Allow 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.
Signed-off-by: Vitaly Chikunov <vt@xxxxxxxxxxxx>
---
README | 1 +
src/evmctl.c | 22 ++++++++++---
src/imaevm.h | 1 +
src/libimaevm.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++
tests/sign_verify.test | 1 +
5 files changed, 105 insertions(+), 5 deletions(-)
diff --git a/README b/README
index 8cd66e0..0e1f6ba 100644
--- a/README
+++ b/README
@@ -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)
diff --git a/src/evmctl.c b/src/evmctl.c
index 8ae5488..6a60599 100644
--- a/src/evmctl.c
+++ b/src/evmctl.c
@@ -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);
diff --git a/src/imaevm.h b/src/imaevm.h
index 9f38059..eab7f32 100644
--- a/src/imaevm.h
+++ b/src/imaevm.h
@@ -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);
diff --git a/src/libimaevm.c b/src/libimaevm.c
index 481d29d..a22d9bb 100644
--- a/src/libimaevm.c
+++ b/src/libimaevm.c
@@ -57,6 +57,7 @@
#include <openssl/pem.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
+#include <openssl/x509v3.h>
#include <openssl/err.h>
#include "imaevm.h"
@@ -748,6 +749,90 @@ void calc_keyid_v2(uint32_t *keyid, char *str, EVP_PKEY *pkey)
X509_PUBKEY_free(pk);
}
+enum keyid_file_type {
+ KEYID_FILE_PEM_KEY = 0,
+ KEYID_FILE_UNK_CERT,
+};
+
+/*
+ * @is_cert: 1 - this is a x509 cert file (maybe PEM, maybe DER encoded);
+ * 0 - this is a PEM encoded private key file with possible appended
+ * x509 cert.
+ */
+static unsigned long _ima_read_keyid(const char *certfile, uint32_t *keyid,
+ enum keyid_file_type file_type)
+{
+ uint32_t keyid_raw;
+ const ASN1_OCTET_STRING *skid;
+ int skid_len;
+ X509 *x = NULL;
+ FILE *fp;
+
+ if (!(fp = fopen(certfile, "r"))) {
+ log_err("read keyid: %s: Cannot open: %s\n", certfile,
+ strerror(errno));
+ return -1;
+ }
+ if (!PEM_read_X509(fp, &x, NULL, NULL)) {
+ if (ERR_GET_REASON(ERR_peek_last_error()) == PEM_R_NO_START_LINE) {
+ ERR_clear_error();
+ if (file_type == KEYID_FILE_PEM_KEY) {
+ log_debug("%s: x509 certificate not found\n",
+ certfile);
+ fclose(fp);
+ return -1;
+ }
+ rewind(fp);
+ d2i_X509_fp(fp, &x);
+ }
+ if (!x) {
+ ERR_print_errors_fp(stderr);
+ log_err("read keyid: %s: Error reading x509 certificate\n",
+ certfile);
+ fclose(fp);
+ return -1;
+ }
+ }
+ fclose(fp);
+
+ if (!(skid = X509_get0_subject_key_id(x))) {
+ log_err("read keyid: %s: SKID not found\n", certfile);
+ goto err_free;
+ }
+ skid_len = ASN1_STRING_length(skid);
+ if (skid_len < sizeof(keyid_raw)) {
+ log_err("read keyid: %s: SKID too short (len %d)\n", certfile,
+ skid_len);
+ goto err_free;
+ }
+ memcpy(&keyid_raw, ASN1_STRING_get0_data(skid) + skid_len
+ - sizeof(keyid_raw), sizeof(keyid_raw));
+ if (keyid)
+ memcpy(keyid, &keyid_raw, sizeof(*keyid));
+ log_info("keyid %04x (from %s)\n", ntohl(keyid_raw), certfile);
+ return ntohl(keyid_raw);
+
+err_free:
+ X509_free(x);
+ return -1;
+}
+
+/**
+ * ima_read_keyid() - Read 32-bit keyid from the cert file.
+ * @certfile: File possibly containing certificate in DER/PEM format.
+ * @keyid: Output keyid in network order.
+ *
+ * Try to read keyid from Subject Key Identifier (SKID) of certificate.
+ * Autodetect if cert is in PEM or DER encoding.
+ *
+ * Return: -1 (ULONG_MAX) on error;
+ * 32-bit keyid as unsigned integer in host order.
+ */
+unsigned long ima_read_keyid(const char *certfile, uint32_t *keyid)
+{
+ return _ima_read_keyid(certfile, keyid, KEYID_FILE_UNK_CERT);
+}
+
static EVP_PKEY *read_priv_pkey(const char *keyfile, const char *keypass)
{
FILE *fp;
diff --git a/tests/sign_verify.test b/tests/sign_verify.test
index 2c21812..52ea33a 100755
--- a/tests/sign_verify.test
+++ b/tests/sign_verify.test
@@ -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 OPTS=--keyid=@test-rsa1024.cer
sign_verify rsa1024 sha256 0x030204:K:0080
try_different_keys
try_different_sigs
--
2.11.0
