[tls] Use hybrid MD5+SHA1 algorithm

TLSv1.1 and earlier use a hybrid of MD5 and SHA-1 to generate digests
over the handshake messages.  Formalise this as a separate digest
algorithm "md5+sha1".

Signed-off-by: Michael Brown <mcb30@ipxe.org>
pull/6/head
Michael Brown 2012-03-20 04:07:53 +00:00
parent 8583c323a2
commit a156c15746
2 changed files with 90 additions and 17 deletions

View File

@ -145,6 +145,28 @@ struct tls_client_random {
uint8_t random[28];
} __attribute__ (( packed ));
/** An MD5+SHA1 context */
struct md5_sha1_context {
/** MD5 context */
uint8_t md5[MD5_CTX_SIZE];
/** SHA-1 context */
uint8_t sha1[SHA1_CTX_SIZE];
} __attribute__ (( packed ));
/** MD5+SHA1 context size */
#define MD5_SHA1_CTX_SIZE sizeof ( struct md5_sha1_context )
/** An MD5+SHA1 digest */
struct md5_sha1_digest {
/** MD5 digest */
uint8_t md5[MD5_DIGEST_SIZE];
/** SHA-1 digest */
uint8_t sha1[SHA1_DIGEST_SIZE];
} __attribute__ (( packed ));
/** MD5+SHA1 digest size */
#define MD5_SHA1_DIGEST_SIZE sizeof ( struct md5_sha1_digest )
/** A TLS session */
struct tls_session {
/** Reference counter */
@ -175,10 +197,8 @@ struct tls_session {
uint8_t server_random[32];
/** Client random bytes */
struct tls_client_random client_random;
/** MD5 context for handshake verification */
uint8_t handshake_md5_ctx[MD5_CTX_SIZE];
/** SHA1 context for handshake verification */
uint8_t handshake_sha1_ctx[SHA1_CTX_SIZE];
/** MD5+SHA1 context for handshake verification */
uint8_t handshake_md5_sha1_ctx[MD5_SHA1_CTX_SIZE];
/** SHA256 context for handshake verification */
uint8_t handshake_sha256_ctx[SHA256_CTX_SIZE];

View File

@ -79,6 +79,64 @@ static unsigned long tls_uint24 ( const uint8_t field24[3] ) {
return ( ( field24[0] << 16 ) + ( field24[1] << 8 ) + field24[2] );
}
/******************************************************************************
*
* Hybrid MD5+SHA1 hash as used by TLSv1.1 and earlier
*
******************************************************************************
*/
/**
* Initialise MD5+SHA1 algorithm
*
* @v ctx MD5+SHA1 context
*/
static void md5_sha1_init ( void *ctx ) {
struct md5_sha1_context *context = ctx;
digest_init ( &md5_algorithm, context->md5 );
digest_init ( &sha1_algorithm, context->sha1 );
}
/**
* Accumulate data with MD5+SHA1 algorithm
*
* @v ctx MD5+SHA1 context
* @v data Data
* @v len Length of data
*/
static void md5_sha1_update ( void *ctx, const void *data, size_t len ) {
struct md5_sha1_context *context = ctx;
digest_update ( &md5_algorithm, context->md5, data, len );
digest_update ( &sha1_algorithm, context->sha1, data, len );
}
/**
* Generate MD5+SHA1 digest
*
* @v ctx MD5+SHA1 context
* @v out Output buffer
*/
static void md5_sha1_final ( void *ctx, void *out ) {
struct md5_sha1_context *context = ctx;
struct md5_sha1_digest *digest = out;
digest_final ( &md5_algorithm, context->md5, digest->md5 );
digest_final ( &sha1_algorithm, context->sha1, digest->sha1 );
}
/** Hybrid MD5+SHA1 digest algorithm */
static struct digest_algorithm md5_sha1_algorithm = {
.name = "md5+sha1",
.ctxsize = sizeof ( struct md5_sha1_context ),
.blocksize = 0, /* Not applicable */
.digestsize = sizeof ( struct md5_sha1_digest ),
.init = md5_sha1_init,
.update = md5_sha1_update,
.final = md5_sha1_final,
};
/******************************************************************************
*
* Cleanup functions
@ -633,8 +691,8 @@ static int tls_change_cipher ( struct tls_session *tls,
static void tls_add_handshake ( struct tls_session *tls,
const void *data, size_t len ) {
digest_update ( &md5_algorithm, tls->handshake_md5_ctx, data, len );
digest_update ( &sha1_algorithm, tls->handshake_sha1_ctx, data, len );
digest_update ( &md5_sha1_algorithm, tls->handshake_md5_sha1_ctx,
data, len );
digest_update ( &sha256_algorithm, tls->handshake_sha256_ctx,
data, len );
}
@ -651,7 +709,7 @@ static size_t tls_verify_handshake_len ( struct tls_session *tls ) {
return SHA256_DIGEST_SIZE;
} else {
/* Use MD5+SHA1 for TLSv1.1 and earlier */
return ( MD5_DIGEST_SIZE + SHA1_DIGEST_SIZE );
return MD5_SHA1_DIGEST_SIZE;
}
}
@ -666,8 +724,7 @@ static size_t tls_verify_handshake_len ( struct tls_session *tls ) {
*/
static void tls_verify_handshake ( struct tls_session *tls, void *out ) {
union {
uint8_t md5[MD5_CTX_SIZE];
uint8_t sha1[SHA1_CTX_SIZE];
uint8_t md5_sha1[MD5_SHA1_CTX_SIZE];
uint8_t sha256[SHA256_CTX_SIZE];
} ctx;
@ -678,12 +735,9 @@ static void tls_verify_handshake ( struct tls_session *tls, void *out ) {
digest_final ( &sha256_algorithm, ctx.sha256, out );
} else {
/* Use MD5+SHA1 for TLSv1.1 and earlier */
memcpy ( ctx.md5, tls->handshake_md5_ctx, sizeof ( ctx.md5 ) );
digest_final ( &md5_algorithm, ctx.md5, out );
memcpy ( ctx.sha1, tls->handshake_sha1_ctx,
sizeof ( ctx.sha1 ) );
digest_final ( &sha1_algorithm, ctx.sha1,
( out + MD5_DIGEST_SIZE ) );
memcpy ( ctx.md5_sha1, tls->handshake_md5_sha1_ctx,
sizeof ( ctx.md5_sha1 ) );
digest_final ( &md5_sha1_algorithm, ctx.md5_sha1, out );
}
}
@ -2043,8 +2097,7 @@ int add_tls ( struct interface *xfer, const char *name,
( sizeof ( tls->pre_master_secret.random ) ) ) ) != 0 ) {
goto err_random;
}
digest_init ( &md5_algorithm, tls->handshake_md5_ctx );
digest_init ( &sha1_algorithm, tls->handshake_sha1_ctx );
digest_init ( &md5_sha1_algorithm, tls->handshake_md5_sha1_ctx );
digest_init ( &sha256_algorithm, tls->handshake_sha256_ctx );
tls->tx_pending = TLS_TX_CLIENT_HELLO;
process_init ( &tls->process, &tls_process_desc, &tls->refcnt );