ima-evm-utils: Add --keyid option
v3 cover ima-evm-utils: Add --keyid option
Allow user to set signature's keyid using `--keyid' option. Keyid should correspond to SKID in certificate. When keyid is calculated using SHA-1 in libimaevm it may mismatch keyid extracted by the kernel from SKID of certificate (the way public key is presented to the kernel), thus making signatures not verifiable. This may happen when certificate is using non SHA-1 SKID (see rfc7093) or just 'unique number' (see rfc5280 4.2.1.2). As a last resort user may specify arbitrary keyid using the new option. Certificate @filename could be used instead of the hex number. And, third option is to read keyid from the cert appended to the key file.
These commits create backward incompatible ABI change for libimaevm,
thus soname should be incremented on release.
Changes from v2:
- Add ima_read_keyid() function to libemaevm and use it in both evmctl (for --keyid) and sign_hash_v2() (for concatenated PEMs). Suggested by Stefan Berger.
- Autodetect PEM by openssl reading it instead of magic string. Suggested by Stefan Berger.
- Trivial change: s/unsigned long int/unsigned long/ for keyid type.
Changes from v1:
- Extract keyid from cert associated to key file.
- Use sizeof instead of constant.
Changes since rfc version:
- `imaevm_params.keyid' now stored as native integer (instead of network order). Suggested by Stefan Berger.
- Added support for `--keyid=@filename'.
Vitaly Chikunov (3):
ima-evm-utils: Allow manual setting keyid for signing
ima-evm-utils: Allow manual setting keyid from a cert file
ima-evm-utils: Read keyid from the cert appended to the key file
README | 5 ++++ src/evmctl.c | 27 +++++++++++++++++++ src/imaevm.h | 2 ++ src/libimaevm.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++--- tests/sign_verify.test | 2 ++ 5 files changed, 105 insertions(+), 3 deletions(-)
Signature · 1 line
2.11.0
PATCH v3 1/3 ima-evm-utils: Allow manual setting keyid for signing
Allow user to set signature's keyid using `--keyid' option. Keyid should correspond to SKID in certificate, when keyid is calculated using SHA-1 in libimaevm it may mismatch keyid extracted by the kernel from SKID of certificate (the way public key is presented to the kernel), thus making signatures not verifiable. This may happen when certificate is using non SHA-1 SKID (see rfc7093) or just 'unique number' (see rfc5280 4.2.1.2). As a last resort user may specify arbitrary keyid using the new option.
This commit creates ABI change for libimaevm, because of adding additional parameter to imaevm_params - newer libimaevm cannot work with older clients.
--- README | 1 + src/evmctl.c | 15 +++++++++++++++ src/imaevm.h | 1 + src/libimaevm.c | 8 +++++--- tests/sign_verify.test | 1 + 5 files changed, 23 insertions(+), 3 deletions(-)
README +1 -0
@@ -48,6 +48,7 @@ OPTIONS --xattr-user store xattrs in user namespace (for testing purposes) --rsa use RSA key type and signing scheme v1 -k, --key path to signing key (default: /etc/keys/{privkey,pubkey}_evm.pem) + --keyid val overwrite signature keyid with a value (for signing) -o, --portable generate portable EVM signatures -p, --pass password for encrypted signing key -r, --recursive recurse into directories (sign)
src/evmctl.c +15 -0
@@ -2446,6 +2446,7 @@ static void usage(void)" --xattr-user store xattrs in user namespace (for testing purposes)\n" " --rsa use RSA key type and signing scheme v1\n" " -k, --key path to signing key (default: /etc/keys/{privkey,pubkey}_evm.pem)\n" +" --keyid val overwrite signature keyid with a value (for signing)\n" " -o, --portable generate portable EVM signatures\n" " -p, --pass password for encrypted signing key\n" " -r, --recursive recurse into directories (sign)\n"
@@ -2525,6 +2526,7 @@ static struct option opts[] = { {"xattr-user", 0, 0, 140}, {"ignore-violations", 0, 0, 141}, {"pcrs", 1, 0, 142}, + {"keyid", 1, 0, 143}, {} };
@@ -2569,6 +2571,8 @@ int main(int argc, char *argv[]) {int err =0 , c, lind;ENGINE *eng =NULL ; +unsigned long keyid; +char *eptr;#if !(OPENSSL_VERSION_NUMBER <0x10100000 ) OPENSSL_init_crypto(
@@ -2713,6 +2717,17 @@ int main(int argc, char *argv[]) } pcrfile[npcrfile++] = optarg;break ; +case 143 : + errno =0 ; + keyid =strtoul (optarg, &eptr,16 ); +if (errno || eptr - optarg !=strlen (optarg) || + keyid ==ULONG_MAX || keyid >UINT_MAX || + keyid ==0 ) { +log_err ("Invalid keyid value.\n" ); +exit (1 ); + } + imaevm_params.keyid = keyid; +break ;case '?' :exit (1 );break ;
src/imaevm.h +1 -0
@@ -196,6 +196,7 @@ struct libimaevm_params {const char *hash_algo;const char *keyfile;const char *keypass; +uint32_t keyid;/* keyid overriding value, unless 0. */ };struct RSA_ASN1_template {
src/libimaevm.c +5 -3
@@ -45,6 +45,7 @@#include <sys/param.h> #include <sys/stat.h> #include <asm/byteorder.h> +#include <arpa/inet.h> #include <unistd.h> #include <dirent.h> #include <string.h>
@@ -894,7 +895,6 @@ static int sign_hash_v2(const char *algo, const unsigned char *hash,const EVP_MD *md;size_t sigsize;const char *st; -uint32_t keyid;if (!hash) {log_err ("sign_hash_v2: hash is null\n" );
@@ -932,8 +932,10 @@ static int sign_hash_v2(const char *algo, const unsigned char *hash,return -1 ; } -calc_keyid_v2 (&keyid, name, pkey); - hdr->keyid = keyid; +if (imaevm_params.keyid) + hdr->keyid =htonl (imaevm_params.keyid); +else +calc_keyid_v2 (&hdr->keyid, name, pkey); st ="EVP_PKEY_CTX_new" ;if (!(ctx =EVP_PKEY_CTX_new (pkey,NULL )))
tests/sign_verify.test +1 -0
@@ -359,6 +359,7 @@ sign_verify rsa1024 sha256 0x0301 --rsa sign_verify rsa1024 md5 0x030201:K:0080 sign_verify rsa1024 sha1 0x030202:K:0080 sign_verify rsa1024 sha224 0x030207:K:0080 +expect_pass check_sign TYPE=ima KEY=rsa1024 ALG=sha256 PREFIX=0x030204aabbccdd0080 OPTS=--keyid=aabbccdd sign_verify rsa1024 sha256 0x030204:K:0080 try_different_keys try_different_sigs
Signature · 1 line
2.11.0
PATCH v3 2/3 ima-evm-utils: Allow manual setting keyid from a cert file
In reply to Vitaly ChikunovAllow user to specify `--keyid @/path/to/cert.pem' to extract keyid from SKID of the certificate file. PEM or DER format is auto-detected.
--keyid' option is reused instead of adding a new option (like possible --cert') to signify to the user it's only keyid extraction and nothing more.
This commit creates ABI change for libimaevm, due to adding new function ima_read_keyid(). Newer clients cannot work with older libimaevm. Together with previous commit it creates backward-incompatible ABI change, thus soname should be incremented on release.
--- README | 1 + src/evmctl.c | 22 ++++++++++++++---- src/imaevm.h | 1 + src/libimaevm.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++ tests/sign_verify.test | 1 + 5 files changed, 82 insertions(+), 5 deletions(-)
README +1 -0
@@ -49,6 +49,7 @@ OPTIONS --rsa use RSA key type and signing scheme v1 -k, --key path to signing key (default: /etc/keys/{privkey,pubkey}_evm.pem) --keyid val overwrite signature keyid with a value (for signing) + val is a x509 cert file if prefixed with '@' -o, --portable generate portable EVM signatures -p, --pass password for encrypted signing key -r, --recursive recurse into directories (sign)
src/evmctl.c +17 -5
@@ -42,6 +42,7 @@#include <sys/param.h> #include <sys/stat.h> #include <sys/ioctl.h> +#include <arpa/inet.h> #include <fcntl.h> #include <unistd.h> #include <stdlib.h>
@@ -57,12 +58,14 @@#include <termios.h> #include <assert.h> +#include <openssl/asn1.h> #include <openssl/sha.h> #include <openssl/pem.h> #include <openssl/hmac.h> #include <openssl/err.h> #include <openssl/rsa.h> #include <openssl/engine.h> +#include <openssl/x509v3.h> #include "hash_info.h" #include "pcr.h" #include "utils.h"
@@ -2447,6 +2450,7 @@ static void usage(void)" --rsa use RSA key type and signing scheme v1\n" " -k, --key path to signing key (default: /etc/keys/{privkey,pubkey}_evm.pem)\n" " --keyid val overwrite signature keyid with a value (for signing)\n" +" val is a x509 cert file if prefixed with '@'\n" " -o, --portable generate portable EVM signatures\n" " -p, --pass password for encrypted signing key\n" " -r, --recursive recurse into directories (sign)\n"
@@ -2572,7 +2576,6 @@ int main(int argc, char *argv[])int err =0 , c, lind;ENGINE *eng =NULL ;unsigned long keyid; -char *eptr;#if !(OPENSSL_VERSION_NUMBER <0x10100000 ) OPENSSL_init_crypto(
@@ -2718,10 +2721,19 @@ int main(int argc, char *argv[]) pcrfile[npcrfile++] = optarg;break ;case 143 : - errno =0 ; - keyid =strtoul (optarg, &eptr,16 ); -if (errno || eptr - optarg !=strlen (optarg) || - keyid ==ULONG_MAX || keyid >UINT_MAX || +if (optarg[0 ] =='@' ) { + keyid =ima_read_keyid (optarg +1 ,NULL ); + }else { +char *eptr; + + errno =0 ; + keyid =strtoul (optarg, &eptr,16 ); +if (eptr - optarg !=strlen (optarg) || errno) { +log_err ("Invalid keyid value.\n" ); +exit (1 ); + } + } +if (keyid ==ULONG_MAX || keyid >UINT_MAX || keyid ==0 ) {log_err ("Invalid keyid value.\n" );exit (1 );
src/imaevm.h +1 -0
@@ -219,6 +219,7 @@ EVP_PKEY *read_pub_pkey(const char *keyfile, int x509);void calc_keyid_v1 (uint8_t *keyid,char *str,const unsigned char *pkey,int len);void calc_keyid_v2 (uint32_t *keyid,char *str,EVP_PKEY *pkey);int key2bin (RSA *key,unsigned char *pub); +unsigned long ima_read_keyid (const char *certfile,uint32_t *keyid);int sign_hash (const char *algo,const unsigned char *hash,int size,const char *keyfile,const char *keypass,unsigned char *sig);int verify_hash (const char *file,const unsigned char *hash,int size,unsigned char *sig,int siglen);
src/libimaevm.c +62 -0
74 lines not on this page · raw message
tests/sign_verify.test +1 -0
@@ -360,6 +360,7 @@ sign_verify rsa1024 md5 0x030201:K:0080 sign_verify rsa1024 sha1 0x030202:K:0080 sign_verify rsa1024 sha224 0x030207:K:0080 expect_pass check_sign TYPE=ima KEY=rsa1024 ALG=sha256 PREFIX=0x030204aabbccdd0080 OPTS=--keyid=aabbccdd +expect_pass check_sign TYPE=ima KEY=rsa1024 ALG=sha256 PREFIX=0x030204:K:0080 [email protected] sign_verify rsa1024 sha256 0x030204:K:0080 try_different_keys try_different_sigs
Signature · 1 line
2.11.0
PATCH v3 3/3 ima-evm-utils: Read keyid from the cert appended to the key file
In reply to Vitaly ChikunovAllow to have certificate appended to the private key of `--key' specified (PEM) file (for v2 signing) to facilitate reading of keyid from the associated cert. This will allow users to have private and public key as a single file. There is no check that public key form the cert matches associated private key.
--- README | 3 +++ src/libimaevm.c | 8 +++++--- 2 files changed, 8 insertions(+), 3 deletions(-)
README +3 -0
@@ -127,6 +127,9 @@ for signing and importing the key. Second key format uses X509 DER encoded public key certificates and uses asymmetric key support in the kernel (since kernel 3.9). CONFIG_INTEGRITY_ASYMMETRIC_KEYS must be enabled (default). +For v2 signatures x509 certificate with the public key could be appended to the private +key (both are in PEM format) to properly determine its Subject Key Identifier (SKID). + Integrity keyrings ----------------
src/libimaevm.c +5 -3
@@ -994,10 +994,12 @@ static int sign_hash_v2(const char *algo, const unsigned char *hash,return -1 ; } -if (imaevm_params.keyid) +if (imaevm_params.keyid) { hdr->keyid =htonl (imaevm_params.keyid); -else -calc_keyid_v2 (&hdr->keyid, name, pkey); + }else { +if (ima_read_keyid (keyfile, &hdr->keyid) ==ULONG_MAX ) +calc_keyid_v2 (&hdr->keyid, name, pkey); + } st ="EVP_PKEY_CTX_new" ;if (!(ctx =EVP_PKEY_CTX_new (pkey,NULL )))
Signature · 1 line
2.11.0