kernel/linux.git/include/crypto/public_key.h, branch v6.1.168

keys: X.509 public key issuer lookup without AKID

2022-01-08T22:18:42+00:00

There are non-root X.509 v3 certificates in use out there that contain no Authority Key Identifier extension (RFC5280 section 4.2.1.1). For trust verification purposes the kernel asymmetric key type keeps two struct asymmetric_key_id instances that the key can be looked up by, and another two to look up the key's issuer. The x509 public key type and the PKCS7 type generate them from the SKID and AKID extensions in the certificate. In effect current code has no way to look up the issuer certificate for verification without the AKID. To remedy this, add a third asymmetric_key_id blob to the arrays in both asymmetric_key_id's (for certficate subject) and in the public_keys_signature's auth_ids (for issuer lookup), using just raw subject and issuer DNs from the certificate. Adapt asymmetric_key_ids() and its callers to use the third ID for lookups when none of the other two are available. Attempt to keep the logic intact when they are, to minimise behaviour changes. Adapt the restrict functions' NULL-checks to include that ID too. Do not modify the lookup logic in pkcs7_verify.c, the AKID extensions are still required there. Internally use a new "dn:" prefix to the search specifier string generated for the key lookup in find_asymmetric_key(). This tells asymmetric_key_match_preparse to only match the data against the raw DN in the third ID and shouldn't conflict with search specifiers already in use. In effect implement what (2) in the struct asymmetric_key_id comment (include/keys/asymmetric-type.h) is probably talking about already, so do not modify that comment. It is also how "openssl verify" looks up issuer certificates without the AKID available. Lookups by the raw DN are unambiguous only provided that the CAs respect the condition in RFC5280 4.2.1.1 that the AKID may only be omitted if the CA uses a single signing key. The following is an example of two things that this change enables. A self-signed ceritficate is generated following the example from https://letsencrypt.org/docs/certificates-for-localhost/, and can be looked up by an identifier and verified against itself by linking to a restricted keyring -- both things not possible before due to the missing AKID extension: $ openssl req -x509 -out localhost.crt -outform DER -keyout localhost.key \ -newkey rsa:2048 -nodes -sha256 \ -subj '/CN=localhost' -extensions EXT -config <( \ echo -e "[dn]\nCN=localhost\n[req]\ndistinguished_name = dn\n[EXT]\n" \ "subjectAltName=DNS:localhost\nkeyUsage=digitalSignature\n" \ "extendedKeyUsage=serverAuth") $ keyring=`keyctl newring test @u` $ trusted=`keyctl padd asymmetric trusted $keyring < localhost.crt`; \ echo $trusted 39726322 $ keyctl search $keyring asymmetric dn:3112301006035504030c096c6f63616c686f7374 39726322 $ keyctl restrict_keyring $keyring asymmetric key_or_keyring:$trusted $ keyctl padd asymmetric verified $keyring < localhost.crt Signed-off-by: Andrew Zaborowski Reviewed-by: Jarkko Sakkinen Acked-by: Jarkko Sakkinen Acked-by: David Howells Signed-off-by: Jarkko Sakkinen

crypto: public_key: fix overflow during implicit conversion

2021-08-23T17:25:24+00:00

Hit kernel warning like this, it can be reproduced by verifying 256 bytes datafile by keyctl command, run script: RAWDATA=rawdata SIGDATA=sigdata modprobe pkcs8_key_parser rm -rf *.der *.pem *.pfx rm -rf $RAWDATA dd if=/dev/random of=$RAWDATA bs=256 count=1 openssl req -nodes -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem \ -subj "/C=CN/ST=GD/L=SZ/O=vihoo/OU=dev/CN=xx.com/emailAddress=yy@xx.com" KEY_ID=`openssl pkcs8 -in key.pem -topk8 -nocrypt -outform DER | keyctl \ padd asymmetric 123 @s` keyctl pkey_sign $KEY_ID 0 $RAWDATA enc=pkcs1 hash=sha1 > $SIGDATA keyctl pkey_verify $KEY_ID 0 $RAWDATA $SIGDATA enc=pkcs1 hash=sha1 Then the kernel reports: WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540 pkcs1pad_verify+0x160/0x190 ... Call Trace: public_key_verify_signature+0x282/0x380 ? software_key_query+0x12d/0x180 ? keyctl_pkey_params_get+0xd6/0x130 asymmetric_key_verify_signature+0x66/0x80 keyctl_pkey_verify+0xa5/0x100 do_syscall_64+0x35/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae The reason of this issue, in function 'asymmetric_key_verify_signature': '.digest_size(u8) = params->in_len(u32)' leads overflow of an u8 value, so use u32 instead of u8 for digest_size field. And reorder struct public_key_signature, it saves 8 bytes on a 64-bit machine. Cc: stable@vger.kernel.org Signed-off-by: zhenwei pi Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen

crypto: public_key: Remove redundant header file from public_key.h

2021-01-21T16:16:10+00:00

The akcipher.h header file was originally introduced in SM2, and then the definition of SM2 was moved to the existing code. This header file is left and should be removed. Signed-off-by: Tianjia Zhang Signed-off-by: David Howells Reviewed-by: Ben Boeckel

X.509: Fix modular build of public_key_sm2

2020-10-08T05:39:14+00:00

The sm2 code was split out of public_key.c in a way that breaks modular builds. This patch moves the code back into the same file as the original motivation was to minimise ifdefs and that has nothing to do with splitting the code out. Fixes: 215525639631 ("X.509: support OSCCA SM2-with-SM3...") Reported-by: kernel test robot Signed-off-by: Herbert Xu

X.509: support OSCCA SM2-with-SM3 certificate verification

2020-09-25T07:48:55+00:00

The digital certificate format based on SM2 crypto algorithm as specified in GM/T 0015-2012. It was published by State Encryption Management Bureau, China. The method of generating Other User Information is defined as ZA=H256(ENTLA || IDA || a || b || xG || yG || xA || yA), it also specified in https://tools.ietf.org/html/draft-shen-sm2-ecdsa-02. The x509 certificate supports SM2-with-SM3 type certificate verification. Because certificate verification requires ZA in addition to tbs data, ZA also depends on elliptic curve parameters and public key data, so you need to access tbs in sig and calculate ZA. Finally calculate the digest of the signature and complete the verification work. The calculation process of ZA is declared in specifications GM/T 0009-2012 and GM/T 0003.2-2012. Signed-off-by: Tianjia Zhang Tested-by: Xufeng Zhang Reviewed-by: Gilad Ben-Yossef Signed-off-by: Herbert Xu

docs: crypto: convert asymmetric-keys.txt to ReST

2020-06-19T20:03:46+00:00

This file is almost compatible with ReST. Just minor changes were needed: - Adjust document and titles markups; - Adjust numbered list markups; - Add a comments markup for the Contents section; - Add markups for literal blocks. Acked-by: Jarkko Sakkinen Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/c2275ea94e0507a01b020ab66dfa824d8b1c2545.1592203650.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36

2019-05-24T15:27:11+00:00

Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 114 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Kate Stewart Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de Signed-off-by: Greg Kroah-Hartman

X.509: parse public key parameters from x509 for akcipher

2019-04-18T14:15:02+00:00

Some public key algorithms (like EC-DSA) keep in parameters field important data such as digest and curve OIDs (possibly more for different EC-DSA variants). Thus, just setting a public key (as for RSA) is not enough. Append parameters into the key stream for akcipher_set_{pub,priv}_key. Appended data is: (u32) algo OID, (u32) parameters length, parameters data. This does not affect current akcipher API nor RSA ciphers (they could ignore it). Idea of appending parameters to the key stream is by Herbert Xu. Cc: David Howells Cc: Denis Kenzior Cc: keyrings@vger.kernel.org Signed-off-by: Vitaly Chikunov Reviewed-by: Denis Kenzior Signed-off-by: Herbert Xu

KEYS: Allow the public_key struct to hold a private key [ver #2]

2018-10-26T08:30:46+00:00

Put a flag in the public_key struct to indicate if the structure is holding a private key. The private key must be held ASN.1 encoded in the format specified in RFC 3447 A.1.2. This is the form required by crypto/rsa.c. The software encryption subtype's verification and query functions then need to select the appropriate crypto function to set the key. Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris

KEYS: Provide missing asymmetric key subops for new key type ops [ver #2]

2018-10-26T08:30:46+00:00

Provide the missing asymmetric key subops for new key type ops. This include query, encrypt, decrypt and create signature. Verify signature already exists. Also provided are accessor functions for this: int query_asymmetric_key(const struct key *key, struct kernel_pkey_query *info); int encrypt_blob(struct kernel_pkey_params *params, const void *data, void *enc); int decrypt_blob(struct kernel_pkey_params *params, const void *enc, void *data); int create_signature(struct kernel_pkey_params *params, const void *data, void *enc); The public_key_signature struct gains an encoding field to carry the encoding for verify_signature(). Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris