Add control to retrieve signature MD.

crypto/dsa/dsa_pmeth.c

@@ -199,6 +199,10 @@ static int pkey_dsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 		dctx->md = p2;
 		return 1;
 
+		case EVP_PKEY_CTRL_GET_MD:
+		*(const EVP_MD **)p2 = dctx->md;
+		return 1;
+
 		case EVP_PKEY_CTRL_DIGESTINIT:
 		case EVP_PKEY_CTRL_PKCS7_SIGN:
 		case EVP_PKEY_CTRL_CMS_SIGN:

crypto/ec/ec_pmeth.c

@@ -242,6 +242,10 @@ static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 		dctx->md = p2;
 		return 1;
 
+		case EVP_PKEY_CTRL_GET_MD:
+		*(const EVP_MD **)p2 = dctx->md;
+		return 1;
+
 		case EVP_PKEY_CTRL_PEER_KEY:
 		/* Default behaviour is OK */
 		case EVP_PKEY_CTRL_DIGESTINIT:

crypto/evp/evp.h

@@ -1113,6 +1113,10 @@ void EVP_PKEY_asn1_set_ctrl(EVP_PKEY_ASN1_METHOD *ameth,
 		EVP_PKEY_CTX_ctrl(ctx, -1, EVP_PKEY_OP_TYPE_SIG,  \
 					EVP_PKEY_CTRL_MD, 0, (void *)md)
 
+#define	 EVP_PKEY_CTX_get_signature_md(ctx, pmd)	\
+		EVP_PKEY_CTX_ctrl(ctx, -1, EVP_PKEY_OP_TYPE_SIG,  \
+					EVP_PKEY_CTRL_GET_MD, 0, (void *)pmd)
+
 #define EVP_PKEY_CTRL_MD		1
 #define EVP_PKEY_CTRL_PEER_KEY		2
 
@@ -1134,6 +1138,8 @@ void EVP_PKEY_asn1_set_ctrl(EVP_PKEY_ASN1_METHOD *ameth,
 
 #define EVP_PKEY_CTRL_CIPHER		12
 
+#define EVP_PKEY_CTRL_GET_MD		13
+
 #define EVP_PKEY_ALG_CTRL		0x1000
 
 

crypto/rsa/rsa_pmeth.c

@@ -534,6 +534,10 @@ static int pkey_rsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 		rctx->md = p2;
 		return 1;
 
+		case EVP_PKEY_CTRL_GET_MD:
+		*(const EVP_MD **)p2 = rctx->md;
+		return 1;
+
 		case EVP_PKEY_CTRL_RSA_MGF1_MD:
 		case EVP_PKEY_CTRL_GET_RSA_MGF1_MD:
 		if (rctx->pad_mode != RSA_PKCS1_PSS_PADDING

engines/ccgost/gost_pmeth.c

@@ -86,6 +86,10 @@ static int pkey_gost_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 		}
 		break;
 
+		case EVP_PKEY_CTRL_GET_MD:
+		*(const EVP_MD **)p2 = pctx->md;
+		return 1;
+
 		case EVP_PKEY_CTRL_PKCS7_ENCRYPT:
 		case EVP_PKEY_CTRL_PKCS7_DECRYPT:
 		case EVP_PKEY_CTRL_PKCS7_SIGN:
@@ -464,6 +468,10 @@ static int pkey_gost_mac_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 		}
 		break;
 
+		case EVP_PKEY_CTRL_GET_MD:
+		*(const EVP_MD **)p2 = data->md;
+		return 1;
+
 		case EVP_PKEY_CTRL_PKCS7_ENCRYPT:
 		case EVP_PKEY_CTRL_PKCS7_DECRYPT:
 		case EVP_PKEY_CTRL_PKCS7_SIGN: