diff options
author | Ulf Möller <ulf@openssl.org> | 2000-01-23 22:06:24 +0000 |
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committer | Ulf Möller <ulf@openssl.org> | 2000-01-23 22:06:24 +0000 |
commit | dd8dec69b825c9fdafc26a200961702d850496b5 (patch) | |
tree | b7d7ca7365271c822226e1ddc6a4fd68c72273ad /doc/crypto/BN_bn2bin.pod | |
parent | ce052b6c3b18d4ab5f74990d82d09827a6014823 (diff) |
Document the BN library.
Diffstat (limited to 'doc/crypto/BN_bn2bin.pod')
-rw-r--r-- | doc/crypto/BN_bn2bin.pod | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/doc/crypto/BN_bn2bin.pod b/doc/crypto/BN_bn2bin.pod new file mode 100644 index 0000000000..5d26765dd9 --- /dev/null +++ b/doc/crypto/BN_bn2bin.pod @@ -0,0 +1,93 @@ +=pod + +=head1 NAME + +BN_bn2bin, BN_bin2bn, BN_bn2hex, BN_bn2dec, BN_hex2bn, BN_dec2bn, +BN_print_fp, BN_print, BN_bn2mpi, BN_mpi2bn - Format conversions + +=head1 SYNOPSIS + + #include <openssl/bn.h> + + int BN_bn2bin(const BIGNUM *a, unsigned char *to); + BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret); + + char *BN_bn2hex(const BIGNUM *a); + char *BN_bn2dec(const BIGNUM *a); + int BN_hex2bn(BIGNUM **a, const char *str); + int BN_dec2bn(BIGNUM **a, const char *str); + + int BN_print_fp(FILE *fp, BIGNUM *a); + int BN_print(BIO *fp, const BIGNUM *a); + + int BN_bn2mpi(const BIGNUM *a, unsigned char *to); + BIGNUM *BN_mpi2bn(unsigned char *s, int len, BIGNUM *ret); + +=head1 DESCRIPTION + +BN_bn2bin() converts the absolute value of B<a> into big-endian form +and stores it at B<to>. B<to> must point to BN_num_bytes(B<a>) bytes of +memory. + +BN_bin2bn() converts the positive integer in big-endian form of length +B<len> at B<s> into a B<BIGNUM> and places it in B<ret>. If B<ret> is +NULL, a new B<BIGNUM> is created. + +BN_bn2hex() and BN_bn2dec() return printable strings containing the +hexadecimal and decimal encoding of B<a> respectively. For negative +numbers, the string is prefaced with a leading '-'. The string must be +Free()d later. + +BN_hex2bn() converts the string B<str> containing a hexadecimal number +to a B<BIGNUM> and stores it in **B<bn>. If *B<bn> is NULL, a new +B<BIGNUM> is created. If B<bn> is NULL, it only computes the number's +length in hexadecimal digits. If the string starts with '-', the +number is negative. BN_dec2bn() is the same using the decimal system. + +BN_print_fp() and BN_print() write the hexadecimal encoding of B<a>, +with a leading '-' for negative numbers, to the B<FILE> or B<BIO> +B<fp>. + +BN_bn2mpi() and BN_mpi2bn() convert B<BIGNUM>s from and to a format +that consists of the number's length in bytes represented as a 3-byte +big-endian number, and the number itself in big-endian format, where +the most significant bit signals a negative number (the representation +of numbers with the MSB set is prefixed with null byte). + +BN_bn2mpi() stores the representation of B<a> at B<to>, where B<to> +must be large enough to hold the result. The size can be determined by +calling BN_bn2mpi(B<a>, NULL). + +BN_mpi2bn() converts the B<len> bytes long representation at B<s> to +a B<BIGNUM> and stores it ar B<ret>, or in a newly allocated B<BIGNUM> +if B<ret> is NULL. + +=head1 RETURN VALUES + +BN_bn2bin() returns the length of the big-endian number placed at B<to>. +BN_bin2bn() returns the B<BIGNUM>, NULL on error. + +BN_bn2hex() and BN_bn2dec() return a null-terminated string, or NULL +on error. BN_hex2bn() and BN_dec2bn() return the number's length in +hexadecimal or decimal digits, and 0 on error. + +BN_print_fp() and BN_print() return 1 on success, 0 on write errors. + +BN_bn2mpi() returns the length of the representation. BN_mpi2bn() +returns the B<BIGNUM>, and NULL on error. + +The error codes can be obtained by ERR_get_error(3). + +=head1 SEE ALSO + +bn(3), err(3), BN_zero(3), ASN1_INTEGER_to_BN(3), BN_num_bytes(3) + +=head1 HISTORY + +BN_bn2bin(), BN_bin2bn(), BN_print_fp() and BN_print() are available +in all versions of SSLeay and OpenSSL. + +BN_bn2hex(), BN_bn2dec(), BN_hex2bn(), BN_dec2bn(), BN_bn2mpi() and +BN_mpi2bn() were added in SSLeay 0.9.0. + +=cut |