[mirror_ubuntu-artful-kernel.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;
		}
	}

	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;

	/* 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(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";
		ctx->cert->sig->pkey_algo = "rsa";
		break;

	case OID_sha1WithRSAEncryption:
		ctx->cert->sig->hash_algo = "sha1";
		ctx->cert->sig->pkey_algo = "rsa";
		break;

	case OID_sha256WithRSAEncryption:
		ctx->cert->sig->hash_algo = "sha256";
		ctx->cert->sig->pkey_algo = "rsa";
		break;

	case OID_sha384WithRSAEncryption:
		ctx->cert->sig->hash_algo = "sha384";
		ctx->cert->sig->pkey_algo = "rsa";
		break;

	case OID_sha512WithRSAEncryption:
		ctx->cert->sig->hash_algo = "sha512";
		ctx->cert->sig->pkey_algo = "rsa";
		break;

	case OID_sha224WithRSAEncryption:
		ctx->cert->sig->hash_algo = "sha224";
		ctx->cert->sig->pkey_algo = "rsa";
		break;
	}

	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
4e880168	105	ret = -ENOMEM;
db6c43bd TS	106	cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
db6c43bd TS	107	if (!cert->pub->key)
c26fd69f DH	108	goto error_decode;
c26fd69f DH	109
db6c43bd TS	110	cert->pub->keylen = ctx->key_size;
db6c43bd TS	111
6c2dc5ae DH	112	/* Grab the signature bits */
	113	ret = x509_get_sig_params(cert);
	114	if (ret < 0)
	115	goto error_decode;
	116
46963b77 DH	117	/* Generate cert issuer + serial number key ID */
	118	kid = asymmetric_key_generate_id(cert->raw_serial,
	119	cert->raw_serial_size,
	120	cert->raw_issuer,
	121	cert->raw_issuer_size);
	122	if (IS_ERR(kid)) {
	123	ret = PTR_ERR(kid);
	124	goto error_decode;
	125	}
	126	cert->id = kid;
	127
6c2dc5ae DH	128	/* Detect self-signed certificates */
	129	ret = x509_check_for_self_signed(cert);
	130	if (ret < 0)
	131	goto error_decode;
	132
c26fd69f DH	133	kfree(ctx);
	134	return cert;
	135
	136	error_decode:
	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 DH	201	ctx->cert->sig->hash_algo = "md4";
77d0910d DH	202	ctx->cert->sig->pkey_algo = "rsa";
c26fd69f DH	203	break;
	204
	205	case OID_sha1WithRSAEncryption:
77d0910d DH	206	ctx->cert->sig->hash_algo = "sha1";
77d0910d DH	207	ctx->cert->sig->pkey_algo = "rsa";
c26fd69f DH	208	break;
	209
	210	case OID_sha256WithRSAEncryption:
77d0910d DH	211	ctx->cert->sig->hash_algo = "sha256";
77d0910d DH	212	ctx->cert->sig->pkey_algo = "rsa";
c26fd69f DH	213	break;
	214
	215	case OID_sha384WithRSAEncryption:
77d0910d DH	216	ctx->cert->sig->hash_algo = "sha384";
77d0910d DH	217	ctx->cert->sig->pkey_algo = "rsa";
c26fd69f DH	218	break;
	219
	220	case OID_sha512WithRSAEncryption:
77d0910d DH	221	ctx->cert->sig->hash_algo = "sha512";
77d0910d DH	222	ctx->cert->sig->pkey_algo = "rsa";
c26fd69f DH	223	break;
	224
	225	case OID_sha224WithRSAEncryption:
77d0910d DH	226	ctx->cert->sig->hash_algo = "sha224";
77d0910d DH	227	ctx->cert->sig->pkey_algo = "rsa";
c26fd69f DH	228	break;
	229	}
	230
	231	ctx->algo_oid = ctx->last_oid;
	232	return 0;
	233	}
	234
	235	/*
	236	* Note the whereabouts and type of the signature.
	237	*/
	238	int x509_note_signature(void *context, size_t hdrlen,
	239	unsigned char tag,
	240	const void *value, size_t vlen)
	241	{
	242	struct x509_parse_context *ctx = context;
	243
	244	pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
	245
	246	if (ctx->last_oid != ctx->algo_oid) {
	247	pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
	248	ctx->algo_oid, ctx->last_oid);
	249	return -EINVAL;
	250	}
	251
b426beb6 DH	252	ctx->cert->raw_sig = value;
b426beb6 DH	253	ctx->cert->raw_sig_size = vlen;
c26fd69f DH	254	return 0;
	255	}
	256
84aabd46 DH	257	/*
	258	* Note the certificate serial number
	259	*/
	260	int x509_note_serial(void *context, size_t hdrlen,
	261	unsigned char tag,
	262	const void *value, size_t vlen)
	263	{
	264	struct x509_parse_context *ctx = context;
	265	ctx->cert->raw_serial = value;
	266	ctx->cert->raw_serial_size = vlen;
	267	return 0;
	268	}
	269
c26fd69f DH	270	/*
	271	* Note some of the name segments from which we'll fabricate a name.
	272	*/
	273	int x509_extract_name_segment(void *context, size_t hdrlen,
	274	unsigned char tag,
	275	const void *value, size_t vlen)
	276	{
	277	struct x509_parse_context *ctx = context;
	278
	279	switch (ctx->last_oid) {
	280	case OID_commonName:
	281	ctx->cn_size = vlen;
	282	ctx->cn_offset = (unsigned long)value - ctx->data;
	283	break;
	284	case OID_organizationName:
	285	ctx->o_size = vlen;
	286	ctx->o_offset = (unsigned long)value - ctx->data;
	287	break;
	288	case OID_email_address:
	289	ctx->email_size = vlen;
	290	ctx->email_offset = (unsigned long)value - ctx->data;
	291	break;
	292	default:
	293	break;
	294	}
	295
	296	return 0;
	297	}
	298
	299	/*
	300	* Fabricate and save the issuer and subject names
	301	*/
	302	static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
	303	unsigned char tag,
	304	char **_name, size_t vlen)
	305	{
	306	const void name, data = (const void *)ctx->data;
	307	size_t namesize;
	308	char *buffer;
	309
	310	if (*_name)
	311	return -EINVAL;
	312
	313	/* Empty name string if no material */
	314	if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
	315	buffer = kmalloc(1, GFP_KERNEL);
	316	if (!buffer)
	317	return -ENOMEM;
	318	buffer[0] = 0;
	319	goto done;
	320	}
	321
	322	if (ctx->cn_size && ctx->o_size) {
	323	/* Consider combining O and CN, but use only the CN if it is
	324	* prefixed by the O, or a significant portion thereof.
	325	*/
	326	namesize = ctx->cn_size;
	327	name = data + ctx->cn_offset;
	328	if (ctx->cn_size >= ctx->o_size &&
	329	memcmp(data + ctx->cn_offset, data + ctx->o_offset,
	330	ctx->o_size) == 0)
	331	goto single_component;
	332	if (ctx->cn_size >= 7 &&
	333	ctx->o_size >= 7 &&
334	memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
335	goto single_component;
336
337	buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
338	GFP_KERNEL);
339	if (!buffer)
340	return -ENOMEM;
341
342	memcpy(buffer,
343	data + ctx->o_offset, ctx->o_size);
344	buffer[ctx->o_size + 0] = ':';
345	buffer[ctx->o_size + 1] = ' ';
346	memcpy(buffer + ctx->o_size + 2,
347	data + ctx->cn_offset, ctx->cn_size);
348	buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
349	goto done;
350
351	} else if (ctx->cn_size) {
352	namesize = ctx->cn_size;
353	name = data + ctx->cn_offset;
354	} else if (ctx->o_size) {
355	namesize = ctx->o_size;
356	name = data + ctx->o_offset;
357	} else {
358	namesize = ctx->email_size;
359	name = data + ctx->email_offset;
360	}
361
362	single_component:
363	buffer = kmalloc(namesize + 1, GFP_KERNEL);
364	if (!buffer)
365	return -ENOMEM;
366	memcpy(buffer, name, namesize);
367	buffer[namesize] = 0;
368
369	done:
370	*_name = buffer;
371	ctx->cn_size = 0;
372	ctx->o_size = 0;
373	ctx->email_size = 0;
374	return 0;
375	}
376
377	int x509_note_issuer(void *context, size_t hdrlen,
378	unsigned char tag,
379	const void *value, size_t vlen)
380	{
381	struct x509_parse_context *ctx = context;
84aabd46 DH	382	ctx->cert->raw_issuer = value;
84aabd46 DH	383	ctx->cert->raw_issuer_size = vlen;
c26fd69f DH	384	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
	385	}
	386
	387	int x509_note_subject(void *context, size_t hdrlen,
	388	unsigned char tag,
	389	const void *value, size_t vlen)
	390	{
	391	struct x509_parse_context *ctx = context;
84aabd46 DH	392	ctx->cert->raw_subject = value;
84aabd46 DH	393	ctx->cert->raw_subject_size = vlen;
c26fd69f DH	394	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
	395	}
	396
	397	/*
	398	* Extract the data for the public key algorithm
	399	*/
	400	int x509_extract_key_data(void *context, size_t hdrlen,
	401	unsigned char tag,
	402	const void *value, size_t vlen)
	403	{
	404	struct x509_parse_context *ctx = context;
	405
	406	if (ctx->last_oid != OID_rsaEncryption)
	407	return -ENOPKG;
	408
4e8ae72a	409	ctx->cert->pub->pkey_algo = "rsa";
67f7d60b DH	410
67f7d60b DH	411	/* Discard the BIT STRING metadata */
c26fd69f DH	412	ctx->key = value + 1;
	413	ctx->key_size = vlen - 1;
	414	return 0;
	415	}
	416
04b00bdb CYL	417	/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
	418	#define SEQ_TAG_KEYID (ASN1_CONT << 6)
	419
c26fd69f DH	420	/*
	421	* Process certificate extensions that are used to qualify the certificate.
	422	*/
	423	int x509_process_extension(void *context, size_t hdrlen,
	424	unsigned char tag,
	425	const void *value, size_t vlen)
	426	{
	427	struct x509_parse_context *ctx = context;
46963b77	428	struct asymmetric_key_id *kid;
c26fd69f	429	const unsigned char *v = value;
c26fd69f DH	430
	431	pr_debug("Extension: %u\n", ctx->last_oid);
	432
	433	if (ctx->last_oid == OID_subjectKeyIdentifier) {
	434	/* Get hold of the key fingerprint */
46963b77	435	if (ctx->cert->skid \|\| vlen < 3)
c26fd69f DH	436	return -EBADMSG;
	437	if (v[0] != ASN1_OTS \|\| v[1] != vlen - 2)
	438	return -EBADMSG;
	439	v += 2;
	440	vlen -= 2;
	441
dd2f6c44 DH	442	ctx->cert->raw_skid_size = vlen;
dd2f6c44 DH	443	ctx->cert->raw_skid = v;
a4c6e57f	444	kid = asymmetric_key_generate_id(v, vlen, "", 0);
46963b77 DH	445	if (IS_ERR(kid))
	446	return PTR_ERR(kid);
	447	ctx->cert->skid = kid;
	448	pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
c26fd69f DH	449	return 0;
	450	}
	451
	452	if (ctx->last_oid == OID_authorityKeyIdentifier) {
	453	/* Get hold of the CA key fingerprint */
b92e6570 DH	454	ctx->raw_akid = v;
b92e6570 DH	455	ctx->raw_akid_size = vlen;
c26fd69f DH	456	return 0;
	457	}
	458
	459	return 0;
	460	}
	461
fd19a3d1 DH	462	/**
	463	* x509_decode_time - Decode an X.509 time ASN.1 object
	464	* @_t: The time to fill in
	465	* @hdrlen: The length of the object header
	466	* @tag: The object tag
	467	* @value: The object value
	468	* @vlen: The size of the object value
	469	*
	470	* Decode an ASN.1 universal time or generalised time field into a struct the
	471	* kernel can handle and check it for validity. The time is decoded thus:
	472	*
	473	* [RFC5280 §4.1.2.5]
	474	* CAs conforming to this profile MUST always encode certificate validity
	475	* dates through the year 2049 as UTCTime; certificate validity dates in
	476	* 2050 or later MUST be encoded as GeneralizedTime. Conforming
	477	* applications MUST be able to process validity dates that are encoded in
	478	* either UTCTime or GeneralizedTime.
c26fd69f	479	*/
fd19a3d1 DH	480	int x509_decode_time(time64_t *_t, size_t hdrlen,
	481	unsigned char tag,
	482	const unsigned char *value, size_t vlen)
c26fd69f	483	{
ac4cbedf	484	static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
fd19a3d1	485	31, 31, 30, 31, 30, 31 };
c26fd69f	486	const unsigned char *p = value;
fd19a3d1	487	unsigned year, mon, day, hour, min, sec, mon_len;
c26fd69f	488
fd19a3d1	489	#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
c26fd69f DH	490	#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
	491
	492	if (tag == ASN1_UNITIM) {
	493	/* UTCTime: YYMMDDHHMMSSZ */
	494	if (vlen != 13)
	495	goto unsupported_time;
fd19a3d1 DH	496	year = DD2bin(p);
	497	if (year >= 50)
	498	year += 1900;
c26fd69f	499	else
fd19a3d1	500	year += 2000;
c26fd69f DH	501	} else if (tag == ASN1_GENTIM) {
	502	/* GenTime: YYYYMMDDHHMMSSZ */
	503	if (vlen != 15)
	504	goto unsupported_time;
fd19a3d1 DH	505	year = DD2bin(p) * 100 + DD2bin(p);
	506	if (year >= 1950 && year <= 2049)
	507	goto invalid_time;
c26fd69f DH	508	} else {
	509	goto unsupported_time;
	510	}
	511
fd19a3d1 DH	512	mon = DD2bin(p);
	513	day = DD2bin(p);
	514	hour = DD2bin(p);
	515	min = DD2bin(p);
	516	sec = DD2bin(p);
c26fd69f DH	517
	518	if (*p != 'Z')
	519	goto unsupported_time;
	520
cc25b994 DH	521	if (year < 1970 \|\|
	522	mon < 1 \|\| mon > 12)
	523	goto invalid_time;
	524
	525	mon_len = month_lengths[mon - 1];
fd19a3d1 DH	526	if (mon == 2) {
	527	if (year % 4 == 0) {
	528	mon_len = 29;
	529	if (year % 100 == 0) {
ac4cbedf DH	530	mon_len = 28;
	531	if (year % 400 == 0)
	532	mon_len = 29;
fd19a3d1 DH	533	}
	534	}
	535	}
	536
cc25b994	537	if (day < 1 \|\| day > mon_len \|\|
7650cb80	538	hour > 24 \|\| /* ISO 8601 permits 24:00:00 as midnight tomorrow */
4dd17c9c	539	min > 59 \|\|
da02559c	540	sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
fd19a3d1	541	goto invalid_time;
cc25b994	542
fd19a3d1	543	*_t = mktime64(year, mon, day, hour, min, sec);
c26fd69f DH	544	return 0;
	545
	546	unsupported_time:
fd19a3d1 DH	547	pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
	548	tag, (int)vlen, value);
	549	return -EBADMSG;
	550	invalid_time:
	551	pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
	552	tag, (int)vlen, value);
c26fd69f DH	553	return -EBADMSG;
c26fd69f DH	554	}
fd19a3d1	555	EXPORT_SYMBOL_GPL(x509_decode_time);
c26fd69f DH	556
	557	int x509_note_not_before(void *context, size_t hdrlen,
	558	unsigned char tag,
	559	const void *value, size_t vlen)
	560	{
	561	struct x509_parse_context *ctx = context;
fd19a3d1	562	return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
c26fd69f DH	563	}
	564
	565	int x509_note_not_after(void *context, size_t hdrlen,
	566	unsigned char tag,
	567	const void *value, size_t vlen)
	568	{
	569	struct x509_parse_context *ctx = context;
fd19a3d1	570	return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
c26fd69f	571	}
b92e6570 DH	572
	573	/*
	574	* Note a key identifier-based AuthorityKeyIdentifier
	575	*/
	576	int x509_akid_note_kid(void *context, size_t hdrlen,
	577	unsigned char tag,
	578	const void *value, size_t vlen)
	579	{
	580	struct x509_parse_context *ctx = context;
	581	struct asymmetric_key_id *kid;
	582
	583	pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
	584
77d0910d	585	if (ctx->cert->sig->auth_ids[1])
b92e6570 DH	586	return 0;
b92e6570 DH	587
a4c6e57f	588	kid = asymmetric_key_generate_id(value, vlen, "", 0);
b92e6570 DH	589	if (IS_ERR(kid))
	590	return PTR_ERR(kid);
	591	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
77d0910d	592	ctx->cert->sig->auth_ids[1] = kid;
b92e6570 DH	593	return 0;
	594	}
	595
	596	/*
	597	* Note a directoryName in an AuthorityKeyIdentifier
	598	*/
	599	int x509_akid_note_name(void *context, size_t hdrlen,
	600	unsigned char tag,
	601	const void *value, size_t vlen)
	602	{
	603	struct x509_parse_context *ctx = context;
	604
	605	pr_debug("AKID: name: %*phN\n", (int)vlen, value);
	606
	607	ctx->akid_raw_issuer = value;
	608	ctx->akid_raw_issuer_size = vlen;
	609	return 0;
	610	}
	611
	612	/*
	613	* Note a serial number in an AuthorityKeyIdentifier
	614	*/
	615	int x509_akid_note_serial(void *context, size_t hdrlen,
	616	unsigned char tag,
	617	const void *value, size_t vlen)
	618	{
	619	struct x509_parse_context *ctx = context;
	620	struct asymmetric_key_id *kid;
	621
	622	pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
	623
77d0910d	624	if (!ctx->akid_raw_issuer \|\| ctx->cert->sig->auth_ids[0])
b92e6570 DH	625	return 0;
	626
	627	kid = asymmetric_key_generate_id(value,
	628	vlen,
	629	ctx->akid_raw_issuer,
	630	ctx->akid_raw_issuer_size);
	631	if (IS_ERR(kid))
	632	return PTR_ERR(kid);
	633
	634	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
77d0910d	635	ctx->cert->sig->auth_ids[0] = kid;
b92e6570 DH	636	return 0;
b92e6570 DH	637	}