1 files changed, 155 insertions, 74 deletions

diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index a668d90302d3..1995d6d962f5 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -18,6 +18,7 @@
 #include "public_key.h"
 #include "x509_parser.h"
 #include "x509-asn1.h"
+#include "x509_akid-asn1.h"
 #include "x509_rsakey-asn1.h"
 
 struct x509_parse_context {
@@ -35,6 +36,10 @@ struct x509_parse_context {
 	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;
 };
 
 /*
@@ -48,7 +53,8 @@ void x509_free_certificate(struct x509_certificate *cert)
 		kfree(cert->subject);
 		kfree(cert->id);
 		kfree(cert->skid);
-		kfree(cert->authority);
+		kfree(cert->akid_id);
+		kfree(cert->akid_skid);
 		kfree(cert->sig.digest);
 		mpi_free(cert->sig.rsa.s);
 		kfree(cert);
@@ -85,6 +91,18 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t 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;
+		}
+	}
+
 	/* Decode the public key */
 	ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx,
 			       ctx->key, ctx->key_size);
@@ -422,7 +440,6 @@ int x509_process_extension(void *context, size_t hdrlen,
 	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);
 
@@ -449,117 +466,113 @@ int x509_process_extension(void *context, size_t hdrlen,
 
 	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;
+		ctx->raw_akid = v;
+		ctx->raw_akid_size = vlen;
 		return 0;
 	}
 
 	return 0;
 }
 
-/*
- * Record a certificate time.
+/**
+ * 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.
  */
-static int x509_note_time(struct tm *tm,  size_t hdrlen,
-			  unsigned char tag,
-			  const unsigned char *value, size_t vlen)
+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) ((X) - '0')
+#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;
-		tm->tm_year = DD2bin(p);
-		if (tm->tm_year >= 50)
-			tm->tm_year += 1900;
+		year = DD2bin(p);
+		if (year >= 50)
+			year += 1900;
 		else
-			tm->tm_year += 2000;
+			year += 2000;
 	} else if (tag == ASN1_GENTIM) {
 		/* GenTime: YYYYMMDDHHMMSSZ */
 		if (vlen != 15)
 			goto unsupported_time;
-		tm->tm_year = DD2bin(p) * 100 + DD2bin(p);
+		year = DD2bin(p) * 100 + DD2bin(p);
+		if (year >= 1950 && year <= 2049)
+			goto invalid_time;
 	} 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);
+	mon  = DD2bin(p);
+	day = DD2bin(p);
+	hour = DD2bin(p);
+	min  = DD2bin(p);
+	sec  = DD2bin(p);
 
 	if (*p != 'Z')
 		goto unsupported_time;
 
+	mon_len = month_lengths[mon];
+	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 (year < 1970 ||
+	    mon < 1 || mon > 12 ||
+	    day < 1 || day > mon_len ||
+	    hour < 0 || hour > 23 ||
+	    min < 0 || min > 59 ||
+	    sec < 0 || sec > 59)
+		goto invalid_time;
+	
+	*_t = mktime64(year, mon, day, hour, min, sec);
 	return 0;
 
 unsupported_time:
-	pr_debug("Got unsupported time [tag %02x]: '%*.*s'\n",
-		 tag, (int)vlen, (int)vlen, value);
+	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_note_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
+	return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
 }
 
 int x509_note_not_after(void *context, size_t hdrlen,
@@ -567,5 +580,73 @@ int x509_note_not_after(void *context, size_t hdrlen,
 			const void *value, size_t vlen)
 {
 	struct x509_parse_context *ctx = context;
-	return x509_note_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
+	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(ctx->cert->raw_issuer,
+					 ctx->cert->raw_issuer_size,
+					 value, vlen);
+	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;
 }