Merge pull request #5436 from mpg/prog-hmac-cipher-psa

PSA: example programs for HMAC and AEAD vs legacy
This commit is contained in:
Manuel Pégourié-Gonnard 2022-02-09 10:53:49 +01:00 committed by GitHub
commit 9193f7d836
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GPG key ID: 4AEE18F83AFDEB23
10 changed files with 928 additions and 7 deletions

4
programs/.gitignore vendored
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@ -13,8 +13,10 @@
*.exe
aes/crypt_and_hash
cipher/cipher_aead_demo
hash/generic_sum
hash/hello
hash/md_hmac_demo
hash/md5sum
hash/sha1sum
hash/sha2sum
@ -38,7 +40,9 @@ pkey/rsa_sign
pkey/rsa_sign_pss
pkey/rsa_verify
pkey/rsa_verify_pss
psa/aead_demo
psa/crypto_examples
psa/hmac_demo
psa/key_ladder_demo
psa/psa_constant_names
random/gen_entropy

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@ -1,4 +1,5 @@
add_subdirectory(aes)
add_subdirectory(cipher)
if (NOT WIN32)
add_subdirectory(fuzz)
endif()

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@ -80,8 +80,10 @@ endif
## make sure to check that it still works if you tweak the format here.
APPS = \
aes/crypt_and_hash \
cipher/cipher_aead_demo \
hash/generic_sum \
hash/hello \
hash/md_hmac_demo \
pkey/dh_client \
pkey/dh_genprime \
pkey/dh_server \
@ -102,7 +104,9 @@ APPS = \
pkey/rsa_sign_pss \
pkey/rsa_verify \
pkey/rsa_verify_pss \
psa/aead_demo \
psa/crypto_examples \
psa/hmac_demo \
psa/key_ladder_demo \
psa/psa_constant_names \
random/gen_entropy \
@ -195,14 +199,22 @@ aes/crypt_and_hash$(EXEXT): aes/crypt_and_hash.c $(DEP)
echo " CC aes/crypt_and_hash.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) aes/crypt_and_hash.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
hash/hello$(EXEXT): hash/hello.c $(DEP)
echo " CC hash/hello.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) hash/hello.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
cipher/cipher_aead_demo$(EXEXT): cipher/cipher_aead_demo.c $(DEP)
echo " CC cipher/cipher_aead_demo.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) cipher/cipher_aead_demo.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
hash/generic_sum$(EXEXT): hash/generic_sum.c $(DEP)
echo " CC hash/generic_sum.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) hash/generic_sum.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
hash/hello$(EXEXT): hash/hello.c $(DEP)
echo " CC hash/hello.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) hash/hello.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
hash/md_hmac_demo$(EXEXT): hash/md_hmac_demo.c $(DEP)
echo " CC hash/md_hmac_demo.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) hash/md_hmac_demo.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
pkey/dh_client$(EXEXT): pkey/dh_client.c $(DEP)
echo " CC pkey/dh_client.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) pkey/dh_client.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
@ -283,6 +295,18 @@ pkey/rsa_encrypt$(EXEXT): pkey/rsa_encrypt.c $(DEP)
echo " CC pkey/rsa_encrypt.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) pkey/rsa_encrypt.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
psa/aead_demo$(EXEXT): psa/aead_demo.c $(DEP)
echo " CC psa/aead_demo.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) psa/aead_demo.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
psa/crypto_examples$(EXEXT): psa/crypto_examples.c $(DEP)
echo " CC psa/crypto_examples.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) psa/crypto_examples.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
psa/hmac_demo$(EXEXT): psa/hmac_demo.c $(DEP)
echo " CC psa/hmac_demo.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) psa/hmac_demo.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
psa/key_ladder_demo$(EXEXT): psa/key_ladder_demo.c $(DEP)
echo " CC psa/key_ladder_demo.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) psa/key_ladder_demo.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
@ -427,10 +451,6 @@ x509/req_app$(EXEXT): x509/req_app.c $(DEP)
echo " CC x509/req_app.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) x509/req_app.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
psa/crypto_examples$(EXEXT): psa/crypto_examples.c $(DEP)
echo " CC psa/crypto_examples.c"
$(CC) $(LOCAL_CFLAGS) $(CFLAGS) psa/crypto_examples.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
clean:
ifndef WINDOWS
rm -f $(EXES)

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@ -0,0 +1,13 @@
set(executables
cipher_aead_demo
)
foreach(exe IN LISTS executables)
add_executable(${exe} ${exe}.c $<TARGET_OBJECTS:mbedtls_test>)
target_link_libraries(${exe} ${mbedcrypto_target})
target_include_directories(${exe} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../tests/include)
endforeach()
install(TARGETS ${executables}
DESTINATION "bin"
PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)

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@ -0,0 +1,271 @@
/**
* Cipher API multi-part AEAD demonstration.
*
* This program AEAD-encrypts a message, using the algorithm and key size
* specified on the command line, using the multi-part API.
*
* It comes with a companion program psa/aead_demo.c, which does the same
* operations with the PSA Crypto API. The goal is that comparing the two
* programs will help people migrating to the PSA Crypto API.
*
* When used with multi-part AEAD operations, the `mbedtls_cipher_context`
* serves a triple purpose (1) hold the key, (2) store the algorithm when no
* operation is active, and (3) save progress information for the current
* operation. With PSA those roles are held by disinct objects: (1) a
* psa_key_id_t to hold the key, a (2) psa_algorithm_t to represent the
* algorithm, and (3) a psa_operation_t for multi-part progress.
*
* On the other hand, with PSA, the algorithms encodes the desired tag length;
* with Cipher the desired tag length needs to be tracked separately.
*
* This program and its companion psa/aead_demo.c illustrate this by doing the
* same sequence of multi-part AEAD computation with both APIs; looking at the
* two side by side should make the differences and similarities clear.
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* First include Mbed TLS headers to get the Mbed TLS configuration and
* platform definitions that we'll use in this program. Also include
* standard C headers for functions we'll use here. */
#include "mbedtls/build_info.h"
#include "mbedtls/cipher.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
/* If the build options we need are not enabled, compile a placeholder. */
#if !defined(MBEDTLS_CIPHER_C) || \
!defined(MBEDTLS_AES_C) || !defined(MBEDTLS_GCM_C) || \
!defined(MBEDTLS_CHACHAPOLY_C)
int main( void )
{
printf( "MBEDTLS_MD_C and/or "
"MBEDTLS_AES_C and/or MBEDTLS_GCM_C and/or "
"MBEDTLS_CHACHAPOLY_C not defined\r\n" );
return( 0 );
}
#else
/* The real program starts here. */
const char usage[] =
"Usage: cipher_aead_demo [aes128-gcm|aes256-gcm|aes128-gcm_8|chachapoly]";
/* Dummy data for encryption: IV/nonce, additional data, 2-part message */
const unsigned char iv1[12] = { 0x00 };
const unsigned char add_data1[] = { 0x01, 0x02 };
const unsigned char msg1_part1[] = { 0x03, 0x04 };
const unsigned char msg1_part2[] = { 0x05, 0x06, 0x07 };
/* Dummy data (2nd message) */
const unsigned char iv2[12] = { 0x10 };
const unsigned char add_data2[] = { 0x11, 0x12 };
const unsigned char msg2_part1[] = { 0x13, 0x14 };
const unsigned char msg2_part2[] = { 0x15, 0x16, 0x17 };
/* Maximum total size of the messages */
#define MSG1_SIZE ( sizeof( msg1_part1 ) + sizeof( msg1_part2 ) )
#define MSG2_SIZE ( sizeof( msg2_part1 ) + sizeof( msg2_part2 ) )
#define MSG_MAX_SIZE ( MSG1_SIZE > MSG2_SIZE ? MSG1_SIZE : MSG2_SIZE )
/* Dummy key material - never do this in production!
* 32-byte is enough to all the key size supported by this program. */
const unsigned char key_bytes[32] = { 0x2a };
/* Print the contents of a buffer in hex */
void print_buf( const char *title, unsigned char *buf, size_t len )
{
printf( "%s:", title );
for( size_t i = 0; i < len; i++ )
printf( " %02x", buf[i] );
printf( "\n" );
}
/* Run an Mbed TLS function and bail out if it fails.
* A string description of the error code can be recovered with:
* programs/util/strerror <value> */
#define CHK( expr ) \
do \
{ \
ret = ( expr ); \
if( ret != 0 ) \
{ \
printf( "Error %d at line %d: %s\n", \
ret, \
__LINE__, \
#expr ); \
goto exit; \
} \
} while( 0 )
/*
* Prepare encryption material:
* - interpret command-line argument
* - set up key
* - outputs: context and tag length, which together hold all the information
*/
static int aead_prepare( const char *info,
mbedtls_cipher_context_t *ctx,
size_t *tag_len )
{
int ret;
/* Convert arg to type + tag_len */
mbedtls_cipher_type_t type;
if( strcmp( info, "aes128-gcm" ) == 0 ) {
type = MBEDTLS_CIPHER_AES_128_GCM;
*tag_len = 16;
} else if( strcmp( info, "aes256-gcm" ) == 0 ) {
type = MBEDTLS_CIPHER_AES_256_GCM;
*tag_len = 16;
} else if( strcmp( info, "aes128-gcm_8" ) == 0 ) {
type = MBEDTLS_CIPHER_AES_128_GCM;
*tag_len = 8;
} else if( strcmp( info, "chachapoly" ) == 0 ) {
type = MBEDTLS_CIPHER_CHACHA20_POLY1305;
*tag_len = 16;
} else {
puts( usage );
return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
}
/* Prepare context for the given type */
CHK( mbedtls_cipher_setup( ctx,
mbedtls_cipher_info_from_type( type ) ) );
/* Import key */
int key_len = mbedtls_cipher_get_key_bitlen( ctx );
CHK( mbedtls_cipher_setkey( ctx, key_bytes, key_len, MBEDTLS_ENCRYPT ) );
exit:
return( ret );
}
/*
* Print out some information.
*
* All of this information was present in the command line argument, but his
* function demonstrates how each piece can be recovered from (ctx, tag_len).
*/
static void aead_info( const mbedtls_cipher_context_t *ctx, size_t tag_len )
{
mbedtls_cipher_type_t type = mbedtls_cipher_get_type( ctx );
const mbedtls_cipher_info_t *info = mbedtls_cipher_info_from_type( type );
const char *ciph = mbedtls_cipher_info_get_name( info );
int key_bits = mbedtls_cipher_get_key_bitlen( ctx );
mbedtls_cipher_mode_t mode = mbedtls_cipher_get_cipher_mode( ctx );
const char *mode_str = mode == MBEDTLS_MODE_GCM ? "GCM"
: mode == MBEDTLS_MODE_CHACHAPOLY ? "ChachaPoly"
: "???";
printf( "%s, %d, %s, %u\n",
ciph, key_bits, mode_str, (unsigned) tag_len );
}
/*
* Encrypt a 2-part message.
*/
static int aead_encrypt( mbedtls_cipher_context_t *ctx, size_t tag_len,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *part1, size_t part1_len,
const unsigned char *part2, size_t part2_len )
{
int ret;
size_t olen;
#define MAX_TAG_LENGTH 16
unsigned char out[MSG_MAX_SIZE + MAX_TAG_LENGTH];
unsigned char *p = out;
CHK( mbedtls_cipher_set_iv( ctx, iv, iv_len ) );
CHK( mbedtls_cipher_reset( ctx ) );
CHK( mbedtls_cipher_update_ad( ctx, ad, ad_len ) );
CHK( mbedtls_cipher_update( ctx, part1, part1_len, p, &olen ) );
p += olen;
CHK( mbedtls_cipher_update( ctx, part2, part2_len, p, &olen ) );
p += olen;
CHK( mbedtls_cipher_finish( ctx, p, &olen ) );
p += olen;
CHK( mbedtls_cipher_write_tag( ctx, p, tag_len ) );
p += tag_len;
olen = p - out;
print_buf( "out", out, olen );
exit:
return( ret );
}
/*
* AEAD demo: set up key/alg, print out info, encrypt messages.
*/
static int aead_demo( const char *info )
{
int ret = 0;
mbedtls_cipher_context_t ctx;
size_t tag_len;
mbedtls_cipher_init( &ctx );
CHK( aead_prepare( info, &ctx, &tag_len ) );
aead_info( &ctx, tag_len );
CHK( aead_encrypt( &ctx, tag_len,
iv1, sizeof( iv1 ), add_data1, sizeof( add_data1 ),
msg1_part1, sizeof( msg1_part1 ),
msg1_part2, sizeof( msg1_part2 ) ) );
CHK( aead_encrypt( &ctx, tag_len,
iv2, sizeof( iv2 ), add_data2, sizeof( add_data2 ),
msg2_part1, sizeof( msg2_part1 ),
msg2_part2, sizeof( msg2_part2 ) ) );
exit:
mbedtls_cipher_free( &ctx );
return( ret );
}
/*
* Main function
*/
int main( int argc, char **argv )
{
/* Check usage */
if( argc != 2 )
{
puts( usage );
return( 1 );
}
int ret;
/* Run the demo */
CHK( aead_demo( argv[1] ) );
exit:
return( ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE );
}
#endif

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@ -1,6 +1,7 @@
set(executables
generic_sum
hello
md_hmac_demo
)
foreach(exe IN LISTS executables)

View file

@ -0,0 +1,147 @@
/**
* MD API multi-part HMAC demonstration.
*
* This programs computes the HMAC of two messages using the multi-part API.
*
* This is a companion to psa/hmac_demo.c, doing the same operations with the
* legacy MD API. The goal is that comparing the two programs will help people
* migrating to the PSA Crypto API.
*
* When it comes to multi-part HMAC operations, the `mbedtls_md_context`
* serves a dual purpose (1) hold the key, and (2) save progress information
* for the current operation. With PSA those roles are held by two disinct
* objects: (1) a psa_key_id_t to hold the key, and (2) a psa_operation_t for
* multi-part progress.
*
* This program and its companion psa/hmac_demo.c illustrate this by doing the
* same sequence of multi-part HMAC computation with both APIs; looking at the
* two side by side should make the differences and similarities clear.
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* First include Mbed TLS headers to get the Mbed TLS configuration and
* platform definitions that we'll use in this program. Also include
* standard C headers for functions we'll use here. */
#include "mbedtls/build_info.h"
#include "mbedtls/md.h"
#include "mbedtls/platform_util.h" // for mbedtls_platform_zeroize
#include <stdlib.h>
#include <stdio.h>
/* If the build options we need are not enabled, compile a placeholder. */
#if !defined(MBEDTLS_MD_C)
int main( void )
{
printf( "MBEDTLS_MD_C not defined\r\n" );
return( 0 );
}
#else
/* The real program starts here. */
/* Dummy inputs for HMAC */
const unsigned char msg1_part1[] = { 0x01, 0x02 };
const unsigned char msg1_part2[] = { 0x03, 0x04 };
const unsigned char msg2_part1[] = { 0x05, 0x05 };
const unsigned char msg2_part2[] = { 0x06, 0x06 };
/* Dummy key material - never do this in production!
* This example program uses SHA-256, so a 32-byte key makes sense. */
const unsigned char key_bytes[32] = { 0 };
/* Print the contents of a buffer in hex */
void print_buf( const char *title, unsigned char *buf, size_t len )
{
printf( "%s:", title );
for( size_t i = 0; i < len; i++ )
printf( " %02x", buf[i] );
printf( "\n" );
}
/* Run an Mbed TLS function and bail out if it fails.
* A string description of the error code can be recovered with:
* programs/util/strerror <value> */
#define CHK( expr ) \
do \
{ \
ret = ( expr ); \
if( ret != 0 ) \
{ \
printf( "Error %d at line %d: %s\n", \
ret, \
__LINE__, \
#expr ); \
goto exit; \
} \
} while( 0 )
/*
* This function demonstrates computation of the HMAC of two messages using
* the multipart API.
*/
int hmac_demo(void)
{
int ret;
const mbedtls_md_type_t alg = MBEDTLS_MD_SHA256;
unsigned char out[MBEDTLS_MD_MAX_SIZE]; // safe but not optimal
mbedtls_md_context_t ctx;
mbedtls_md_init( &ctx );
/* prepare context and load key */
// the last argument to setup is 1 to enable HMAC (not just hashing)
const mbedtls_md_info_t *info = mbedtls_md_info_from_type( alg );
CHK( mbedtls_md_setup( &ctx, info, 1 ) );
CHK( mbedtls_md_hmac_starts( &ctx, key_bytes, sizeof( key_bytes ) ) );
/* compute HMAC(key, msg1_part1 | msg1_part2) */
CHK( mbedtls_md_hmac_update( &ctx, msg1_part1, sizeof( msg1_part1 ) ) );
CHK( mbedtls_md_hmac_update( &ctx, msg1_part2, sizeof( msg1_part2 ) ) );
CHK( mbedtls_md_hmac_finish( &ctx, out ) );
print_buf( "msg1", out, mbedtls_md_get_size( info ) );
/* compute HMAC(key, msg2_part1 | msg2_part2) */
CHK( mbedtls_md_hmac_reset( &ctx ) ); // prepare for new operation
CHK( mbedtls_md_hmac_update( &ctx, msg2_part1, sizeof( msg2_part1 ) ) );
CHK( mbedtls_md_hmac_update( &ctx, msg2_part2, sizeof( msg2_part2 ) ) );
CHK( mbedtls_md_hmac_finish( &ctx, out ) );
print_buf( "msg2", out, mbedtls_md_get_size( info ) );
exit:
mbedtls_md_free( &ctx );
mbedtls_platform_zeroize( out, sizeof( out ) );
return( ret );
}
int main(void)
{
int ret;
CHK( hmac_demo() );
exit:
return( ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE );
}
#endif

View file

@ -1,5 +1,7 @@
set(executables
aead_demo
crypto_examples
hmac_demo
key_ladder_demo
psa_constant_names
)

293
programs/psa/aead_demo.c Normal file
View file

@ -0,0 +1,293 @@
/**
* PSA API multi-part AEAD demonstration.
*
* This program AEAD-encrypts a message, using the algorithm and key size
* specified on the command line, using the multi-part API.
*
* It comes with a companion program cipher/cipher_aead_demo.c, which does the
* same operations with the legacy Cipher API. The goal is that comparing the
* two programs will help people migrating to the PSA Crypto API.
*
* When used with multi-part AEAD operations, the `mbedtls_cipher_context`
* serves a triple purpose (1) hold the key, (2) store the algorithm when no
* operation is active, and (3) save progress information for the current
* operation. With PSA those roles are held by disinct objects: (1) a
* psa_key_id_t to hold the key, a (2) psa_algorithm_t to represent the
* algorithm, and (3) a psa_operation_t for multi-part progress.
*
* On the other hand, with PSA, the algorithms encodes the desired tag length;
* with Cipher the desired tag length needs to be tracked separately.
*
* This program and its companion cipher/cipher_aead_demo.c illustrate this by
* doing the same sequence of multi-part AEAD computation with both APIs;
* looking at the two side by side should make the differences and
* similarities clear.
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* First include Mbed TLS headers to get the Mbed TLS configuration and
* platform definitions that we'll use in this program. Also include
* standard C headers for functions we'll use here. */
#include "mbedtls/build_info.h"
#include "psa/crypto.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
/* If the build options we need are not enabled, compile a placeholder. */
#if !defined(MBEDTLS_PSA_CRYPTO_C) || \
!defined(MBEDTLS_AES_C) || !defined(MBEDTLS_GCM_C) || \
!defined(MBEDTLS_CHACHAPOLY_C) || \
defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
int main( void )
{
printf( "MBEDTLS_PSA_CRYPTO_C and/or "
"MBEDTLS_AES_C and/or MBEDTLS_GCM_C and/or "
"MBEDTLS_CHACHAPOLY_C not defined, and/or "
"MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER defined\r\n" );
return( 0 );
}
#else
/* The real program starts here. */
const char usage[] =
"Usage: aead_demo [aes128-gcm|aes256-gcm|aes128-gcm_8|chachapoly]";
/* Dummy data for encryption: IV/nonce, additional data, 2-part message */
const unsigned char iv1[12] = { 0x00 };
const unsigned char add_data1[] = { 0x01, 0x02 };
const unsigned char msg1_part1[] = { 0x03, 0x04 };
const unsigned char msg1_part2[] = { 0x05, 0x06, 0x07 };
/* Dummy data (2nd message) */
const unsigned char iv2[12] = { 0x10 };
const unsigned char add_data2[] = { 0x11, 0x12 };
const unsigned char msg2_part1[] = { 0x13, 0x14 };
const unsigned char msg2_part2[] = { 0x15, 0x16, 0x17 };
/* Maximum total size of the messages */
#define MSG1_SIZE ( sizeof( msg1_part1 ) + sizeof( msg1_part2 ) )
#define MSG2_SIZE ( sizeof( msg2_part1 ) + sizeof( msg2_part2 ) )
#define MSG_MAX_SIZE ( MSG1_SIZE > MSG2_SIZE ? MSG1_SIZE : MSG2_SIZE )
/* Dummy key material - never do this in production!
* 32-byte is enough to all the key size supported by this program. */
const unsigned char key_bytes[32] = { 0x2a };
/* Print the contents of a buffer in hex */
void print_buf( const char *title, uint8_t *buf, size_t len )
{
printf( "%s:", title );
for( size_t i = 0; i < len; i++ )
printf( " %02x", buf[i] );
printf( "\n" );
}
/* Run a PSA function and bail out if it fails.
* The symbolic name of the error code can be recovered using:
* programs/psa/psa_consant_name status <value> */
#define PSA_CHECK( expr ) \
do \
{ \
status = ( expr ); \
if( status != PSA_SUCCESS ) \
{ \
printf( "Error %d at line %d: %s\n", \
(int) status, \
__LINE__, \
#expr ); \
goto exit; \
} \
} \
while( 0 )
/*
* Prepare encryption material:
* - interpret command-line argument
* - set up key
* - outputs: key and algorithm, which together hold all the information
*/
static psa_status_t aead_prepare( const char *info,
psa_key_id_t *key,
psa_algorithm_t *alg )
{
psa_status_t status;
/* Convert arg to alg + key_bits + key_type */
size_t key_bits;
psa_key_type_t key_type;
if( strcmp( info, "aes128-gcm" ) == 0 ) {
*alg = PSA_ALG_GCM;
key_bits = 128;
key_type = PSA_KEY_TYPE_AES;
} else if( strcmp( info, "aes256-gcm" ) == 0 ) {
*alg = PSA_ALG_GCM;
key_bits = 256;
key_type = PSA_KEY_TYPE_AES;
} else if( strcmp( info, "aes128-gcm_8" ) == 0 ) {
*alg = PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 8);
key_bits = 128;
key_type = PSA_KEY_TYPE_AES;
} else if( strcmp( info, "chachapoly" ) == 0 ) {
*alg = PSA_ALG_CHACHA20_POLY1305;
key_bits = 256;
key_type = PSA_KEY_TYPE_CHACHA20;
} else {
puts( usage );
return( PSA_ERROR_INVALID_ARGUMENT );
}
/* Prepare key attibutes */
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_ENCRYPT );
psa_set_key_algorithm( &attributes, *alg );
psa_set_key_type( &attributes, key_type );
psa_set_key_bits( &attributes, key_bits ); // optional
/* Import key */
PSA_CHECK( psa_import_key( &attributes, key_bytes, key_bits / 8, key ) );
exit:
return( status );
}
/*
* Print out some information.
*
* All of this information was present in the command line argument, but his
* function demonstrates how each piece can be recovered from (key, alg).
*/
static void aead_info( psa_key_id_t key, psa_algorithm_t alg )
{
psa_key_attributes_t attr = PSA_KEY_ATTRIBUTES_INIT;
(void) psa_get_key_attributes( key, &attr );
psa_key_type_t key_type = psa_get_key_type( &attr );
size_t key_bits = psa_get_key_bits( &attr );
psa_algorithm_t base_alg = PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG( alg );
size_t tag_len = PSA_AEAD_TAG_LENGTH( key_type, key_bits, alg );
const char *type_str = key_type == PSA_KEY_TYPE_AES ? "AES"
: key_type == PSA_KEY_TYPE_CHACHA20 ? "Chacha"
: "???";
const char *base_str = base_alg == PSA_ALG_GCM ? "GCM"
: base_alg == PSA_ALG_CHACHA20_POLY1305 ? "ChachaPoly"
: "???";
printf( "%s, %u, %s, %u\n",
type_str, (unsigned) key_bits, base_str, (unsigned) tag_len );
}
/*
* Encrypt a 2-part message.
*/
static int aead_encrypt( psa_key_id_t key, psa_algorithm_t alg,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *part1, size_t part1_len,
const unsigned char *part2, size_t part2_len )
{
psa_status_t status;
size_t olen, olen_tag;
unsigned char out[PSA_AEAD_ENCRYPT_OUTPUT_MAX_SIZE(MSG_MAX_SIZE)];
unsigned char *p = out, *end = out + sizeof( out );
unsigned char tag[PSA_AEAD_TAG_MAX_SIZE];
psa_aead_operation_t op = PSA_AEAD_OPERATION_INIT;
PSA_CHECK( psa_aead_encrypt_setup( &op, key, alg ) );
PSA_CHECK( psa_aead_set_nonce( &op, iv, iv_len ) );
PSA_CHECK( psa_aead_update_ad( &op, ad, ad_len ) );
PSA_CHECK( psa_aead_update( &op, part1, part1_len, p, end - p, &olen ) );
p += olen;
PSA_CHECK( psa_aead_update( &op, part2, part2_len, p, end - p, &olen ) );
p += olen;
PSA_CHECK( psa_aead_finish( &op, p, end - p, &olen,
tag, sizeof( tag ), &olen_tag ) );
p += olen;
memcpy( p, tag, olen_tag );
p += olen_tag;
olen = p - out;
print_buf( "out", out, olen );
exit:
psa_aead_abort( &op ); // required on errors, harmless on success
return( status );
}
/*
* AEAD demo: set up key/alg, print out info, encrypt messages.
*/
static psa_status_t aead_demo( const char *info )
{
psa_status_t status;
psa_key_id_t key;
psa_algorithm_t alg;
PSA_CHECK( aead_prepare( info, &key, &alg ) );
aead_info( key, alg );
PSA_CHECK( aead_encrypt( key, alg,
iv1, sizeof( iv1 ), add_data1, sizeof( add_data1 ),
msg1_part1, sizeof( msg1_part1 ),
msg1_part2, sizeof( msg1_part2 ) ) );
PSA_CHECK( aead_encrypt( key, alg,
iv2, sizeof( iv2 ), add_data2, sizeof( add_data2 ),
msg2_part1, sizeof( msg2_part1 ),
msg2_part2, sizeof( msg2_part2 ) ) );
exit:
psa_destroy_key( key );
return( status );
}
/*
* Main function
*/
int main( int argc, char **argv )
{
psa_status_t status = PSA_SUCCESS;
/* Check usage */
if( argc != 2 )
{
puts( usage );
return( EXIT_FAILURE );
}
/* Initialize the PSA crypto library. */
PSA_CHECK( psa_crypto_init( ) );
/* Run the demo */
PSA_CHECK( aead_demo( argv[1] ) );
/* Deinitialize the PSA crypto library. */
mbedtls_psa_crypto_free( );
exit:
return( status == PSA_SUCCESS ? EXIT_SUCCESS : EXIT_FAILURE );
}
#endif

169
programs/psa/hmac_demo.c Normal file
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@ -0,0 +1,169 @@
/**
* PSA API multi-part HMAC demonstration.
*
* This programs computes the HMAC of two messages using the multi-part API.
*
* It comes with a companion program hash/md_hmac_demo.c, which does the same
* operations with the legacy MD API. The goal is that comparing the two
* programs will help people migrating to the PSA Crypto API.
*
* When it comes to multi-part HMAC operations, the `mbedtls_md_context`
* serves a dual purpose (1) hold the key, and (2) save progress information
* for the current operation. With PSA those roles are held by two disinct
* objects: (1) a psa_key_id_t to hold the key, and (2) a psa_operation_t for
* multi-part progress.
*
* This program and its companion hash/md_hmac_demo.c illustrate this by doing
* the same sequence of multi-part HMAC computation with both APIs; looking at
* the two side by side should make the differences and similarities clear.
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* First include Mbed TLS headers to get the Mbed TLS configuration and
* platform definitions that we'll use in this program. Also include
* standard C headers for functions we'll use here. */
#include "mbedtls/build_info.h"
#include "psa/crypto.h"
#include "mbedtls/platform_util.h" // for mbedtls_platform_zeroize
#include <stdlib.h>
#include <stdio.h>
/* If the build options we need are not enabled, compile a placeholder. */
#if !defined(MBEDTLS_PSA_CRYPTO_C) || \
defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
int main( void )
{
printf( "MBEDTLS_PSA_CRYPTO_C not defined, "
"and/or MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER defined\r\n" );
return( 0 );
}
#else
/* The real program starts here. */
/* Dummy inputs for HMAC */
const unsigned char msg1_part1[] = { 0x01, 0x02 };
const unsigned char msg1_part2[] = { 0x03, 0x04 };
const unsigned char msg2_part1[] = { 0x05, 0x05 };
const unsigned char msg2_part2[] = { 0x06, 0x06 };
/* Dummy key material - never do this in production!
* This example program uses SHA-256, so a 32-byte key makes sense. */
const unsigned char key_bytes[32] = { 0 };
/* Print the contents of a buffer in hex */
void print_buf( const char *title, uint8_t *buf, size_t len )
{
printf( "%s:", title );
for( size_t i = 0; i < len; i++ )
printf( " %02x", buf[i] );
printf( "\n" );
}
/* Run a PSA function and bail out if it fails.
* The symbolic name of the error code can be recovered using:
* programs/psa/psa_consant_name status <value> */
#define PSA_CHECK( expr ) \
do \
{ \
status = ( expr ); \
if( status != PSA_SUCCESS ) \
{ \
printf( "Error %d at line %d: %s\n", \
(int) status, \
__LINE__, \
#expr ); \
goto exit; \
} \
} \
while( 0 )
/*
* This function demonstrates computation of the HMAC of two messages using
* the multipart API.
*/
psa_status_t hmac_demo(void)
{
psa_status_t status;
const psa_algorithm_t alg = PSA_ALG_HMAC(PSA_ALG_SHA_256);
uint8_t out[PSA_MAC_MAX_SIZE]; // safe but not optimal
/* PSA_MAC_LENGTH(PSA_KEY_TYPE_HMAC, 8 * sizeof( key_bytes ), alg)
* should work but see https://github.com/ARMmbed/mbedtls/issues/4320 */
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_key_id_t key = 0;
/* prepare key */
psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_SIGN_MESSAGE );
psa_set_key_algorithm( &attributes, alg );
psa_set_key_type( &attributes, PSA_KEY_TYPE_HMAC );
psa_set_key_bits( &attributes, 8 * sizeof( key_bytes ) ); // optional
status = psa_import_key( &attributes,
key_bytes, sizeof( key_bytes ), &key );
if( status != PSA_SUCCESS )
return( status );
/* prepare operation */
psa_mac_operation_t op = PSA_MAC_OPERATION_INIT;
size_t out_len = 0;
/* compute HMAC(key, msg1_part1 | msg1_part2) */
PSA_CHECK( psa_mac_sign_setup( &op, key, alg ) );
PSA_CHECK( psa_mac_update( &op, msg1_part1, sizeof( msg1_part1 ) ) );
PSA_CHECK( psa_mac_update( &op, msg1_part2, sizeof( msg1_part2 ) ) );
PSA_CHECK( psa_mac_sign_finish( &op, out, sizeof( out ), &out_len ) );
print_buf( "msg1", out, out_len );
/* compute HMAC(key, msg2_part1 | msg2_part2) */
PSA_CHECK( psa_mac_sign_setup( &op, key, alg ) );
PSA_CHECK( psa_mac_update( &op, msg2_part1, sizeof( msg2_part1 ) ) );
PSA_CHECK( psa_mac_update( &op, msg2_part2, sizeof( msg2_part2 ) ) );
PSA_CHECK( psa_mac_sign_finish( &op, out, sizeof( out ), &out_len ) );
print_buf( "msg2", out, out_len );
exit:
psa_mac_abort( &op ); // needed on error, harmless on success
psa_destroy_key( key );
mbedtls_platform_zeroize( out, sizeof( out ) );
return( status );
}
int main(void)
{
psa_status_t status = PSA_SUCCESS;
/* Initialize the PSA crypto library. */
PSA_CHECK( psa_crypto_init( ) );
/* Run the demo */
PSA_CHECK( hmac_demo() );
/* Deinitialize the PSA crypto library. */
mbedtls_psa_crypto_free( );
exit:
return( status == PSA_SUCCESS ? EXIT_SUCCESS : EXIT_FAILURE );
}
#endif