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| author | Dmitry V. Levin <ldv@strace.io> | 2024-12-30 08:00:00 +0000 |
|---|---|---|
| committer | Dmitry V. Levin <ldv@strace.io> | 2024-12-30 08:00:00 +0000 |
| commit | e634a3a9be9484ada6e93970dfaf0f055ca17332 (patch) | |
| tree | 18ed0f317b95dd08c94f98569fd1d27d7b9f5745 | |
| parent | c6efd4e8696233c8c180a10dbcbcb035e1bd8536 (diff) | |
| download | pam-e634a3a9be9484ada6e93970dfaf0f055ca17332.tar.gz pam-e634a3a9be9484ada6e93970dfaf0f055ca17332.tar.bz2 pam-e634a3a9be9484ada6e93970dfaf0f055ca17332.zip | |
pam_unix: do not overwrite the string returned by crypt_r
Given that the crypt_data storage passed to crypt_r is cleared
afterwards, there is no point in clearing the string returned by
crypt_r. This also fixes the issue with those crypt_r implementations
that can return a pointer to read-only memory.
Resolves: https://github.com/linux-pam/linux-pam/issues/866
| -rw-r--r-- | modules/pam_unix/bigcrypt.c | 4 | ||||
| -rw-r--r-- | modules/pam_unix/passverify.c | 8 |
2 files changed, 8 insertions, 4 deletions
diff --git a/modules/pam_unix/bigcrypt.c b/modules/pam_unix/bigcrypt.c index 296e01f7..f960d978 100644 --- a/modules/pam_unix/bigcrypt.c +++ b/modules/pam_unix/bigcrypt.c @@ -116,7 +116,9 @@ char *bigcrypt(const char *key, const char *salt) } /* and place in the static area */ strncpy(cipher_ptr, tmp_ptr, 13); +#ifndef HAVE_CRYPT_R pam_overwrite_string(tmp_ptr); +#endif cipher_ptr += ESEGMENT_SIZE + SALT_SIZE; plaintext_ptr += SEGMENT_SIZE; /* first block of SEGMENT_SIZE */ @@ -149,7 +151,9 @@ char *bigcrypt(const char *key, const char *salt) /* skip the salt for seg!=0 */ strncpy(cipher_ptr, (tmp_ptr + SALT_SIZE), ESEGMENT_SIZE); +#ifndef HAVE_CRYPT_R pam_overwrite_string(tmp_ptr); +#endif cipher_ptr += ESEGMENT_SIZE; plaintext_ptr += SEGMENT_SIZE; diff --git a/modules/pam_unix/passverify.c b/modules/pam_unix/passverify.c index e8d0b91d..85e7841e 100644 --- a/modules/pam_unix/passverify.c +++ b/modules/pam_unix/passverify.c @@ -522,20 +522,20 @@ PAMH_ARG_DECL(char * create_password_hash, on(UNIX_BLOWFISH_PASS, ctrl) ? "blowfish" : on(UNIX_SHA256_PASS, ctrl) ? "sha256" : on(UNIX_SHA512_PASS, ctrl) ? "sha512" : algoid); - if(sp) { - pam_overwrite_string(sp); - } #ifdef HAVE_CRYPT_R pam_overwrite_object(cdata); free(cdata); +#else + pam_overwrite_string(sp); #endif return NULL; } ret = strdup(sp); - pam_overwrite_string(sp); #ifdef HAVE_CRYPT_R pam_overwrite_object(cdata); free(cdata); +#else + pam_overwrite_string(sp); #endif return ret; } |