ECDSA: Refactor mbedtls_ecdsa_signature_to_raw

Change mbedtls_ecdsa_signature_to_raw so that it does not use MPI.
Add documentation changes.
This commit is contained in:
Andrzej Kurek 2018-02-27 09:23:22 -05:00
parent 6518fc8355
commit dfedd825c8
4 changed files with 60 additions and 43 deletions

View File

@ -256,8 +256,8 @@ int mbedtls_ecdsa_write_signature_det( mbedtls_ecdsa_context *ctx,
*/
int mbedtls_ecdsa_signature_to_raw( const unsigned char *sig,
size_t ssize, uint16_t byte_len,
unsigned char *buf, size_t bufsize,
size_t* buflen );
unsigned char *buf, size_t* buflen,
size_t bufsize );
/**
* \brief Convert a signature from numbers to ASN.1
*

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@ -4,7 +4,7 @@
* \brief Generic wrapper for Cryptoki (PKCS#11) support
*/
/*
* Copyright (C) 2017, ARM Limited, All Rights Reserved
* Copyright (C) 2017-2018, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
@ -70,10 +70,9 @@ extern "C" {
* \return 0 on success,
* or MBEDTLS_ERR_PK_XXX error code.
*
* \note The session and the key(s) must remain valid until the
* PK context is closed with mbedtls_pk_free(). As an
* exception, it's ok to call mbedtls_pk_free() itself
* even if the Cryptoki handles have become invalid.
* \note If any of the handles become invalid, then you may no
* longer do anything with the pk object except call
* mbedtls_pk_free on it.
*/
int mbedtls_pkcs11_setup_pk( mbedtls_pk_context *ctx,
CK_SESSION_HANDLE hSession,
@ -110,7 +109,7 @@ int mbedtls_pkcs11_setup_pk( mbedtls_pk_context *ctx,
* - #MBEDTLS_PK_FLAG_VERIFY: if set, the public key
* will be authorized for verification.
* - #MBEDTLS_PK_FLAG_DECRYPT: if set, the private key
* will be authorized for signing.
* will be authorized for decryption.
* - #MBEDTLS_PK_FLAG_ENCRYPT: if set, the public key
* will be authorized for encryption.
*

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@ -291,60 +291,78 @@ cleanup:
*/
int mbedtls_ecdsa_signature_to_raw( const unsigned char *sig,
size_t ssize, uint16_t byte_len,
unsigned char *buf, size_t bufsize,
size_t* buflen )
unsigned char *buf, size_t* buflen,
size_t bufsize)
{
int ret;
unsigned char *p = (unsigned char *) sig;
unsigned char *buf_ptr;
const unsigned char *end = sig + ssize;
size_t len;
mbedtls_mpi r, s;
size_t len, bytes_skipped, i;
if( 2 * byte_len > bufsize )
{
return (MBEDTLS_ERR_ECP_BAD_INPUT_DATA);
}
mbedtls_mpi_init( &r );
mbedtls_mpi_init( &s );
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
return ret;
}
if( p + len != end )
{
ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA +
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
goto cleanup;
}
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &r ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &s ) ) != 0 )
{
ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
}
p = (unsigned char *) buf;
if( ( ret = mbedtls_mpi_write_binary( &r, p, byte_len) ) )
{
ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
}
p += byte_len;
if( ( ret = mbedtls_mpi_write_binary( &s, p, byte_len) ) )
{
ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
}
*buflen = 2*byte_len;
/*
* Step 1: write R
*/
buf_ptr = buf;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
return( ret );
cleanup:
mbedtls_mpi_free( &r );
mbedtls_mpi_free( &s );
for( bytes_skipped = 0; bytes_skipped < len; bytes_skipped++ )
if( p[bytes_skipped] != 0 )
break;
if( len - bytes_skipped > bufsize )
{
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
*buflen = len - bytes_skipped;
for( i = bytes_skipped; i < len; i++ )
{
buf_ptr[i - bytes_skipped] = p[i];
}
p += len;
buf_ptr += *buflen;
/*
* Step 2: write S
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
return( ret );
for( bytes_skipped = 0; bytes_skipped < len; bytes_skipped++ )
if( p[bytes_skipped] != 0 )
break;
if( len - bytes_skipped + *buflen > bufsize )
{
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
*buflen += len - bytes_skipped;
for( i = bytes_skipped; i < len; i++ )
{
buf_ptr[i - bytes_skipped] = p[i];
}
return( ret );
}

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@ -1,7 +1,7 @@
/*
* Generic wrapper for Cryptoki (PKCS#11) support
*
* Copyright (C) 2017, ARM Limited, All Rights Reserved
* Copyright (C) 2017-2018, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
@ -292,8 +292,8 @@ static int pkcs11_verify( void *ctx_arg,
return( MBEDTLS_ERR_PK_ALLOC_FAILED );
}
if( mbedtls_ecdsa_signature_to_raw( sig, sig_len, byte_len,
decoded_sig, 2 * byte_len,
&decoded_sig_len ) != 0 )
decoded_sig, &decoded_sig_len,
2 * byte_len ) != 0 )
{
rv = CKR_GENERAL_ERROR;
goto exit;