X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fpk%2Fasn1%2Fder%2Fsequence%2Fder_decode_sequence_flexi.c;fp=libtomcrypt%2Fsrc%2Fpk%2Fasn1%2Fder%2Fsequence%2Fder_decode_sequence_flexi.c;h=cb93e8f6ba31084284210ea51d35aec6c1fd3407;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage diff --git a/libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence_flexi.c b/libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence_flexi.c new file mode 100644 index 0000000..cb93e8f --- /dev/null +++ b/libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence_flexi.c @@ -0,0 +1,484 @@ +/* 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. + */ +#include "tomcrypt.h" + +/** + @file der_decode_sequence_flexi.c + ASN.1 DER, decode an array of ASN.1 types with a flexi parser, Tom St Denis +*/ + +#ifdef LTC_DER + +static unsigned long _fetch_length(const unsigned char *in, unsigned long inlen, unsigned long *data_offset) +{ + unsigned long x, z; + + *data_offset = 0; + + /* skip type and read len */ + if (inlen < 2) { + return 0xFFFFFFFF; + } + ++in; ++(*data_offset); + + /* read len */ + x = *in++; ++(*data_offset); + + /* <128 means literal */ + if (x < 128) { + return x+*data_offset; + } + x &= 0x7F; /* the lower 7 bits are the length of the length */ + inlen -= 2; + + /* len means len of len! */ + if (x == 0 || x > 4 || x > inlen) { + return 0xFFFFFFFF; + } + + *data_offset += x; + z = 0; + while (x--) { + z = (z<<8) | ((unsigned long)*in); + ++in; + } + return z+*data_offset; +} + +static int _new_element(ltc_asn1_list **l) +{ + /* alloc new link */ + if (*l == NULL) { + *l = XCALLOC(1, sizeof(ltc_asn1_list)); + if (*l == NULL) { + return CRYPT_MEM; + } + } else { + (*l)->next = XCALLOC(1, sizeof(ltc_asn1_list)); + if ((*l)->next == NULL) { + return CRYPT_MEM; + } + (*l)->next->prev = *l; + *l = (*l)->next; + } + return CRYPT_OK; +} + +/** + ASN.1 DER Flexi(ble) decoder will decode arbitrary DER packets and create a linked list of the decoded elements. + @param in The input buffer + @param inlen [in/out] The length of the input buffer and on output the amount of decoded data + @param out [out] A pointer to the linked list + @return CRYPT_OK on success. +*/ +int der_decode_sequence_flexi(const unsigned char *in, unsigned long *inlen, ltc_asn1_list **out) +{ + ltc_asn1_list *l, *t; + unsigned long err, type, len, totlen, data_offset, len_len; + void *realloc_tmp; + + LTC_ARGCHK(in != NULL); + LTC_ARGCHK(inlen != NULL); + LTC_ARGCHK(out != NULL); + + l = NULL; + totlen = 0; + + if (*inlen == 0) { + /* alloc new link */ + if ((err = _new_element(&l)) != CRYPT_OK) { + goto error; + } + } + + /* scan the input and and get lengths and what not */ + while (*inlen) { + /* read the type byte */ + type = *in; + + /* fetch length */ + len = _fetch_length(in, *inlen, &data_offset); + if (len > *inlen) { + err = CRYPT_INVALID_PACKET; + goto error; + } + + /* alloc new link */ + if ((err = _new_element(&l)) != CRYPT_OK) { + goto error; + } + + if ((type & 0x20) && (type != 0x30) && (type != 0x31)) { + /* constructed, use the 'used' field to store the original identifier */ + l->used = type; + /* treat constructed elements like SETs */ + type = 0x20; + } + else if ((type & 0xC0) == 0x80) { + /* context-specific, use the 'used' field to store the original identifier */ + l->used = type; + /* context-specific elements are treated as opaque data */ + type = 0x80; + } + + /* now switch on type */ + switch (type) { + case 0x01: /* BOOLEAN */ + l->type = LTC_ASN1_BOOLEAN; + l->size = 1; + l->data = XCALLOC(1, sizeof(int)); + + if ((err = der_decode_boolean(in, *inlen, l->data)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_boolean(&len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x02: /* INTEGER */ + /* init field */ + l->type = LTC_ASN1_INTEGER; + l->size = 1; + if ((err = mp_init(&l->data)) != CRYPT_OK) { + goto error; + } + + /* decode field */ + if ((err = der_decode_integer(in, *inlen, l->data)) != CRYPT_OK) { + goto error; + } + + /* calc length of object */ + if ((err = der_length_integer(l->data, &len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x03: /* BIT */ + /* init field */ + l->type = LTC_ASN1_BIT_STRING; + l->size = len * 8; /* *8 because we store decoded bits one per char and they are encoded 8 per char. */ + + if ((l->data = XCALLOC(1, l->size)) == NULL) { + err = CRYPT_MEM; + goto error; + } + + if ((err = der_decode_bit_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_bit_string(l->size, &len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x04: /* OCTET */ + + /* init field */ + l->type = LTC_ASN1_OCTET_STRING; + l->size = len; + + if ((l->data = XCALLOC(1, l->size)) == NULL) { + err = CRYPT_MEM; + goto error; + } + + if ((err = der_decode_octet_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_octet_string(l->size, &len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x05: /* NULL */ + + /* valid NULL is 0x05 0x00 */ + if (in[0] != 0x05 || in[1] != 0x00) { + err = CRYPT_INVALID_PACKET; + goto error; + } + + /* simple to store ;-) */ + l->type = LTC_ASN1_NULL; + l->data = NULL; + l->size = 0; + len = 2; + + break; + + case 0x06: /* OID */ + + /* init field */ + l->type = LTC_ASN1_OBJECT_IDENTIFIER; + l->size = len; + + if ((l->data = XCALLOC(len, sizeof(unsigned long))) == NULL) { + err = CRYPT_MEM; + goto error; + } + + if ((err = der_decode_object_identifier(in, *inlen, l->data, &l->size)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_object_identifier(l->data, l->size, &len)) != CRYPT_OK) { + goto error; + } + + /* resize it to save a bunch of mem */ + if ((realloc_tmp = XREALLOC(l->data, l->size * sizeof(unsigned long))) == NULL) { + /* out of heap but this is not an error */ + break; + } + l->data = realloc_tmp; + break; + + case 0x0C: /* UTF8 */ + + /* init field */ + l->type = LTC_ASN1_UTF8_STRING; + l->size = len; + + if ((l->data = XCALLOC(sizeof(wchar_t), l->size)) == NULL) { + err = CRYPT_MEM; + goto error; + } + + if ((err = der_decode_utf8_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_utf8_string(l->data, l->size, &len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x13: /* PRINTABLE */ + + /* init field */ + l->type = LTC_ASN1_PRINTABLE_STRING; + l->size = len; + + if ((l->data = XCALLOC(1, l->size)) == NULL) { + err = CRYPT_MEM; + goto error; + } + + if ((err = der_decode_printable_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_printable_string(l->data, l->size, &len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x14: /* TELETEXT */ + + /* init field */ + l->type = LTC_ASN1_TELETEX_STRING; + l->size = len; + + if ((l->data = XCALLOC(1, l->size)) == NULL) { + err = CRYPT_MEM; + goto error; + } + + if ((err = der_decode_teletex_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_teletex_string(l->data, l->size, &len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x16: /* IA5 */ + + /* init field */ + l->type = LTC_ASN1_IA5_STRING; + l->size = len; + + if ((l->data = XCALLOC(1, l->size)) == NULL) { + err = CRYPT_MEM; + goto error; + } + + if ((err = der_decode_ia5_string(in, *inlen, l->data, &l->size)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_ia5_string(l->data, l->size, &len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x17: /* UTC TIME */ + + /* init field */ + l->type = LTC_ASN1_UTCTIME; + l->size = 1; + + if ((l->data = XCALLOC(1, sizeof(ltc_utctime))) == NULL) { + err = CRYPT_MEM; + goto error; + } + + len = *inlen; + if ((err = der_decode_utctime(in, &len, l->data)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_utctime(l->data, &len)) != CRYPT_OK) { + goto error; + } + break; + + case 0x18: + l->type = LTC_ASN1_GENERALIZEDTIME; + l->size = len; + + if ((l->data = XCALLOC(1, sizeof(ltc_generalizedtime))) == NULL) { + err = CRYPT_MEM; + goto error; + } + + if ((err = der_decode_generalizedtime(in, &len, l->data)) != CRYPT_OK) { + goto error; + } + + if ((err = der_length_generalizedtime(l->data, &len)) != CRYPT_OK) { + goto error; + } + + break; + + case 0x20: /* Any CONSTRUCTED element that is neither SEQUENCE nor SET */ + case 0x30: /* SEQUENCE */ + case 0x31: /* SET */ + + /* init field */ + if (type == 0x20) { + l->type = LTC_ASN1_CONSTRUCTED; + } + else if (type == 0x30) { + l->type = LTC_ASN1_SEQUENCE; + } + else { + l->type = LTC_ASN1_SET; + } + + if ((l->data = XMALLOC(len)) == NULL) { + err = CRYPT_MEM; + goto error; + } + + XMEMCPY(l->data, in, len); + l->size = len; + + + /* jump to the start of the data */ + in += data_offset; + *inlen -= data_offset; + len = len - data_offset; + + /* Sequence elements go as child */ + if ((err = der_decode_sequence_flexi(in, &len, &(l->child))) != CRYPT_OK) { + goto error; + } + + /* len update */ + totlen += data_offset; + + /* the flexi decoder can also do nothing, so make sure a child has been allocated */ + if (l->child) { + /* link them up y0 */ + l->child->parent = l; + } + + t = l; + len_len = 0; + while((t != NULL) && (t->child != NULL)) { + len_len++; + t = t->child; + } + if (len_len > LTC_DER_MAX_RECURSION) { + err = CRYPT_ERROR; + goto error; + } + + break; + + case 0x80: /* Context-specific */ + l->type = LTC_ASN1_CONTEXT_SPECIFIC; + + if ((l->data = XCALLOC(1, len - data_offset)) == NULL) { + err = CRYPT_MEM; + goto error; + } + + XMEMCPY(l->data, in + data_offset, len - data_offset); + l->size = len - data_offset; + + break; + + default: + /* invalid byte ... this is a soft error */ + /* remove link */ + if (l->prev) { + l = l->prev; + XFREE(l->next); + l->next = NULL; + } + goto outside; + } + + /* advance pointers */ + totlen += len; + in += len; + *inlen -= len; + } + +outside: + + /* in case we processed anything */ + if (totlen) { + /* rewind l please */ + while (l->prev != NULL || l->parent != NULL) { + if (l->parent != NULL) { + l = l->parent; + } else { + l = l->prev; + } + } + } + + /* return */ + *out = l; + *inlen = totlen; + return CRYPT_OK; + +error: + /* free list */ + der_sequence_free(l); + + return err; +} + +#endif + + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */