[mirror_ubuntu-jammy-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/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->fingerprint);
		kfree(cert->authority);
		kfree(cert->sig.digest);
		mpi_free(cert->sig.rsa.s);
		kfree(cert);
	}
}

/*
 * 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;
	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;

	kfree(ctx);
	return cert;

error_decode:
	kfree(ctx);
error_no_ctx:
	x509_free_certificate(cert);
error_no_cert:
	return ERR_PTR(ret);
}

/*
 * 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 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;
	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;
	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;
	const unsigned char *v = value;
	char *f;
	int i;

	pr_debug("Extension: %u\n", ctx->last_oid);

	if (ctx->last_oid == OID_subjectKeyIdentifier) {
		/* Get hold of the key fingerprint */
		if (vlen < 3)
			return -EBADMSG;
		if (v[0] != ASN1_OTS || v[1] != vlen - 2)
			return -EBADMSG;
		v += 2;
		vlen -= 2;

		f = kmalloc(vlen * 2 + 1, GFP_KERNEL);
		if (!f)
			return -ENOMEM;
		for (i = 0; i < vlen; i++)
			sprintf(f + i * 2, "%02x", v[i]);
		pr_debug("fingerprint %s\n", f);
		ctx->cert->fingerprint = f;
		return 0;
	}

	if (ctx->last_oid == OID_authorityKeyIdentifier) {
		size_t key_len;

		/* Get hold of the CA key fingerprint */
		if (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;

			key_len = 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;

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

		f = kmalloc(key_len * 2 + 1, GFP_KERNEL);
		if (!f)
			return -ENOMEM;
		for (i = 0; i < key_len; i++)
			sprintf(f + i * 2, "%02x", v[i]);
		pr_debug("authority   %s\n", f);
		ctx->cert->authority = f;
		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>
	14	#include <linux/slab.h>
	15	#include <linux/err.h>
	16	#include <linux/oid_registry.h>
	17	#include "public_key.h"
	18	#include "x509_parser.h"
	19	#include "x509-asn1.h"
	20	#include "x509_rsakey-asn1.h"
	21
	22	struct x509_parse_context {
	23	struct x509_certificate cert; / Certificate being constructed */
	24	unsigned long data; /* Start of data */
	25	const void cert_start; / Start of cert content */
	26	const void key; / Key data */
	27	size_t key_size; /* Size of key data */
	28	enum OID last_oid; /* Last OID encountered */
	29	enum OID algo_oid; /* Algorithm OID */
	30	unsigned char nr_mpi; /* Number of MPIs stored */
	31	u8 o_size; /* Size of organizationName (O) */
	32	u8 cn_size; /* Size of commonName (CN) */
	33	u8 email_size; /* Size of emailAddress */
	34	u16 o_offset; /* Offset of organizationName (O) */
	35	u16 cn_offset; /* Offset of commonName (CN) */
	36	u16 email_offset; /* Offset of emailAddress */
	37	};
	38
	39	/*
	40	* Free an X.509 certificate
	41	*/
	42	void x509_free_certificate(struct x509_certificate *cert)
	43	{
	44	if (cert) {
	45	public_key_destroy(cert->pub);
	46	kfree(cert->issuer);
	47	kfree(cert->subject);
	48	kfree(cert->fingerprint);
	49	kfree(cert->authority);
b426beb6 DH	50	kfree(cert->sig.digest);
b426beb6 DH	51	mpi_free(cert->sig.rsa.s);
c26fd69f DH	52	kfree(cert);
	53	}
	54	}
	55
	56	/*
	57	* Parse an X.509 certificate
	58	*/
	59	struct x509_certificate x509_cert_parse(const void data, size_t datalen)
	60	{
	61	struct x509_certificate *cert;
	62	struct x509_parse_context *ctx;
	63	long ret;
	64
	65	ret = -ENOMEM;
	66	cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
	67	if (!cert)
	68	goto error_no_cert;
	69	cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
	70	if (!cert->pub)
	71	goto error_no_ctx;
	72	ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
	73	if (!ctx)
	74	goto error_no_ctx;
	75
	76	ctx->cert = cert;
	77	ctx->data = (unsigned long)data;
	78
	79	/* Attempt to decode the certificate */
	80	ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
	81	if (ret < 0)
	82	goto error_decode;
	83
	84	/* Decode the public key */
	85	ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx,
	86	ctx->key, ctx->key_size);
	87	if (ret < 0)
	88	goto error_decode;
	89
	90	kfree(ctx);
	91	return cert;
	92
	93	error_decode:
	94	kfree(ctx);
	95	error_no_ctx:
	96	x509_free_certificate(cert);
	97	error_no_cert:
	98	return ERR_PTR(ret);
	99	}
	100
	101	/*
	102	* Note an OID when we find one for later processing when we know how
	103	* to interpret it.
	104	*/
	105	int x509_note_OID(void *context, size_t hdrlen,
	106	unsigned char tag,
	107	const void *value, size_t vlen)
	108	{
	109	struct x509_parse_context *ctx = context;
	110
	111	ctx->last_oid = look_up_OID(value, vlen);
	112	if (ctx->last_oid == OID__NR) {
	113	char buffer[50];
	114	sprint_oid(value, vlen, buffer, sizeof(buffer));
cf75446e	115	pr_debug("Unknown OID: [%lu] %s\n",
c26fd69f DH	116	(unsigned long)value - ctx->data, buffer);
	117	}
	118	return 0;
	119	}
	120
	121	/*
	122	* Save the position of the TBS data so that we can check the signature over it
	123	* later.
	124	*/
	125	int x509_note_tbs_certificate(void *context, size_t hdrlen,
	126	unsigned char tag,
	127	const void *value, size_t vlen)
	128	{
	129	struct x509_parse_context *ctx = context;
	130
	131	pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
	132	hdrlen, tag, (unsigned long)value - ctx->data, vlen);
	133
	134	ctx->cert->tbs = value - hdrlen;
	135	ctx->cert->tbs_size = vlen + hdrlen;
	136	return 0;
	137	}
	138
	139	/*
	140	* Record the public key algorithm
	141	*/
	142	int x509_note_pkey_algo(void *context, size_t hdrlen,
	143	unsigned char tag,
	144	const void *value, size_t vlen)
	145	{
	146	struct x509_parse_context *ctx = context;
	147
	148	pr_debug("PubKey Algo: %u\n", ctx->last_oid);
	149
	150	switch (ctx->last_oid) {
	151	case OID_md2WithRSAEncryption:
	152	case OID_md3WithRSAEncryption:
	153	default:
	154	return -ENOPKG; /* Unsupported combination */
	155
	156	case OID_md4WithRSAEncryption:
3fe78ca2	157	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_MD5;
b426beb6	158	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	159	break;
	160
	161	case OID_sha1WithRSAEncryption:
3fe78ca2	162	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA1;
b426beb6	163	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	164	break;
	165
	166	case OID_sha256WithRSAEncryption:
3fe78ca2	167	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA256;
b426beb6	168	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	169	break;
	170
	171	case OID_sha384WithRSAEncryption:
3fe78ca2	172	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA384;
b426beb6	173	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	174	break;
	175
	176	case OID_sha512WithRSAEncryption:
3fe78ca2	177	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA512;
b426beb6	178	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	179	break;
	180
	181	case OID_sha224WithRSAEncryption:
3fe78ca2	182	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA224;
b426beb6	183	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	184	break;
	185	}
	186
	187	ctx->algo_oid = ctx->last_oid;
	188	return 0;
	189	}
	190
	191	/*
	192	* Note the whereabouts and type of the signature.
	193	*/
	194	int x509_note_signature(void *context, size_t hdrlen,
	195	unsigned char tag,
	196	const void *value, size_t vlen)
	197	{
	198	struct x509_parse_context *ctx = context;
	199
	200	pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
	201
	202	if (ctx->last_oid != ctx->algo_oid) {
	203	pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
	204	ctx->algo_oid, ctx->last_oid);
	205	return -EINVAL;
	206	}
	207
b426beb6 DH	208	ctx->cert->raw_sig = value;
b426beb6 DH	209	ctx->cert->raw_sig_size = vlen;
c26fd69f DH	210	return 0;
	211	}
	212
	213	/*
	214	* Note some of the name segments from which we'll fabricate a name.
	215	*/
	216	int x509_extract_name_segment(void *context, size_t hdrlen,
	217	unsigned char tag,
	218	const void *value, size_t vlen)
	219	{
	220	struct x509_parse_context *ctx = context;
	221
	222	switch (ctx->last_oid) {
	223	case OID_commonName:
	224	ctx->cn_size = vlen;
	225	ctx->cn_offset = (unsigned long)value - ctx->data;
	226	break;
	227	case OID_organizationName:
	228	ctx->o_size = vlen;
	229	ctx->o_offset = (unsigned long)value - ctx->data;
	230	break;
	231	case OID_email_address:
	232	ctx->email_size = vlen;
	233	ctx->email_offset = (unsigned long)value - ctx->data;
	234	break;
	235	default:
	236	break;
	237	}
	238
	239	return 0;
	240	}
	241
	242	/*
	243	* Fabricate and save the issuer and subject names
	244	*/
	245	static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
	246	unsigned char tag,
	247	char **_name, size_t vlen)
	248	{
	249	const void name, data = (const void *)ctx->data;
	250	size_t namesize;
	251	char *buffer;
	252
	253	if (*_name)
	254	return -EINVAL;
	255
	256	/* Empty name string if no material */
	257	if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
	258	buffer = kmalloc(1, GFP_KERNEL);
	259	if (!buffer)
	260	return -ENOMEM;
	261	buffer[0] = 0;
	262	goto done;
	263	}
	264
	265	if (ctx->cn_size && ctx->o_size) {
	266	/* Consider combining O and CN, but use only the CN if it is
	267	* prefixed by the O, or a significant portion thereof.
	268	*/
	269	namesize = ctx->cn_size;
	270	name = data + ctx->cn_offset;
	271	if (ctx->cn_size >= ctx->o_size &&
	272	memcmp(data + ctx->cn_offset, data + ctx->o_offset,
	273	ctx->o_size) == 0)
274	goto single_component;
275	if (ctx->cn_size >= 7 &&
276	ctx->o_size >= 7 &&
277	memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
278	goto single_component;
279
280	buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
281	GFP_KERNEL);
282	if (!buffer)
283	return -ENOMEM;
284
285	memcpy(buffer,
286	data + ctx->o_offset, ctx->o_size);
287	buffer[ctx->o_size + 0] = ':';
288	buffer[ctx->o_size + 1] = ' ';
289	memcpy(buffer + ctx->o_size + 2,
290	data + ctx->cn_offset, ctx->cn_size);
291	buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
292	goto done;
293
294	} else if (ctx->cn_size) {
295	namesize = ctx->cn_size;
296	name = data + ctx->cn_offset;
297	} else if (ctx->o_size) {
298	namesize = ctx->o_size;
299	name = data + ctx->o_offset;
300	} else {
301	namesize = ctx->email_size;
302	name = data + ctx->email_offset;
303	}
304
305	single_component:
306	buffer = kmalloc(namesize + 1, GFP_KERNEL);
307	if (!buffer)
308	return -ENOMEM;
309	memcpy(buffer, name, namesize);
310	buffer[namesize] = 0;
311
312	done:
313	*_name = buffer;
314	ctx->cn_size = 0;
315	ctx->o_size = 0;
316	ctx->email_size = 0;
317	return 0;
318	}
319
320	int x509_note_issuer(void *context, size_t hdrlen,
321	unsigned char tag,
322	const void *value, size_t vlen)
323	{
324	struct x509_parse_context *ctx = context;
325	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
326	}
327
328	int x509_note_subject(void *context, size_t hdrlen,
329	unsigned char tag,
330	const void *value, size_t vlen)
331	{
332	struct x509_parse_context *ctx = context;
333	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
334	}
335
336	/*
337	* Extract the data for the public key algorithm
338	*/
339	int x509_extract_key_data(void *context, size_t hdrlen,
340	unsigned char tag,
341	const void *value, size_t vlen)
342	{
343	struct x509_parse_context *ctx = context;
344
345	if (ctx->last_oid != OID_rsaEncryption)
346	return -ENOPKG;
347
67f7d60b DH	348	ctx->cert->pub->pkey_algo = PKEY_ALGO_RSA;
	349
	350	/* Discard the BIT STRING metadata */
c26fd69f DH	351	ctx->key = value + 1;
	352	ctx->key_size = vlen - 1;
	353	return 0;
	354	}
	355
	356	/*
	357	* Extract a RSA public key value
	358	*/
	359	int rsa_extract_mpi(void *context, size_t hdrlen,
	360	unsigned char tag,
	361	const void *value, size_t vlen)
	362	{
	363	struct x509_parse_context *ctx = context;
	364	MPI mpi;
	365
	366	if (ctx->nr_mpi >= ARRAY_SIZE(ctx->cert->pub->mpi)) {
	367	pr_err("Too many public key MPIs in certificate\n");
	368	return -EBADMSG;
	369	}
	370
	371	mpi = mpi_read_raw_data(value, vlen);
	372	if (!mpi)
	373	return -ENOMEM;
	374
	375	ctx->cert->pub->mpi[ctx->nr_mpi++] = mpi;
	376	return 0;
	377	}
	378
04b00bdb CYL	379	/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
	380	#define SEQ_TAG_KEYID (ASN1_CONT << 6)
	381
c26fd69f DH	382	/*
	383	* Process certificate extensions that are used to qualify the certificate.
	384	*/
	385	int x509_process_extension(void *context, size_t hdrlen,
	386	unsigned char tag,
	387	const void *value, size_t vlen)
	388	{
	389	struct x509_parse_context *ctx = context;
	390	const unsigned char *v = value;
	391	char *f;
	392	int i;
	393
	394	pr_debug("Extension: %u\n", ctx->last_oid);
	395
	396	if (ctx->last_oid == OID_subjectKeyIdentifier) {
	397	/* Get hold of the key fingerprint */
	398	if (vlen < 3)
	399	return -EBADMSG;
	400	if (v[0] != ASN1_OTS \|\| v[1] != vlen - 2)
	401	return -EBADMSG;
	402	v += 2;
	403	vlen -= 2;
	404
	405	f = kmalloc(vlen * 2 + 1, GFP_KERNEL);
	406	if (!f)
	407	return -ENOMEM;
	408	for (i = 0; i < vlen; i++)
	409	sprintf(f + i * 2, "%02x", v[i]);
	410	pr_debug("fingerprint %s\n", f);
	411	ctx->cert->fingerprint = f;
	412	return 0;
	413	}
	414
	415	if (ctx->last_oid == OID_authorityKeyIdentifier) {
04b00bdb CYL	416	size_t key_len;
04b00bdb CYL	417
c26fd69f DH	418	/* Get hold of the CA key fingerprint */
	419	if (vlen < 5)
	420	return -EBADMSG;
04b00bdb CYL	421
	422	/* Authority Key Identifier must be a Constructed SEQUENCE */
	423	if (v[0] != (ASN1_SEQ \| (ASN1_CONS << 5)))
c26fd69f	424	return -EBADMSG;
c26fd69f	425
04b00bdb CYL	426	/* Authority Key Identifier is not indefinite length */
	427	if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
	428	return -EBADMSG;
	429
	430	if (vlen < ASN1_INDEFINITE_LENGTH) {
	431	/* Short Form length */
	432	if (v[1] != vlen - 2 \|\|
	433	v[2] != SEQ_TAG_KEYID \|\|
	434	v[3] > vlen - 4)
	435	return -EBADMSG;
	436
	437	key_len = v[3];
	438	v += 4;
	439	} else {
	440	/* Long Form length */
	441	size_t seq_len = 0;
	442	size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;
	443
	444	if (sub > 2)
	445	return -EBADMSG;
	446
	447	/* calculate the length from subsequent octets */
	448	v += 2;
	449	for (i = 0; i < sub; i++) {
	450	seq_len <<= 8;
	451	seq_len \|= v[i];
	452	}
	453
	454	if (seq_len != vlen - 2 - sub \|\|
	455	v[sub] != SEQ_TAG_KEYID \|\|
	456	v[sub + 1] > vlen - 4 - sub)
	457	return -EBADMSG;
	458
	459	key_len = v[sub + 1];
	460	v += (sub + 2);
	461	}
	462
	463	f = kmalloc(key_len * 2 + 1, GFP_KERNEL);
c26fd69f DH	464	if (!f)
c26fd69f DH	465	return -ENOMEM;
04b00bdb	466	for (i = 0; i < key_len; i++)
c26fd69f DH	467	sprintf(f + i * 2, "%02x", v[i]);
	468	pr_debug("authority %s\n", f);
	469	ctx->cert->authority = f;
	470	return 0;
	471	}
	472
	473	return 0;
	474	}
	475
	476	/*
	477	* Record a certificate time.
	478	*/
a5752d11	479	static int x509_note_time(struct tm *tm, size_t hdrlen,
c26fd69f DH	480	unsigned char tag,
	481	const unsigned char *value, size_t vlen)
	482	{
c26fd69f DH	483	const unsigned char *p = value;
	484
	485	#define dec2bin(X) ((X) - '0')
	486	#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
	487
	488	if (tag == ASN1_UNITIM) {
	489	/* UTCTime: YYMMDDHHMMSSZ */
	490	if (vlen != 13)
	491	goto unsupported_time;
a5752d11 DH	492	tm->tm_year = DD2bin(p);
	493	if (tm->tm_year >= 50)
	494	tm->tm_year += 1900;
c26fd69f	495	else
a5752d11	496	tm->tm_year += 2000;
c26fd69f DH	497	} else if (tag == ASN1_GENTIM) {
	498	/* GenTime: YYYYMMDDHHMMSSZ */
	499	if (vlen != 15)
	500	goto unsupported_time;
a5752d11	501	tm->tm_year = DD2bin(p) * 100 + DD2bin(p);
c26fd69f DH	502	} else {
	503	goto unsupported_time;
	504	}
	505
a5752d11 DH	506	tm->tm_year -= 1900;
	507	tm->tm_mon = DD2bin(p) - 1;
	508	tm->tm_mday = DD2bin(p);
	509	tm->tm_hour = DD2bin(p);
	510	tm->tm_min = DD2bin(p);
	511	tm->tm_sec = DD2bin(p);
c26fd69f DH	512
	513	if (*p != 'Z')
	514	goto unsupported_time;
	515
c26fd69f DH	516	return 0;
	517
	518	unsupported_time:
	519	pr_debug("Got unsupported time [tag %02x]: '%.s'\n",
	520	tag, (int)vlen, (int)vlen, value);
	521	return -EBADMSG;
	522	}
	523
	524	int x509_note_not_before(void *context, size_t hdrlen,
	525	unsigned char tag,
	526	const void *value, size_t vlen)
	527	{
	528	struct x509_parse_context *ctx = context;
	529	return x509_note_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
	530	}
	531
	532	int x509_note_not_after(void *context, size_t hdrlen,
	533	unsigned char tag,
	534	const void *value, size_t vlen)
	535	{
	536	struct x509_parse_context *ctx = context;
	537	return x509_note_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
	538	}