Support setting SM2 ID

[oweals/openssl.git] / crypto / sm2 / sm2_pmeth.c

diff --git a/crypto/sm2/sm2_pmeth.c b/crypto/sm2/sm2_pmeth.c
index 63c93891e25a85bd202bd6f56d6ab07ac74034b0..aed7f33044575bbdca9444daae815c1f3723d4ec 100644 (file)
--- a/crypto/sm2/sm2_pmeth.c
+++ b/crypto/sm2/sm2_pmeth.c
@@ -22,30 +22,34 @@ typedef struct {
     EC_GROUP *gen_group;
     /* message digest */
     const EVP_MD *md;
+    /* Distinguishing Identifier, ISO/IEC 15946-3 */
     uint8_t *id;
     size_t id_len;
+    /* id_set indicates if the 'id' field is set (1) or not (0) */
+    int id_set;
 } SM2_PKEY_CTX;
 
 static int pkey_sm2_init(EVP_PKEY_CTX *ctx)
 {
-    SM2_PKEY_CTX *dctx;
+    SM2_PKEY_CTX *smctx;
 
-    if ((dctx = OPENSSL_zalloc(sizeof(*dctx))) == NULL) {
+    if ((smctx = OPENSSL_zalloc(sizeof(*smctx))) == NULL) {
         SM2err(SM2_F_PKEY_SM2_INIT, ERR_R_MALLOC_FAILURE);
         return 0;
     }
 
-    ctx->data = dctx;
+    ctx->data = smctx;
     return 1;
 }
 
 static void pkey_sm2_cleanup(EVP_PKEY_CTX *ctx)
 {
-    SM2_PKEY_CTX *dctx = ctx->data;
+    SM2_PKEY_CTX *smctx = ctx->data;
 
-    if (dctx != NULL) {
-        EC_GROUP_free(dctx->gen_group);
-        OPENSSL_free(dctx);
+    if (smctx != NULL) {
+        EC_GROUP_free(smctx->gen_group);
+        OPENSSL_free(smctx->id);
+        OPENSSL_free(smctx);
         ctx->data = NULL;
     }
 }
@@ -65,6 +69,16 @@ static int pkey_sm2_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
             return 0;
         }
     }
+    if (sctx->id != NULL) {
+        dctx->id = OPENSSL_malloc(sctx->id_len);
+        if (dctx->id == NULL) {
+            pkey_sm2_cleanup(dst);
+            return 0;
+        }
+        memcpy(dctx->id, sctx->id, sctx->id_len);
+    }
+    dctx->id_len = sctx->id_len;
+    dctx->id_set = sctx->id_set;
     dctx->md = sctx->md;
 
     return 1;
@@ -147,7 +161,7 @@ static int pkey_sm2_decrypt(EVP_PKEY_CTX *ctx,
 
 static int pkey_sm2_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 {
-    SM2_PKEY_CTX *dctx = ctx->data;
+    SM2_PKEY_CTX *smctx = ctx->data;
     EC_GROUP *group;
 
     switch (type) {
@@ -157,29 +171,51 @@ static int pkey_sm2_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
             SM2err(SM2_F_PKEY_SM2_CTRL, SM2_R_INVALID_CURVE);
             return 0;
         }
-        EC_GROUP_free(dctx->gen_group);
-        dctx->gen_group = group;
+        EC_GROUP_free(smctx->gen_group);
+        smctx->gen_group = group;
         return 1;
 
     case EVP_PKEY_CTRL_EC_PARAM_ENC:
-        if (dctx->gen_group == NULL) {
+        if (smctx->gen_group == NULL) {
             SM2err(SM2_F_PKEY_SM2_CTRL, SM2_R_NO_PARAMETERS_SET);
             return 0;
         }
-        EC_GROUP_set_asn1_flag(dctx->gen_group, p1);
+        EC_GROUP_set_asn1_flag(smctx->gen_group, p1);
         return 1;
 
     case EVP_PKEY_CTRL_MD:
-        dctx->md = p2;
+        smctx->md = p2;
         return 1;
 
     case EVP_PKEY_CTRL_GET_MD:
-        *(const EVP_MD **)p2 = dctx->md;
+        *(const EVP_MD **)p2 = smctx->md;
+        return 1;
+
+    case EVP_PKEY_CTRL_SET1_ID:
+        OPENSSL_free(smctx->id);
+        if (p1 > 0) {
+            smctx->id = OPENSSL_malloc(p1);
+            if (smctx->id == NULL)
+                return 0;
+            memcpy(smctx->id, p2, p1);
+        } else {
+            /* set null-ID */
+            smctx->id = NULL;
+        }
+        smctx->id_len = (size_t)p1;
+        smctx->id_set = 1;
+        return 1;
+
+    case EVP_PKEY_CTRL_GET1_ID:
+        memcpy(p2, smctx->id, smctx->id_len);
+        return 1;
+
+    case EVP_PKEY_CTRL_GET1_ID_LEN:
+        *(size_t *)p2 = smctx->id_len;
         return 1;
 
     default:
         return -2;
-
     }
 }
 
@@ -214,21 +250,21 @@ static int pkey_sm2_ctrl_str(EVP_PKEY_CTX *ctx,
 static int pkey_sm2_digest_custom(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)
 {
     uint8_t z[EVP_MAX_MD_SIZE];
-    SM2_PKEY_CTX *sctx = ctx->data;
+    SM2_PKEY_CTX *smctx = ctx->data;
     EC_KEY *ec = ctx->pkey->pkey.ec;
     const EVP_MD *md = EVP_MD_CTX_md(mctx);
 
-    if (sctx->id == NULL) {
-        /* XXX:
-         * currently we reject all null-ID for SM2, but this needs
-         * more considerations and discussion since the specifications
-         * on SM2 are not clear on null-ID
+    if (!smctx->id_set) {
+        /*
+         * An ID value must be set. The specifications are not clear whether a
+         * NULL is allowed. We only allow it if set explicitly for maximum
+         * flexibility.
          */
         return 0;
     }
 
-    /* get hashed prefix of tbs message */
-    if (!sm2_compute_userid_digest(z, md, sctx->id, sctx->id_len, ec))
+    /* get hashed prefix 'z' of tbs message */
+    if (!sm2_compute_z_digest(z, md, smctx->id, smctx->id_len, ec))
         return 0;
 
     return EVP_DigestUpdate(mctx, z, EVP_MD_size(md));