[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 ([email protected])
 *
 * 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_destroy(cert->pub);
		kfree(cert->issuer);
		kfree(cert->subject);
		kfree(cert->id);
		kfree(cert->skid);
		kfree(cert->akid_id);
		kfree(cert->akid_skid);
		kfree(cert->sig.digest);
		kfree(cert->sig.s);
		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;
	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;

	/* 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;

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