[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 "public_key.h"
#include "x509_parser.h"
#include "x509-asn1.h"
#include "x509_rsakey-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 */
};

/*
 * 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->authority);
		kfree(cert->sig.digest);
		mpi_free(cert->sig.rsa.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 public key */
	ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx,
			       ctx->key, ctx->key_size);
	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;

	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.pkey_hash_algo = HASH_ALGO_MD5;
		ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
		break;

	case OID_sha1WithRSAEncryption:
		ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA1;
		ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
		break;

	case OID_sha256WithRSAEncryption:
		ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA256;
		ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
		break;

	case OID_sha384WithRSAEncryption:
		ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA384;
		ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
		break;

	case OID_sha512WithRSAEncryption:
		ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA512;
		ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
		break;

	case OID_sha224WithRSAEncryption:
		ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA224;
		ctx->cert->sig.pkey_algo = 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 = PKEY_ALGO_RSA;

	/* Discard the BIT STRING metadata */
	ctx->key = value + 1;
	ctx->key_size = vlen - 1;
	return 0;
}

/*
 * Extract a RSA public key value
 */
int rsa_extract_mpi(void *context, size_t hdrlen,
		    unsigned char tag,
		    const void *value, size_t vlen)
{
	struct x509_parse_context *ctx = context;
	MPI mpi;

	if (ctx->nr_mpi >= ARRAY_SIZE(ctx->cert->pub->mpi)) {
		pr_err("Too many public key MPIs in certificate\n");
		return -EBADMSG;
	}

	mpi = mpi_read_raw_data(value, vlen);
	if (!mpi)
		return -ENOMEM;

	ctx->cert->pub->mpi[ctx->nr_mpi++] = mpi;
	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;
	int i;

	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(ctx->cert->raw_subject,
						 ctx->cert->raw_subject_size,
						 v, vlen);
		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 */
		if (ctx->cert->authority || vlen < 5)
			return -EBADMSG;

		/* Authority Key Identifier must be a Constructed SEQUENCE */
		if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)))
			return -EBADMSG;

		/* Authority Key Identifier is not indefinite length */
		if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
			return -EBADMSG;

		if (vlen < ASN1_INDEFINITE_LENGTH) {
			/* Short Form length */
			if (v[1] != vlen - 2 ||
			    v[2] != SEQ_TAG_KEYID ||
			    v[3] > vlen - 4)
				return -EBADMSG;

			vlen = v[3];
			v += 4;
		} else {
			/* Long Form length */
			size_t seq_len = 0;
			size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;

			if (sub > 2)
				return -EBADMSG;

			/* calculate the length from subsequent octets */
			v += 2;
			for (i = 0; i < sub; i++) {
				seq_len <<= 8;
				seq_len |= v[i];
			}

			if (seq_len != vlen - 2 - sub ||
			    v[sub] != SEQ_TAG_KEYID ||
			    v[sub + 1] > vlen - 4 - sub)
				return -EBADMSG;

			vlen = v[sub + 1];
			v += (sub + 2);
		}

		kid = asymmetric_key_generate_id(ctx->cert->raw_issuer,
						 ctx->cert->raw_issuer_size,
						 v, vlen);
		if (IS_ERR(kid))
			return PTR_ERR(kid);
		pr_debug("authkeyid %*phN\n", kid->len, kid->data);
		ctx->cert->authority = kid;
		return 0;
	}

	return 0;
}

/*
 * Record a certificate time.
 */
static int x509_note_time(struct tm *tm,  size_t hdrlen,
			  unsigned char tag,
			  const unsigned char *value, size_t vlen)
{
	const unsigned char *p = value;

#define dec2bin(X) ((X) - '0')
#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;
		tm->tm_year = DD2bin(p);
		if (tm->tm_year >= 50)
			tm->tm_year += 1900;
		else
			tm->tm_year += 2000;
	} else if (tag == ASN1_GENTIM) {
		/* GenTime: YYYYMMDDHHMMSSZ */
		if (vlen != 15)
			goto unsupported_time;
		tm->tm_year = DD2bin(p) * 100 + DD2bin(p);
	} else {
		goto unsupported_time;
	}

	tm->tm_year -= 1900;
	tm->tm_mon  = DD2bin(p) - 1;
	tm->tm_mday = DD2bin(p);
	tm->tm_hour = DD2bin(p);
	tm->tm_min  = DD2bin(p);
	tm->tm_sec  = DD2bin(p);

	if (*p != 'Z')
		goto unsupported_time;

	return 0;

unsupported_time:
	pr_debug("Got unsupported time [tag %02x]: '%*.*s'\n",
		 tag, (int)vlen, (int)vlen, value);
	return -EBADMSG;
}

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_note_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_note_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
}
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>
	18	#include "public_key.h"
	19	#include "x509_parser.h"
	20	#include "x509-asn1.h"
	21	#include "x509_rsakey-asn1.h"
	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 */
	38	};
	39
	40	/*
	41	* Free an X.509 certificate
	42	*/
	43	void x509_free_certificate(struct x509_certificate *cert)
	44	{
	45	if (cert) {
	46	public_key_destroy(cert->pub);
	47	kfree(cert->issuer);
	48	kfree(cert->subject);
46963b77 DH	49	kfree(cert->id);
46963b77 DH	50	kfree(cert->skid);
c26fd69f	51	kfree(cert->authority);
b426beb6 DH	52	kfree(cert->sig.digest);
b426beb6 DH	53	mpi_free(cert->sig.rsa.s);
c26fd69f DH	54	kfree(cert);
	55	}
	56	}
ace0107a	57	EXPORT_SYMBOL_GPL(x509_free_certificate);
c26fd69f DH	58
	59	/*
	60	* Parse an X.509 certificate
	61	*/
	62	struct x509_certificate x509_cert_parse(const void data, size_t datalen)
	63	{
	64	struct x509_certificate *cert;
	65	struct x509_parse_context *ctx;
46963b77	66	struct asymmetric_key_id *kid;
c26fd69f DH	67	long ret;
	68
	69	ret = -ENOMEM;
	70	cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
	71	if (!cert)
	72	goto error_no_cert;
	73	cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
	74	if (!cert->pub)
	75	goto error_no_ctx;
	76	ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
	77	if (!ctx)
	78	goto error_no_ctx;
	79
	80	ctx->cert = cert;
	81	ctx->data = (unsigned long)data;
	82
	83	/* Attempt to decode the certificate */
	84	ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
	85	if (ret < 0)
	86	goto error_decode;
	87
	88	/* Decode the public key */
	89	ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx,
	90	ctx->key, ctx->key_size);
	91	if (ret < 0)
	92	goto error_decode;
	93
46963b77 DH	94	/* Generate cert issuer + serial number key ID */
	95	kid = asymmetric_key_generate_id(cert->raw_serial,
	96	cert->raw_serial_size,
	97	cert->raw_issuer,
	98	cert->raw_issuer_size);
	99	if (IS_ERR(kid)) {
	100	ret = PTR_ERR(kid);
	101	goto error_decode;
	102	}
	103	cert->id = kid;
	104
c26fd69f DH	105	kfree(ctx);
	106	return cert;
	107
	108	error_decode:
	109	kfree(ctx);
	110	error_no_ctx:
	111	x509_free_certificate(cert);
	112	error_no_cert:
	113	return ERR_PTR(ret);
	114	}
ace0107a	115	EXPORT_SYMBOL_GPL(x509_cert_parse);
c26fd69f DH	116
	117	/*
	118	* Note an OID when we find one for later processing when we know how
	119	* to interpret it.
	120	*/
	121	int x509_note_OID(void *context, size_t hdrlen,
	122	unsigned char tag,
	123	const void *value, size_t vlen)
	124	{
	125	struct x509_parse_context *ctx = context;
	126
	127	ctx->last_oid = look_up_OID(value, vlen);
	128	if (ctx->last_oid == OID__NR) {
	129	char buffer[50];
	130	sprint_oid(value, vlen, buffer, sizeof(buffer));
cf75446e	131	pr_debug("Unknown OID: [%lu] %s\n",
c26fd69f DH	132	(unsigned long)value - ctx->data, buffer);
	133	}
	134	return 0;
	135	}
	136
	137	/*
	138	* Save the position of the TBS data so that we can check the signature over it
	139	* later.
	140	*/
	141	int x509_note_tbs_certificate(void *context, size_t hdrlen,
	142	unsigned char tag,
	143	const void *value, size_t vlen)
	144	{
	145	struct x509_parse_context *ctx = context;
	146
	147	pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
	148	hdrlen, tag, (unsigned long)value - ctx->data, vlen);
	149
	150	ctx->cert->tbs = value - hdrlen;
	151	ctx->cert->tbs_size = vlen + hdrlen;
	152	return 0;
	153	}
	154
	155	/*
	156	* Record the public key algorithm
	157	*/
	158	int x509_note_pkey_algo(void *context, size_t hdrlen,
	159	unsigned char tag,
	160	const void *value, size_t vlen)
	161	{
	162	struct x509_parse_context *ctx = context;
	163
	164	pr_debug("PubKey Algo: %u\n", ctx->last_oid);
	165
	166	switch (ctx->last_oid) {
	167	case OID_md2WithRSAEncryption:
	168	case OID_md3WithRSAEncryption:
	169	default:
	170	return -ENOPKG; /* Unsupported combination */
	171
	172	case OID_md4WithRSAEncryption:
3fe78ca2	173	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_MD5;
b426beb6	174	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	175	break;
	176
	177	case OID_sha1WithRSAEncryption:
3fe78ca2	178	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA1;
b426beb6	179	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	180	break;
	181
	182	case OID_sha256WithRSAEncryption:
3fe78ca2	183	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA256;
b426beb6	184	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	185	break;
	186
	187	case OID_sha384WithRSAEncryption:
3fe78ca2	188	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA384;
b426beb6	189	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	190	break;
	191
	192	case OID_sha512WithRSAEncryption:
3fe78ca2	193	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA512;
b426beb6	194	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	195	break;
	196
	197	case OID_sha224WithRSAEncryption:
3fe78ca2	198	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA224;
b426beb6	199	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	200	break;
	201	}
	202
	203	ctx->algo_oid = ctx->last_oid;
	204	return 0;
	205	}
	206
	207	/*
	208	* Note the whereabouts and type of the signature.
	209	*/
	210	int x509_note_signature(void *context, size_t hdrlen,
	211	unsigned char tag,
	212	const void *value, size_t vlen)
	213	{
	214	struct x509_parse_context *ctx = context;
	215
	216	pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
	217
	218	if (ctx->last_oid != ctx->algo_oid) {
	219	pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
	220	ctx->algo_oid, ctx->last_oid);
	221	return -EINVAL;
	222	}
	223
b426beb6 DH	224	ctx->cert->raw_sig = value;
b426beb6 DH	225	ctx->cert->raw_sig_size = vlen;
c26fd69f DH	226	return 0;
	227	}
	228
84aabd46 DH	229	/*
	230	* Note the certificate serial number
	231	*/
	232	int x509_note_serial(void *context, size_t hdrlen,
	233	unsigned char tag,
	234	const void *value, size_t vlen)
	235	{
	236	struct x509_parse_context *ctx = context;
	237	ctx->cert->raw_serial = value;
	238	ctx->cert->raw_serial_size = vlen;
	239	return 0;
	240	}
	241
c26fd69f DH	242	/*
	243	* Note some of the name segments from which we'll fabricate a name.
	244	*/
	245	int x509_extract_name_segment(void *context, size_t hdrlen,
	246	unsigned char tag,
	247	const void *value, size_t vlen)
	248	{
	249	struct x509_parse_context *ctx = context;
	250
	251	switch (ctx->last_oid) {
	252	case OID_commonName:
	253	ctx->cn_size = vlen;
	254	ctx->cn_offset = (unsigned long)value - ctx->data;
	255	break;
	256	case OID_organizationName:
	257	ctx->o_size = vlen;
	258	ctx->o_offset = (unsigned long)value - ctx->data;
	259	break;
	260	case OID_email_address:
	261	ctx->email_size = vlen;
	262	ctx->email_offset = (unsigned long)value - ctx->data;
	263	break;
	264	default:
	265	break;
	266	}
	267
	268	return 0;
	269	}
	270
	271	/*
	272	* Fabricate and save the issuer and subject names
	273	*/
	274	static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
	275	unsigned char tag,
	276	char **_name, size_t vlen)
	277	{
	278	const void name, data = (const void *)ctx->data;
	279	size_t namesize;
	280	char *buffer;
	281
	282	if (*_name)
	283	return -EINVAL;
	284
	285	/* Empty name string if no material */
	286	if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
	287	buffer = kmalloc(1, GFP_KERNEL);
	288	if (!buffer)
	289	return -ENOMEM;
	290	buffer[0] = 0;
	291	goto done;
	292	}
	293
	294	if (ctx->cn_size && ctx->o_size) {
	295	/* Consider combining O and CN, but use only the CN if it is
	296	* prefixed by the O, or a significant portion thereof.
	297	*/
	298	namesize = ctx->cn_size;
	299	name = data + ctx->cn_offset;
	300	if (ctx->cn_size >= ctx->o_size &&
	301	memcmp(data + ctx->cn_offset, data + ctx->o_offset,
	302	ctx->o_size) == 0)
	303	goto single_component;
	304	if (ctx->cn_size >= 7 &&
	305	ctx->o_size >= 7 &&
306	memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
307	goto single_component;
308
309	buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
310	GFP_KERNEL);
311	if (!buffer)
312	return -ENOMEM;
313
314	memcpy(buffer,
315	data + ctx->o_offset, ctx->o_size);
316	buffer[ctx->o_size + 0] = ':';
317	buffer[ctx->o_size + 1] = ' ';
318	memcpy(buffer + ctx->o_size + 2,
319	data + ctx->cn_offset, ctx->cn_size);
320	buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
321	goto done;
322
323	} else if (ctx->cn_size) {
324	namesize = ctx->cn_size;
325	name = data + ctx->cn_offset;
326	} else if (ctx->o_size) {
327	namesize = ctx->o_size;
328	name = data + ctx->o_offset;
329	} else {
330	namesize = ctx->email_size;
331	name = data + ctx->email_offset;
332	}
333
334	single_component:
335	buffer = kmalloc(namesize + 1, GFP_KERNEL);
336	if (!buffer)
337	return -ENOMEM;
338	memcpy(buffer, name, namesize);
339	buffer[namesize] = 0;
340
341	done:
342	*_name = buffer;
343	ctx->cn_size = 0;
344	ctx->o_size = 0;
345	ctx->email_size = 0;
346	return 0;
347	}
348
349	int x509_note_issuer(void *context, size_t hdrlen,
350	unsigned char tag,
351	const void *value, size_t vlen)
352	{
353	struct x509_parse_context *ctx = context;
84aabd46 DH	354	ctx->cert->raw_issuer = value;
84aabd46 DH	355	ctx->cert->raw_issuer_size = vlen;
c26fd69f DH	356	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
	357	}
	358
	359	int x509_note_subject(void *context, size_t hdrlen,
	360	unsigned char tag,
	361	const void *value, size_t vlen)
	362	{
	363	struct x509_parse_context *ctx = context;
84aabd46 DH	364	ctx->cert->raw_subject = value;
84aabd46 DH	365	ctx->cert->raw_subject_size = vlen;
c26fd69f DH	366	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
	367	}
	368
	369	/*
	370	* Extract the data for the public key algorithm
	371	*/
	372	int x509_extract_key_data(void *context, size_t hdrlen,
	373	unsigned char tag,
	374	const void *value, size_t vlen)
	375	{
	376	struct x509_parse_context *ctx = context;
	377
	378	if (ctx->last_oid != OID_rsaEncryption)
	379	return -ENOPKG;
	380
67f7d60b DH	381	ctx->cert->pub->pkey_algo = PKEY_ALGO_RSA;
	382
	383	/* Discard the BIT STRING metadata */
c26fd69f DH	384	ctx->key = value + 1;
	385	ctx->key_size = vlen - 1;
	386	return 0;
	387	}
	388
	389	/*
	390	* Extract a RSA public key value
	391	*/
	392	int rsa_extract_mpi(void *context, size_t hdrlen,
	393	unsigned char tag,
	394	const void *value, size_t vlen)
	395	{
	396	struct x509_parse_context *ctx = context;
	397	MPI mpi;
	398
	399	if (ctx->nr_mpi >= ARRAY_SIZE(ctx->cert->pub->mpi)) {
	400	pr_err("Too many public key MPIs in certificate\n");
	401	return -EBADMSG;
	402	}
	403
	404	mpi = mpi_read_raw_data(value, vlen);
	405	if (!mpi)
	406	return -ENOMEM;
	407
	408	ctx->cert->pub->mpi[ctx->nr_mpi++] = mpi;
	409	return 0;
	410	}
	411
04b00bdb CYL	412	/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
	413	#define SEQ_TAG_KEYID (ASN1_CONT << 6)
	414
c26fd69f DH	415	/*
	416	* Process certificate extensions that are used to qualify the certificate.
	417	*/
	418	int x509_process_extension(void *context, size_t hdrlen,
	419	unsigned char tag,
	420	const void *value, size_t vlen)
	421	{
	422	struct x509_parse_context *ctx = context;
46963b77	423	struct asymmetric_key_id *kid;
c26fd69f	424	const unsigned char *v = value;
c26fd69f DH	425	int i;
	426
	427	pr_debug("Extension: %u\n", ctx->last_oid);
	428
	429	if (ctx->last_oid == OID_subjectKeyIdentifier) {
	430	/* Get hold of the key fingerprint */
46963b77	431	if (ctx->cert->skid \|\| vlen < 3)
c26fd69f DH	432	return -EBADMSG;
	433	if (v[0] != ASN1_OTS \|\| v[1] != vlen - 2)
	434	return -EBADMSG;
	435	v += 2;
	436	vlen -= 2;
	437
dd2f6c44 DH	438	ctx->cert->raw_skid_size = vlen;
dd2f6c44 DH	439	ctx->cert->raw_skid = v;
8dd60980 DK	440	kid = asymmetric_key_generate_id(ctx->cert->raw_subject,
	441	ctx->cert->raw_subject_size,
	442	v, vlen);
46963b77 DH	443	if (IS_ERR(kid))
	444	return PTR_ERR(kid);
	445	ctx->cert->skid = kid;
	446	pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
c26fd69f DH	447	return 0;
	448	}
	449
	450	if (ctx->last_oid == OID_authorityKeyIdentifier) {
	451	/* Get hold of the CA key fingerprint */
46963b77	452	if (ctx->cert->authority \|\| vlen < 5)
c26fd69f	453	return -EBADMSG;
04b00bdb CYL	454
	455	/* Authority Key Identifier must be a Constructed SEQUENCE */
	456	if (v[0] != (ASN1_SEQ \| (ASN1_CONS << 5)))
c26fd69f	457	return -EBADMSG;
c26fd69f	458
04b00bdb CYL	459	/* Authority Key Identifier is not indefinite length */
	460	if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
	461	return -EBADMSG;
	462
	463	if (vlen < ASN1_INDEFINITE_LENGTH) {
	464	/* Short Form length */
	465	if (v[1] != vlen - 2 \|\|
	466	v[2] != SEQ_TAG_KEYID \|\|
	467	v[3] > vlen - 4)
	468	return -EBADMSG;
	469
46963b77	470	vlen = v[3];
04b00bdb CYL	471	v += 4;
	472	} else {
	473	/* Long Form length */
	474	size_t seq_len = 0;
	475	size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;
	476
	477	if (sub > 2)
	478	return -EBADMSG;
	479
	480	/* calculate the length from subsequent octets */
	481	v += 2;
	482	for (i = 0; i < sub; i++) {
	483	seq_len <<= 8;
	484	seq_len \|= v[i];
	485	}
	486
	487	if (seq_len != vlen - 2 - sub \|\|
	488	v[sub] != SEQ_TAG_KEYID \|\|
	489	v[sub + 1] > vlen - 4 - sub)
	490	return -EBADMSG;
	491
46963b77	492	vlen = v[sub + 1];
04b00bdb CYL	493	v += (sub + 2);
	494	}
	495
8dd60980 DK	496	kid = asymmetric_key_generate_id(ctx->cert->raw_issuer,
	497	ctx->cert->raw_issuer_size,
	498	v, vlen);
46963b77 DH	499	if (IS_ERR(kid))
	500	return PTR_ERR(kid);
	501	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
	502	ctx->cert->authority = kid;
c26fd69f DH	503	return 0;
	504	}
	505
	506	return 0;
	507	}
	508
	509	/*
	510	* Record a certificate time.
	511	*/
a5752d11	512	static int x509_note_time(struct tm *tm, size_t hdrlen,
c26fd69f DH	513	unsigned char tag,
	514	const unsigned char *value, size_t vlen)
	515	{
c26fd69f DH	516	const unsigned char *p = value;
	517
	518	#define dec2bin(X) ((X) - '0')
	519	#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
	520
	521	if (tag == ASN1_UNITIM) {
	522	/* UTCTime: YYMMDDHHMMSSZ */
	523	if (vlen != 13)
	524	goto unsupported_time;
a5752d11 DH	525	tm->tm_year = DD2bin(p);
	526	if (tm->tm_year >= 50)
	527	tm->tm_year += 1900;
c26fd69f	528	else
a5752d11	529	tm->tm_year += 2000;
c26fd69f DH	530	} else if (tag == ASN1_GENTIM) {
	531	/* GenTime: YYYYMMDDHHMMSSZ */
	532	if (vlen != 15)
	533	goto unsupported_time;
a5752d11	534	tm->tm_year = DD2bin(p) * 100 + DD2bin(p);
c26fd69f DH	535	} else {
	536	goto unsupported_time;
	537	}
	538
a5752d11 DH	539	tm->tm_year -= 1900;
	540	tm->tm_mon = DD2bin(p) - 1;
	541	tm->tm_mday = DD2bin(p);
	542	tm->tm_hour = DD2bin(p);
	543	tm->tm_min = DD2bin(p);
	544	tm->tm_sec = DD2bin(p);
c26fd69f DH	545
	546	if (*p != 'Z')
	547	goto unsupported_time;
	548
c26fd69f DH	549	return 0;
	550
	551	unsupported_time:
	552	pr_debug("Got unsupported time [tag %02x]: '%.s'\n",
	553	tag, (int)vlen, (int)vlen, value);
	554	return -EBADMSG;
	555	}
	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;
	562	return x509_note_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
	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;
	570	return x509_note_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
	571	}