Fix for pkcs12 with NULL or zero length password

Previously passing a NULL or zero length password into either
mbedtls_pkcs12_pbe() or mbedtls_pkcs12_derive() could cause an infinate
loop, and it was also possible to pass a NULL password, with a non-zero
length, which would cause memory corruption.
I have fixed these errors, and improved the documentation to reflect the
changes and further explain what is expected of the inputs.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
This commit is contained in:
Paul Elliott 2021-11-11 19:00:38 +00:00
parent f1a7ea88d1
commit 853c0da8de
3 changed files with 31 additions and 14 deletions

View file

@ -0,0 +1,2 @@
Bugfix
* Fix issues in pkcs12 when a NULL and/or zero length password was supplied.

View file

@ -56,11 +56,13 @@ extern "C" {
* \brief PKCS12 Password Based function (encryption / decryption)
* for cipher-based and mbedtls_md-based PBE's
*
* \param pbe_params an ASN1 buffer containing the pkcs-12PbeParams structure
* \param mode either MBEDTLS_PKCS12_PBE_ENCRYPT or MBEDTLS_PKCS12_PBE_DECRYPT
* \param pbe_params an ASN1 buffer containing the pkcs-12 PbeParams structure
* \param mode either MBEDTLS_PKCS12_PBE_ENCRYPT or
* MBEDTLS_PKCS12_PBE_DECRYPT
* \param cipher_type the cipher used
* \param md_type the mbedtls_md used
* \param pwd the password used (may be NULL if no password is used)
* \param md_type the mbedtls_md used
* \param pwd Latin1-encoded password used (may be NULL if no password is
* used, but not if pwdlen is non-zero)
* \param pwdlen length of the password (may be 0)
* \param input the input data
* \param len data length
@ -85,14 +87,16 @@ int mbedtls_pkcs12_pbe( mbedtls_asn1_buf *pbe_params, int mode,
* integrity key.
*
* \param data buffer to store the derived data in
* \param datalen length to fill
* \param pwd password to use (may be NULL if no password is used)
* \param datalen length of buffer to fill
* \param pwd Null terminated BMPString password to use (may be NULL if
* no password is used, but not if pwdlen is non-zero)
* \param pwdlen length of the password (may be 0)
* \param salt salt buffer to use
* \param saltlen length of the salt
* \param mbedtls_md mbedtls_md type to use during the derivation
* \param id id that describes the purpose (can be MBEDTLS_PKCS12_DERIVE_KEY,
* MBEDTLS_PKCS12_DERIVE_IV or MBEDTLS_PKCS12_DERIVE_MAC_KEY)
* \param mbedtls_md mbedtls_md type to use during the derivation
* \param id id that describes the purpose (can be
* MBEDTLS_PKCS12_DERIVE_KEY, MBEDTLS_PKCS12_DERIVE_IV or
* MBEDTLS_PKCS12_DERIVE_MAC_KEY)
* \param iterations number of iterations
*
* \return 0 if successful, or a MD, BIGNUM type error.

View file

@ -134,6 +134,9 @@ int mbedtls_pkcs12_pbe( mbedtls_asn1_buf *pbe_params, int mode,
mbedtls_cipher_context_t cipher_ctx;
size_t olen = 0;
if( pwd == NULL && pwdlen != 0 )
return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
cipher_info = mbedtls_cipher_info_from_type( cipher_type );
if( cipher_info == NULL )
return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );
@ -186,13 +189,18 @@ static void pkcs12_fill_buffer( unsigned char *data, size_t data_len,
unsigned char *p = data;
size_t use_len;
while( data_len > 0 )
if( filler != NULL && fill_len != 0 )
{
use_len = ( data_len > fill_len ) ? fill_len : data_len;
memcpy( p, filler, use_len );
p += use_len;
data_len -= use_len;
while( data_len > 0 )
{
use_len = ( data_len > fill_len ) ? fill_len : data_len;
memcpy( p, filler, use_len );
p += use_len;
data_len -= use_len;
}
}
else
memset( data, 0, data_len );
}
int mbedtls_pkcs12_derivation( unsigned char *data, size_t datalen,
@ -218,6 +226,9 @@ int mbedtls_pkcs12_derivation( unsigned char *data, size_t datalen,
if( datalen > 128 || pwdlen > 64 || saltlen > 64 )
return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
if( pwd == NULL && pwdlen != 0 )
return( MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA );
md_info = mbedtls_md_info_from_type( md_type );
if( md_info == NULL )
return( MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE );