1*e87ff5aeSjsing /* $OpenBSD: bytestring.h,v 1.16 2017/11/28 16:34:20 jsing Exp $ */ 2c4905cd3Sdoug /* 3c4905cd3Sdoug * Copyright (c) 2014, Google Inc. 4c4905cd3Sdoug * 5c4905cd3Sdoug * Permission to use, copy, modify, and/or distribute this software for any 6c4905cd3Sdoug * purpose with or without fee is hereby granted, provided that the above 7c4905cd3Sdoug * copyright notice and this permission notice appear in all copies. 8c4905cd3Sdoug * 9c4905cd3Sdoug * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10c4905cd3Sdoug * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11c4905cd3Sdoug * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 12c4905cd3Sdoug * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13c4905cd3Sdoug * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 14c4905cd3Sdoug * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 15c4905cd3Sdoug * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ 16c4905cd3Sdoug 17c4905cd3Sdoug #ifndef OPENSSL_HEADER_BYTESTRING_H 18c4905cd3Sdoug #define OPENSSL_HEADER_BYTESTRING_H 19c4905cd3Sdoug 20c4905cd3Sdoug #include <sys/types.h> 21c4905cd3Sdoug #include <stdint.h> 22c4905cd3Sdoug 23c4905cd3Sdoug #include <openssl/opensslconf.h> 24c4905cd3Sdoug 25a9f45c63Sguenther __BEGIN_HIDDEN_DECLS 26a9f45c63Sguenther 27732f1cb2Sdoug /* 28732f1cb2Sdoug * Bytestrings are used for parsing and building TLS and ASN.1 messages. 29c4905cd3Sdoug * 30c4905cd3Sdoug * A "CBS" (CRYPTO ByteString) represents a string of bytes in memory and 31c4905cd3Sdoug * provides utility functions for safely parsing length-prefixed structures 32c4905cd3Sdoug * like TLS and ASN.1 from it. 33c4905cd3Sdoug * 34c4905cd3Sdoug * A "CBB" (CRYPTO ByteBuilder) is a memory buffer that grows as needed and 35732f1cb2Sdoug * provides utility functions for building length-prefixed messages. 36732f1cb2Sdoug */ 37c4905cd3Sdoug 38c4905cd3Sdoug /* CRYPTO ByteString */ 39c4905cd3Sdoug typedef struct cbs_st { 40c4905cd3Sdoug const uint8_t *data; 4134e475baSdoug size_t initial_len; 42c4905cd3Sdoug size_t len; 43c4905cd3Sdoug } CBS; 44c4905cd3Sdoug 45732f1cb2Sdoug /* 46732f1cb2Sdoug * CBS_init sets |cbs| to point to |data|. It does not take ownership of 47732f1cb2Sdoug * |data|. 48732f1cb2Sdoug */ 49c4905cd3Sdoug void CBS_init(CBS *cbs, const uint8_t *data, size_t len); 50c4905cd3Sdoug 51732f1cb2Sdoug /* 52732f1cb2Sdoug * CBS_skip advances |cbs| by |len| bytes. It returns one on success and zero 53732f1cb2Sdoug * otherwise. 54732f1cb2Sdoug */ 55c4905cd3Sdoug int CBS_skip(CBS *cbs, size_t len); 56c4905cd3Sdoug 57732f1cb2Sdoug /* 583b087d0eSdoug * CBS_data returns a pointer to the contents of |cbs|. 59732f1cb2Sdoug */ 60c4905cd3Sdoug const uint8_t *CBS_data(const CBS *cbs); 61c4905cd3Sdoug 62732f1cb2Sdoug /* 63732f1cb2Sdoug * CBS_len returns the number of bytes remaining in |cbs|. 64732f1cb2Sdoug */ 65c4905cd3Sdoug size_t CBS_len(const CBS *cbs); 66c4905cd3Sdoug 67732f1cb2Sdoug /* 6834e475baSdoug * CBS_offset returns the current offset into the original data of |cbs|. 6934e475baSdoug */ 7034e475baSdoug size_t CBS_offset(const CBS *cbs); 7134e475baSdoug 7234e475baSdoug /* 73732f1cb2Sdoug * CBS_stow copies the current contents of |cbs| into |*out_ptr| and 74c4905cd3Sdoug * |*out_len|. If |*out_ptr| is not NULL, the contents are freed with 751f70f88bSdoug * free. It returns one on success and zero on allocation failure. On 761f70f88bSdoug * success, |*out_ptr| should be freed with free. If |cbs| is empty, 77732f1cb2Sdoug * |*out_ptr| will be NULL. 78732f1cb2Sdoug */ 79c4905cd3Sdoug int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len); 80c4905cd3Sdoug 81732f1cb2Sdoug /* 82732f1cb2Sdoug * CBS_strdup copies the current contents of |cbs| into |*out_ptr| as a 83c4905cd3Sdoug * NUL-terminated C string. If |*out_ptr| is not NULL, the contents are freed 841f70f88bSdoug * with free. It returns one on success and zero on allocation 851f70f88bSdoug * failure. On success, |*out_ptr| should be freed with free. 86c4905cd3Sdoug * 87c4905cd3Sdoug * NOTE: If |cbs| contains NUL bytes, the string will be truncated. Call 88732f1cb2Sdoug * |CBS_contains_zero_byte(cbs)| to check for NUL bytes. 89732f1cb2Sdoug */ 90c4905cd3Sdoug int CBS_strdup(const CBS *cbs, char **out_ptr); 91c4905cd3Sdoug 92732f1cb2Sdoug /* 93df129122Sdoug * CBS_write_bytes writes all of the remaining data from |cbs| into |dst| 94df129122Sdoug * if it is at most |dst_len| bytes. If |copied| is not NULL, it will be set 95df129122Sdoug * to the amount copied. It returns one on success and zero otherwise. 96df129122Sdoug */ 97df129122Sdoug int CBS_write_bytes(const CBS *cbs, uint8_t *dst, size_t dst_len, 98df129122Sdoug size_t *copied); 99df129122Sdoug 100df129122Sdoug /* 101732f1cb2Sdoug * CBS_contains_zero_byte returns one if the current contents of |cbs| contains 102732f1cb2Sdoug * a NUL byte and zero otherwise. 103732f1cb2Sdoug */ 104c4905cd3Sdoug int CBS_contains_zero_byte(const CBS *cbs); 105c4905cd3Sdoug 106732f1cb2Sdoug /* 107732f1cb2Sdoug * CBS_mem_equal compares the current contents of |cbs| with the |len| bytes 108c4905cd3Sdoug * starting at |data|. If they're equal, it returns one, otherwise zero. If the 109732f1cb2Sdoug * lengths match, it uses a constant-time comparison. 110732f1cb2Sdoug */ 111732f1cb2Sdoug int CBS_mem_equal(const CBS *cbs, const uint8_t *data, size_t len); 112c4905cd3Sdoug 113732f1cb2Sdoug /* 114732f1cb2Sdoug * CBS_get_u8 sets |*out| to the next uint8_t from |cbs| and advances |cbs|. It 115732f1cb2Sdoug * returns one on success and zero on error. 116732f1cb2Sdoug */ 117c4905cd3Sdoug int CBS_get_u8(CBS *cbs, uint8_t *out); 118c4905cd3Sdoug 119732f1cb2Sdoug /* 120732f1cb2Sdoug * CBS_get_u16 sets |*out| to the next, big-endian uint16_t from |cbs| and 121732f1cb2Sdoug * advances |cbs|. It returns one on success and zero on error. 122732f1cb2Sdoug */ 123c4905cd3Sdoug int CBS_get_u16(CBS *cbs, uint16_t *out); 124c4905cd3Sdoug 125732f1cb2Sdoug /* 126732f1cb2Sdoug * CBS_get_u24 sets |*out| to the next, big-endian 24-bit value from |cbs| and 127732f1cb2Sdoug * advances |cbs|. It returns one on success and zero on error. 128732f1cb2Sdoug */ 129c4905cd3Sdoug int CBS_get_u24(CBS *cbs, uint32_t *out); 130c4905cd3Sdoug 131732f1cb2Sdoug /* 132732f1cb2Sdoug * CBS_get_u32 sets |*out| to the next, big-endian uint32_t value from |cbs| 133732f1cb2Sdoug * and advances |cbs|. It returns one on success and zero on error. 134732f1cb2Sdoug */ 135c4905cd3Sdoug int CBS_get_u32(CBS *cbs, uint32_t *out); 136c4905cd3Sdoug 137732f1cb2Sdoug /* 138732f1cb2Sdoug * CBS_get_bytes sets |*out| to the next |len| bytes from |cbs| and advances 139732f1cb2Sdoug * |cbs|. It returns one on success and zero on error. 140732f1cb2Sdoug */ 141c4905cd3Sdoug int CBS_get_bytes(CBS *cbs, CBS *out, size_t len); 142c4905cd3Sdoug 143732f1cb2Sdoug /* 144732f1cb2Sdoug * CBS_get_u8_length_prefixed sets |*out| to the contents of an 8-bit, 145c4905cd3Sdoug * length-prefixed value from |cbs| and advances |cbs| over it. It returns one 146732f1cb2Sdoug * on success and zero on error. 147732f1cb2Sdoug */ 148c4905cd3Sdoug int CBS_get_u8_length_prefixed(CBS *cbs, CBS *out); 149c4905cd3Sdoug 150732f1cb2Sdoug /* 151732f1cb2Sdoug * CBS_get_u16_length_prefixed sets |*out| to the contents of a 16-bit, 152c4905cd3Sdoug * big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It 153732f1cb2Sdoug * returns one on success and zero on error. 154732f1cb2Sdoug */ 155c4905cd3Sdoug int CBS_get_u16_length_prefixed(CBS *cbs, CBS *out); 156c4905cd3Sdoug 157732f1cb2Sdoug /* 158732f1cb2Sdoug * CBS_get_u24_length_prefixed sets |*out| to the contents of a 24-bit, 159c4905cd3Sdoug * big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It 160732f1cb2Sdoug * returns one on success and zero on error. 161732f1cb2Sdoug */ 162c4905cd3Sdoug int CBS_get_u24_length_prefixed(CBS *cbs, CBS *out); 163c4905cd3Sdoug 164c4905cd3Sdoug 165c4905cd3Sdoug /* Parsing ASN.1 */ 166c4905cd3Sdoug 167844e66cbSdoug /* 168844e66cbSdoug * While an identifier can be multiple octets, this library only handles the 169844e66cbSdoug * single octet variety currently. This limits support up to tag number 30 170844e66cbSdoug * since tag number 31 is a reserved value to indicate multiple octets. 171844e66cbSdoug */ 172c4905cd3Sdoug 173844e66cbSdoug /* Bits 8 and 7: class tag type: See X.690 section 8.1.2.2. */ 174844e66cbSdoug #define CBS_ASN1_UNIVERSAL 0x00 175844e66cbSdoug #define CBS_ASN1_APPLICATION 0x40 176c4905cd3Sdoug #define CBS_ASN1_CONTEXT_SPECIFIC 0x80 177844e66cbSdoug #define CBS_ASN1_PRIVATE 0xc0 178844e66cbSdoug 179844e66cbSdoug /* Bit 6: Primitive or constructed: See X.690 section 8.1.2.3. */ 180844e66cbSdoug #define CBS_ASN1_PRIMITIVE 0x00 181844e66cbSdoug #define CBS_ASN1_CONSTRUCTED 0x20 182844e66cbSdoug 183844e66cbSdoug /* 184844e66cbSdoug * Bits 5 to 1 are the tag number. See X.680 section 8.6 for tag numbers of 185844e66cbSdoug * the universal class. 186844e66cbSdoug */ 187844e66cbSdoug 188844e66cbSdoug /* 189844e66cbSdoug * Common universal identifier octets. 190844e66cbSdoug * See X.690 section 8.1 and X.680 section 8.6 for universal tag numbers. 191844e66cbSdoug * 192844e66cbSdoug * Note: These definitions are the cause of some of the strange behavior in 193844e66cbSdoug * CBS's bs_ber.c. 194844e66cbSdoug * 195844e66cbSdoug * In BER, it is the sender's option to use primitive or constructed for 196844e66cbSdoug * bitstring (X.690 section 8.6.1) and octetstring (X.690 section 8.7.1). 197844e66cbSdoug * 198844e66cbSdoug * In DER, bitstring and octetstring are required to be primitive 199844e66cbSdoug * (X.690 section 10.2). 200844e66cbSdoug */ 201844e66cbSdoug #define CBS_ASN1_BOOLEAN (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x1) 202844e66cbSdoug #define CBS_ASN1_INTEGER (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x2) 203844e66cbSdoug #define CBS_ASN1_BITSTRING (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x3) 204844e66cbSdoug #define CBS_ASN1_OCTETSTRING (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x4) 205844e66cbSdoug #define CBS_ASN1_OBJECT (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x6) 206844e66cbSdoug #define CBS_ASN1_ENUMERATED (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0xa) 207844e66cbSdoug #define CBS_ASN1_SEQUENCE (CBS_ASN1_UNIVERSAL | CBS_ASN1_CONSTRUCTED | 0x10) 208844e66cbSdoug #define CBS_ASN1_SET (CBS_ASN1_UNIVERSAL | CBS_ASN1_CONSTRUCTED | 0x11) 209c4905cd3Sdoug 210732f1cb2Sdoug /* 211732f1cb2Sdoug * CBS_get_asn1 sets |*out| to the contents of DER-encoded, ASN.1 element (not 212c4905cd3Sdoug * including tag and length bytes) and advances |cbs| over it. The ASN.1 213c4905cd3Sdoug * element must match |tag_value|. It returns one on success and zero 214c4905cd3Sdoug * on error. 215c4905cd3Sdoug * 2163b087d0eSdoug * Tag numbers greater than 30 are not supported (i.e. short form only). 217732f1cb2Sdoug */ 2180ad3dcfdSdoug int CBS_get_asn1(CBS *cbs, CBS *out, unsigned int tag_value); 219c4905cd3Sdoug 220732f1cb2Sdoug /* 221732f1cb2Sdoug * CBS_get_asn1_element acts like |CBS_get_asn1| but |out| will include the 222732f1cb2Sdoug * ASN.1 header bytes too. 223732f1cb2Sdoug */ 2240ad3dcfdSdoug int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned int tag_value); 225c4905cd3Sdoug 226732f1cb2Sdoug /* 227732f1cb2Sdoug * CBS_peek_asn1_tag looks ahead at the next ASN.1 tag and returns one 228c4905cd3Sdoug * if the next ASN.1 element on |cbs| would have tag |tag_value|. If 229c4905cd3Sdoug * |cbs| is empty or the tag does not match, it returns zero. Note: if 230c4905cd3Sdoug * it returns one, CBS_get_asn1 may still fail if the rest of the 231732f1cb2Sdoug * element is malformed. 232732f1cb2Sdoug */ 2330ad3dcfdSdoug int CBS_peek_asn1_tag(const CBS *cbs, unsigned int tag_value); 234c4905cd3Sdoug 235732f1cb2Sdoug /* 236732f1cb2Sdoug * CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from 237c4905cd3Sdoug * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to 2380870ee34Sdoug * the tag number and |*out_header_len| to the length of the ASN.1 header. 2390870ee34Sdoug * Each of |out|, |out_tag|, and |out_header_len| may be NULL to ignore 240c4905cd3Sdoug * the value. 241c4905cd3Sdoug * 2423b087d0eSdoug * Tag numbers greater than 30 are not supported (i.e. short form only). 243732f1cb2Sdoug */ 2440ad3dcfdSdoug int CBS_get_any_asn1_element(CBS *cbs, CBS *out, unsigned int *out_tag, 245c4905cd3Sdoug size_t *out_header_len); 246c4905cd3Sdoug 247732f1cb2Sdoug /* 248732f1cb2Sdoug * CBS_get_asn1_uint64 gets an ASN.1 INTEGER from |cbs| using |CBS_get_asn1| 249c4905cd3Sdoug * and sets |*out| to its value. It returns one on success and zero on error, 250c4905cd3Sdoug * where error includes the integer being negative, or too large to represent 251732f1cb2Sdoug * in 64 bits. 252732f1cb2Sdoug */ 253c4905cd3Sdoug int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out); 254c4905cd3Sdoug 255732f1cb2Sdoug /* 256732f1cb2Sdoug * CBS_get_optional_asn1 gets an optional explicitly-tagged element 257c4905cd3Sdoug * from |cbs| tagged with |tag| and sets |*out| to its contents. If 258c4905cd3Sdoug * present, it sets |*out_present| to one, otherwise zero. It returns 259c4905cd3Sdoug * one on success, whether or not the element was present, and zero on 260732f1cb2Sdoug * decode failure. 261732f1cb2Sdoug */ 2620ad3dcfdSdoug int CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, 2630ad3dcfdSdoug unsigned int tag); 264c4905cd3Sdoug 265732f1cb2Sdoug /* 266732f1cb2Sdoug * CBS_get_optional_asn1_octet_string gets an optional 267c4905cd3Sdoug * explicitly-tagged OCTET STRING from |cbs|. If present, it sets 268c4905cd3Sdoug * |*out| to the string and |*out_present| to one. Otherwise, it sets 269c4905cd3Sdoug * |*out| to empty and |*out_present| to zero. |out_present| may be 270c4905cd3Sdoug * NULL. It returns one on success, whether or not the element was 271732f1cb2Sdoug * present, and zero on decode failure. 272732f1cb2Sdoug */ 273732f1cb2Sdoug int CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out, int *out_present, 2740ad3dcfdSdoug unsigned int tag); 275c4905cd3Sdoug 276732f1cb2Sdoug /* 277732f1cb2Sdoug * CBS_get_optional_asn1_uint64 gets an optional explicitly-tagged 278c4905cd3Sdoug * INTEGER from |cbs|. If present, it sets |*out| to the 279c4905cd3Sdoug * value. Otherwise, it sets |*out| to |default_value|. It returns one 280c4905cd3Sdoug * on success, whether or not the element was present, and zero on 281732f1cb2Sdoug * decode failure. 282732f1cb2Sdoug */ 2830ad3dcfdSdoug int CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out, unsigned int tag, 284c4905cd3Sdoug uint64_t default_value); 285c4905cd3Sdoug 286732f1cb2Sdoug /* 287732f1cb2Sdoug * CBS_get_optional_asn1_bool gets an optional, explicitly-tagged BOOLEAN from 288c4905cd3Sdoug * |cbs|. If present, it sets |*out| to either zero or one, based on the 289c4905cd3Sdoug * boolean. Otherwise, it sets |*out| to |default_value|. It returns one on 290c4905cd3Sdoug * success, whether or not the element was present, and zero on decode 291732f1cb2Sdoug * failure. 292732f1cb2Sdoug */ 2930ad3dcfdSdoug int CBS_get_optional_asn1_bool(CBS *cbs, int *out, unsigned int tag, 294c4905cd3Sdoug int default_value); 295c4905cd3Sdoug 296c4905cd3Sdoug 297732f1cb2Sdoug /* 298732f1cb2Sdoug * CRYPTO ByteBuilder. 299c4905cd3Sdoug * 300c4905cd3Sdoug * |CBB| objects allow one to build length-prefixed serialisations. A |CBB| 301c4905cd3Sdoug * object is associated with a buffer and new buffers are created with 302c4905cd3Sdoug * |CBB_init|. Several |CBB| objects can point at the same buffer when a 303c4905cd3Sdoug * length-prefix is pending, however only a single |CBB| can be 'current' at 304c4905cd3Sdoug * any one time. For example, if one calls |CBB_add_u8_length_prefixed| then 305c4905cd3Sdoug * the new |CBB| points at the same buffer as the original. But if the original 306c4905cd3Sdoug * |CBB| is used then the length prefix is written out and the new |CBB| must 307c4905cd3Sdoug * not be used again. 308c4905cd3Sdoug * 309c4905cd3Sdoug * If one needs to force a length prefix to be written out because a |CBB| is 310732f1cb2Sdoug * going out of scope, use |CBB_flush|. 311732f1cb2Sdoug */ 312c4905cd3Sdoug 313c4905cd3Sdoug struct cbb_buffer_st { 314c4905cd3Sdoug uint8_t *buf; 315732f1cb2Sdoug 316732f1cb2Sdoug /* The number of valid bytes. */ 317732f1cb2Sdoug size_t len; 318732f1cb2Sdoug 319732f1cb2Sdoug /* The size of buf. */ 320732f1cb2Sdoug size_t cap; 321732f1cb2Sdoug 322732f1cb2Sdoug /* 323732f1cb2Sdoug * One iff |buf| is owned by this object. If not then |buf| cannot be 324732f1cb2Sdoug * resized. 325732f1cb2Sdoug */ 326732f1cb2Sdoug char can_resize; 327c4905cd3Sdoug }; 328c4905cd3Sdoug 329c4905cd3Sdoug typedef struct cbb_st { 330c4905cd3Sdoug struct cbb_buffer_st *base; 331732f1cb2Sdoug 332732f1cb2Sdoug /* 333732f1cb2Sdoug * offset is the offset from the start of |base->buf| to the position of any 334732f1cb2Sdoug * pending length-prefix. 335732f1cb2Sdoug */ 336c4905cd3Sdoug size_t offset; 337732f1cb2Sdoug 338c4905cd3Sdoug /* child points to a child CBB if a length-prefix is pending. */ 339c4905cd3Sdoug struct cbb_st *child; 340732f1cb2Sdoug 341732f1cb2Sdoug /* 342732f1cb2Sdoug * pending_len_len contains the number of bytes in a pending length-prefix, 343732f1cb2Sdoug * or zero if no length-prefix is pending. 344732f1cb2Sdoug */ 345c4905cd3Sdoug uint8_t pending_len_len; 346732f1cb2Sdoug 347c4905cd3Sdoug char pending_is_asn1; 348732f1cb2Sdoug 349732f1cb2Sdoug /* 350732f1cb2Sdoug * is_top_level is true iff this is a top-level |CBB| (as opposed to a child 351732f1cb2Sdoug * |CBB|). Top-level objects are valid arguments for |CBB_finish|. 352732f1cb2Sdoug */ 353c4905cd3Sdoug char is_top_level; 354c4905cd3Sdoug } CBB; 355c4905cd3Sdoug 356732f1cb2Sdoug /* 357732f1cb2Sdoug * CBB_init initialises |cbb| with |initial_capacity|. Since a |CBB| grows as 358c4905cd3Sdoug * needed, the |initial_capacity| is just a hint. It returns one on success or 359732f1cb2Sdoug * zero on error. 360732f1cb2Sdoug */ 361c4905cd3Sdoug int CBB_init(CBB *cbb, size_t initial_capacity); 362c4905cd3Sdoug 363732f1cb2Sdoug /* 364732f1cb2Sdoug * CBB_init_fixed initialises |cbb| to write to |len| bytes at |buf|. Since 365c4905cd3Sdoug * |buf| cannot grow, trying to write more than |len| bytes will cause CBB 366732f1cb2Sdoug * functions to fail. It returns one on success or zero on error. 367732f1cb2Sdoug */ 368c4905cd3Sdoug int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len); 369c4905cd3Sdoug 370732f1cb2Sdoug /* 371732f1cb2Sdoug * CBB_cleanup frees all resources owned by |cbb| and other |CBB| objects 372c4905cd3Sdoug * writing to the same buffer. This should be used in an error case where a 373732f1cb2Sdoug * serialisation is abandoned. 374732f1cb2Sdoug */ 375c4905cd3Sdoug void CBB_cleanup(CBB *cbb); 376c4905cd3Sdoug 377732f1cb2Sdoug /* 378732f1cb2Sdoug * CBB_finish completes any pending length prefix and sets |*out_data| to a 379c4905cd3Sdoug * malloced buffer and |*out_len| to the length of that buffer. The caller 380c4905cd3Sdoug * takes ownership of the buffer and, unless the buffer was fixed with 3811f70f88bSdoug * |CBB_init_fixed|, must call |free| when done. 382c4905cd3Sdoug * 383c4905cd3Sdoug * It can only be called on a "top level" |CBB|, i.e. one initialised with 384c4905cd3Sdoug * |CBB_init| or |CBB_init_fixed|. It returns one on success and zero on 385732f1cb2Sdoug * error. 386732f1cb2Sdoug */ 387c4905cd3Sdoug int CBB_finish(CBB *cbb, uint8_t **out_data, size_t *out_len); 388c4905cd3Sdoug 389732f1cb2Sdoug /* 390732f1cb2Sdoug * CBB_flush causes any pending length prefixes to be written out and any child 391c4905cd3Sdoug * |CBB| objects of |cbb| to be invalidated. It returns one on success or zero 392732f1cb2Sdoug * on error. 393732f1cb2Sdoug */ 394c4905cd3Sdoug int CBB_flush(CBB *cbb); 395c4905cd3Sdoug 396732f1cb2Sdoug /* 397*e87ff5aeSjsing * CBB_discard_child discards the current unflushed child of |cbb|. Neither the 398*e87ff5aeSjsing * child's contents nor the length prefix will be included in the output. 399*e87ff5aeSjsing */ 400*e87ff5aeSjsing void CBB_discard_child(CBB *cbb); 401*e87ff5aeSjsing 402*e87ff5aeSjsing /* 403732f1cb2Sdoug * CBB_add_u8_length_prefixed sets |*out_contents| to a new child of |cbb|. The 404c4905cd3Sdoug * data written to |*out_contents| will be prefixed in |cbb| with an 8-bit 405732f1cb2Sdoug * length. It returns one on success or zero on error. 406732f1cb2Sdoug */ 407c4905cd3Sdoug int CBB_add_u8_length_prefixed(CBB *cbb, CBB *out_contents); 408c4905cd3Sdoug 409732f1cb2Sdoug /* 410732f1cb2Sdoug * CBB_add_u16_length_prefixed sets |*out_contents| to a new child of |cbb|. 411c4905cd3Sdoug * The data written to |*out_contents| will be prefixed in |cbb| with a 16-bit, 412732f1cb2Sdoug * big-endian length. It returns one on success or zero on error. 413732f1cb2Sdoug */ 414c4905cd3Sdoug int CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents); 415c4905cd3Sdoug 416732f1cb2Sdoug /* 417732f1cb2Sdoug * CBB_add_u24_length_prefixed sets |*out_contents| to a new child of |cbb|. 418c4905cd3Sdoug * The data written to |*out_contents| will be prefixed in |cbb| with a 24-bit, 419732f1cb2Sdoug * big-endian length. It returns one on success or zero on error. 420732f1cb2Sdoug */ 421c4905cd3Sdoug int CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents); 422c4905cd3Sdoug 423732f1cb2Sdoug /* 424732f1cb2Sdoug * CBB_add_asn sets |*out_contents| to a |CBB| into which the contents of an 425c4905cd3Sdoug * ASN.1 object can be written. The |tag| argument will be used as the tag for 426d7a08d8fSdoug * the object. Passing in |tag| number 31 will return in an error since only 427d7a08d8fSdoug * single octet identifiers are supported. It returns one on success or zero 428d7a08d8fSdoug * on error. 429732f1cb2Sdoug */ 4309d4b5ca7Sdoug int CBB_add_asn1(CBB *cbb, CBB *out_contents, unsigned int tag); 431c4905cd3Sdoug 432732f1cb2Sdoug /* 433732f1cb2Sdoug * CBB_add_bytes appends |len| bytes from |data| to |cbb|. It returns one on 434732f1cb2Sdoug * success and zero otherwise. 435732f1cb2Sdoug */ 436c4905cd3Sdoug int CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len); 437c4905cd3Sdoug 438732f1cb2Sdoug /* 439732f1cb2Sdoug * CBB_add_space appends |len| bytes to |cbb| and sets |*out_data| to point to 440c4905cd3Sdoug * the beginning of that space. The caller must then write |len| bytes of 441c4905cd3Sdoug * actual contents to |*out_data|. It returns one on success and zero 442732f1cb2Sdoug * otherwise. 443732f1cb2Sdoug */ 444c4905cd3Sdoug int CBB_add_space(CBB *cbb, uint8_t **out_data, size_t len); 445c4905cd3Sdoug 446732f1cb2Sdoug /* 447732f1cb2Sdoug * CBB_add_u8 appends an 8-bit number from |value| to |cbb|. It returns one on 448732f1cb2Sdoug * success and zero otherwise. 449732f1cb2Sdoug */ 4509d4b5ca7Sdoug int CBB_add_u8(CBB *cbb, size_t value); 451c4905cd3Sdoug 452732f1cb2Sdoug /* 453732f1cb2Sdoug * CBB_add_u8 appends a 16-bit, big-endian number from |value| to |cbb|. It 454732f1cb2Sdoug * returns one on success and zero otherwise. 455732f1cb2Sdoug */ 4569d4b5ca7Sdoug int CBB_add_u16(CBB *cbb, size_t value); 457c4905cd3Sdoug 458732f1cb2Sdoug /* 459732f1cb2Sdoug * CBB_add_u24 appends a 24-bit, big-endian number from |value| to |cbb|. It 460732f1cb2Sdoug * returns one on success and zero otherwise. 461732f1cb2Sdoug */ 4629d4b5ca7Sdoug int CBB_add_u24(CBB *cbb, size_t value); 463c4905cd3Sdoug 464732f1cb2Sdoug /* 465732f1cb2Sdoug * CBB_add_asn1_uint64 writes an ASN.1 INTEGER into |cbb| using |CBB_add_asn1| 466c4905cd3Sdoug * and writes |value| in its contents. It returns one on success and zero on 467732f1cb2Sdoug * error. 468732f1cb2Sdoug */ 469c4905cd3Sdoug int CBB_add_asn1_uint64(CBB *cbb, uint64_t value); 470c4905cd3Sdoug 471c4905cd3Sdoug #ifdef LIBRESSL_INTERNAL 472732f1cb2Sdoug /* 47342fa457bSdoug * CBS_dup sets |out| to point to cbs's |data| and |len|. It results in two 47442fa457bSdoug * CBS that point to the same buffer. 47542fa457bSdoug */ 47642fa457bSdoug void CBS_dup(const CBS *cbs, CBS *out); 47742fa457bSdoug 47842fa457bSdoug /* 4792b93cbaaSdoug * cbs_get_any_asn1_element sets |*out| to contain the next ASN.1 element from 4800870ee34Sdoug * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to 4810870ee34Sdoug * the tag number and |*out_header_len| to the length of the ASN.1 header. If 4820870ee34Sdoug * strict mode is disabled and the element has indefinite length then |*out| 4830870ee34Sdoug * will only contain the header. Each of |out|, |out_tag|, and 4840870ee34Sdoug * |out_header_len| may be NULL to ignore the value. 4850870ee34Sdoug * 4860870ee34Sdoug * Tag numbers greater than 30 are not supported (i.e. short form only). 4870870ee34Sdoug */ 4880ad3dcfdSdoug int cbs_get_any_asn1_element_internal(CBS *cbs, CBS *out, unsigned int *out_tag, 4890870ee34Sdoug size_t *out_header_len, int strict); 4900870ee34Sdoug 4910870ee34Sdoug /* 49250933c7bSdoug * CBS_asn1_indefinite_to_definite reads an ASN.1 structure from |in|. If it 49350933c7bSdoug * finds indefinite-length elements that otherwise appear to be valid DER, it 49450933c7bSdoug * attempts to convert the DER-like data to DER and sets |*out| and 49550933c7bSdoug * |*out_length| to describe a malloced buffer containing the DER data. 49650933c7bSdoug * Additionally, |*in| will be advanced over the ASN.1 data. 497c4905cd3Sdoug * 498c4905cd3Sdoug * If it doesn't find any indefinite-length elements then it sets |*out| to 499c4905cd3Sdoug * NULL and |*in| is unmodified. 500c4905cd3Sdoug * 50150933c7bSdoug * This is NOT a conversion from BER to DER. There are many restrictions when 50250933c7bSdoug * dealing with DER data. This is only concerned with one: indefinite vs. 50350933c7bSdoug * definite form. However, this suffices to handle the PKCS#7 and PKCS#12 output 504c4905cd3Sdoug * from NSS. 505c4905cd3Sdoug * 506732f1cb2Sdoug * It returns one on success and zero otherwise. 507732f1cb2Sdoug */ 50850933c7bSdoug int CBS_asn1_indefinite_to_definite(CBS *in, uint8_t **out, size_t *out_len); 509c4905cd3Sdoug #endif /* LIBRESSL_INTERNAL */ 510c4905cd3Sdoug 511a9f45c63Sguenther __END_HIDDEN_DECLS 512c4905cd3Sdoug 513c4905cd3Sdoug #endif /* OPENSSL_HEADER_BYTESTRING_H */ 514