/* Coding Buffer Specifications */ #ifndef __ASN1BUF_H__ #define __ASN1BUF_H__ #include "k5-int.h" #include "krbasn1.h" typedef struct code_buffer_rep { char *base, *bound, *next; } asn1buf; /**************** Private Procedures ****************/ int asn1buf_size (const asn1buf *buf); /* requires *buf has been created and not destroyed effects Returns the total size (in octets) of buf's octet buffer. */ #define asn1buf_size(buf) \ (((buf) == NULL || (buf)->base == NULL) \ ? 0 \ : ((buf)->bound - (buf)->base + 1)) int asn1buf_free (const asn1buf *buf); /* requires *buf is allocated effects Returns the number of unused, allocated octets in *buf. */ #define asn1buf_free(buf) \ (((buf) == NULL || (buf)->base == NULL) \ ? 0 \ : ((buf)->bound - (buf)->next + 1)) asn1_error_code asn1buf_ensure_space (asn1buf *buf, const unsigned int amount); /* requires *buf is allocated modifies *buf effects If buf has less than amount octets of free space, then it is expanded to have at least amount octets of free space. Returns ENOMEM memory is exhausted. */ #define asn1buf_ensure_space(buf,amount) \ ((asn1buf_free(buf) < (amount)) \ ? (asn1buf_expand((buf), (amount)-asn1buf_free(buf))) \ : 0) asn1_error_code asn1buf_expand (asn1buf *buf, unsigned int inc); /* requires *buf is allocated modifies *buf effects Expands *buf by allocating space for inc more octets. Returns ENOMEM if memory is exhausted. */ int asn1buf_len (const asn1buf *buf); /* requires *buf is allocated effects Returns the length of the encoding in *buf. */ #define asn1buf_len(buf) ((buf)->next - (buf)->base) /****** End of private procedures *****/ /* Overview The coding buffer is an array of char (to match a krb5_data structure) with 3 reference pointers: 1) base - The bottom of the octet array. Used for memory management operations on the array (e.g. alloc, realloc, free). 2) next - Points to the next available octet position in the array. During encoding, this is the next free position, and it advances as octets are added to the array. During decoding, this is the next unread position, and it advances as octets are read from the array. 3) bound - Points to the top of the array. Used for bounds-checking. All pointers to encoding buffers should be initalized to NULL. Operations asn1buf_create asn1buf_wrap_data asn1buf_destroy asn1buf_insert_octet asn1buf_insert_charstring asn1buf_remove_octet asn1buf_remove_charstring asn1buf_unparse asn1buf_hex_unparse asn12krb5_buf asn1buf_remains (asn1buf_size) (asn1buf_free) (asn1buf_ensure_space) (asn1buf_expand) (asn1buf_len) */ asn1_error_code asn1buf_create (asn1buf **buf); /* effects Creates a new encoding buffer pointed to by *buf. Returns ENOMEM if the buffer can't be created. */ asn1_error_code asn1buf_wrap_data (asn1buf *buf, const krb5_data *code); /* requires *buf has already been allocated effects Turns *buf into a "wrapper" for *code. i.e. *buf is set up such that its bottom is the beginning of *code, and its top is the top of *code. Returns ASN1_MISSING_FIELD if code is empty. */ asn1_error_code asn1buf_imbed (asn1buf *subbuf, const asn1buf *buf, const unsigned int length, const int indef); /* requires *subbuf and *buf are allocated effects *subbuf becomes a sub-buffer of *buf. *subbuf begins at *buf's current position and is length octets long. (Unless this would exceed the bounds of *buf -- in that case, ASN1_OVERRUN is returned) *subbuf's current position starts at the beginning of *subbuf. */ asn1_error_code asn1buf_sync (asn1buf *buf, asn1buf *subbuf, const asn1_class Class, const asn1_tagnum lasttag, const unsigned int length, const int indef, const int seqindef); /* requires *subbuf is a sub-buffer of *buf, as created by asn1buf_imbed. lasttag is the last tagnumber read. effects Synchronizes *buf's current position to match that of *subbuf. */ asn1_error_code asn1buf_skiptail (asn1buf *buf, const unsigned int length, const int indef); /* requires *buf is a subbuffer used in a decoding of a constructed indefinite sequence. effects skips trailing fields. */ asn1_error_code asn1buf_destroy (asn1buf **buf); /* effects Deallocates **buf, sets *buf to NULL. */ asn1_error_code asn1buf_insert_octet (asn1buf *buf, const int o); /* requires *buf is allocated effects Inserts o into the buffer *buf, expanding the buffer if necessary. Returns ENOMEM memory is exhausted. */ #if ((__GNUC__ >= 2) && !defined(ASN1BUF_OMIT_INLINE_FUNCS)) extern __inline__ asn1_error_code asn1buf_insert_octet(asn1buf *buf, const int o) { asn1_error_code retval; retval = asn1buf_ensure_space(buf,1U); if(retval) return retval; *(buf->next) = (char)o; (buf->next)++; return 0; } #endif asn1_error_code asn1buf_insert_octetstring (asn1buf *buf, const unsigned int len, const asn1_octet *s); /* requires *buf is allocated modifies *buf effects Inserts the contents of s (an octet array of length len) into the buffer *buf, expanding the buffer if necessary. Returns ENOMEM if memory is exhausted. */ asn1_error_code asn1buf_insert_charstring (asn1buf *buf, const unsigned int len, const char *s); /* requires *buf is allocated modifies *buf effects Inserts the contents of s (a character array of length len) into the buffer *buf, expanding the buffer if necessary. Returns ENOMEM if memory is exhausted. */ asn1_error_code asn1buf_remove_octet (asn1buf *buf, asn1_octet *o); /* requires *buf is allocated effects Returns *buf's current octet in *o and advances to the next octet. Returns ASN1_OVERRUN if *buf has already been exhausted. */ #define asn1buf_remove_octet(buf,o) \ (((buf)->next > (buf)->bound) \ ? ASN1_OVERRUN \ : ((*(o) = (asn1_octet)(*(((buf)->next)++))),0)) asn1_error_code asn1buf_remove_octetstring (asn1buf *buf, const unsigned int len, asn1_octet **s); /* requires *buf is allocated effects Removes the next len octets of *buf and returns them in **s. Returns ASN1_OVERRUN if there are fewer than len unread octets left in *buf. Returns ENOMEM if *s could not be allocated. */ asn1_error_code asn1buf_remove_charstring (asn1buf *buf, const unsigned int len, char **s); /* requires *buf is allocated effects Removes the next len octets of *buf and returns them in **s. Returns ASN1_OVERRUN if there are fewer than len unread octets left in *buf. Returns ENOMEM if *s could not be allocated. */ asn1_error_code asn1buf_unparse (const asn1buf *buf, char **s); /* modifies *s effects Returns a human-readable representation of *buf in *s, where each octet in *buf is represented by a character in *s. */ asn1_error_code asn1buf_hex_unparse (const asn1buf *buf, char **s); /* modifies *s effects Returns a human-readable representation of *buf in *s, where each octet in *buf is represented by a 2-digit hexadecimal number in *s. */ asn1_error_code asn12krb5_buf (const asn1buf *buf, krb5_data **code); /* modifies *code effects Instantiates **code with the krb5_data representation of **buf. */ int asn1buf_remains (asn1buf *buf, int indef); /* requires *buf is a buffer containing an asn.1 structure or array modifies *buf effects Returns the number of unprocessed octets remaining in *buf. */ #endif