Use OPENSSL_strlcpy instead of strncpy in e_afalg.c

This avoids a spurious gcc warning:
./config enable-asan --strict-warnings
=>
In function 'afalg_create_sk',
    inlined from 'afalg_cipher_init' at engines/e_afalg.c:545:11:
engines/e_afalg.c:376:5: error: '__builtin_strncpy' output may be
    truncated copying 63 bytes from a string of length 63 [-Werror=stringop-truncation]
  376 |     strncpy((char *) sa.salg_name, ciphername, ALG_MAX_SALG_NAME);
      |     ^~~~~~~

[extended tests]

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9478)

diff --git a/engines/e_afalg.c b/engines/e_afalg.c
index c3f622e7521c71fa92da793a096bfd9273692403..dacbe358cb6a8628dd0ecd93f8912052835fd954 100644 (file)
--- a/engines/e_afalg.c
+++ b/engines/e_afalg.c
@@ -63,9 +63,6 @@ void engine_load_afalg_int(void)
 # define ALG_OP_TYPE     unsigned int
 # define ALG_OP_LEN      (sizeof(ALG_OP_TYPE))
 
-#define ALG_MAX_SALG_NAME       64
-#define ALG_MAX_SALG_TYPE       14
-
 # ifdef OPENSSL_NO_DYNAMIC_ENGINE
 void engine_load_afalg_int(void);
 # endif
@@ -371,10 +368,8 @@ static int afalg_create_sk(afalg_ctx *actx, const char *ciphertype,
 
     memset(&sa, 0, sizeof(sa));
     sa.salg_family = AF_ALG;
-    strncpy((char *) sa.salg_type, ciphertype, ALG_MAX_SALG_TYPE);
-    sa.salg_type[ALG_MAX_SALG_TYPE-1] = '\0';
-    strncpy((char *) sa.salg_name, ciphername, ALG_MAX_SALG_NAME);
-    sa.salg_name[ALG_MAX_SALG_NAME-1] = '\0';
+    OPENSSL_strlcpy((char *) sa.salg_type, ciphertype, sizeof(sa.salg_type));
+    OPENSSL_strlcpy((char *) sa.salg_name, ciphername, sizeof(sa.salg_name));
 
     actx->bfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
     if (actx->bfd == -1) {
@@ -503,7 +498,7 @@ static int afalg_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
     int ciphertype;
     int ret;
     afalg_ctx *actx;
-    char ciphername[ALG_MAX_SALG_NAME];
+    const char *ciphername;
 
     if (ctx == NULL || key == NULL) {
         ALG_WARN("%s(%d): Null Parameter\n", __FILE__, __LINE__);
@@ -526,14 +521,13 @@ static int afalg_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
     case NID_aes_128_cbc:
     case NID_aes_192_cbc:
     case NID_aes_256_cbc:
-        strncpy(ciphername, "cbc(aes)", ALG_MAX_SALG_NAME);
+        ciphername = "cbc(aes)";
         break;
     default:
         ALG_WARN("%s(%d): Unsupported Cipher type %d\n", __FILE__, __LINE__,
                  ciphertype);
         return 0;
     }
-    ciphername[ALG_MAX_SALG_NAME-1]='\0';
 
     if (ALG_AES_IV_LEN != EVP_CIPHER_CTX_iv_length(ctx)) {
         ALG_WARN("%s(%d): Unsupported IV length :%d\n", __FILE__, __LINE__,