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cipher: handle ChaCha20 as a stream cipher

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That's what it is. So we shouldn't set a block size != 1.

While at it, move call to chachapoly_update() closer to the one for GCM, as
they are similar (AEAD).
This commit is contained in:
Manuel Pégourié-Gonnard 2018-05-10 12:30:19 +02:00
parent c0dfcd4bf1
commit 32902e6eae
3 changed files with 27 additions and 30 deletions
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2
include/mbedtls/cipher.h
View File

@ -193,7 +193,7 @@ enum {
/** Maximum length of any IV, in Bytes. */
#define MBEDTLS_MAX_IV_LENGTH 16
/** Maximum block size of any cipher, in Bytes. */
#define MBEDTLS_MAX_BLOCK_LENGTH 64
#define MBEDTLS_MAX_BLOCK_LENGTH 16
/**
* Base cipher information (opaque struct).

34
library/cipher.c
View File

@ -367,6 +367,15 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *i
}
#endif
#if defined(MBEDTLS_CHACHAPOLY_C)
if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 )
{
*olen = ilen;
return mbedtls_chachapoly_update( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
ilen, input, output );
}
#endif
if ( 0 == block_size )
{
return MBEDTLS_ERR_CIPHER_INVALID_CONTEXT;
@ -378,31 +387,6 @@ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *i
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_CHACHA20_C)
if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20 )
{
*olen = ilen;
return mbedtls_chacha20_update( (mbedtls_chacha20_context*) ctx->cipher_ctx,
ilen, input, output );
}
#endif
if( input == output &&
( ctx->unprocessed_len != 0 || ilen % mbedtls_cipher_get_block_size( ctx ) ) )
{
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
#if defined(MBEDTLS_CHACHAPOLY_C)
if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 )
{
*olen = ilen;
return mbedtls_chachapoly_update( (mbedtls_chachapoly_context*) ctx->cipher_ctx,
ilen, input, output );
}
#endif
#if defined(MBEDTLS_CIPHER_MODE_CBC)
if( ctx->cipher_info->mode == MBEDTLS_MODE_CBC )
{

21
library/cipher_wrap.c
View File

@ -1305,6 +1305,19 @@ static int chacha20_setkey_wrap( void *ctx, const unsigned char *key,
return( 0 );
}
static int chacha20_stream_wrap( void *ctx, size_t length,
const unsigned char *input,
unsigned char *output )
{
int ret;
ret = mbedtls_chacha20_update( ctx, length, input, output );
if( ret == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA )
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
return( ret );
}
static void * chacha20_ctx_alloc( void )
{
mbedtls_chacha20_context *ctx;
@ -1337,7 +1350,7 @@ static const mbedtls_cipher_base_t chacha20_base_info = {
NULL,
#endif
#if defined(MBEDTLS_CIPHER_MODE_STREAM)
NULL,
chacha20_stream_wrap,
#endif
chacha20_setkey_wrap,
chacha20_setkey_wrap,
@ -1346,12 +1359,12 @@ static const mbedtls_cipher_base_t chacha20_base_info = {
};
static const mbedtls_cipher_info_t chacha20_info = {
MBEDTLS_CIPHER_CHACHA20,
MBEDTLS_MODE_NONE,
MBEDTLS_MODE_STREAM,
256,
"CHACHA20",
12,
0,
64,
1,
&chacha20_base_info
};
#endif /* MBEDTLS_CHACHA20_C */
@ -1417,7 +1430,7 @@ static const mbedtls_cipher_info_t chachapoly_info = {
"CHACHA20-POLY1305",
12,
0,
64,
1,
&chachapoly_base_info
};
#endif /* MBEDTLS_CHACHAPOLY_C */