[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/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->fingerprint);
		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;
	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);
}
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;
	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>
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);
	49	kfree(cert->fingerprint);
	50	kfree(cert->authority);
b426beb6 DH	51	kfree(cert->sig.digest);
b426beb6 DH	52	mpi_free(cert->sig.rsa.s);
c26fd69f DH	53	kfree(cert);
	54	}
	55	}
ace0107a	56	EXPORT_SYMBOL_GPL(x509_free_certificate);
c26fd69f DH	57
	58	/*
	59	* Parse an X.509 certificate
	60	*/
	61	struct x509_certificate x509_cert_parse(const void data, size_t datalen)
	62	{
	63	struct x509_certificate *cert;
	64	struct x509_parse_context *ctx;
	65	long ret;
	66
	67	ret = -ENOMEM;
	68	cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
	69	if (!cert)
	70	goto error_no_cert;
	71	cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
	72	if (!cert->pub)
	73	goto error_no_ctx;
	74	ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
	75	if (!ctx)
	76	goto error_no_ctx;
	77
	78	ctx->cert = cert;
	79	ctx->data = (unsigned long)data;
	80
	81	/* Attempt to decode the certificate */
	82	ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
	83	if (ret < 0)
	84	goto error_decode;
	85
	86	/* Decode the public key */
	87	ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx,
	88	ctx->key, ctx->key_size);
	89	if (ret < 0)
	90	goto error_decode;
	91
	92	kfree(ctx);
	93	return cert;
	94
	95	error_decode:
	96	kfree(ctx);
	97	error_no_ctx:
	98	x509_free_certificate(cert);
	99	error_no_cert:
	100	return ERR_PTR(ret);
	101	}
ace0107a	102	EXPORT_SYMBOL_GPL(x509_cert_parse);
c26fd69f DH	103
	104	/*
	105	* Note an OID when we find one for later processing when we know how
	106	* to interpret it.
	107	*/
	108	int x509_note_OID(void *context, size_t hdrlen,
	109	unsigned char tag,
	110	const void *value, size_t vlen)
	111	{
	112	struct x509_parse_context *ctx = context;
	113
	114	ctx->last_oid = look_up_OID(value, vlen);
	115	if (ctx->last_oid == OID__NR) {
	116	char buffer[50];
	117	sprint_oid(value, vlen, buffer, sizeof(buffer));
cf75446e	118	pr_debug("Unknown OID: [%lu] %s\n",
c26fd69f DH	119	(unsigned long)value - ctx->data, buffer);
	120	}
	121	return 0;
	122	}
	123
	124	/*
	125	* Save the position of the TBS data so that we can check the signature over it
	126	* later.
	127	*/
	128	int x509_note_tbs_certificate(void *context, size_t hdrlen,
	129	unsigned char tag,
	130	const void *value, size_t vlen)
	131	{
	132	struct x509_parse_context *ctx = context;
	133
	134	pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
	135	hdrlen, tag, (unsigned long)value - ctx->data, vlen);
	136
	137	ctx->cert->tbs = value - hdrlen;
	138	ctx->cert->tbs_size = vlen + hdrlen;
	139	return 0;
	140	}
	141
	142	/*
	143	* Record the public key algorithm
	144	*/
	145	int x509_note_pkey_algo(void *context, size_t hdrlen,
	146	unsigned char tag,
	147	const void *value, size_t vlen)
	148	{
	149	struct x509_parse_context *ctx = context;
	150
	151	pr_debug("PubKey Algo: %u\n", ctx->last_oid);
	152
	153	switch (ctx->last_oid) {
	154	case OID_md2WithRSAEncryption:
	155	case OID_md3WithRSAEncryption:
	156	default:
	157	return -ENOPKG; /* Unsupported combination */
	158
	159	case OID_md4WithRSAEncryption:
3fe78ca2	160	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_MD5;
b426beb6	161	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	162	break;
	163
	164	case OID_sha1WithRSAEncryption:
3fe78ca2	165	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA1;
b426beb6	166	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	167	break;
	168
	169	case OID_sha256WithRSAEncryption:
3fe78ca2	170	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA256;
b426beb6	171	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	172	break;
	173
	174	case OID_sha384WithRSAEncryption:
3fe78ca2	175	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA384;
b426beb6	176	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	177	break;
	178
	179	case OID_sha512WithRSAEncryption:
3fe78ca2	180	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA512;
b426beb6	181	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	182	break;
	183
	184	case OID_sha224WithRSAEncryption:
3fe78ca2	185	ctx->cert->sig.pkey_hash_algo = HASH_ALGO_SHA224;
b426beb6	186	ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
c26fd69f DH	187	break;
	188	}
	189
	190	ctx->algo_oid = ctx->last_oid;
	191	return 0;
	192	}
	193
	194	/*
	195	* Note the whereabouts and type of the signature.
	196	*/
	197	int x509_note_signature(void *context, size_t hdrlen,
	198	unsigned char tag,
	199	const void *value, size_t vlen)
	200	{
	201	struct x509_parse_context *ctx = context;
	202
	203	pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
	204
	205	if (ctx->last_oid != ctx->algo_oid) {
	206	pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
	207	ctx->algo_oid, ctx->last_oid);
	208	return -EINVAL;
	209	}
	210
b426beb6 DH	211	ctx->cert->raw_sig = value;
b426beb6 DH	212	ctx->cert->raw_sig_size = vlen;
c26fd69f DH	213	return 0;
	214	}
	215
84aabd46 DH	216	/*
	217	* Note the certificate serial number
	218	*/
	219	int x509_note_serial(void *context, size_t hdrlen,
	220	unsigned char tag,
	221	const void *value, size_t vlen)
	222	{
	223	struct x509_parse_context *ctx = context;
	224	ctx->cert->raw_serial = value;
	225	ctx->cert->raw_serial_size = vlen;
	226	return 0;
	227	}
	228
c26fd69f DH	229	/*
	230	* Note some of the name segments from which we'll fabricate a name.
	231	*/
	232	int x509_extract_name_segment(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
	238	switch (ctx->last_oid) {
	239	case OID_commonName:
	240	ctx->cn_size = vlen;
	241	ctx->cn_offset = (unsigned long)value - ctx->data;
	242	break;
	243	case OID_organizationName:
	244	ctx->o_size = vlen;
	245	ctx->o_offset = (unsigned long)value - ctx->data;
	246	break;
	247	case OID_email_address:
	248	ctx->email_size = vlen;
	249	ctx->email_offset = (unsigned long)value - ctx->data;
	250	break;
	251	default:
	252	break;
	253	}
	254
	255	return 0;
	256	}
	257
	258	/*
	259	* Fabricate and save the issuer and subject names
	260	*/
	261	static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
	262	unsigned char tag,
	263	char **_name, size_t vlen)
	264	{
	265	const void name, data = (const void *)ctx->data;
	266	size_t namesize;
	267	char *buffer;
	268
	269	if (*_name)
	270	return -EINVAL;
	271
	272	/* Empty name string if no material */
	273	if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
	274	buffer = kmalloc(1, GFP_KERNEL);
	275	if (!buffer)
	276	return -ENOMEM;
	277	buffer[0] = 0;
	278	goto done;
	279	}
	280
	281	if (ctx->cn_size && ctx->o_size) {
	282	/* Consider combining O and CN, but use only the CN if it is
	283	* prefixed by the O, or a significant portion thereof.
	284	*/
	285	namesize = ctx->cn_size;
	286	name = data + ctx->cn_offset;
	287	if (ctx->cn_size >= ctx->o_size &&
	288	memcmp(data + ctx->cn_offset, data + ctx->o_offset,
	289	ctx->o_size) == 0)
	290	goto single_component;
	291	if (ctx->cn_size >= 7 &&
	292	ctx->o_size >= 7 &&
293	memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
294	goto single_component;
295
296	buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
297	GFP_KERNEL);
298	if (!buffer)
299	return -ENOMEM;
300
301	memcpy(buffer,
302	data + ctx->o_offset, ctx->o_size);
303	buffer[ctx->o_size + 0] = ':';
304	buffer[ctx->o_size + 1] = ' ';
305	memcpy(buffer + ctx->o_size + 2,
306	data + ctx->cn_offset, ctx->cn_size);
307	buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
308	goto done;
309
310	} else if (ctx->cn_size) {
311	namesize = ctx->cn_size;
312	name = data + ctx->cn_offset;
313	} else if (ctx->o_size) {
314	namesize = ctx->o_size;
315	name = data + ctx->o_offset;
316	} else {
317	namesize = ctx->email_size;
318	name = data + ctx->email_offset;
319	}
320
321	single_component:
322	buffer = kmalloc(namesize + 1, GFP_KERNEL);
323	if (!buffer)
324	return -ENOMEM;
325	memcpy(buffer, name, namesize);
326	buffer[namesize] = 0;
327
328	done:
329	*_name = buffer;
330	ctx->cn_size = 0;
331	ctx->o_size = 0;
332	ctx->email_size = 0;
333	return 0;
334	}
335
336	int x509_note_issuer(void *context, size_t hdrlen,
337	unsigned char tag,
338	const void *value, size_t vlen)
339	{
340	struct x509_parse_context *ctx = context;
84aabd46 DH	341	ctx->cert->raw_issuer = value;
84aabd46 DH	342	ctx->cert->raw_issuer_size = vlen;
c26fd69f DH	343	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
	344	}
	345
	346	int x509_note_subject(void *context, size_t hdrlen,
	347	unsigned char tag,
	348	const void *value, size_t vlen)
	349	{
	350	struct x509_parse_context *ctx = context;
84aabd46 DH	351	ctx->cert->raw_subject = value;
84aabd46 DH	352	ctx->cert->raw_subject_size = vlen;
c26fd69f DH	353	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
	354	}
	355
	356	/*
	357	* Extract the data for the public key algorithm
	358	*/
	359	int x509_extract_key_data(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
	365	if (ctx->last_oid != OID_rsaEncryption)
	366	return -ENOPKG;
	367
67f7d60b DH	368	ctx->cert->pub->pkey_algo = PKEY_ALGO_RSA;
	369
	370	/* Discard the BIT STRING metadata */
c26fd69f DH	371	ctx->key = value + 1;
	372	ctx->key_size = vlen - 1;
	373	return 0;
	374	}
	375
	376	/*
	377	* Extract a RSA public key value
	378	*/
	379	int rsa_extract_mpi(void *context, size_t hdrlen,
	380	unsigned char tag,
	381	const void *value, size_t vlen)
	382	{
	383	struct x509_parse_context *ctx = context;
	384	MPI mpi;
	385
	386	if (ctx->nr_mpi >= ARRAY_SIZE(ctx->cert->pub->mpi)) {
	387	pr_err("Too many public key MPIs in certificate\n");
	388	return -EBADMSG;
	389	}
	390
	391	mpi = mpi_read_raw_data(value, vlen);
	392	if (!mpi)
	393	return -ENOMEM;
	394
	395	ctx->cert->pub->mpi[ctx->nr_mpi++] = mpi;
	396	return 0;
	397	}
	398
04b00bdb CYL	399	/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
	400	#define SEQ_TAG_KEYID (ASN1_CONT << 6)
	401
c26fd69f DH	402	/*
	403	* Process certificate extensions that are used to qualify the certificate.
	404	*/
	405	int x509_process_extension(void *context, size_t hdrlen,
	406	unsigned char tag,
	407	const void *value, size_t vlen)
	408	{
	409	struct x509_parse_context *ctx = context;
	410	const unsigned char *v = value;
	411	char *f;
	412	int i;
	413
	414	pr_debug("Extension: %u\n", ctx->last_oid);
	415
	416	if (ctx->last_oid == OID_subjectKeyIdentifier) {
	417	/* Get hold of the key fingerprint */
	418	if (vlen < 3)
	419	return -EBADMSG;
	420	if (v[0] != ASN1_OTS \|\| v[1] != vlen - 2)
	421	return -EBADMSG;
	422	v += 2;
	423	vlen -= 2;
	424
	425	f = kmalloc(vlen * 2 + 1, GFP_KERNEL);
	426	if (!f)
	427	return -ENOMEM;
	428	for (i = 0; i < vlen; i++)
	429	sprintf(f + i * 2, "%02x", v[i]);
	430	pr_debug("fingerprint %s\n", f);
	431	ctx->cert->fingerprint = f;
	432	return 0;
	433	}
	434
	435	if (ctx->last_oid == OID_authorityKeyIdentifier) {
04b00bdb CYL	436	size_t key_len;
04b00bdb CYL	437
c26fd69f DH	438	/* Get hold of the CA key fingerprint */
	439	if (vlen < 5)
	440	return -EBADMSG;
04b00bdb CYL	441
	442	/* Authority Key Identifier must be a Constructed SEQUENCE */
	443	if (v[0] != (ASN1_SEQ \| (ASN1_CONS << 5)))
c26fd69f	444	return -EBADMSG;
c26fd69f	445
04b00bdb CYL	446	/* Authority Key Identifier is not indefinite length */
	447	if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
	448	return -EBADMSG;
	449
	450	if (vlen < ASN1_INDEFINITE_LENGTH) {
	451	/* Short Form length */
	452	if (v[1] != vlen - 2 \|\|
	453	v[2] != SEQ_TAG_KEYID \|\|
	454	v[3] > vlen - 4)
	455	return -EBADMSG;
	456
	457	key_len = v[3];
	458	v += 4;
	459	} else {
	460	/* Long Form length */
	461	size_t seq_len = 0;
	462	size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;
	463
	464	if (sub > 2)
	465	return -EBADMSG;
	466
	467	/* calculate the length from subsequent octets */
	468	v += 2;
	469	for (i = 0; i < sub; i++) {
	470	seq_len <<= 8;
	471	seq_len \|= v[i];
	472	}
	473
	474	if (seq_len != vlen - 2 - sub \|\|
	475	v[sub] != SEQ_TAG_KEYID \|\|
	476	v[sub + 1] > vlen - 4 - sub)
	477	return -EBADMSG;
	478
	479	key_len = v[sub + 1];
	480	v += (sub + 2);
	481	}
	482
	483	f = kmalloc(key_len * 2 + 1, GFP_KERNEL);
c26fd69f DH	484	if (!f)
c26fd69f DH	485	return -ENOMEM;
04b00bdb	486	for (i = 0; i < key_len; i++)
c26fd69f DH	487	sprintf(f + i * 2, "%02x", v[i]);
	488	pr_debug("authority %s\n", f);
	489	ctx->cert->authority = f;
	490	return 0;
	491	}
	492
	493	return 0;
	494	}
	495
	496	/*
	497	* Record a certificate time.
	498	*/
a5752d11	499	static int x509_note_time(struct tm *tm, size_t hdrlen,
c26fd69f DH	500	unsigned char tag,
	501	const unsigned char *value, size_t vlen)
	502	{
c26fd69f DH	503	const unsigned char *p = value;
	504
	505	#define dec2bin(X) ((X) - '0')
	506	#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
	507
	508	if (tag == ASN1_UNITIM) {
	509	/* UTCTime: YYMMDDHHMMSSZ */
	510	if (vlen != 13)
	511	goto unsupported_time;
a5752d11 DH	512	tm->tm_year = DD2bin(p);
	513	if (tm->tm_year >= 50)
	514	tm->tm_year += 1900;
c26fd69f	515	else
a5752d11	516	tm->tm_year += 2000;
c26fd69f DH	517	} else if (tag == ASN1_GENTIM) {
	518	/* GenTime: YYYYMMDDHHMMSSZ */
	519	if (vlen != 15)
	520	goto unsupported_time;
a5752d11	521	tm->tm_year = DD2bin(p) * 100 + DD2bin(p);
c26fd69f DH	522	} else {
	523	goto unsupported_time;
	524	}
	525
a5752d11 DH	526	tm->tm_year -= 1900;
	527	tm->tm_mon = DD2bin(p) - 1;
	528	tm->tm_mday = DD2bin(p);
	529	tm->tm_hour = DD2bin(p);
	530	tm->tm_min = DD2bin(p);
	531	tm->tm_sec = DD2bin(p);
c26fd69f DH	532
	533	if (*p != 'Z')
	534	goto unsupported_time;
	535
c26fd69f DH	536	return 0;
	537
	538	unsupported_time:
	539	pr_debug("Got unsupported time [tag %02x]: '%.s'\n",
	540	tag, (int)vlen, (int)vlen, value);
	541	return -EBADMSG;
	542	}
	543
	544	int x509_note_not_before(void *context, size_t hdrlen,
	545	unsigned char tag,
	546	const void *value, size_t vlen)
	547	{
	548	struct x509_parse_context *ctx = context;
	549	return x509_note_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
	550	}
	551
	552	int x509_note_not_after(void *context, size_t hdrlen,
	553	unsigned char tag,
	554	const void *value, size_t vlen)
	555	{
	556	struct x509_parse_context *ctx = context;
	557	return x509_note_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
	558	}