X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=doc%2Fcrypto%2FBN_bn2bin.pod;fp=doc%2Fcrypto%2FBN_bn2bin.pod;h=5d26765dd96e43e7568514641f3a795bc83e0d13;hp=0000000000000000000000000000000000000000;hb=dd8dec69b825c9fdafc26a200961702d850496b5;hpb=ce052b6c3b18d4ab5f74990d82d09827a6014823 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 + + 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 into big-endian form +and stores it at B. B must point to BN_num_bytes(B) bytes of +memory. + +BN_bin2bn() converts the positive integer in big-endian form of length +B at B into a B and places it in B. If B is +NULL, a new B is created. + +BN_bn2hex() and BN_bn2dec() return printable strings containing the +hexadecimal and decimal encoding of B respectively. For negative +numbers, the string is prefaced with a leading '-'. The string must be +Free()d later. + +BN_hex2bn() converts the string B containing a hexadecimal number +to a B and stores it in **B. If *B is NULL, a new +B is created. If B 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, +with a leading '-' for negative numbers, to the B or B +B. + +BN_bn2mpi() and BN_mpi2bn() convert Bs 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 at B, where B +must be large enough to hold the result. The size can be determined by +calling BN_bn2mpi(B, NULL). + +BN_mpi2bn() converts the B bytes long representation at B to +a B and stores it ar B, or in a newly allocated B +if B is NULL. + +=head1 RETURN VALUES + +BN_bn2bin() returns the length of the big-endian number placed at B. +BN_bin2bn() returns the B, 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, 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