TLS: Add negative tests for non-EtM CBC decryption

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
This commit is contained in:
Manuel Pégourié-Gonnard 2020-07-03 12:49:10 +02:00
parent bfbdca8bb4
commit 0ac01a1c59
2 changed files with 206 additions and 0 deletions

View File

@ -9374,6 +9374,102 @@ Record crypt, little space, NULL cipher, SSL3, MD5, short tag, EtM
depends_on:MBEDTLS_CIPHER_NULL_CIPHER:MBEDTLS_SSL_PROTO_SSL3:MBEDTLS_MD5_C:MBEDTLS_SSL_ENCRYPT_THEN_MAC
ssl_crypt_record_small:MBEDTLS_CIPHER_NULL:MBEDTLS_MD_MD5:1:1:MBEDTLS_SSL_MINOR_VERSION_0:0:0
Decrypt CBC !EtM, AES SHA256 !trunc, 0, good min pad, good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:0:"0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f":0
Decrypt CBC !EtM, AES SHA256 !trunc, 0, good min pad, bad mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:1:"0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, bad min pad (byte 0), good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:0:"0E0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, bad min pad (byte 0), bad mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:1:"0E0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, bad min pad (len), good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:0:"0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0E":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, overlong pad 1, good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:0:"10101010101010101010101010101010":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, overlong pad 2, good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:0:"30303030303030303030303030303030":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, good maxlen pad, good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:0:"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":0
Decrypt CBC !EtM, AES SHA256 !trunc, 0, good maxlen pad, bad mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:1:"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, bad maxlen pad (byte 0), good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:0:"fEffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, bad maxlen pad (byte 0), bad mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:1:"fEffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 !trunc, 0, bad maxlen (len), good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:0:0:0:"fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffE":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, good min pad, good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:0:"050505050505":0
Decrypt CBC !EtM, AES SHA256 trunc, 0, good min pad, bad mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:1:"050505050505":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, bad min pad (byte 0), good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:0:"040505050505":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, bad min pad (byte 0), bad mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:1:"040505050505":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, bad min pad (len), good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:0:"050505050504":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, overlong pad 1, good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:0:"060606060606":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, overlong pad 2, good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:0:"101010101010":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, good maxlen pad, good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:0:"f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5":0
Decrypt CBC !EtM, AES SHA256 trunc, 0, good maxlen pad, bad mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:1:"f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, bad maxlen pad (byte 0), good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:0:"E5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, bad maxlen pad (byte 0), bad mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:1:"E5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5":MBEDTLS_ERR_SSL_INVALID_MAC
Decrypt CBC !EtM, AES SHA256 trunc, 0, bad maxlen (len), good mac
depends_on:MBEDTLS_AES_C:MBEDTLS_SHA256_C
ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_SHA256:1:0:0:"f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f4":MBEDTLS_ERR_SSL_INVALID_MAC
SSL TLS_PRF MBEDTLS_SSL_TLS_PRF_NONE
ssl_tls_prf:MBEDTLS_SSL_TLS_PRF_NONE:"":"":"test tls_prf label":"":MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE

View File

@ -3452,6 +3452,116 @@ exit:
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_SSL_PROTO_TLS1_2 */
void ssl_decrypt_non_etm_cbc( int cipher_type, int hash_id, int trunc_hmac,
int plaintext_len, int badmac, data_t *padding,
int exp_ret )
{
/*
* Test record decryption for CBC without EtM with possibly incorrect
* padding (provided as input) or MAC (generated by this function).
*
* Actually depends on TLS >= 1.0 (SSL 3.0 computes the MAC differently),
* but since the test framework doesn't support alternation in dependency
* statements, just depend on TLS 1.2.
*/
mbedtls_ssl_context ssl; /* ONLY for debugging */
mbedtls_ssl_transform t0, t1;
mbedtls_record rec;
unsigned char *buf = NULL;
size_t buflen, olen = 0;
const size_t rec_data_offset = 16; /* IV size */
unsigned char add_data[13];
unsigned char mac[MBEDTLS_MD_MAX_SIZE];
mbedtls_ssl_init( &ssl );
mbedtls_ssl_transform_init( &t0 );
mbedtls_ssl_transform_init( &t1 );
/* Set up transforms with dummy keys */
TEST_ASSERT( build_transforms( &t0, &t1, cipher_type, hash_id,
0, trunc_hmac,
MBEDTLS_SSL_MINOR_VERSION_3,
0 , 0 ) == 0 );
/* Prepare a buffer for record data */
buflen = rec_data_offset
+ plaintext_len
+ t0.maclen
+ padding->len;
ASSERT_ALLOC( buf, buflen );
/* Prepare a dummy record header */
memset( rec.ctr, 0, sizeof( rec.ctr ) );
rec.type = MBEDTLS_SSL_MSG_APPLICATION_DATA;
rec.ver[0] = MBEDTLS_SSL_MAJOR_VERSION_3;
rec.ver[1] = MBEDTLS_SSL_MINOR_VERSION_3;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
rec.cid_len = 0;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
/* Prepare dummy record content */
rec.buf = buf;
rec.buf_len = buflen;
rec.data_offset = rec_data_offset;
rec.data_len = plaintext_len;
memset( rec.buf + rec.data_offset, 42, rec.data_len );
/*
* MAC, "pad" and encrypt - this near-duplicates the TLS 1.x non-EtM CBC
* code path of mbedtls_ssl_encrypt_buf(), but with user-provided padding,
* and possibly wrong HMAC. Also, without safety checks or CID support.
*/
/* MAC with additional data */
memcpy( add_data, rec.ctr, 8 );
add_data[8] = rec.type;
add_data[9] = rec.ver[0];
add_data[10] = rec.ver[1];
add_data[11] = ( rec.data_len >> 8 ) & 0xff;
add_data[12] = ( rec.data_len >> 0 ) & 0xff;
TEST_EQUAL( 0, mbedtls_md_hmac_update( &t0.md_ctx_enc, add_data, 13 ) );
TEST_EQUAL( 0, mbedtls_md_hmac_update( &t0.md_ctx_enc,
rec.buf + rec.data_offset,
rec.data_len ) );
TEST_EQUAL( 0, mbedtls_md_hmac_finish( &t0.md_ctx_enc, mac ) );
memcpy( rec.buf + rec.data_offset + rec.data_len, mac, t0.maclen );
rec.data_len += t0.maclen;
/* Possibly falsify the MAC */
rec.buf[rec.data_offset + rec.data_len - 1] ^= badmac;
/* Append the user-provided padding */
memcpy( rec.buf + rec.data_offset + rec.data_len, padding->x, padding->len );
rec.data_len += padding->len;
/* Set dummy IV and encrypt */
memset( t0.iv_enc, 0x55, t0.ivlen );
TEST_ASSERT( t0.ivlen == rec_data_offset );
memcpy( rec.buf, t0.iv_enc, rec_data_offset );
TEST_EQUAL( 0, mbedtls_cipher_crypt( &t0.cipher_ctx_enc,
t0.iv_enc, t0.ivlen,
rec.buf + rec.data_offset, rec.data_len,
rec.buf + rec.data_offset, &olen ) );
rec.data_offset -= t0.ivlen;
rec.data_len += t0.ivlen;
/*
* Try to decrypt and check that we get the expected result
*/
TEST_EQUAL( exp_ret, mbedtls_ssl_decrypt_buf( &ssl, &t1, &rec ) );
exit:
mbedtls_ssl_free( &ssl );
mbedtls_ssl_transform_free( &t0 );
mbedtls_ssl_transform_free( &t1 );
mbedtls_free( buf );
}
/* END_CASE */
/* BEGIN_CASE */
void ssl_tls_prf( int type, data_t * secret, data_t * random,
char *label, data_t *result_hex_str, int exp_ret )