X-Git-Url: https://git.stg.codes/stg.git/blobdiff_plain/46b0747592074017ff0ea4b33d4a7194235886e5..f4333737c7e347efe9258ccf85c1237e03be619c:/libs/smux/per_decoder.c?ds=sidebyside diff --git a/libs/smux/per_decoder.c b/libs/smux/per_decoder.c index 16dee369..461b7262 100644 --- a/libs/smux/per_decoder.c +++ b/libs/smux/per_decoder.c @@ -2,6 +2,40 @@ #include #include +/* + * Decode a "Production of a complete encoding", X.691#10.1. + * The complete encoding contains at least one byte, and is an integral + * multiple of 8 bytes. + */ +asn_dec_rval_t +uper_decode_complete(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, void **sptr, const void *buffer, size_t size) { + asn_dec_rval_t rval; + + rval = uper_decode(opt_codec_ctx, td, sptr, buffer, size, 0, 0); + if(rval.consumed) { + /* + * We've always given 8-aligned data, + * so convert bits to integral bytes. + */ + rval.consumed += 7; + rval.consumed >>= 3; + } else if(rval.code == RC_OK) { + if(size) { + if(((const uint8_t *)buffer)[0] == 0) { + rval.consumed = 1; /* 1 byte */ + } else { + ASN_DEBUG("Expecting single zeroed byte"); + rval.code = RC_FAIL; + } + } else { + /* Must contain at least 8 bits. */ + rval.code = RC_WMORE; + } + } + + return rval; +} + asn_dec_rval_t uper_decode(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, void **sptr, const void *buffer, size_t size, int skip_bits, int unused_bits) { asn_codec_ctx_t s_codec_ctx; @@ -11,7 +45,7 @@ uper_decode(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, void **sp if(skip_bits < 0 || skip_bits > 7 || unused_bits < 0 || unused_bits > 7 || (unused_bits > 0 && !size)) - _ASN_DECODE_FAILED; + ASN__DECODE_FAILED; /* * Stack checker requires that the codec context @@ -25,27 +59,31 @@ uper_decode(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, void **sp } else { /* If context is not given, be security-conscious anyway */ memset(&s_codec_ctx, 0, sizeof(s_codec_ctx)); - s_codec_ctx.max_stack_size = _ASN_DEFAULT_STACK_MAX; + s_codec_ctx.max_stack_size = ASN__DEFAULT_STACK_MAX; opt_codec_ctx = &s_codec_ctx; } /* Fill in the position indicator */ + memset(&pd, 0, sizeof(pd)); pd.buffer = (const uint8_t *)buffer; pd.nboff = skip_bits; pd.nbits = 8 * size - unused_bits; /* 8 is CHAR_BIT from */ if(pd.nboff > pd.nbits) - _ASN_DECODE_FAILED; + ASN__DECODE_FAILED; /* * Invoke type-specific decoder. */ if(!td->uper_decoder) - _ASN_DECODE_FAILED; /* PER is not compiled in */ + ASN__DECODE_FAILED; /* PER is not compiled in */ rval = td->uper_decoder(opt_codec_ctx, td, 0, sptr, &pd); if(rval.code == RC_OK) { /* Return the number of consumed bits */ rval.consumed = ((pd.buffer - (const uint8_t *)buffer) << 3) + pd.nboff - skip_bits; + ASN_DEBUG("PER decoding consumed %ld, counted %ld", + (long)rval.consumed, (long)pd.moved); + assert(rval.consumed == pd.moved); } else { /* PER codec is not a restartable */ rval.consumed = 0;