ECDSA: Refactor mbedtls_ecdsa_signature_to_raw
Change mbedtls_ecdsa_signature_to_raw so that it does not use MPI.
Add documentation changes.
diff --git a/include/mbedtls/ecdsa.h b/include/mbedtls/ecdsa.h
index bff30fc..2b25aa6 100644
--- a/include/mbedtls/ecdsa.h
+++ b/include/mbedtls/ecdsa.h
@@ -256,8 +256,8 @@
*/
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
*
diff --git a/include/mbedtls/pkcs11_client.h b/include/mbedtls/pkcs11_client.h
index 97b4291..ac858f9 100644
--- a/include/mbedtls/pkcs11_client.h
+++ b/include/mbedtls/pkcs11_client.h
@@ -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 @@
* \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 @@
* - #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.
*
diff --git a/library/ecdsa.c b/library/ecdsa.c
index dba303b..7c8733e 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -291,60 +291,78 @@
*/
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 );
}
diff --git a/library/pkcs11_client.c b/library/pkcs11_client.c
index cb803cd..b328d8c 100644
--- a/library/pkcs11_client.c
+++ b/library/pkcs11_client.c
@@ -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 @@
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;