1*d82bd181Sjsing /* $OpenBSD: bytestring.h,v 1.24 2022/11/09 23:14:51 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 15d2f1cbaeSjsing * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16d2f1cbaeSjsing */ 17c4905cd3Sdoug 18c4905cd3Sdoug #ifndef OPENSSL_HEADER_BYTESTRING_H 19c4905cd3Sdoug #define OPENSSL_HEADER_BYTESTRING_H 20c4905cd3Sdoug 21c4905cd3Sdoug #include <sys/types.h> 22c4905cd3Sdoug #include <stdint.h> 23c4905cd3Sdoug 24a9f45c63Sguenther __BEGIN_HIDDEN_DECLS 25a9f45c63Sguenther 26732f1cb2Sdoug /* 27732f1cb2Sdoug * Bytestrings are used for parsing and building TLS and ASN.1 messages. 28c4905cd3Sdoug * 29c4905cd3Sdoug * A "CBS" (CRYPTO ByteString) represents a string of bytes in memory and 30c4905cd3Sdoug * provides utility functions for safely parsing length-prefixed structures 31c4905cd3Sdoug * like TLS and ASN.1 from it. 32c4905cd3Sdoug * 33c4905cd3Sdoug * A "CBB" (CRYPTO ByteBuilder) is a memory buffer that grows as needed and 34732f1cb2Sdoug * provides utility functions for building length-prefixed messages. 35732f1cb2Sdoug */ 36c4905cd3Sdoug 37c4905cd3Sdoug /* CRYPTO ByteString */ 38c4905cd3Sdoug typedef struct cbs_st { 39c4905cd3Sdoug const uint8_t *data; 4034e475baSdoug size_t initial_len; 41c4905cd3Sdoug size_t len; 42c4905cd3Sdoug } CBS; 43c4905cd3Sdoug 44732f1cb2Sdoug /* 45732f1cb2Sdoug * CBS_init sets |cbs| to point to |data|. It does not take ownership of 46732f1cb2Sdoug * |data|. 47732f1cb2Sdoug */ 48c4905cd3Sdoug void CBS_init(CBS *cbs, const uint8_t *data, size_t len); 49c4905cd3Sdoug 50732f1cb2Sdoug /* 51732f1cb2Sdoug * CBS_skip advances |cbs| by |len| bytes. It returns one on success and zero 52732f1cb2Sdoug * otherwise. 53732f1cb2Sdoug */ 54c4905cd3Sdoug int CBS_skip(CBS *cbs, size_t len); 55c4905cd3Sdoug 56732f1cb2Sdoug /* 573b087d0eSdoug * CBS_data returns a pointer to the contents of |cbs|. 58732f1cb2Sdoug */ 59c4905cd3Sdoug const uint8_t *CBS_data(const CBS *cbs); 60c4905cd3Sdoug 61732f1cb2Sdoug /* 62732f1cb2Sdoug * CBS_len returns the number of bytes remaining in |cbs|. 63732f1cb2Sdoug */ 64c4905cd3Sdoug size_t CBS_len(const CBS *cbs); 65c4905cd3Sdoug 66732f1cb2Sdoug /* 6734e475baSdoug * CBS_offset returns the current offset into the original data of |cbs|. 6834e475baSdoug */ 6934e475baSdoug size_t CBS_offset(const CBS *cbs); 7034e475baSdoug 7134e475baSdoug /* 72732f1cb2Sdoug * CBS_stow copies the current contents of |cbs| into |*out_ptr| and 73c4905cd3Sdoug * |*out_len|. If |*out_ptr| is not NULL, the contents are freed with 741f70f88bSdoug * free. It returns one on success and zero on allocation failure. On 751f70f88bSdoug * success, |*out_ptr| should be freed with free. If |cbs| is empty, 76732f1cb2Sdoug * |*out_ptr| will be NULL. 77732f1cb2Sdoug */ 78c4905cd3Sdoug int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len); 79c4905cd3Sdoug 80732f1cb2Sdoug /* 81732f1cb2Sdoug * CBS_strdup copies the current contents of |cbs| into |*out_ptr| as a 82c4905cd3Sdoug * NUL-terminated C string. If |*out_ptr| is not NULL, the contents are freed 83*d82bd181Sjsing * with free. It returns one on success and zero on failure. On success, 84*d82bd181Sjsing * |*out_ptr| should be freed with free. If |cbs| contains NUL bytes, 85*d82bd181Sjsing * CBS_strdup will fail. 86732f1cb2Sdoug */ 87c4905cd3Sdoug int CBS_strdup(const CBS *cbs, char **out_ptr); 88c4905cd3Sdoug 89732f1cb2Sdoug /* 90df129122Sdoug * CBS_write_bytes writes all of the remaining data from |cbs| into |dst| 91df129122Sdoug * if it is at most |dst_len| bytes. If |copied| is not NULL, it will be set 92df129122Sdoug * to the amount copied. It returns one on success and zero otherwise. 93df129122Sdoug */ 94df129122Sdoug int CBS_write_bytes(const CBS *cbs, uint8_t *dst, size_t dst_len, 95df129122Sdoug size_t *copied); 96df129122Sdoug 97df129122Sdoug /* 98732f1cb2Sdoug * CBS_contains_zero_byte returns one if the current contents of |cbs| contains 99732f1cb2Sdoug * a NUL byte and zero otherwise. 100732f1cb2Sdoug */ 101c4905cd3Sdoug int CBS_contains_zero_byte(const CBS *cbs); 102c4905cd3Sdoug 103732f1cb2Sdoug /* 104732f1cb2Sdoug * CBS_mem_equal compares the current contents of |cbs| with the |len| bytes 105c4905cd3Sdoug * starting at |data|. If they're equal, it returns one, otherwise zero. If the 106732f1cb2Sdoug * lengths match, it uses a constant-time comparison. 107732f1cb2Sdoug */ 108732f1cb2Sdoug int CBS_mem_equal(const CBS *cbs, const uint8_t *data, size_t len); 109c4905cd3Sdoug 110732f1cb2Sdoug /* 111732f1cb2Sdoug * CBS_get_u8 sets |*out| to the next uint8_t from |cbs| and advances |cbs|. It 112732f1cb2Sdoug * returns one on success and zero on error. 113732f1cb2Sdoug */ 114c4905cd3Sdoug int CBS_get_u8(CBS *cbs, uint8_t *out); 115c4905cd3Sdoug 116732f1cb2Sdoug /* 117732f1cb2Sdoug * CBS_get_u16 sets |*out| to the next, big-endian uint16_t from |cbs| and 118732f1cb2Sdoug * advances |cbs|. It returns one on success and zero on error. 119732f1cb2Sdoug */ 120c4905cd3Sdoug int CBS_get_u16(CBS *cbs, uint16_t *out); 121c4905cd3Sdoug 122732f1cb2Sdoug /* 123732f1cb2Sdoug * CBS_get_u24 sets |*out| to the next, big-endian 24-bit value from |cbs| and 124732f1cb2Sdoug * advances |cbs|. It returns one on success and zero on error. 125732f1cb2Sdoug */ 126c4905cd3Sdoug int CBS_get_u24(CBS *cbs, uint32_t *out); 127c4905cd3Sdoug 128732f1cb2Sdoug /* 129732f1cb2Sdoug * CBS_get_u32 sets |*out| to the next, big-endian uint32_t value from |cbs| 130732f1cb2Sdoug * and advances |cbs|. It returns one on success and zero on error. 131732f1cb2Sdoug */ 132c4905cd3Sdoug int CBS_get_u32(CBS *cbs, uint32_t *out); 133c4905cd3Sdoug 134732f1cb2Sdoug /* 135d2653aa9Sjsing * CBS_get_u64 sets |*out| to the next, big-endian uint64_t value from |cbs| 136d2653aa9Sjsing * and advances |cbs|. It returns one on success and zero on error. 137d2653aa9Sjsing */ 138d2653aa9Sjsing int CBS_get_u64(CBS *cbs, uint64_t *out); 139d2653aa9Sjsing 140d2653aa9Sjsing /* 141a44c0c8fSjsing * CBS_get_last_u8 sets |*out| to the last uint8_t from |cbs| and shortens 142a44c0c8fSjsing * |cbs|. It returns one on success and zero on error. 143a44c0c8fSjsing */ 144a44c0c8fSjsing int CBS_get_last_u8(CBS *cbs, uint8_t *out); 145a44c0c8fSjsing 146a44c0c8fSjsing /* 147732f1cb2Sdoug * CBS_get_bytes sets |*out| to the next |len| bytes from |cbs| and advances 148732f1cb2Sdoug * |cbs|. It returns one on success and zero on error. 149732f1cb2Sdoug */ 150c4905cd3Sdoug int CBS_get_bytes(CBS *cbs, CBS *out, size_t len); 151c4905cd3Sdoug 152732f1cb2Sdoug /* 153732f1cb2Sdoug * CBS_get_u8_length_prefixed sets |*out| to the contents of an 8-bit, 154c4905cd3Sdoug * length-prefixed value from |cbs| and advances |cbs| over it. It returns one 155732f1cb2Sdoug * on success and zero on error. 156732f1cb2Sdoug */ 157c4905cd3Sdoug int CBS_get_u8_length_prefixed(CBS *cbs, CBS *out); 158c4905cd3Sdoug 159732f1cb2Sdoug /* 160732f1cb2Sdoug * CBS_get_u16_length_prefixed sets |*out| to the contents of a 16-bit, 161c4905cd3Sdoug * big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It 162732f1cb2Sdoug * returns one on success and zero on error. 163732f1cb2Sdoug */ 164c4905cd3Sdoug int CBS_get_u16_length_prefixed(CBS *cbs, CBS *out); 165c4905cd3Sdoug 166732f1cb2Sdoug /* 167732f1cb2Sdoug * CBS_get_u24_length_prefixed sets |*out| to the contents of a 24-bit, 168c4905cd3Sdoug * big-endian, length-prefixed value from |cbs| and advances |cbs| over it. It 169732f1cb2Sdoug * returns one on success and zero on error. 170732f1cb2Sdoug */ 171c4905cd3Sdoug int CBS_get_u24_length_prefixed(CBS *cbs, CBS *out); 172c4905cd3Sdoug 1739c2102cfSjsing /* 1749c2102cfSjsing * CBS_peek_u8 sets |*out| to the next uint8_t from |cbs|, but does not advance 1759c2102cfSjsing * |cbs|. It returns one on success and zero on error. 1769c2102cfSjsing */ 1779c2102cfSjsing int CBS_peek_u8(CBS *cbs, uint8_t *out); 1789c2102cfSjsing 1799c2102cfSjsing /* 1809c2102cfSjsing * CBS_peek_u16 sets |*out| to the next, big-endian uint16_t from |cbs|, but 1819c2102cfSjsing * does not advance |cbs|. It returns one on success and zero on error. 1829c2102cfSjsing */ 1839c2102cfSjsing int CBS_peek_u16(CBS *cbs, uint16_t *out); 1849c2102cfSjsing 1859c2102cfSjsing /* 1869c2102cfSjsing * CBS_peek_u24 sets |*out| to the next, big-endian 24-bit value from |cbs|, but 1879c2102cfSjsing * does not advance |cbs|. It returns one on success and zero on error. 1889c2102cfSjsing */ 1899c2102cfSjsing int CBS_peek_u24(CBS *cbs, uint32_t *out); 1909c2102cfSjsing 1919c2102cfSjsing /* 1929c2102cfSjsing * CBS_peek_u32 sets |*out| to the next, big-endian uint32_t value from |cbs|, 1939c2102cfSjsing * but does not advance |cbs|. It returns one on success and zero on error. 1949c2102cfSjsing */ 1959c2102cfSjsing int CBS_peek_u32(CBS *cbs, uint32_t *out); 1969c2102cfSjsing 1979c2102cfSjsing /* 1989c2102cfSjsing * CBS_peek_last_u8 sets |*out| to the last uint8_t from |cbs|, but does not 1999c2102cfSjsing * shorten |cbs|. It returns one on success and zero on error. 2009c2102cfSjsing */ 2019c2102cfSjsing int CBS_peek_last_u8(CBS *cbs, uint8_t *out); 2029c2102cfSjsing 203c4905cd3Sdoug 204c4905cd3Sdoug /* Parsing ASN.1 */ 205c4905cd3Sdoug 206844e66cbSdoug /* 207844e66cbSdoug * While an identifier can be multiple octets, this library only handles the 208844e66cbSdoug * single octet variety currently. This limits support up to tag number 30 209844e66cbSdoug * since tag number 31 is a reserved value to indicate multiple octets. 210844e66cbSdoug */ 211c4905cd3Sdoug 212844e66cbSdoug /* Bits 8 and 7: class tag type: See X.690 section 8.1.2.2. */ 213844e66cbSdoug #define CBS_ASN1_UNIVERSAL 0x00 214844e66cbSdoug #define CBS_ASN1_APPLICATION 0x40 215c4905cd3Sdoug #define CBS_ASN1_CONTEXT_SPECIFIC 0x80 216844e66cbSdoug #define CBS_ASN1_PRIVATE 0xc0 217844e66cbSdoug 218844e66cbSdoug /* Bit 6: Primitive or constructed: See X.690 section 8.1.2.3. */ 219844e66cbSdoug #define CBS_ASN1_PRIMITIVE 0x00 220844e66cbSdoug #define CBS_ASN1_CONSTRUCTED 0x20 221844e66cbSdoug 222844e66cbSdoug /* 223844e66cbSdoug * Bits 5 to 1 are the tag number. See X.680 section 8.6 for tag numbers of 224844e66cbSdoug * the universal class. 225844e66cbSdoug */ 226844e66cbSdoug 227844e66cbSdoug /* 228844e66cbSdoug * Common universal identifier octets. 229844e66cbSdoug * See X.690 section 8.1 and X.680 section 8.6 for universal tag numbers. 230844e66cbSdoug * 231844e66cbSdoug * Note: These definitions are the cause of some of the strange behavior in 232844e66cbSdoug * CBS's bs_ber.c. 233844e66cbSdoug * 234844e66cbSdoug * In BER, it is the sender's option to use primitive or constructed for 235844e66cbSdoug * bitstring (X.690 section 8.6.1) and octetstring (X.690 section 8.7.1). 236844e66cbSdoug * 237844e66cbSdoug * In DER, bitstring and octetstring are required to be primitive 238844e66cbSdoug * (X.690 section 10.2). 239844e66cbSdoug */ 240844e66cbSdoug #define CBS_ASN1_BOOLEAN (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x1) 241844e66cbSdoug #define CBS_ASN1_INTEGER (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x2) 242844e66cbSdoug #define CBS_ASN1_BITSTRING (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x3) 243844e66cbSdoug #define CBS_ASN1_OCTETSTRING (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x4) 244844e66cbSdoug #define CBS_ASN1_OBJECT (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0x6) 245844e66cbSdoug #define CBS_ASN1_ENUMERATED (CBS_ASN1_UNIVERSAL | CBS_ASN1_PRIMITIVE | 0xa) 246844e66cbSdoug #define CBS_ASN1_SEQUENCE (CBS_ASN1_UNIVERSAL | CBS_ASN1_CONSTRUCTED | 0x10) 247844e66cbSdoug #define CBS_ASN1_SET (CBS_ASN1_UNIVERSAL | CBS_ASN1_CONSTRUCTED | 0x11) 248c4905cd3Sdoug 249732f1cb2Sdoug /* 250732f1cb2Sdoug * CBS_get_asn1 sets |*out| to the contents of DER-encoded, ASN.1 element (not 251c4905cd3Sdoug * including tag and length bytes) and advances |cbs| over it. The ASN.1 252c4905cd3Sdoug * element must match |tag_value|. It returns one on success and zero 253c4905cd3Sdoug * on error. 254c4905cd3Sdoug * 2553b087d0eSdoug * Tag numbers greater than 30 are not supported (i.e. short form only). 256732f1cb2Sdoug */ 2570ad3dcfdSdoug int CBS_get_asn1(CBS *cbs, CBS *out, unsigned int tag_value); 258c4905cd3Sdoug 259732f1cb2Sdoug /* 260732f1cb2Sdoug * CBS_get_asn1_element acts like |CBS_get_asn1| but |out| will include the 261732f1cb2Sdoug * ASN.1 header bytes too. 262732f1cb2Sdoug */ 2630ad3dcfdSdoug int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned int tag_value); 264c4905cd3Sdoug 265732f1cb2Sdoug /* 266732f1cb2Sdoug * CBS_peek_asn1_tag looks ahead at the next ASN.1 tag and returns one 267c4905cd3Sdoug * if the next ASN.1 element on |cbs| would have tag |tag_value|. If 268c4905cd3Sdoug * |cbs| is empty or the tag does not match, it returns zero. Note: if 269c4905cd3Sdoug * it returns one, CBS_get_asn1 may still fail if the rest of the 270732f1cb2Sdoug * element is malformed. 271732f1cb2Sdoug */ 2720ad3dcfdSdoug int CBS_peek_asn1_tag(const CBS *cbs, unsigned int tag_value); 273c4905cd3Sdoug 274732f1cb2Sdoug /* 275732f1cb2Sdoug * CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from 276c4905cd3Sdoug * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to 2770870ee34Sdoug * the tag number and |*out_header_len| to the length of the ASN.1 header. 2780870ee34Sdoug * Each of |out|, |out_tag|, and |out_header_len| may be NULL to ignore 279c4905cd3Sdoug * the value. 280c4905cd3Sdoug * 2813b087d0eSdoug * Tag numbers greater than 30 are not supported (i.e. short form only). 282732f1cb2Sdoug */ 2830ad3dcfdSdoug int CBS_get_any_asn1_element(CBS *cbs, CBS *out, unsigned int *out_tag, 284c4905cd3Sdoug size_t *out_header_len); 285c4905cd3Sdoug 286732f1cb2Sdoug /* 287732f1cb2Sdoug * CBS_get_asn1_uint64 gets an ASN.1 INTEGER from |cbs| using |CBS_get_asn1| 288c4905cd3Sdoug * and sets |*out| to its value. It returns one on success and zero on error, 289c4905cd3Sdoug * where error includes the integer being negative, or too large to represent 290732f1cb2Sdoug * in 64 bits. 291732f1cb2Sdoug */ 292c4905cd3Sdoug int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out); 293c4905cd3Sdoug 294732f1cb2Sdoug /* 295732f1cb2Sdoug * CBS_get_optional_asn1 gets an optional explicitly-tagged element 296c4905cd3Sdoug * from |cbs| tagged with |tag| and sets |*out| to its contents. If 297c4905cd3Sdoug * present, it sets |*out_present| to one, otherwise zero. It returns 298c4905cd3Sdoug * one on success, whether or not the element was present, and zero on 299732f1cb2Sdoug * decode failure. 300732f1cb2Sdoug */ 3010ad3dcfdSdoug int CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, 3020ad3dcfdSdoug unsigned int tag); 303c4905cd3Sdoug 304732f1cb2Sdoug /* 305732f1cb2Sdoug * CBS_get_optional_asn1_octet_string gets an optional 306c4905cd3Sdoug * explicitly-tagged OCTET STRING from |cbs|. If present, it sets 307c4905cd3Sdoug * |*out| to the string and |*out_present| to one. Otherwise, it sets 308c4905cd3Sdoug * |*out| to empty and |*out_present| to zero. |out_present| may be 309c4905cd3Sdoug * NULL. It returns one on success, whether or not the element was 310732f1cb2Sdoug * present, and zero on decode failure. 311732f1cb2Sdoug */ 312732f1cb2Sdoug int CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out, int *out_present, 3130ad3dcfdSdoug unsigned int tag); 314c4905cd3Sdoug 315732f1cb2Sdoug /* 316732f1cb2Sdoug * CBS_get_optional_asn1_uint64 gets an optional explicitly-tagged 317c4905cd3Sdoug * INTEGER from |cbs|. If present, it sets |*out| to the 318c4905cd3Sdoug * value. Otherwise, it sets |*out| to |default_value|. It returns one 319c4905cd3Sdoug * on success, whether or not the element was present, and zero on 320732f1cb2Sdoug * decode failure. 321732f1cb2Sdoug */ 3220ad3dcfdSdoug int CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out, unsigned int tag, 323c4905cd3Sdoug uint64_t default_value); 324c4905cd3Sdoug 325732f1cb2Sdoug /* 326732f1cb2Sdoug * CBS_get_optional_asn1_bool gets an optional, explicitly-tagged BOOLEAN from 327c4905cd3Sdoug * |cbs|. If present, it sets |*out| to either zero or one, based on the 328c4905cd3Sdoug * boolean. Otherwise, it sets |*out| to |default_value|. It returns one on 329c4905cd3Sdoug * success, whether or not the element was present, and zero on decode 330732f1cb2Sdoug * failure. 331732f1cb2Sdoug */ 3320ad3dcfdSdoug int CBS_get_optional_asn1_bool(CBS *cbs, int *out, unsigned int tag, 333c4905cd3Sdoug int default_value); 334c4905cd3Sdoug 335c4905cd3Sdoug 336732f1cb2Sdoug /* 337732f1cb2Sdoug * CRYPTO ByteBuilder. 338c4905cd3Sdoug * 339c4905cd3Sdoug * |CBB| objects allow one to build length-prefixed serialisations. A |CBB| 340c4905cd3Sdoug * object is associated with a buffer and new buffers are created with 341c4905cd3Sdoug * |CBB_init|. Several |CBB| objects can point at the same buffer when a 342c4905cd3Sdoug * length-prefix is pending, however only a single |CBB| can be 'current' at 343c4905cd3Sdoug * any one time. For example, if one calls |CBB_add_u8_length_prefixed| then 344c4905cd3Sdoug * the new |CBB| points at the same buffer as the original. But if the original 345c4905cd3Sdoug * |CBB| is used then the length prefix is written out and the new |CBB| must 346c4905cd3Sdoug * not be used again. 347c4905cd3Sdoug * 348c4905cd3Sdoug * If one needs to force a length prefix to be written out because a |CBB| is 349732f1cb2Sdoug * going out of scope, use |CBB_flush|. 350732f1cb2Sdoug */ 351c4905cd3Sdoug 352c4905cd3Sdoug struct cbb_buffer_st { 353c4905cd3Sdoug uint8_t *buf; 354732f1cb2Sdoug 355732f1cb2Sdoug /* The number of valid bytes. */ 356732f1cb2Sdoug size_t len; 357732f1cb2Sdoug 358732f1cb2Sdoug /* The size of buf. */ 359732f1cb2Sdoug size_t cap; 360732f1cb2Sdoug 361732f1cb2Sdoug /* 362732f1cb2Sdoug * One iff |buf| is owned by this object. If not then |buf| cannot be 363732f1cb2Sdoug * resized. 364732f1cb2Sdoug */ 365732f1cb2Sdoug char can_resize; 366c4905cd3Sdoug }; 367c4905cd3Sdoug 368c4905cd3Sdoug typedef struct cbb_st { 369c4905cd3Sdoug struct cbb_buffer_st *base; 370732f1cb2Sdoug 371732f1cb2Sdoug /* 372732f1cb2Sdoug * offset is the offset from the start of |base->buf| to the position of any 373732f1cb2Sdoug * pending length-prefix. 374732f1cb2Sdoug */ 375c4905cd3Sdoug size_t offset; 376732f1cb2Sdoug 377c4905cd3Sdoug /* child points to a child CBB if a length-prefix is pending. */ 378c4905cd3Sdoug struct cbb_st *child; 379732f1cb2Sdoug 380732f1cb2Sdoug /* 381732f1cb2Sdoug * pending_len_len contains the number of bytes in a pending length-prefix, 382732f1cb2Sdoug * or zero if no length-prefix is pending. 383732f1cb2Sdoug */ 384c4905cd3Sdoug uint8_t pending_len_len; 385732f1cb2Sdoug 386c4905cd3Sdoug char pending_is_asn1; 387732f1cb2Sdoug 388732f1cb2Sdoug /* 389732f1cb2Sdoug * is_top_level is true iff this is a top-level |CBB| (as opposed to a child 390732f1cb2Sdoug * |CBB|). Top-level objects are valid arguments for |CBB_finish|. 391732f1cb2Sdoug */ 392c4905cd3Sdoug char is_top_level; 393c4905cd3Sdoug } CBB; 394c4905cd3Sdoug 395732f1cb2Sdoug /* 396732f1cb2Sdoug * CBB_init initialises |cbb| with |initial_capacity|. Since a |CBB| grows as 397c4905cd3Sdoug * needed, the |initial_capacity| is just a hint. It returns one on success or 398732f1cb2Sdoug * zero on error. 399732f1cb2Sdoug */ 400c4905cd3Sdoug int CBB_init(CBB *cbb, size_t initial_capacity); 401c4905cd3Sdoug 402732f1cb2Sdoug /* 403732f1cb2Sdoug * CBB_init_fixed initialises |cbb| to write to |len| bytes at |buf|. Since 404c4905cd3Sdoug * |buf| cannot grow, trying to write more than |len| bytes will cause CBB 405732f1cb2Sdoug * functions to fail. It returns one on success or zero on error. 406732f1cb2Sdoug */ 407c4905cd3Sdoug int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len); 408c4905cd3Sdoug 409732f1cb2Sdoug /* 410732f1cb2Sdoug * CBB_cleanup frees all resources owned by |cbb| and other |CBB| objects 411c4905cd3Sdoug * writing to the same buffer. This should be used in an error case where a 412732f1cb2Sdoug * serialisation is abandoned. 413732f1cb2Sdoug */ 414c4905cd3Sdoug void CBB_cleanup(CBB *cbb); 415c4905cd3Sdoug 416732f1cb2Sdoug /* 417732f1cb2Sdoug * CBB_finish completes any pending length prefix and sets |*out_data| to a 418c4905cd3Sdoug * malloced buffer and |*out_len| to the length of that buffer. The caller 419c4905cd3Sdoug * takes ownership of the buffer and, unless the buffer was fixed with 4201f70f88bSdoug * |CBB_init_fixed|, must call |free| when done. 421c4905cd3Sdoug * 422c4905cd3Sdoug * It can only be called on a "top level" |CBB|, i.e. one initialised with 423c4905cd3Sdoug * |CBB_init| or |CBB_init_fixed|. It returns one on success and zero on 424732f1cb2Sdoug * error. 425732f1cb2Sdoug */ 426c4905cd3Sdoug int CBB_finish(CBB *cbb, uint8_t **out_data, size_t *out_len); 427c4905cd3Sdoug 428732f1cb2Sdoug /* 429732f1cb2Sdoug * CBB_flush causes any pending length prefixes to be written out and any child 430c4905cd3Sdoug * |CBB| objects of |cbb| to be invalidated. It returns one on success or zero 431732f1cb2Sdoug * on error. 432732f1cb2Sdoug */ 433c4905cd3Sdoug int CBB_flush(CBB *cbb); 434c4905cd3Sdoug 435732f1cb2Sdoug /* 436e87ff5aeSjsing * CBB_discard_child discards the current unflushed child of |cbb|. Neither the 437e87ff5aeSjsing * child's contents nor the length prefix will be included in the output. 438e87ff5aeSjsing */ 439e87ff5aeSjsing void CBB_discard_child(CBB *cbb); 440e87ff5aeSjsing 441e87ff5aeSjsing /* 442732f1cb2Sdoug * CBB_add_u8_length_prefixed sets |*out_contents| to a new child of |cbb|. The 443c4905cd3Sdoug * data written to |*out_contents| will be prefixed in |cbb| with an 8-bit 444732f1cb2Sdoug * length. It returns one on success or zero on error. 445732f1cb2Sdoug */ 446c4905cd3Sdoug int CBB_add_u8_length_prefixed(CBB *cbb, CBB *out_contents); 447c4905cd3Sdoug 448732f1cb2Sdoug /* 449732f1cb2Sdoug * CBB_add_u16_length_prefixed sets |*out_contents| to a new child of |cbb|. 450c4905cd3Sdoug * The data written to |*out_contents| will be prefixed in |cbb| with a 16-bit, 451732f1cb2Sdoug * big-endian length. It returns one on success or zero on error. 452732f1cb2Sdoug */ 453c4905cd3Sdoug int CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents); 454c4905cd3Sdoug 455732f1cb2Sdoug /* 456732f1cb2Sdoug * CBB_add_u24_length_prefixed sets |*out_contents| to a new child of |cbb|. 457c4905cd3Sdoug * The data written to |*out_contents| will be prefixed in |cbb| with a 24-bit, 458732f1cb2Sdoug * big-endian length. It returns one on success or zero on error. 459732f1cb2Sdoug */ 460c4905cd3Sdoug int CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents); 461c4905cd3Sdoug 462732f1cb2Sdoug /* 463732f1cb2Sdoug * CBB_add_asn sets |*out_contents| to a |CBB| into which the contents of an 464c4905cd3Sdoug * ASN.1 object can be written. The |tag| argument will be used as the tag for 465d7a08d8fSdoug * the object. Passing in |tag| number 31 will return in an error since only 466d7a08d8fSdoug * single octet identifiers are supported. It returns one on success or zero 467d7a08d8fSdoug * on error. 468732f1cb2Sdoug */ 4699d4b5ca7Sdoug int CBB_add_asn1(CBB *cbb, CBB *out_contents, unsigned int tag); 470c4905cd3Sdoug 471732f1cb2Sdoug /* 472732f1cb2Sdoug * CBB_add_bytes appends |len| bytes from |data| to |cbb|. It returns one on 473732f1cb2Sdoug * success and zero otherwise. 474732f1cb2Sdoug */ 475c4905cd3Sdoug int CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len); 476c4905cd3Sdoug 477732f1cb2Sdoug /* 478732f1cb2Sdoug * CBB_add_space appends |len| bytes to |cbb| and sets |*out_data| to point to 479c4905cd3Sdoug * the beginning of that space. The caller must then write |len| bytes of 480c4905cd3Sdoug * actual contents to |*out_data|. It returns one on success and zero 481732f1cb2Sdoug * otherwise. 482732f1cb2Sdoug */ 483c4905cd3Sdoug int CBB_add_space(CBB *cbb, uint8_t **out_data, size_t len); 484c4905cd3Sdoug 485732f1cb2Sdoug /* 486732f1cb2Sdoug * CBB_add_u8 appends an 8-bit number from |value| to |cbb|. It returns one on 487732f1cb2Sdoug * success and zero otherwise. 488732f1cb2Sdoug */ 4899d4b5ca7Sdoug int CBB_add_u8(CBB *cbb, size_t value); 490c4905cd3Sdoug 491732f1cb2Sdoug /* 492732f1cb2Sdoug * CBB_add_u8 appends a 16-bit, big-endian number from |value| to |cbb|. It 493732f1cb2Sdoug * returns one on success and zero otherwise. 494732f1cb2Sdoug */ 4959d4b5ca7Sdoug int CBB_add_u16(CBB *cbb, size_t value); 496c4905cd3Sdoug 497732f1cb2Sdoug /* 498732f1cb2Sdoug * CBB_add_u24 appends a 24-bit, big-endian number from |value| to |cbb|. It 499732f1cb2Sdoug * returns one on success and zero otherwise. 500732f1cb2Sdoug */ 5019d4b5ca7Sdoug int CBB_add_u24(CBB *cbb, size_t value); 502c4905cd3Sdoug 503732f1cb2Sdoug /* 504bd94b8a5Sjsing * CBB_add_u32 appends a 32-bit, big-endian number from |value| to |cbb|. It 505bd94b8a5Sjsing * returns one on success and zero otherwise. 506bd94b8a5Sjsing */ 507bd94b8a5Sjsing int CBB_add_u32(CBB *cbb, size_t value); 508bd94b8a5Sjsing 509bd94b8a5Sjsing /* 51054ced76bSjsing * CBB_add_u64 appends a 64-bit, big-endian number from |value| to |cbb|. It 51154ced76bSjsing * returns one on success and zero otherwise. 51254ced76bSjsing */ 51354ced76bSjsing int CBB_add_u64(CBB *cbb, uint64_t value); 51454ced76bSjsing 51554ced76bSjsing /* 516732f1cb2Sdoug * CBB_add_asn1_uint64 writes an ASN.1 INTEGER into |cbb| using |CBB_add_asn1| 517c4905cd3Sdoug * and writes |value| in its contents. It returns one on success and zero on 518732f1cb2Sdoug * error. 519732f1cb2Sdoug */ 520c4905cd3Sdoug int CBB_add_asn1_uint64(CBB *cbb, uint64_t value); 521c4905cd3Sdoug 522c4905cd3Sdoug #ifdef LIBRESSL_INTERNAL 523732f1cb2Sdoug /* 52442fa457bSdoug * CBS_dup sets |out| to point to cbs's |data| and |len|. It results in two 52542fa457bSdoug * CBS that point to the same buffer. 52642fa457bSdoug */ 52742fa457bSdoug void CBS_dup(const CBS *cbs, CBS *out); 52842fa457bSdoug 52942fa457bSdoug /* 5302b93cbaaSdoug * cbs_get_any_asn1_element sets |*out| to contain the next ASN.1 element from 5310870ee34Sdoug * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to 5320870ee34Sdoug * the tag number and |*out_header_len| to the length of the ASN.1 header. If 5330870ee34Sdoug * strict mode is disabled and the element has indefinite length then |*out| 5340870ee34Sdoug * will only contain the header. Each of |out|, |out_tag|, and 5350870ee34Sdoug * |out_header_len| may be NULL to ignore the value. 5360870ee34Sdoug * 5370870ee34Sdoug * Tag numbers greater than 30 are not supported (i.e. short form only). 5380870ee34Sdoug */ 5390ad3dcfdSdoug int cbs_get_any_asn1_element_internal(CBS *cbs, CBS *out, unsigned int *out_tag, 5400870ee34Sdoug size_t *out_header_len, int strict); 5410870ee34Sdoug 5420870ee34Sdoug /* 54350933c7bSdoug * CBS_asn1_indefinite_to_definite reads an ASN.1 structure from |in|. If it 54450933c7bSdoug * finds indefinite-length elements that otherwise appear to be valid DER, it 54550933c7bSdoug * attempts to convert the DER-like data to DER and sets |*out| and 54650933c7bSdoug * |*out_length| to describe a malloced buffer containing the DER data. 54750933c7bSdoug * Additionally, |*in| will be advanced over the ASN.1 data. 548c4905cd3Sdoug * 549c4905cd3Sdoug * If it doesn't find any indefinite-length elements then it sets |*out| to 550c4905cd3Sdoug * NULL and |*in| is unmodified. 551c4905cd3Sdoug * 55250933c7bSdoug * This is NOT a conversion from BER to DER. There are many restrictions when 55350933c7bSdoug * dealing with DER data. This is only concerned with one: indefinite vs. 55450933c7bSdoug * definite form. However, this suffices to handle the PKCS#7 and PKCS#12 output 555c4905cd3Sdoug * from NSS. 556c4905cd3Sdoug * 557732f1cb2Sdoug * It returns one on success and zero otherwise. 558732f1cb2Sdoug */ 55950933c7bSdoug int CBS_asn1_indefinite_to_definite(CBS *in, uint8_t **out, size_t *out_len); 560c4905cd3Sdoug #endif /* LIBRESSL_INTERNAL */ 561c4905cd3Sdoug 562a9f45c63Sguenther __END_HIDDEN_DECLS 563c4905cd3Sdoug 564c4905cd3Sdoug #endif /* OPENSSL_HEADER_BYTESTRING_H */ 565