Document more error codes.

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

diff --git a/doc/crypto/dsa.pod b/doc/crypto/dsa.pod
index 2c092448990f76499886bbb4365317cca26d8fd0..da07d2b930ce51925287e9df047e2643d4889259 100644 (file)
--- a/doc/crypto/dsa.pod
+++ b/doc/crypto/dsa.pod
@@ -7,17 +7,18 @@ dsa - Digital Signature Algorithm
 =head1 SYNOPSIS
 
  #include <openssl/dsa.h>
+ #include <openssl/engine.h>
 
  DSA * DSA_new(void);
  void  DSA_free(DSA *dsa);
 
- int   DSA_size(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(DSA *r);
+ DH *  DSA_dup_DH(const DSA *r);
 
  int   DSA_generate_key(DSA *dsa);
 
@@ -26,13 +27,13 @@ dsa - Digital Signature Algorithm
  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);
+               const 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);
+ 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)());
@@ -41,7 +42,7 @@ dsa - Digital Signature Algorithm
 
  DSA_SIG *DSA_SIG_new(void);
  void  DSA_SIG_free(DSA_SIG *a);
- int   i2d_DSA_SIG(DSA_SIG *a, unsigned char **pp);
+ 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);
@@ -51,14 +52,14 @@ dsa - Digital Signature Algorithm
  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   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, 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);
+ 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);
 
 =head1 DESCRIPTION
 
@@ -84,6 +85,14 @@ The B<DSA> structure consists of several BIGNUM components.
 
 In public keys, B<priv_key> is NULL.
 
+Note that DSA keys may use non-standard B<DSA_METHOD> implementations,
+either directly or by the use of B<ENGINE> modules. In some cases (eg. an
+ENGINE providing support for hardware-embedded keys), these BIGNUM values
+will not be used by the implementation or may be used for alternative data
+storage. For this reason, applications should generally avoid using DSA
+structure elements directly and instead use API functions to query or
+modify keys.
+
 =head1 CONFORMING TO
 
 US Federal Information Processing Standard FIPS 186 (Digital Signature
@@ -92,7 +101,8 @@ Standard, DSS), ANSI X9.30
 =head1 SEE ALSO
 
 L<bn(3)|bn(3)>, L<dh(3)|dh(3)>, L<err(3)|err(3)>, L<rand(3)|rand(3)>,
-L<rsa(3)|rsa(3)>, L<sha(3)|sha(3)>, L<DSA_new(3)|DSA_new(3)>,
+L<rsa(3)|rsa(3)>, L<sha(3)|sha(3)>, L<engine(3)|engine(3)>,
+L<DSA_new(3)|DSA_new(3)>,
 L<DSA_size(3)|DSA_size(3)>,
 L<DSA_generate_parameters(3)|DSA_generate_parameters(3)>,
 L<DSA_dup_DH(3)|DSA_dup_DH(3)>,