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M467: GCM support one simple mode instead of using composite GHASH & CTR MODE

pull/15337/head
cyliangtw 2022-05-05 20:51:05 +08:00 committed by Chun-Chieh Li
parent 9dc7cd2f23
commit 9f01968d64
1 changed files with 85 additions and 0 deletions
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85
connectivity/drivers/mbedtls/TARGET_NUVOTON/TARGET_M460/gcm/gcm_alt.c
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@ -563,6 +563,90 @@ gcm_exit:
}
//#define NVT_GCM_USE_GHASH_CTR_MODE
#ifndef NVT_GCM_USE_GHASH_CTR_MODE
/*
* Apply GCM mode only for Decrypt, Encrypt & Tag
*/
int mbedtls_gcm_crypt_and_tag( mbedtls_gcm_context *ctx,
int mode,
size_t length,
const unsigned char *iv,
size_t iv_len,
const unsigned char *add,
size_t add_len,
const unsigned char *input,
unsigned char *output,
size_t tag_len,
unsigned char *tag )
{
int ret = MBEDTLS_ERR_GCM_AUTH_FAILED;
GCM_VALIDATE_RET( ctx != NULL );
GCM_VALIDATE_RET( iv != NULL );
GCM_VALIDATE_RET( add_len == 0 || add != NULL );
GCM_VALIDATE_RET( length == 0 || input != NULL );
GCM_VALIDATE_RET( length == 0 || output != NULL );
GCM_VALIDATE_RET( tag != NULL );
if( ( ret = mbedtls_gcm_starts( ctx, mode, iv, iv_len, add, add_len ) ) != 0 )
return( ret );
if( ( ret = mbedtls_gcm_update( ctx, length, input, output ) ) != 0 )
return( ret );
if( ( ret = mbedtls_gcm_finish( ctx, tag, tag_len ) ) != 0 )
return( ret );
return( 0 );
}
int mbedtls_gcm_auth_decrypt( mbedtls_gcm_context *ctx,
size_t length,
const unsigned char *iv,
size_t iv_len,
const unsigned char *add,
size_t add_len,
const unsigned char *tag,
size_t tag_len,
const unsigned char *input,
unsigned char *output )
{
int ret = MBEDTLS_ERR_GCM_AUTH_FAILED;
unsigned char check_tag[16];
size_t i;
int diff;
GCM_VALIDATE_RET( ctx != NULL );
GCM_VALIDATE_RET( iv != NULL );
GCM_VALIDATE_RET( add_len == 0 || add != NULL );
GCM_VALIDATE_RET( tag != NULL );
GCM_VALIDATE_RET( length == 0 || input != NULL );
GCM_VALIDATE_RET( length == 0 || output != NULL );
if( ( ret = mbedtls_gcm_crypt_and_tag( ctx, MBEDTLS_GCM_DECRYPT, length,
iv, iv_len, add, add_len,
input, output, tag_len, check_tag ) ) != 0 )
{
return( ret );
}
/* Check tag in "constant-time" */
for( diff = 0, i = 0; i < tag_len; i++ )
diff |= tag[i] ^ check_tag[i];
if( diff != 0 )
{
mbedtls_platform_zeroize( output, length );
return( MBEDTLS_ERR_GCM_AUTH_FAILED );
}
return( 0 );
}
#else /* NVT_GCM_USE_GHASH_CTR_MODE */
/*
* Apply GHASH & CTR mode for Tag calculation @GCMEnc
*/
@ -1006,5 +1090,6 @@ int mbedtls_gcm_auth_decrypt( mbedtls_gcm_context *ctx,
}
#endif /* NVT_GCM_USE_GHASH_CTR_MODE */
#endif /* MBEDTLS_GCM_ALT */
#endif /* MBEDTLS_GCM_C */