Mercurial > dropbear
view libtomcrypt/src/pk/asn1/der/sequence/der_encode_sequence_multi.c @ 994:5c5ade336926
Prefer stronger algorithms in algorithm negotiation.
Prefer diffie-hellman-group14-sha1 (2048 bit) over
diffie-hellman-group1-sha1 (1024 bit).
Due to meet-in-the-middle attacks the effective key length of
three key 3DES is 112 bits. AES is stronger and faster then 3DES.
Prefer to delay the start of compression until after authentication
has completed. This avoids exposing compression code to attacks
from unauthenticated users.
(github pull request #9)
author | Fedor Brunner <fedor.brunner@azet.sk> |
---|---|
date | Fri, 23 Jan 2015 23:00:25 +0800 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://libtomcrypt.com */ #include "tomcrypt.h" #include <stdarg.h> /** @file der_encode_sequence_multi.c ASN.1 DER, encode a SEQUENCE, Tom St Denis */ #ifdef LTC_DER /** Encode a SEQUENCE type using a VA list @param out [out] Destination for data @param outlen [in/out] Length of buffer and resulting length of output @remark <...> is of the form <type, size, data> (int, unsigned long, void*) @return CRYPT_OK on success */ int der_encode_sequence_multi(unsigned char *out, unsigned long *outlen, ...) { int err, type; unsigned long size, x; void *data; va_list args; ltc_asn1_list *list; LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); /* get size of output that will be required */ va_start(args, outlen); x = 0; for (;;) { type = va_arg(args, int); size = va_arg(args, unsigned long); data = va_arg(args, void*); if (type == LTC_ASN1_EOL) { break; } switch (type) { case LTC_ASN1_BOOLEAN: case LTC_ASN1_INTEGER: case LTC_ASN1_SHORT_INTEGER: case LTC_ASN1_BIT_STRING: case LTC_ASN1_OCTET_STRING: case LTC_ASN1_NULL: case LTC_ASN1_OBJECT_IDENTIFIER: case LTC_ASN1_IA5_STRING: case LTC_ASN1_PRINTABLE_STRING: case LTC_ASN1_UTF8_STRING: case LTC_ASN1_UTCTIME: case LTC_ASN1_SEQUENCE: case LTC_ASN1_SET: case LTC_ASN1_SETOF: ++x; break; default: va_end(args); return CRYPT_INVALID_ARG; } } va_end(args); /* allocate structure for x elements */ if (x == 0) { return CRYPT_NOP; } list = XCALLOC(sizeof(*list), x); if (list == NULL) { return CRYPT_MEM; } /* fill in the structure */ va_start(args, outlen); x = 0; for (;;) { type = va_arg(args, int); size = va_arg(args, unsigned long); data = va_arg(args, void*); if (type == LTC_ASN1_EOL) { break; } switch (type) { case LTC_ASN1_BOOLEAN: case LTC_ASN1_INTEGER: case LTC_ASN1_SHORT_INTEGER: case LTC_ASN1_BIT_STRING: case LTC_ASN1_OCTET_STRING: case LTC_ASN1_NULL: case LTC_ASN1_OBJECT_IDENTIFIER: case LTC_ASN1_IA5_STRING: case LTC_ASN1_PRINTABLE_STRING: case LTC_ASN1_UTF8_STRING: case LTC_ASN1_UTCTIME: case LTC_ASN1_SEQUENCE: case LTC_ASN1_SET: case LTC_ASN1_SETOF: list[x].type = type; list[x].size = size; list[x++].data = data; break; default: va_end(args); err = CRYPT_INVALID_ARG; goto LBL_ERR; } } va_end(args); err = der_encode_sequence(list, x, out, outlen); LBL_ERR: XFREE(list); return err; } #endif /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/sequence/der_encode_sequence_multi.c,v $ */ /* $Revision: 1.11 $ */ /* $Date: 2006/11/26 02:25:18 $ */