diff options
Diffstat (limited to 'libtomcrypt/src/pk/asn1/der/set/der_encode_setof.c')
-rw-r--r-- | libtomcrypt/src/pk/asn1/der/set/der_encode_setof.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/libtomcrypt/src/pk/asn1/der/set/der_encode_setof.c b/libtomcrypt/src/pk/asn1/der/set/der_encode_setof.c new file mode 100644 index 0000000..6c12eb4 --- /dev/null +++ b/libtomcrypt/src/pk/asn1/der/set/der_encode_setof.c @@ -0,0 +1,162 @@ +/* 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, tomstdenis@gmail.com, http://libtomcrypt.com + */ +#include "tomcrypt.h" + +/** + @file der_encode_setof.c + ASN.1 DER, Encode SET OF, Tom St Denis +*/ + +#ifdef LTC_DER + +struct edge { + unsigned char *start; + unsigned long size; +}; + +static int qsort_helper(const void *a, const void *b) +{ + struct edge *A = (struct edge *)a, *B = (struct edge *)b; + int r; + unsigned long x; + + /* compare min length */ + r = XMEMCMP(A->start, B->start, MIN(A->size, B->size)); + + if (r == 0 && A->size != B->size) { + if (A->size > B->size) { + for (x = B->size; x < A->size; x++) { + if (A->start[x]) { + return 1; + } + } + } else { + for (x = A->size; x < B->size; x++) { + if (B->start[x]) { + return -1; + } + } + } + } + + return r; +} + +/** + Encode a SETOF stucture + @param list The list of items to encode + @param inlen The number of items in the list + @param out [out] The destination + @param outlen [in/out] The size of the output + @return CRYPT_OK on success +*/ +int der_encode_setof(ltc_asn1_list *list, unsigned long inlen, + unsigned char *out, unsigned long *outlen) +{ + unsigned long x, y, z, hdrlen; + int err; + struct edge *edges; + unsigned char *ptr, *buf; + + /* check that they're all the same type */ + for (x = 1; x < inlen; x++) { + if (list[x].type != list[x-1].type) { + return CRYPT_INVALID_ARG; + } + } + + /* alloc buffer to store copy of output */ + buf = XCALLOC(1, *outlen); + if (buf == NULL) { + return CRYPT_MEM; + } + + /* encode list */ + if ((err = der_encode_sequence_ex(list, inlen, buf, outlen, LTC_ASN1_SETOF)) != CRYPT_OK) { + XFREE(buf); + return err; + } + + /* allocate edges */ + edges = XCALLOC(inlen, sizeof(*edges)); + if (edges == NULL) { + XFREE(buf); + return CRYPT_MEM; + } + + /* skip header */ + ptr = buf + 1; + + /* now skip length data */ + x = *ptr++; + if (x >= 0x80) { + ptr += (x & 0x7F); + } + + /* get the size of the static header */ + hdrlen = ((unsigned long)ptr) - ((unsigned long)buf); + + + /* scan for edges */ + x = 0; + while (ptr < (buf + *outlen)) { + /* store start */ + edges[x].start = ptr; + + /* skip type */ + z = 1; + + /* parse length */ + y = ptr[z++]; + if (y < 128) { + edges[x].size = y; + } else { + y &= 0x7F; + edges[x].size = 0; + while (y--) { + edges[x].size = (edges[x].size << 8) | ((unsigned long)ptr[z++]); + } + } + + /* skip content */ + edges[x].size += z; + ptr += edges[x].size; + ++x; + } + + /* sort based on contents (using edges) */ + XQSORT(edges, inlen, sizeof(*edges), &qsort_helper); + + /* copy static header */ + XMEMCPY(out, buf, hdrlen); + + /* copy+sort using edges+indecies to output from buffer */ + for (y = hdrlen, x = 0; x < inlen; x++) { + XMEMCPY(out+y, edges[x].start, edges[x].size); + y += edges[x].size; + } + +#ifdef LTC_CLEAN_STACK + zeromem(buf, *outlen); +#endif + + /* free buffers */ + XFREE(edges); + XFREE(buf); + + return CRYPT_OK; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/set/der_encode_setof.c,v $ */ +/* $Revision: 1.11 $ */ +/* $Date: 2006/03/31 14:15:35 $ */ |