vlm | fa67ddc | 2004-06-03 03:38:44 +0000 | [diff] [blame] | 1 | /*- |
| 2 | * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved. |
| 3 | * Redistribution and modifications are permitted subject to BSD license. |
| 4 | */ |
| 5 | #include <constr_TYPE.h> |
| 6 | #include <assert.h> |
vlm | 1ff928d | 2004-08-11 08:10:13 +0000 | [diff] [blame] | 7 | #include <errno.h> |
vlm | fa67ddc | 2004-06-03 03:38:44 +0000 | [diff] [blame] | 8 | |
| 9 | static ssize_t der_write_TL(ber_tlv_tag_t tag, ber_tlv_len_t len, |
| 10 | asn_app_consume_bytes_f *cb, void *app_key, int constructed); |
| 11 | |
| 12 | /* |
| 13 | * The DER encoder of any type. |
| 14 | */ |
| 15 | der_enc_rval_t |
| 16 | der_encode(asn1_TYPE_descriptor_t *type_descriptor, void *struct_ptr, |
| 17 | asn_app_consume_bytes_f *consume_bytes, void *app_key) { |
| 18 | |
| 19 | ASN_DEBUG("DER encoder invoked for %s", |
| 20 | type_descriptor->name); |
| 21 | |
| 22 | /* |
| 23 | * Invoke type-specific encoder. |
| 24 | */ |
| 25 | return type_descriptor->der_encoder(type_descriptor, |
| 26 | struct_ptr, /* Pointer to the destination structure */ |
| 27 | 0, 0, |
| 28 | consume_bytes, app_key); |
| 29 | } |
| 30 | |
| 31 | /* |
| 32 | * Write out leading TL[v] sequence according to the type definition. |
| 33 | */ |
| 34 | ssize_t |
| 35 | der_write_tags(asn1_TYPE_descriptor_t *sd, |
| 36 | size_t struct_length, |
| 37 | int tag_mode, |
| 38 | ber_tlv_tag_t tag, /* EXPLICIT or IMPLICIT tag */ |
| 39 | asn_app_consume_bytes_f *cb, |
| 40 | void *app_key) { |
| 41 | ber_tlv_tag_t *tags; /* Copy of tags stream */ |
| 42 | int tags_count; /* Number of tags */ |
| 43 | size_t overall_length; |
| 44 | ssize_t *lens; |
| 45 | int i; |
| 46 | |
vlm | 796c1da | 2004-07-21 03:55:44 +0000 | [diff] [blame] | 47 | ASN_DEBUG("Writing tags (%s, tm=%d, tc=%d, iskip=%d, tag=%s, mtc=%d)", |
| 48 | sd->name, tag_mode, sd->tags_count, sd->tags_impl_skip, |
| 49 | ber_tlv_tag_string(tag), |
| 50 | tag_mode |
| 51 | ?(sd->tags_count+1 |
| 52 | -((tag_mode==-1)?sd->tags_impl_skip:0)) |
| 53 | :sd->tags_count |
| 54 | ); |
| 55 | |
vlm | fa67ddc | 2004-06-03 03:38:44 +0000 | [diff] [blame] | 56 | if(tag_mode) { |
| 57 | /* |
| 58 | * Instead of doing shaman dance like we do in ber_check_tags(), |
| 59 | * allocate a small array on the stack |
| 60 | * and initialize it appropriately. |
| 61 | */ |
vlm | 796c1da | 2004-07-21 03:55:44 +0000 | [diff] [blame] | 62 | int stag_offset; |
vlm | da67468 | 2004-08-11 09:07:36 +0000 | [diff] [blame] | 63 | tags = (ber_tlv_tag_t *)alloca((sd->tags_count + 1) * sizeof(ber_tlv_tag_t)); |
vlm | 7a6a60e | 2004-08-11 07:41:45 +0000 | [diff] [blame] | 64 | if(!tags) { /* Can fail on !x86 */ |
| 65 | errno = ENOMEM; |
| 66 | return -1; |
| 67 | } |
vlm | fa67ddc | 2004-06-03 03:38:44 +0000 | [diff] [blame] | 68 | tags_count = sd->tags_count |
| 69 | + 1 /* EXPLICIT or IMPLICIT tag is given */ |
| 70 | - ((tag_mode==-1)?sd->tags_impl_skip:0); |
| 71 | /* Copy tags over */ |
| 72 | tags[0] = tag; |
vlm | 796c1da | 2004-07-21 03:55:44 +0000 | [diff] [blame] | 73 | stag_offset = -1 + ((tag_mode==-1)?sd->tags_impl_skip:0); |
vlm | fa67ddc | 2004-06-03 03:38:44 +0000 | [diff] [blame] | 74 | for(i = 1; i < tags_count; i++) |
vlm | 796c1da | 2004-07-21 03:55:44 +0000 | [diff] [blame] | 75 | tags[i] = sd->tags[i + stag_offset]; |
vlm | fa67ddc | 2004-06-03 03:38:44 +0000 | [diff] [blame] | 76 | } else { |
| 77 | tags = sd->tags; |
| 78 | tags_count = sd->tags_count; |
| 79 | } |
| 80 | |
| 81 | /* No tags to write */ |
| 82 | if(tags_count == 0) |
| 83 | return 0; |
| 84 | |
vlm | da67468 | 2004-08-11 09:07:36 +0000 | [diff] [blame] | 85 | lens = (ssize_t *)alloca(tags_count * sizeof(lens[0])); |
vlm | 7a6a60e | 2004-08-11 07:41:45 +0000 | [diff] [blame] | 86 | if(!lens) { |
| 87 | errno = ENOMEM; |
| 88 | return -1; |
| 89 | } |
vlm | fa67ddc | 2004-06-03 03:38:44 +0000 | [diff] [blame] | 90 | |
| 91 | /* |
| 92 | * Array of tags is initialized. |
| 93 | * Now, compute the size of the TLV pairs, from right to left. |
| 94 | */ |
| 95 | overall_length = struct_length; |
| 96 | for(i = tags_count - 1; i >= 0; --i) { |
| 97 | lens[i] = der_write_TL(tags[i], overall_length, 0, 0, 0); |
| 98 | if(lens[i] == -1) return -1; |
| 99 | overall_length += lens[i]; |
| 100 | lens[i] = overall_length - lens[i]; |
| 101 | } |
| 102 | |
| 103 | if(!cb) return overall_length - struct_length; |
| 104 | |
| 105 | ASN_DEBUG("%s %s TL sequence (%d elements)", |
| 106 | cb?"Encoding":"Estimating", sd->name, tags_count); |
| 107 | |
| 108 | /* |
| 109 | * Encode the TL sequence for real. |
| 110 | */ |
| 111 | for(i = 0; i < tags_count; i++) { |
| 112 | ssize_t len; |
| 113 | int _constr; |
| 114 | |
| 115 | /* If this one happens to be constructed, do it. */ |
| 116 | if(i < (tags_count - 1) || sd->last_tag_form == 1) |
| 117 | _constr = 1; |
| 118 | else _constr = 0; |
| 119 | |
| 120 | len = der_write_TL(tags[i], lens[i], cb, app_key, _constr); |
| 121 | if(len == -1) return -1; |
| 122 | } |
| 123 | |
| 124 | return overall_length - struct_length; |
| 125 | } |
| 126 | |
| 127 | static ssize_t |
| 128 | der_write_TL(ber_tlv_tag_t tag, ber_tlv_len_t len, |
| 129 | asn_app_consume_bytes_f *cb, void *app_key, |
| 130 | int constructed) { |
| 131 | uint8_t buf[32]; |
| 132 | size_t size = 0; |
| 133 | int buf_size = cb?sizeof(buf):0; |
| 134 | ssize_t tmp; |
| 135 | |
| 136 | /* Serialize tag (T from TLV) into possibly zero-length buffer */ |
| 137 | tmp = der_tlv_tag_serialize(tag, buf, buf_size); |
vlm | b42843a | 2004-06-05 08:17:50 +0000 | [diff] [blame] | 138 | if(tmp == -1 || tmp > (ssize_t)sizeof(buf)) return -1; |
vlm | fa67ddc | 2004-06-03 03:38:44 +0000 | [diff] [blame] | 139 | size += tmp; |
| 140 | |
| 141 | /* Serialize length (L from TLV) into possibly zero-length buffer */ |
| 142 | tmp = der_tlv_length_serialize(len, buf+size, buf_size?buf_size-size:0); |
| 143 | if(tmp == -1) return -1; |
| 144 | size += tmp; |
| 145 | |
| 146 | if(size > sizeof(buf)) |
| 147 | return -1; |
| 148 | |
| 149 | /* |
| 150 | * If callback is specified, invoke it, and check its return value. |
| 151 | */ |
| 152 | if(cb) { |
| 153 | if(constructed) *buf |= 0x20; |
| 154 | if(cb(buf, size, app_key) == -1) { |
| 155 | return -1; |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | return size; |
| 160 | } |