Document DSA and SHA.

[openssl.git] / doc / crypto / dsa.pod

diff --git a/doc/crypto/dsa.pod b/doc/crypto/dsa.pod
new file mode 100644 (file)
index 0000000..f0abfc0
--- /dev/null
+++ b/doc/crypto/dsa.pod
@@ -0,0 +1,95 @@
+=pod
+
+=head1 NAME
+
+dsa - Digital Signature Algorithm
+
+=head1 SYNOPSIS
+
+ #include <openssl/dsa.h>
+
+ DSA * DSA_new(void);
+ void  DSA_free(DSA *dsa);
+
+ int   DSA_size(DSA *dsa);
+
+ DSA * DSA_generate_parameters(int bits, unsigned char *seed,
+                int seed_len, int *counter_ret, unsigned long *h_ret,
+               void (*callback)(), void *cb_arg);
+
+ DH *  DSA_dup_DH(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,
+               unsigned char *sigbuf, int siglen, DSA *dsa);
+
+ void DSA_set_default_method(DSA_METHOD *meth);
+ DSA_METHOD *DSA_get_default_method(void);
+ DSA_METHOD *DSA_set_method(DSA *dsa, DSA_METHOD *meth);
+ DSA *DSA_new_method(DSA_METHOD *meth);
+ 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(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(DSA *a, unsigned char **pp);
+ int   i2d_DSAPrivateKey(DSA *a, unsigned char **pp);
+ int   i2d_DSAparams(DSA *a,unsigned char **pp);
+
+ int   DSAparams_print(BIO *bp, DSA *x);
+ int   DSAparams_print_fp(FILE *fp, DSA *x);
+ int   DSA_print(BIO *bp, DSA *x, int off);
+ int   DSA_print_fp(FILE *bp, DSA *x, int off);
+
+=head1 DESCRIPTION
+
+These functions implement the Digital Signature Algorithm (DSA).  The
+generation of shared DSA parameters is described in
+L<DSA_generate_parameters(3)>; L<DSA_generate_key(3)> describes how to
+generate a signature key. Signature generation and verification are
+described in L<DSA_sign(3)>.
+
+The B<DSA> structure consists of several BIGNUM components.
+
+ 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;
+
+In public keys, B<priv_key> is NULL.
+
+=head1 CONFORMING TO
+
+US Federal Information Processing Standard FIPS 186 (Digital Signature
+Standard, DSS), ANSI X9.30
+
+=head1 SEE ALSO
+
+bn(3), dh(3), err(3), rand(3), rsa(3), sha(3)
+
+=cut