto/public_key.h>
c26fd69f DH	19	#include "x509_parser.h"
c26fd69f DH	20	#include "x509-asn1.h"
b92e6570	21	#include "x509_akid-asn1.h"
c26fd69f DH	22
	23	struct x509_parse_context {
	24	struct x509_certificate cert; / Certificate being constructed */
	25	unsigned long data; /* Start of data */
	26	const void cert_start; / Start of cert content */
	27	const void key; / Key data */
	28	size_t key_size; /* Size of key data */
	29	enum OID last_oid; /* Last OID encountered */
	30	enum OID algo_oid; /* Algorithm OID */
	31	unsigned char nr_mpi; /* Number of MPIs stored */
	32	u8 o_size; /* Size of organizationName (O) */
	33	u8 cn_size; /* Size of commonName (CN) */
	34	u8 email_size; /* Size of emailAddress */
	35	u16 o_offset; /* Offset of organizationName (O) */
	36	u16 cn_offset; /* Offset of commonName (CN) */
	37	u16 email_offset; /* Offset of emailAddress */
b92e6570 DH	38	unsigned raw_akid_size;
	39	const void raw_akid; / Raw authorityKeyId in ASN.1 */
	40	const void akid_raw_issuer; / Raw directoryName in authorityKeyId */
	41	unsigned akid_raw_issuer_size;
c26fd69f DH	42	};
	43
	44	/*
	45	* Free an X.509 certificate
	46	*/
	47	void x509_free_certificate(struct x509_certificate *cert)
	48	{
	49	if (cert) {
3b764563	50	public_key_free(cert->pub);
77d0910d	51	public_key_signature_free(cert->sig);
c26fd69f DH	52	kfree(cert->issuer);
c26fd69f DH	53	kfree(cert->subject);
46963b77 DH	54	kfree(cert->id);
46963b77 DH	55	kfree(cert->skid);
c26fd69f DH	56	kfree(cert);
	57	}
	58	}
ace0107a	59	EXPORT_SYMBOL_GPL(x509_free_certificate);
c26fd69f DH	60
	61	/*
	62	* Parse an X.509 certificate
	63	*/
	64	struct x509_certificate x509_cert_parse(const void data, size_t datalen)
	65	{
	66	struct x509_certificate *cert;
	67	struct x509_parse_context *ctx;
46963b77	68	struct asymmetric_key_id *kid;
c26fd69f DH	69	long ret;
	70
	71	ret = -ENOMEM;
	72	cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
	73	if (!cert)
	74	goto error_no_cert;
	75	cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
	76	if (!cert->pub)
	77	goto error_no_ctx;
77d0910d DH	78	cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
	79	if (!cert->sig)
	80	goto error_no_ctx;
c26fd69f DH	81	ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
	82	if (!ctx)
	83	goto error_no_ctx;
	84
	85	ctx->cert = cert;
	86	ctx->data = (unsigned long)data;
	87
	88	/* Attempt to decode the certificate */
	89	ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
	90	if (ret < 0)
	91	goto error_decode;
	92
b92e6570 DH	93	/* Decode the AuthorityKeyIdentifier */
	94	if (ctx->raw_akid) {
	95	pr_devel("AKID: %u %*phN\n",
	96	ctx->raw_akid_size, ctx->raw_akid_size, ctx->raw_akid);
	97	ret = asn1_ber_decoder(&x509_akid_decoder, ctx,
	98	ctx->raw_akid, ctx->raw_akid_size);
	99	if (ret < 0) {
	100	pr_warn("Couldn't decode AuthKeyIdentifier\n");
	101	goto error_decode;
	102	}
	103	}
	104
db6c43bd TS	105	cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
db6c43bd TS	106	if (!cert->pub->key)
c26fd69f DH	107	goto error_decode;
c26fd69f DH	108
db6c43bd TS	109	cert->pub->keylen = ctx->key_size;
db6c43bd TS	110
6c2dc5ae DH	111	/* Grab the signature bits */
	112	ret = x509_get_sig_params(cert);
	113	if (ret < 0)
	114	goto error_decode;
	115
46963b77 DH	116	/* Generate cert issuer + serial number key ID */
	117	kid = asymmetric_key_generate_id(cert->raw_serial,
	118	cert->raw_serial_size,
	119	cert->raw_issuer,
	120	cert->raw_issuer_size);
	121	if (IS_ERR(kid)) {
	122	ret = PTR_ERR(kid);
	123	goto error_decode;
	124	}
	125	cert->id = kid;
	126
6c2dc5ae DH	127	/* Detect self-signed certificates */
	128	ret = x509_check_for_self_signed(cert);
	129	if (ret < 0)
	130	goto error_decode;
	131
c26fd69f DH	132	kfree(ctx);
	133	return cert;
	134
	135	error_decode:
db6c43bd	136	kfree(cert->pub->key);
c26fd69f DH	137	kfree(ctx);
	138	error_no_ctx:
	139	x509_free_certificate(cert);
	140	error_no_cert:
	141	return ERR_PTR(ret);
	142	}
ace0107a	143	EXPORT_SYMBOL_GPL(x509_cert_parse);
c26fd69f DH	144
	145	/*
	146	* Note an OID when we find one for later processing when we know how
	147	* to interpret it.
	148	*/
	149	int x509_note_OID(void *context, size_t hdrlen,
	150	unsigned char tag,
	151	const void *value, size_t vlen)
	152	{
	153	struct x509_parse_context *ctx = context;
	154
	155	ctx->last_oid = look_up_OID(value, vlen);
	156	if (ctx->last_oid == OID__NR) {
	157	char buffer[50];
	158	sprint_oid(value, vlen, buffer, sizeof(buffer));
cf75446e	159	pr_debug("Unknown OID: [%lu] %s\n",
c26fd69f DH	160	(unsigned long)value - ctx->data, buffer);
	161	}
	162	return 0;
	163	}
	164
	165	/*
	166	* Save the position of the TBS data so that we can check the signature over it
	167	* later.
	168	*/
	169	int x509_note_tbs_certificate(void *context, size_t hdrlen,
	170	unsigned char tag,
	171	const void *value, size_t vlen)
	172	{
	173	struct x509_parse_context *ctx = context;
	174
	175	pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
	176	hdrlen, tag, (unsigned long)value - ctx->data, vlen);
	177
	178	ctx->cert->tbs = value - hdrlen;
	179	ctx->cert->tbs_size = vlen + hdrlen;
	180	return 0;
	181	}
	182
	183	/*
	184	* Record the public key algorithm
	185	*/
	186	int x509_note_pkey_algo(void *context, size_t hdrlen,
	187	unsigned char tag,
	188	const void *value, size_t vlen)
	189	{
	190	struct x509_parse_context *ctx = context;
	191
	192	pr_debug("PubKey Algo: %u\n", ctx->last_oid);
	193
	194	switch (ctx->last_oid) {
	195	case OID_md2WithRSAEncryption:
	196	case OID_md3WithRSAEncryption:
	197	default:
	198	return -ENOPKG; /* Unsupported combination */
	199
	200	case OID_md4WithRSAEncryption:
77d0910d	201	ctx->cert->sig->hash_algo = "md4";
dc083565	202	goto rsa_pkcs1;
c26fd69f DH	203
c26fd69f DH	204	case OID_sha1WithRSAEncryption:
77d0910d	205	ctx->cert->sig->hash_algo = "sha1";
dc083565	206	goto rsa_pkcs1;
c26fd69f DH	207
c26fd69f DH	208	case OID_sha256WithRSAEncryption:
77d0910d	209	ctx->cert->sig->hash_algo = "sha256";
dc083565	210	goto rsa_pkcs1;
c26fd69f DH	211
c26fd69f DH	212	case OID_sha384WithRSAEncryption:
77d0910d	213	ctx->cert->sig->hash_algo = "sha384";
dc083565	214	goto rsa_pkcs1;
c26fd69f DH	215
c26fd69f DH	216	case OID_sha512WithRSAEncryption:
77d0910d	217	ctx->cert->sig->hash_algo = "sha512";
dc083565	218	goto rsa_pkcs1;
c26fd69f DH	219
c26fd69f DH	220	case OID_sha224WithRSAEncryption:
77d0910d	221	ctx->cert->sig->hash_algo = "sha224";
dc083565	222	goto rsa_pkcs1;
c26fd69f DH	223	}
c26fd69f DH	224
dc083565 DH	225	rsa_pkcs1:
	226	ctx->cert->sig->pkey_algo = "rsa";
	227	ctx->cert->sig->encoding = "pkcs1";
c26fd69f DH	228	ctx->algo_oid = ctx->last_oid;
	229	return 0;
	230	}
	231
	232	/*
	233	* Note the whereabouts and type of the signature.
	234	*/
	235	int x509_note_signature(void *context, size_t hdrlen,
	236	unsigned char tag,
	237	const void *value, size_t vlen)
	238	{
	239	struct x509_parse_context *ctx = context;
	240
	241	pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
	242
	243	if (ctx->last_oid != ctx->algo_oid) {
	244	pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
	245	ctx->algo_oid, ctx->last_oid);
	246	return -EINVAL;
	247	}
	248
b426beb6 DH	249	ctx->cert->raw_sig = value;
b426beb6 DH	250	ctx->cert->raw_sig_size = vlen;
c26fd69f DH	251	return 0;
	252	}
	253
84aabd46 DH	254	/*
	255	* Note the certificate serial number
	256	*/
	257	int x509_note_serial(void *context, size_t hdrlen,
	258	unsigned char tag,
	259	const void *value, size_t vlen)
	260	{
	261	struct x509_parse_context *ctx = context;
	262	ctx->cert->raw_serial = value;
	263	ctx->cert->raw_serial_size = vlen;
	264	return 0;
	265	}
	266
c26fd69f DH	267	/*
	268	* Note some of the name segments from which we'll fabricate a name.
	269	*/
	270	int x509_extract_name_segment(void *context, size_t hdrlen,
	271	unsigned char tag,
	272	const void *value, size_t vlen)
	273	{
	274	struct x509_parse_context *ctx = context;
	275
	276	switch (ctx->last_oid) {
	277	case OID_commonName:
	278	ctx->cn_size = vlen;
	279	ctx->cn_offset = (unsigned long)value - ctx->data;
	280	break;
	281	case OID_organizationName:
	282	ctx->o_size = vlen;
	283	ctx->o_offset = (unsigned long)value - ctx->data;
	284	break;
	285	case OID_email_address:
	286	ctx->email_size = vlen;
	287	ctx->email_offset = (unsigned long)value - ctx->data;
	288	break;
	289	default:
	290	break;
	291	}
	292
	293	return 0;
	294	}
	295
	296	/*
	297	* Fabricate and save the issuer and subject names
	298	*/
	299	static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
	300	unsigned char tag,
	301	char **_name, size_t vlen)
	302	{
	303	const void name, data = (const void *)ctx->data;
	304	size_t namesize;
	305	char *buffer;
	306
	307	if (*_name)
	308	return -EINVAL;
	309
	310	/* Empty name string if no material */
	311	if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
	312	buffer = kmalloc(1, GFP_KERNEL);
	313	if (!buffer)
	314	return -ENOMEM;
	315	buffer[0] = 0;
	316	goto done;
	317	}
	318
	319	if (ctx->cn_size && ctx->o_size) {
	320	/* Consider combining O and CN, but use only the CN if it is
	321	* prefixed by the O, or a significant portion thereof.
	322	*/
	323	namesize = ctx->cn_size;
	324	name = data + ctx->cn_offset;
	325	if (ctx->cn_size >= ctx->o_size &&
	326	memcmp(data + ctx->cn_offset, data + ctx->o_offset,
	327	ctx->o_size) == 0)
	328	goto single_component;
	329	if (ctx->cn_size >= 7 &&
	330	ctx->o_size >= 7 &&
331	memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
332	goto single_component;
333
334	buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
335	GFP_KERNEL);
336	if (!buffer)
337	return -ENOMEM;
338
339	memcpy(buffer,
340	data + ctx->o_offset, ctx->o_size);
341	buffer[ctx->o_size + 0] = ':';
342	buffer[ctx->o_size + 1] = ' ';
343	memcpy(buffer + ctx->o_size + 2,
344	data + ctx->cn_offset, ctx->cn_size);
345	buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
346	goto done;
347
348	} else if (ctx->cn_size) {
349	namesize = ctx->cn_size;
350	name = data + ctx->cn_offset;
351	} else if (ctx->o_size) {
352	namesize = ctx->o_size;
353	name = data + ctx->o_offset;
354	} else {
355	namesize = ctx->email_size;
356	name = data + ctx->email_offset;
357	}
358
359	single_component:
360	buffer = kmalloc(namesize + 1, GFP_KERNEL);
361	if (!buffer)
362	return -ENOMEM;
363	memcpy(buffer, name, namesize);
364	buffer[namesize] = 0;
365
366	done:
367	*_name = buffer;
368	ctx->cn_size = 0;
369	ctx->o_size = 0;
370	ctx->email_size = 0;
371	return 0;
372	}
373
374	int x509_note_issuer(void *context, size_t hdrlen,
375	unsigned char tag,
376	const void *value, size_t vlen)
377	{
378	struct x509_parse_context *ctx = context;
84aabd46 DH	379	ctx->cert->raw_issuer = value;
84aabd46 DH	380	ctx->cert->raw_issuer_size = vlen;
c26fd69f DH	381	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
	382	}
	383
	384	int x509_note_subject(void *context, size_t hdrlen,
	385	unsigned char tag,
	386	const void *value, size_t vlen)
	387	{
	388	struct x509_parse_context *ctx = context;
84aabd46 DH	389	ctx->cert->raw_subject = value;
84aabd46 DH	390	ctx->cert->raw_subject_size = vlen;
c26fd69f DH	391	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
	392	}
	393
	394	/*
	395	* Extract the data for the public key algorithm
	396	*/
	397	int x509_extract_key_data(void *context, size_t hdrlen,
	398	unsigned char tag,
	399	const void *value, size_t vlen)
	400	{
	401	struct x509_parse_context *ctx = context;
	402
	403	if (ctx->last_oid != OID_rsaEncryption)
	404	return -ENOPKG;
	405
4e8ae72a	406	ctx->cert->pub->pkey_algo = "rsa";
67f7d60b DH	407
67f7d60b DH	408	/* Discard the BIT STRING metadata */
c26fd69f DH	409	ctx->key = value + 1;
	410	ctx->key_size = vlen - 1;
	411	return 0;
	412	}
	413
04b00bdb CYL	414	/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
	415	#define SEQ_TAG_KEYID (ASN1_CONT << 6)
	416
c26fd69f DH	417	/*
	418	* Process certificate extensions that are used to qualify the certificate.
	419	*/
	420	int x509_process_extension(void *context, size_t hdrlen,
	421	unsigned char tag,
	422	const void *value, size_t vlen)
	423	{
	424	struct x509_parse_context *ctx = context;
46963b77	425	struct asymmetric_key_id *kid;
c26fd69f	426	const unsigned char *v = value;
c26fd69f DH	427
	428	pr_debug("Extension: %u\n", ctx->last_oid);
	429
	430	if (ctx->last_oid == OID_subjectKeyIdentifier) {
	431	/* Get hold of the key fingerprint */
46963b77	432	if (ctx->cert->skid \|\| vlen < 3)
c26fd69f DH	433	return -EBADMSG;
	434	if (v[0] != ASN1_OTS \|\| v[1] != vlen - 2)
	435	return -EBADMSG;
	436	v += 2;
	437	vlen -= 2;
	438
dd2f6c44 DH	439	ctx->cert->raw_skid_size = vlen;
dd2f6c44 DH	440	ctx->cert->raw_skid = v;
a4c6e57f	441	kid = asymmetric_key_generate_id(v, vlen, "", 0);
46963b77 DH	442	if (IS_ERR(kid))
	443	return PTR_ERR(kid);
	444	ctx->cert->skid = kid;
	445	pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
c26fd69f DH	446	return 0;
	447	}
	448
	449	if (ctx->last_oid == OID_authorityKeyIdentifier) {
	450	/* Get hold of the CA key fingerprint */
b92e6570 DH	451	ctx->raw_akid = v;
b92e6570 DH	452	ctx->raw_akid_size = vlen;
c26fd69f DH	453	return 0;
	454	}
	455
	456	return 0;
	457	}
	458
fd19a3d1 DH	459	/**
	460	* x509_decode_time - Decode an X.509 time ASN.1 object
	461	* @_t: The time to fill in
	462	* @hdrlen: The length of the object header
	463	* @tag: The object tag
	464	* @value: The object value
	465	* @vlen: The size of the object value
	466	*
	467	* Decode an ASN.1 universal time or generalised time field into a struct the
	468	* kernel can handle and check it for validity. The time is decoded thus:
	469	*
	470	* [RFC5280 §4.1.2.5]
	471	* CAs conforming to this profile MUST always encode certificate validity
	472	* dates through the year 2049 as UTCTime; certificate validity dates in
	473	* 2050 or later MUST be encoded as GeneralizedTime. Conforming
	474	* applications MUST be able to process validity dates that are encoded in
	475	* either UTCTime or GeneralizedTime.
c26fd69f	476	*/
fd19a3d1 DH	477	int x509_decode_time(time64_t *_t, size_t hdrlen,
	478	unsigned char tag,
	479	const unsigned char *value, size_t vlen)
c26fd69f	480	{
ac4cbedf	481	static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
fd19a3d1	482	31, 31, 30, 31, 30, 31 };
c26fd69f	483	const unsigned char *p = value;
fd19a3d1	484	unsigned year, mon, day, hour, min, sec, mon_len;
c26fd69f	485
fd19a3d1	486	#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
c26fd69f DH	487	#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
	488
	489	if (tag == ASN1_UNITIM) {
	490	/* UTCTime: YYMMDDHHMMSSZ */
	491	if (vlen != 13)
	492	goto unsupported_time;
fd19a3d1 DH	493	year = DD2bin(p);
	494	if (year >= 50)
	495	year += 1900;
c26fd69f	496	else
fd19a3d1	497	year += 2000;
c26fd69f DH	498	} else if (tag == ASN1_GENTIM) {
	499	/* GenTime: YYYYMMDDHHMMSSZ */
	500	if (vlen != 15)
	501	goto unsupported_time;
fd19a3d1 DH	502	year = DD2bin(p) * 100 + DD2bin(p);
	503	if (year >= 1950 && year <= 2049)
	504	goto invalid_time;
c26fd69f DH	505	} else {
	506	goto unsupported_time;
	507	}
	508
fd19a3d1 DH	509	mon = DD2bin(p);
	510	day = DD2bin(p);
	511	hour = DD2bin(p);
	512	min = DD2bin(p);
	513	sec = DD2bin(p);
c26fd69f DH	514
	515	if (*p != 'Z')
	516	goto unsupported_time;
	517
cc25b994 DH	518	if (year < 1970 \|\|
	519	mon < 1 \|\| mon > 12)
	520	goto invalid_time;
	521
	522	mon_len = month_lengths[mon - 1];
fd19a3d1 DH	523	if (mon == 2) {
	524	if (year % 4 == 0) {
	525	mon_len = 29;
	526	if (year % 100 == 0) {
ac4cbedf DH	527	mon_len = 28;
	528	if (year % 400 == 0)
	529	mon_len = 29;
fd19a3d1 DH	530	}
	531	}
	532	}
	533
cc25b994	534	if (day < 1 \|\| day > mon_len \|\|
7650cb80	535	hour > 24 \|\| /* ISO 8601 permits 24:00:00 as midnight tomorrow */
4dd17c9c	536	min > 59 \|\|
da02559c	537	sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
fd19a3d1	538	goto invalid_time;
cc25b994	539
fd19a3d1	540	*_t = mktime64(year, mon, day, hour, min, sec);
c26fd69f DH	541	return 0;
	542
	543	unsupported_time:
fd19a3d1 DH	544	pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
	545	tag, (int)vlen, value);
	546	return -EBADMSG;
	547	invalid_time:
	548	pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
	549	tag, (int)vlen, value);
c26fd69f DH	550	return -EBADMSG;
c26fd69f DH	551	}
fd19a3d1	552	EXPORT_SYMBOL_GPL(x509_decode_time);
c26fd69f DH	553
	554	int x509_note_not_before(void *context, size_t hdrlen,
	555	unsigned char tag,
	556	const void *value, size_t vlen)
	557	{
	558	struct x509_parse_context *ctx = context;
fd19a3d1	559	return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
c26fd69f DH	560	}
	561
	562	int x509_note_not_after(void *context, size_t hdrlen,
	563	unsigned char tag,
	564	const void *value, size_t vlen)
	565	{
	566	struct x509_parse_context *ctx = context;
fd19a3d1	567	return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
c26fd69f	568	}
b92e6570 DH	569
	570	/*
	571	* Note a key identifier-based AuthorityKeyIdentifier
	572	*/
	573	int x509_akid_note_kid(void *context, size_t hdrlen,
	574	unsigned char tag,
	575	const void *value, size_t vlen)
	576	{
	577	struct x509_parse_context *ctx = context;
	578	struct asymmetric_key_id *kid;
	579
	580	pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
	581
77d0910d	582	if (ctx->cert->sig->auth_ids[1])
b92e6570 DH	583	return 0;
b92e6570 DH	584
a4c6e57f	585	kid = asymmetric_key_generate_id(value, vlen, "", 0);
b92e6570 DH	586	if (IS_ERR(kid))
	587	return PTR_ERR(kid);
	588	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
77d0910d	589	ctx->cert->sig->auth_ids[1] = kid;
b92e6570 DH	590	return 0;
	591	}
	592
	593	/*
	594	* Note a directoryName in an AuthorityKeyIdentifier
	595	*/
	596	int x509_akid_note_name(void *context, size_t hdrlen,
	597	unsigned char tag,
	598	const void *value, size_t vlen)
	599	{
	600	struct x509_parse_context *ctx = context;
	601
	602	pr_debug("AKID: name: %*phN\n", (int)vlen, value);
	603
	604	ctx->akid_raw_issuer = value;
	605	ctx->akid_raw_issuer_size = vlen;
	606	return 0;
	607	}
	608
	609	/*
	610	* Note a serial number in an AuthorityKeyIdentifier
	611	*/
	612	int x509_akid_note_serial(void *context, size_t hdrlen,
	613	unsigned char tag,
	614	const void *value, size_t vlen)
	615	{
	616	struct x509_parse_context *ctx = context;
	617	struct asymmetric_key_id *kid;
	618
	619	pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
	620
77d0910d	621	if (!ctx->akid_raw_issuer \|\| ctx->cert->sig->auth_ids[0])
b92e6570 DH	622	return 0;
	623
	624	kid = asymmetric_key_generate_id(value,
	625	vlen,
	626	ctx->akid_raw_issuer,
	627	ctx->akid_raw_issuer_size);
	628	if (IS_ERR(kid))
	629	return PTR_ERR(kid);
	630
	631	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
77d0910d	632	ctx->cert->sig->auth_ids[0] = kid;
b92e6570 DH	633	return 0;
b92e6570 DH	634	}