Add algorithm specific signature printing. An individual ASN1 method can

now print out signatures instead of the standard hex dump.

More complex signatures (e.g. PSS) can print out more meaningful information.

Sample DSA version included that prints out the signature parameters r, s.

[Note EVP_PKEY_ASN1_METHOD is an application opaque structure so adding
 new fields in the middle has no compatibility issues]

3 files changed, 33 insertions, 7 deletions

diff --git a/crypto/asn1/asn1.h b/crypto/asn1/asn1.h
index 4f9f7f605f..6c94696ae8 100644
--- a/crypto/asn1/asn1.h
+++ b/crypto/asn1/asn1.h
@@ -235,7 +235,7 @@ typedef struct asn1_object_st
  */
 #define ASN1_STRING_FLAG_MSTRING 0x040 
 /* This is the base type that holds just about everything :-) */
-typedef struct asn1_string_st
+struct asn1_string_st
 	{
 	int length;
 	int type;
@@ -245,7 +245,7 @@ typedef struct asn1_string_st
 	 * input data has a non-zero 'unused bits' value, it will be
 	 * handled correctly */
 	long flags;
-	} ASN1_STRING;
+	};
 
 /* ASN1_ENCODING structure: this is used to save the received
  * encoding of an ASN1 type. This is useful to get round
diff --git a/crypto/asn1/asn1_locl.h b/crypto/asn1/asn1_locl.h
index 5aa65e28f5..6f3781045d 100644
--- a/crypto/asn1/asn1_locl.h
+++ b/crypto/asn1/asn1_locl.h
@@ -102,6 +102,9 @@ struct evp_pkey_asn1_method_st
 	int (*param_cmp)(const EVP_PKEY *a, const EVP_PKEY *b);
 	int (*param_print)(BIO *out, const EVP_PKEY *pkey, int indent,
 							ASN1_PCTX *pctx);
+	int (*sig_print)(BIO *out,
+			 const X509_ALGOR *sigalg, const ASN1_STRING *sig,
+					 int indent, ASN1_PCTX *pctx);
 
 	void (*pkey_free)(EVP_PKEY *pkey);
 	int (*pkey_ctrl)(EVP_PKEY *pkey, int op, long arg1, void *arg2);
diff --git a/crypto/asn1/t_x509.c b/crypto/asn1/t_x509.c
index 01cf9e427a..22041a8fc5 100644
--- a/crypto/asn1/t_x509.c
+++ b/crypto/asn1/t_x509.c
@@ -72,6 +72,7 @@
 #include <openssl/objects.h>
 #include <openssl/x509.h>
 #include <openssl/x509v3.h>
+#include "asn1_locl.h"
 
 #ifndef OPENSSL_NO_FP_API
 int X509_print_fp(FILE *fp, X509 *x)
@@ -286,26 +287,48 @@ err:
 	return(0);
 	}
 
-int X509_signature_print(BIO *bp, X509_ALGOR *sigalg, ASN1_STRING *sig)
+int X509_signature_dump(BIO *bp, const ASN1_STRING *sig, int indent)
 {
-	unsigned char *s;
+	const unsigned char *s;
 	int i, n;
-	if (BIO_puts(bp,"    Signature Algorithm: ") <= 0) return 0;
-	if (i2a_ASN1_OBJECT(bp, sigalg->algorithm) <= 0) return 0;
 
 	n=sig->length;
 	s=sig->data;
 	for (i=0; i<n; i++)
 		{
 		if ((i%18) == 0)
-			if (BIO_write(bp,"\n        ",9) <= 0) return 0;
+			if (BIO_write(bp,"\n",1) <= 0) return 0;
+			if (BIO_indent(bp, indent, indent) <= 0) return 0;
 			if (BIO_printf(bp,"%02x%s",s[i],
 				((i+1) == n)?"":":") <= 0) return 0;
 		}
 	if (BIO_write(bp,"\n",1) != 1) return 0;
+
 	return 1;
 }
 
+int X509_signature_print(BIO *bp, X509_ALGOR *sigalg, ASN1_STRING *sig)
+{
+	int sig_nid;
+	if (BIO_puts(bp,"    Signature Algorithm: ") <= 0) return 0;
+	if (i2a_ASN1_OBJECT(bp, sigalg->algorithm) <= 0) return 0;
+
+	sig_nid = OBJ_obj2nid(sigalg->algorithm);
+	if (sig_nid != NID_undef)
+		{
+		int pkey_nid, dig_nid;
+		const EVP_PKEY_ASN1_METHOD *ameth;
+		if (OBJ_find_sigid_algs(sig_nid, &dig_nid, &pkey_nid))
+			{
+			ameth = EVP_PKEY_asn1_find(NULL, pkey_nid);
+			if (ameth && ameth->sig_print)
+				return ameth->sig_print(bp, sigalg, sig, 9, 0);
+			}
+		}
+
+	return X509_signature_dump(bp, sig, 9);
+}
+
 int ASN1_STRING_print(BIO *bp, const ASN1_STRING *v)
 	{
 	int i,n;