Edit File: dsa.3
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Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" dsa \- Digital Signature Algorithm .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 2 \& #include <openssl/dsa.h> \& #include <openssl/engine.h> \& \& DSA * DSA_new(void); \& void DSA_free(DSA *dsa); \& \& int DSA_size(const DSA *dsa); \& \& DSA * DSA_generate_parameters(int bits, unsigned char *seed, \& int seed_len, int *counter_ret, unsigned long *h_ret, \& void (*callback)(int, int, void *), void *cb_arg); \& \& DH * DSA_dup_DH(const DSA *r); \& \& int DSA_generate_key(DSA *dsa); \& \& int DSA_sign(int dummy, const unsigned char *dgst, int len, \& unsigned char *sigret, unsigned int *siglen, DSA *dsa); \& int DSA_sign_setup(DSA *dsa, BN_CTX *ctx, BIGNUM **kinvp, \& BIGNUM **rp); \& int DSA_verify(int dummy, const unsigned char *dgst, int len, \& const unsigned char *sigbuf, int siglen, DSA *dsa); \& \& void DSA_set_default_method(const DSA_METHOD *meth); \& const DSA_METHOD *DSA_get_default_method(void); \& int DSA_set_method(DSA *dsa, const DSA_METHOD *meth); \& DSA *DSA_new_method(ENGINE *engine); \& const DSA_METHOD *DSA_OpenSSL(void); \& \& int DSA_get_ex_new_index(long argl, char *argp, int (*new_func)(), \& int (*dup_func)(), void (*free_func)()); \& int DSA_set_ex_data(DSA *d, int idx, char *arg); \& char *DSA_get_ex_data(DSA *d, int idx); \& \& DSA_SIG *DSA_SIG_new(void); \& void DSA_SIG_free(DSA_SIG *a); \& int i2d_DSA_SIG(const DSA_SIG *a, unsigned char **pp); \& DSA_SIG *d2i_DSA_SIG(DSA_SIG **v, unsigned char **pp, long length); \& \& DSA_SIG *DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa); \& int DSA_do_verify(const unsigned char *dgst, int dgst_len, \& DSA_SIG *sig, DSA *dsa); \& \& DSA * d2i_DSAPublicKey(DSA **a, unsigned char **pp, long length); \& DSA * d2i_DSAPrivateKey(DSA **a, unsigned char **pp, long length); \& DSA * d2i_DSAparams(DSA **a, unsigned char **pp, long length); \& int i2d_DSAPublicKey(const DSA *a, unsigned char **pp); \& int i2d_DSAPrivateKey(const DSA *a, unsigned char **pp); \& int i2d_DSAparams(const DSA *a,unsigned char **pp); \& \& int DSAparams_print(BIO *bp, const DSA *x); \& int DSAparams_print_fp(FILE *fp, const DSA *x); \& int DSA_print(BIO *bp, const DSA *x, int off); \& int DSA_print_fp(FILE *bp, const DSA *x, int off); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" These functions implement the Digital Signature Algorithm (\s-1DSA\s0). The generation of shared \s-1DSA\s0 parameters is described in \&\fBDSA_generate_parameters\fR\|(3); \&\fBDSA_generate_key\fR\|(3) describes how to generate a signature key. Signature generation and verification are described in \fBDSA_sign\fR\|(3). .PP The \fB\s-1DSA\s0\fR structure consists of several \s-1BIGNUM\s0 components. .PP .Vb 10 \& struct \& { \& BIGNUM *p; // prime number (public) \& BIGNUM *q; // 160\-bit subprime, q | p\-1 (public) \& BIGNUM *g; // generator of subgroup (public) \& BIGNUM *priv_key; // private key x \& BIGNUM *pub_key; // public key y = g^x \& // ... \& } \& DSA; .Ve .PP In public keys, \fBpriv_key\fR is \s-1NULL.\s0 .PP Note that \s-1DSA\s0 keys may use non-standard \fB\s-1DSA_METHOD\s0\fR implementations, either directly or by the use of \fB\s-1ENGINE\s0\fR modules. In some cases (eg. an \&\s-1ENGINE\s0 providing support for hardware-embedded keys), these \s-1BIGNUM\s0 values will not be used by the implementation or may be used for alternative data storage. For this reason, applications should generally avoid using \s-1DSA\s0 structure elements directly and instead use \s-1API\s0 functions to query or modify keys. .SH "CONFORMING TO" .IX Header "CONFORMING TO" \&\s-1US\s0 Federal Information Processing Standard \s-1FIPS 186\s0 (Digital Signature Standard, \s-1DSS\s0), \s-1ANSI X9.30\s0 .SH "SEE ALSO" .IX Header "SEE ALSO" \&\fBbn\fR\|(3), \fBdh\fR\|(3), \fBerr\fR\|(3), \fBrand\fR\|(3), \&\fBrsa\fR\|(3), \fBsha\fR\|(3), \fBengine\fR\|(3), \&\fBDSA_new\fR\|(3), \&\fBDSA_size\fR\|(3), \&\fBDSA_generate_parameters\fR\|(3), \&\fBDSA_dup_DH\fR\|(3), \&\fBDSA_generate_key\fR\|(3), \&\fBDSA_sign\fR\|(3), \fBDSA_set_method\fR\|(3), \&\fBDSA_get_ex_new_index\fR\|(3), \&\fBRSA_print\fR\|(3)