[ima-evm-utils PATCH 11/12] Use a file specific hash algorithm variable for signing files

From: Mimi Zohar <zohar@linux.ibm.com>
To: linux-integrity@vger.kernel.org
Cc: Mimi Zohar <zohar@linux.ibm.com>
Subject: [ima-evm-utils PATCH 11/12] Use a file specific hash algorithm variable for signing files
Date: Sun, 19 Nov 2023 11:50:42 -0500	[thread overview]
Message-ID: <20231119165043.46960-12-zohar@linux.ibm.com> (raw)
In-Reply-To: <20231119165043.46960-1-zohar@linux.ibm.com>

Instead of relying on the library "imaevm_params.algo" global variable,
which is not concurrency-safe, define and use an evmctl file specific
hash algorithm variable.

Propogate using the file specific hash algorithm variable in sign_evm(),
sign_ima(), hash_ima(), and sign_hash() function.

Replace using the library function ima_calc_hash() with ima_calc_hash2().

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
---
 src/evmctl.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/evmctl.c b/src/evmctl.c
index 7ae897d8b8b3..b802eeb1bf15 100644
--- a/src/evmctl.c
+++ b/src/evmctl.c
@@ -140,6 +140,7 @@ static bool evm_immutable;
 static bool evm_portable;
 static bool veritysig;
 static bool hwtpm;
+static char *hash_algo;
 
 #define HMAC_FLAG_NO_UUID	0x0001
 #define HMAC_FLAG_CAPS_SET	0x0002
@@ -570,12 +571,12 @@ static int sign_evm(const char *file, const char *key)
 	unsigned char sig[MAX_SIGNATURE_SIZE];
 	int len, err;
 
-	len = calc_evm_hash(file, imaevm_params.hash_algo, hash);
+	len = calc_evm_hash(file, hash_algo, hash);
 	if (len <= 1)
 		return len;
 	assert(len <= sizeof(hash));
 
-	len = sign_hash(imaevm_params.hash_algo, hash, len, key, NULL, sig + 1);
+	len = sign_hash(hash_algo, hash, len, key, NULL, sig + 1);
 	if (len <= 1)
 		return len;
 	assert(len < sizeof(sig));
@@ -609,10 +610,10 @@ static int hash_ima(const char *file)
 {
 	unsigned char hash[MAX_DIGEST_SIZE + 2]; /* +2 byte xattr header */
 	int len, err, offset;
-	int algo = imaevm_get_hash_algo(imaevm_params.hash_algo);
+	int algo = imaevm_get_hash_algo(hash_algo);
 
 	if (algo < 0) {
-		log_err("Unknown hash algo: %s\n", imaevm_params.hash_algo);
+		log_err("Unknown hash algo: %s\n", hash_algo);
 		return -1;
 	}
 	if (algo > PKEY_HASH_SHA1) {
@@ -624,7 +625,7 @@ static int hash_ima(const char *file)
 		offset = 1;
 	}
 
-	len = ima_calc_hash(file, hash + offset);
+	len = ima_calc_hash2(file, hash_algo, hash + offset);
 	if (len <= 1)
 		return len;
 	assert(len + offset <= sizeof(hash));
@@ -632,7 +633,7 @@ static int hash_ima(const char *file)
 	len += offset;
 
 	if (imaevm_params.verbose >= LOG_INFO)
-		log_info("hash(%s): ", imaevm_params.hash_algo);
+		log_info("hash(%s): ", hash_algo);
 
 	if (sigdump || imaevm_params.verbose >= LOG_INFO)
 		imaevm_hexdump(hash, len);
@@ -656,12 +657,12 @@ static int sign_ima(const char *file, const char *key)
 	unsigned char sig[MAX_SIGNATURE_SIZE];
 	int len, err;
 
-	len = ima_calc_hash(file, hash);
+	len = ima_calc_hash2(file, hash_algo, hash);
 	if (len <= 1)
 		return len;
 	assert(len <= sizeof(hash));
 
-	len = sign_hash(imaevm_params.hash_algo, hash, len, key, NULL, sig + 1);
+	len = sign_hash(hash_algo, hash, len, key, NULL, sig + 1);
 	if (len <= 1)
 		return len;
 	assert(len < sizeof(sig));
@@ -854,7 +855,7 @@ static int cmd_sign_hash(struct command *cmd)
 			assert(hashlen / 2 <= sizeof(hash));
 			hex2bin(hash, line, hashlen / 2);
 
-			siglen = sign_hash(imaevm_params.hash_algo, hash,
+			siglen = sign_hash(hash_algo, hash,
 					   hashlen / 2, key, NULL, sig + 1);
 			sig[0] = EVM_IMA_XATTR_DIGSIG;
 		}
@@ -3077,7 +3078,7 @@ int main(int argc, char *argv[])
 			sigdump = 1;
 			break;
 		case 'a':
-			imaevm_params.hash_algo = optarg;
+			hash_algo = optarg;
 			break;
 		case 'p':
 			if (optarg)
-- 
2.39.3

