diff options
author | Ulf Möller <ulf@openssl.org> | 2000-02-05 14:17:32 +0000 |
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committer | Ulf Möller <ulf@openssl.org> | 2000-02-05 14:17:32 +0000 |
commit | 9b141126d4b6f0636bc047e81b846c193ae26611 (patch) | |
tree | c8786c99bfccc8b9899cad5c3aa30f29ada5e1b9 /doc/crypto/BN_CTX_start.pod | |
parent | 7e708ebee066d0308a335579b546326220dc8317 (diff) |
New functions BN_CTX_start(), BN_CTX_get(), BN_CTX_end() to access
temporary BIGNUMs. BN_CTX still uses a fixed number of BIGNUMs, but
the BN_CTX implementation could now easily be changed.
Diffstat (limited to 'doc/crypto/BN_CTX_start.pod')
-rw-r--r-- | doc/crypto/BN_CTX_start.pod | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/doc/crypto/BN_CTX_start.pod b/doc/crypto/BN_CTX_start.pod new file mode 100644 index 0000000000..3e1032375f --- /dev/null +++ b/doc/crypto/BN_CTX_start.pod @@ -0,0 +1,49 @@ +=pod + +=head1 NAME + +BN_CTX_start, BN_CTX_get, BN_CTX_end - use temporary BIGNUM variables + +=head1 SYNOPSIS + + #include <openssl/bn.h> + + void BN_CTX_start(BN_CTX *ctx); + + BIGNUM *BN_CTX_get(BN_CTX *ctx); + + void BN_CTX_end(BN_CTX *ctx); + +=head1 DESCRIPTION + +These functions are used to obtain temporary B<BIGNUM> variables from +a B<BN_CTX> in order to save the overhead of repeatedly creating and +freeing B<BIGNUM>s in functions that are called from inside a loop. + +A function must call BN_CTX_start() first. Then, BN_CTX_get() may be +called repeatedly to obtain temporary B<BIGNUM>s. All BN_CTX_get() +calls must be made before calling any other functions that use the +B<ctx> as an argument. + +Finally, BN_CTX_end() must be called before returning from the function. +When BN_CTX_end() is called, the B<BIGNUM> pointers obtained from +BN_CTX_get() become invalid. + +=head1 RETURN VALUES + +BN_CTX_start() and BN_CTX_end() return no values. + +BN_CTX_get() returns a pointer to the B<BIGNUM>, or B<NULL> on error. +Once BN_CTX_get() has failed, the subsequent calls will return B<NULL> +as well, so it is sufficient to check the return value of the last +BN_CTX_get() call. + +=head1 SEE ALSO + +L<BN_CTX_new(3)|BN_CTX_new(3)> + +=head1 HISTORY + +BN_CTX_start(), BN_CTX_get() and BN_CTX_end() were added in OpenSSL 0.9.5. + +=cut |