From da81214cec87201dc18c0ce71224367e13a6edfb Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Mon, 24 Oct 2022 19:20:41 +0100 Subject: [crypto] Add concept of authentication tag to cipher algorithms Some ciphers (such as GCM) support the concept of a tag that can be used to authenticate the encrypted data. Add a cipher method for generating an authentication tag. Signed-off-by: Michael Brown --- src/crypto/aes.c | 2 ++ src/crypto/arc4.c | 2 ++ src/crypto/crypto_null.c | 6 ++++++ src/include/ipxe/cbc.h | 2 ++ src/include/ipxe/crypto.h | 18 ++++++++++++++++++ src/include/ipxe/ecb.h | 2 ++ src/tests/aes_test.c | 12 ++++++------ src/tests/cipher_test.c | 14 ++++++++++++++ src/tests/cipher_test.h | 13 ++++++++++++- 9 files changed, 64 insertions(+), 7 deletions(-) diff --git a/src/crypto/aes.c b/src/crypto/aes.c index d739328..4a7668b 100644 --- a/src/crypto/aes.c +++ b/src/crypto/aes.c @@ -783,10 +783,12 @@ struct cipher_algorithm aes_algorithm = { .name = "aes", .ctxsize = sizeof ( struct aes_context ), .blocksize = AES_BLOCKSIZE, + .authsize = 0, .setkey = aes_setkey, .setiv = cipher_null_setiv, .encrypt = aes_encrypt, .decrypt = aes_decrypt, + .auth = cipher_null_auth, }; /* AES in Electronic Codebook mode */ diff --git a/src/crypto/arc4.c b/src/crypto/arc4.c index 0dba2fc..4d98abe 100644 --- a/src/crypto/arc4.c +++ b/src/crypto/arc4.c @@ -119,8 +119,10 @@ struct cipher_algorithm arc4_algorithm = { .name = "ARC4", .ctxsize = ARC4_CTX_SIZE, .blocksize = 1, + .authsize = 0, .setkey = arc4_setkey, .setiv = cipher_null_setiv, .encrypt = arc4_xor, .decrypt = arc4_xor, + .auth = cipher_null_auth, }; diff --git a/src/crypto/crypto_null.c b/src/crypto/crypto_null.c index ef6041b..26cfbfc 100644 --- a/src/crypto/crypto_null.c +++ b/src/crypto/crypto_null.c @@ -76,14 +76,20 @@ void cipher_null_decrypt ( void *ctx __unused, const void *src, void *dst, memcpy ( dst, src, len ); } +void cipher_null_auth ( void *ctx __unused, void *auth __unused ) { + /* Do nothing */ +} + struct cipher_algorithm cipher_null = { .name = "null", .ctxsize = 0, .blocksize = 1, + .authsize = 0, .setkey = cipher_null_setkey, .setiv = cipher_null_setiv, .encrypt = cipher_null_encrypt, .decrypt = cipher_null_decrypt, + .auth = cipher_null_auth, }; int pubkey_null_init ( void *ctx __unused, const void *key __unused, diff --git a/src/include/ipxe/cbc.h b/src/include/ipxe/cbc.h index 5c87403..eead045 100644 --- a/src/include/ipxe/cbc.h +++ b/src/include/ipxe/cbc.h @@ -95,10 +95,12 @@ struct cipher_algorithm _cbc_cipher = { \ .name = #_cbc_name, \ .ctxsize = sizeof ( struct _cbc_name ## _context ), \ .blocksize = _blocksize, \ + .authsize = 0, \ .setkey = _cbc_name ## _setkey, \ .setiv = _cbc_name ## _setiv, \ .encrypt = _cbc_name ## _encrypt, \ .decrypt = _cbc_name ## _decrypt, \ + .auth = cipher_null_auth, \ }; #endif /* _IPXE_CBC_H */ diff --git a/src/include/ipxe/crypto.h b/src/include/ipxe/crypto.h index d414480..e807aeb 100644 --- a/src/include/ipxe/crypto.h +++ b/src/include/ipxe/crypto.h @@ -52,6 +52,8 @@ struct cipher_algorithm { size_t ctxsize; /** Block size */ size_t blocksize; + /** Authentication tag size */ + size_t authsize; /** Set key * * @v ctx Context @@ -89,6 +91,12 @@ struct cipher_algorithm { */ void ( * decrypt ) ( void *ctx, const void *src, void *dst, size_t len ); + /** Generate authentication tag + * + * @v ctx Context + * @v auth Authentication tag + */ + void ( * auth ) ( void *ctx, void *auth ); }; /** A public key algorithm */ @@ -215,10 +223,19 @@ static inline void cipher_decrypt ( struct cipher_algorithm *cipher, cipher_decrypt ( (cipher), (ctx), (src), (dst), (len) ); \ } while ( 0 ) +static inline void cipher_auth ( struct cipher_algorithm *cipher, void *ctx, + void *auth ) { + cipher->auth ( ctx, auth ); +} + static inline int is_stream_cipher ( struct cipher_algorithm *cipher ) { return ( cipher->blocksize == 1 ); } +static inline int is_auth_cipher ( struct cipher_algorithm *cipher ) { + return cipher->authsize; +} + static inline int pubkey_init ( struct pubkey_algorithm *pubkey, void *ctx, const void *key, size_t key_len ) { return pubkey->init ( ctx, key, key_len ); @@ -274,6 +291,7 @@ extern void cipher_null_encrypt ( void *ctx, const void *src, void *dst, size_t len ); extern void cipher_null_decrypt ( void *ctx, const void *src, void *dst, size_t len ); +extern void cipher_null_auth ( void *ctx, void *auth ); extern int pubkey_null_init ( void *ctx, const void *key, size_t key_len ); extern size_t pubkey_null_max_len ( void *ctx ); diff --git a/src/include/ipxe/ecb.h b/src/include/ipxe/ecb.h index 6c40c61..1d2ebf7 100644 --- a/src/include/ipxe/ecb.h +++ b/src/include/ipxe/ecb.h @@ -47,10 +47,12 @@ struct cipher_algorithm _ecb_cipher = { \ .name = #_ecb_name, \ .ctxsize = sizeof ( _raw_context ), \ .blocksize = _blocksize, \ + .authsize = 0, \ .setkey = _ecb_name ## _setkey, \ .setiv = _ecb_name ## _setiv, \ .encrypt = _ecb_name ## _encrypt, \ .decrypt = _ecb_name ## _decrypt, \ + .auth = cipher_null_auth, \ }; #endif /* _IPXE_ECB_H */ diff --git a/src/tests/aes_test.c b/src/tests/aes_test.c index e7201fc..be119c8 100644 --- a/src/tests/aes_test.c +++ b/src/tests/aes_test.c @@ -94,7 +94,7 @@ CIPHER_TEST ( aes_128_ecb, &aes_ecb_algorithm, 0x43, 0xb1, 0xcd, 0x7f, 0x59, 0x8e, 0xce, 0x23, 0x88, 0x1b, 0x00, 0xe3, 0xed, 0x03, 0x06, 0x88, 0x7b, 0x0c, 0x78, 0x5e, 0x27, 0xe8, 0xad, 0x3f, - 0x82, 0x23, 0x20, 0x71, 0x04, 0x72, 0x5d, 0xd4 ) ); + 0x82, 0x23, 0x20, 0x71, 0x04, 0x72, 0x5d, 0xd4 ), AUTH() ); /** AES-128-CBC */ CIPHER_TEST ( aes_128_cbc, &aes_cbc_algorithm, @@ -106,7 +106,7 @@ CIPHER_TEST ( aes_128_cbc, &aes_cbc_algorithm, 0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16, 0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, - 0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7 ) ); + 0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7 ), AUTH() ); /** AES-192-ECB (same test as AES-192-Core) */ CIPHER_TEST ( aes_192_ecb, &aes_ecb_algorithm, @@ -118,7 +118,7 @@ CIPHER_TEST ( aes_192_ecb, &aes_ecb_algorithm, 0xef, 0x7a, 0xfd, 0x22, 0x70, 0xe2, 0xe6, 0x0a, 0xdc, 0xe0, 0xba, 0x2f, 0xac, 0xe6, 0x44, 0x4e, 0x9a, 0x4b, 0x41, 0xba, 0x73, 0x8d, 0x6c, 0x72, - 0xfb, 0x16, 0x69, 0x16, 0x03, 0xc1, 0x8e, 0x0e ) ); + 0xfb, 0x16, 0x69, 0x16, 0x03, 0xc1, 0x8e, 0x0e ), AUTH() ); /** AES-192-CBC */ CIPHER_TEST ( aes_192_cbc, &aes_cbc_algorithm, @@ -130,7 +130,7 @@ CIPHER_TEST ( aes_192_cbc, &aes_cbc_algorithm, 0x57, 0x1b, 0x24, 0x20, 0x12, 0xfb, 0x7a, 0xe0, 0x7f, 0xa9, 0xba, 0xac, 0x3d, 0xf1, 0x02, 0xe0, 0x08, 0xb0, 0xe2, 0x79, 0x88, 0x59, 0x88, 0x81, - 0xd9, 0x20, 0xa9, 0xe6, 0x4f, 0x56, 0x15, 0xcd ) ); + 0xd9, 0x20, 0xa9, 0xe6, 0x4f, 0x56, 0x15, 0xcd ), AUTH() ); /** AES-256-ECB (same test as AES-256-Core) */ CIPHER_TEST ( aes_256_ecb, &aes_ecb_algorithm, @@ -142,7 +142,7 @@ CIPHER_TEST ( aes_256_ecb, &aes_ecb_algorithm, 0xb6, 0xed, 0x21, 0xb9, 0x9c, 0xa6, 0xf4, 0xf9, 0xf1, 0x53, 0xe7, 0xb1, 0xbe, 0xaf, 0xed, 0x1d, 0x23, 0x30, 0x4b, 0x7a, 0x39, 0xf9, 0xf3, 0xff, - 0x06, 0x7d, 0x8d, 0x8f, 0x9e, 0x24, 0xec, 0xc7 ) ); + 0x06, 0x7d, 0x8d, 0x8f, 0x9e, 0x24, 0xec, 0xc7 ), AUTH() ); /** AES-256-CBC */ CIPHER_TEST ( aes_256_cbc, &aes_cbc_algorithm, @@ -154,7 +154,7 @@ CIPHER_TEST ( aes_256_cbc, &aes_cbc_algorithm, 0x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf, 0xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61, 0xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc, - 0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b ) ); + 0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b ), AUTH() ); /** * Perform AES self-test diff --git a/src/tests/cipher_test.c b/src/tests/cipher_test.c index c49b4b6..cc732c2 100644 --- a/src/tests/cipher_test.c +++ b/src/tests/cipher_test.c @@ -57,6 +57,7 @@ void cipher_encrypt_okx ( struct cipher_test *test, const char *file, size_t len = test->len; uint8_t ctx[cipher->ctxsize]; uint8_t ciphertext[len]; + uint8_t auth[cipher->authsize]; /* Initialise cipher */ okx ( cipher_setkey ( cipher, ctx, test->key, test->key_len ) == 0, @@ -65,6 +66,7 @@ void cipher_encrypt_okx ( struct cipher_test *test, const char *file, /* Process additional data, if applicable */ if ( test->additional_len ) { + okx ( is_auth_cipher ( cipher ), file, line ); cipher_encrypt ( cipher, ctx, test->additional, NULL, test->additional_len ); } @@ -74,6 +76,11 @@ void cipher_encrypt_okx ( struct cipher_test *test, const char *file, /* Compare against expected ciphertext */ okx ( memcmp ( ciphertext, test->ciphertext, len ) == 0, file, line ); + + /* Check authentication tag */ + okx ( cipher->authsize == test->auth_len, file, line ); + cipher_auth ( cipher, ctx, auth ); + okx ( memcmp ( auth, test->auth, test->auth_len ) == 0, file, line ); } /** @@ -89,6 +96,7 @@ void cipher_decrypt_okx ( struct cipher_test *test, const char *file, size_t len = test->len; uint8_t ctx[cipher->ctxsize]; uint8_t plaintext[len]; + uint8_t auth[cipher->authsize]; /* Initialise cipher */ okx ( cipher_setkey ( cipher, ctx, test->key, test->key_len ) == 0, @@ -97,6 +105,7 @@ void cipher_decrypt_okx ( struct cipher_test *test, const char *file, /* Process additional data, if applicable */ if ( test->additional_len ) { + okx ( is_auth_cipher ( cipher ), file, line ); cipher_decrypt ( cipher, ctx, test->additional, NULL, test->additional_len ); } @@ -106,6 +115,11 @@ void cipher_decrypt_okx ( struct cipher_test *test, const char *file, /* Compare against expected plaintext */ okx ( memcmp ( plaintext, test->plaintext, len ) == 0, file, line ); + + /* Check authentication tag */ + okx ( cipher->authsize == test->auth_len, file, line ); + cipher_auth ( cipher, ctx, auth ); + okx ( memcmp ( auth, test->auth, test->auth_len ) == 0, file, line ); } /** diff --git a/src/tests/cipher_test.h b/src/tests/cipher_test.h index 4139a77..519d12e 100644 --- a/src/tests/cipher_test.h +++ b/src/tests/cipher_test.h @@ -35,6 +35,10 @@ struct cipher_test { const void *ciphertext; /** Length of text */ size_t len; + /** Authentication tag */ + const void *auth; + /** Length of authentication tag */ + size_t auth_len; }; /** Define inline key */ @@ -52,6 +56,9 @@ struct cipher_test { /** Define inline ciphertext data */ #define CIPHERTEXT(...) { __VA_ARGS__ } +/** Define inline authentication tag */ +#define AUTH(...) { __VA_ARGS__ } + /** * Define a cipher test * @@ -62,16 +69,18 @@ struct cipher_test { * @v ADDITIONAL Additional data * @v PLAINTEXT Plaintext * @v CIPHERTEXT Ciphertext + * @v AUTH Authentication tag * @ret test Cipher test */ #define CIPHER_TEST( name, CIPHER, KEY, IV, ADDITIONAL, PLAINTEXT, \ - CIPHERTEXT ) \ + CIPHERTEXT, AUTH ) \ static const uint8_t name ## _key [] = KEY; \ static const uint8_t name ## _iv [] = IV; \ static const uint8_t name ## _additional [] = ADDITIONAL; \ static const uint8_t name ## _plaintext [] = PLAINTEXT; \ static const uint8_t name ## _ciphertext \ [ sizeof ( name ## _plaintext ) ] = CIPHERTEXT; \ + static const uint8_t name ## _auth [] = AUTH; \ static struct cipher_test name = { \ .cipher = CIPHER, \ .key = name ## _key, \ @@ -83,6 +92,8 @@ struct cipher_test { .plaintext = name ## _plaintext, \ .ciphertext = name ## _ciphertext, \ .len = sizeof ( name ## _plaintext ), \ + .auth = name ## _auth, \ + .auth_len = sizeof ( name ## _auth ), \ } extern void cipher_encrypt_okx ( struct cipher_test *test, const char *file, -- cgit v1.1