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Diffstat (limited to 'skeletons/NativeInteger.c')
| -rw-r--r-- | skeletons/NativeInteger.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/skeletons/NativeInteger.c b/skeletons/NativeInteger.c new file mode 100644 index 00000000..d42540ef --- /dev/null +++ b/skeletons/NativeInteger.c @@ -0,0 +1,193 @@ +/*- + * Copyright (c) 2004 Lev Walkin <vlm@lionet.info>. All rights reserved. + * Redistribution and modifications are permitted subject to BSD license. + */ +/* + * Please read the NativeInteger.h for the explanation wrt. differences between + * INTEGER and NativeInteger. + * Basically, both are decoders and encoders of ASN.1 INTEGER type, but this + * implementation deals with the standard (machine-specific) representation + * of them instead of using the platform-independent buffer. + */ +#include <NativeInteger.h> +#include <INTEGER.h> +#include <assert.h> + +/* + * NativeInteger basic type description. + */ +static ber_tlv_tag_t asn1_DEF_NativeInteger_tags[] = { + (ASN_TAG_CLASS_UNIVERSAL | (2 << 2)) +}; +asn1_TYPE_descriptor_t asn1_DEF_NativeInteger = { + "INTEGER", /* The ASN.1 type is still INTEGER */ + asn_generic_no_constraint, + NativeInteger_decode_ber, + NativeInteger_encode_der, + NativeInteger_print, + NativeInteger_free, + 0, /* Use generic outmost tag fetcher */ + asn1_DEF_NativeInteger_tags, + sizeof(asn1_DEF_NativeInteger_tags)/sizeof(asn1_DEF_NativeInteger_tags[0]), + 1, /* Single UNIVERSAL tag may be implicitly overriden */ + 0 /* Always in primitive form */ +}; + +/* + * Decode INTEGER type. + */ +ber_dec_rval_t +NativeInteger_decode_ber(asn1_TYPE_descriptor_t *td, + void **int_ptr, void *buf_ptr, size_t size, int tag_mode) { + int *Int = *int_ptr; + ber_dec_rval_t rval; + ber_dec_ctx_t ctx = { 0 }; + ber_tlv_len_t length; + + /* + * If the structure is not there, allocate it. + */ + if(Int == NULL) { + Int = *int_ptr = CALLOC(1, sizeof(*Int)); + if(Int == NULL) { + rval.code = RC_FAIL; + rval.consumed = 0; + return rval; + } + } + + ASN_DEBUG("Decoding %s as INTEGER (tm=%d)", + td->name, tag_mode); + + /* + * Check tags. + */ + rval = ber_check_tags(td, &ctx, + buf_ptr, size, tag_mode, &length, 0); + if(rval.code != RC_OK) + return rval; + + ASN_DEBUG("%s length is %d bytes", td->name, (int)length); + + /* + * Make sure we have this length. + */ + buf_ptr += rval.consumed; + size -= rval.consumed; + if(length > size) { + rval.code = RC_WMORE; + rval.consumed = 0; + return rval; + } + + /* + * ASN.1 encoded INTEGER: buf_ptr, length + * Fill the Int, at the same time checking for overflow. + * If overflow occured, return with RC_FAIL. + */ + { + INTEGER_t tmp; + long l; + tmp.buf = buf_ptr; + tmp.size = length; + + if(asn1_INTEGER2long(&tmp, &l)) { + rval.code = RC_FAIL; + rval.consumed = 0; + return rval; + } + + *Int = l; + + /* + * Note that int might be shorter than long. + * This expression hopefully will be optimized away + * by compiler. + */ + if(sizeof(int) != sizeof(long) && (*Int != l)) { + *Int = 0; /* Safe value */ + rval.code = RC_FAIL; + rval.consumed = 0; + return rval; + } + } + + rval.code = RC_OK; + rval.consumed += length; + + ASN_DEBUG("Took %ld/%ld bytes to encode %s (%d)", + (long)rval.consumed, (long)length, td->name, *Int); + + return rval; +} + +/* + * Encode the NativeInteger using the standard INTEGER type DER encoder. + */ +der_enc_rval_t +NativeInteger_encode_der(asn1_TYPE_descriptor_t *sd, void *ptr, + int tag_mode, ber_tlv_tag_t tag, + asn_app_consume_bytes_f *cb, void *app_key) { + unsigned int Int = *(unsigned int *)ptr; /* Disable sign ext. */ + der_enc_rval_t erval; + INTEGER_t tmp; + +#ifdef WORDS_BIGENDIAN /* Opportunistic optimization */ + + tmp.buf = ∬ + tmp.size = sizeof(Int); + +#else /* Works even if WORDS_BIGENDIAN is not set where should've been */ + uint8_t buf[sizeof(int)]; + uint8_t *p; + + /* Prepare fake INTEGER */ + for(p = buf + sizeof(buf) - 1; p >= buf; p--, Int >>= 8) + *p = Int & 0xff; + + tmp.buf = buf; + tmp.size = sizeof(buf); +#endif /* WORDS_BIGENDIAN */ + + /* Encode fake INTEGER */ + erval = INTEGER_encode_der(sd, &tmp, tag_mode, tag, cb, app_key); + if(erval.encoded == -1) { + assert(erval.structure_ptr == &tmp); + erval.structure_ptr = ptr; + } + return erval; +} + +/* + * INTEGER specific human-readable output. + */ +int +NativeInteger_print(asn1_TYPE_descriptor_t *td, const void *sptr, int ilevel, + asn_app_consume_bytes_f *cb, void *app_key) { + const int *Int = sptr; + char scratch[32]; + int ret; + + if(Int) { + ret = snprintf(scratch, sizeof(scratch), "%d", *Int); + assert(ret > 0 && ret < sizeof(scratch)); + return cb(scratch, ret, app_key); + } else { + return cb("<absent>", 8, app_key); + } +} + +void +NativeInteger_free(asn1_TYPE_descriptor_t *td, void *ptr, int contents_only) { + + if(!td || !ptr) + return; + + ASN_DEBUG("Freeing %s as INTEGER (%d, %p, Native)", + td->name, contents_only, ptr); + + if(!contents_only) { + FREEMEM(ptr); + } +} + |