Change EVP_CIPHER_CTX_iv_length() to return current ivlen for some modes

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9542)

4 files changed, 54 insertions, 11 deletions

diff --git a/crypto/evp/e_aes.c b/crypto/evp/e_aes.c
index d687a2cac3..a46ac8f92f 100644
--- a/crypto/evp/e_aes.c
+++ b/crypto/evp/e_aes.c
@@ -1334,7 +1334,7 @@ static int s390x_aes_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
 
     switch (type) {
     case EVP_CTRL_INIT:
-        ivlen = EVP_CIPHER_CTX_iv_length(c);
+        ivlen = EVP_CIPHER_iv_length(c->cipher);
         iv = EVP_CIPHER_CTX_iv_noconst(c);
         gctx->key_set = 0;
         gctx->iv_set = 0;
@@ -1345,6 +1345,10 @@ static int s390x_aes_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
         gctx->tls_aad_len = -1;
         return 1;
 
+    case EVP_CTRL_GET_IVLEN:
+        *(int *)ptr = gctx->ivlen;
+        return 1;
+
     case EVP_CTRL_AEAD_SET_IVLEN:
         if (arg <= 0)
             return 0;
@@ -2053,6 +2057,10 @@ static int s390x_aes_ccm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
         cctx->aes.ccm.tls_aad_len = -1;
         return 1;
 
+    case EVP_CTRL_GET_IVLEN:
+        *(int *)ptr = 15 - cctx->aes.ccm.l;
+        return 1;
+
     case EVP_CTRL_AEAD_TLS1_AAD:
         if (arg != EVP_AEAD_TLS1_AAD_LEN)
             return 0;
@@ -2536,13 +2544,17 @@ static int aes_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
     case EVP_CTRL_INIT:
         gctx->key_set = 0;
         gctx->iv_set = 0;
-        gctx->ivlen = c->cipher->iv_len;
+        gctx->ivlen = EVP_CIPHER_iv_length(c->cipher);
         gctx->iv = c->iv;
         gctx->taglen = -1;
         gctx->iv_gen = 0;
         gctx->tls_aad_len = -1;
         return 1;
 
+    case EVP_CTRL_GET_IVLEN:
+        *(int *)ptr = gctx->ivlen;
+        return 1;
+
     case EVP_CTRL_AEAD_SET_IVLEN:
         if (arg <= 0)
             return 0;
@@ -3055,7 +3067,7 @@ static int aes_gcm_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
 #define CUSTOM_FLAGS    (EVP_CIPH_FLAG_DEFAULT_ASN1 \
                 | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER \
                 | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT \
-                | EVP_CIPH_CUSTOM_COPY)
+                | EVP_CIPH_CUSTOM_COPY | EVP_CIPH_CUSTOM_IV_LENGTH)
 
 BLOCK_CIPHER_custom(NID_aes, 128, 1, 12, gcm, GCM,
                     EVP_CIPH_FLAG_AEAD_CIPHER | CUSTOM_FLAGS)
@@ -3260,6 +3272,10 @@ static int aes_ccm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
         cctx->tls_aad_len = -1;
         return 1;
 
+    case EVP_CTRL_GET_IVLEN:
+        *(int *)ptr = 15 - cctx->L;
+        return 1;
+
     case EVP_CTRL_AEAD_TLS1_AAD:
         /* Save the AAD for later use */
         if (arg != EVP_AEAD_TLS1_AAD_LEN)
@@ -3708,13 +3724,17 @@ static int aes_ocb_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
     case EVP_CTRL_INIT:
         octx->key_set = 0;
         octx->iv_set = 0;
-        octx->ivlen = EVP_CIPHER_CTX_iv_length(c);
+        octx->ivlen = EVP_CIPHER_iv_length(c->cipher);
         octx->iv = EVP_CIPHER_CTX_iv_noconst(c);
         octx->taglen = 16;
         octx->data_buf_len = 0;
         octx->aad_buf_len = 0;
         return 1;
 
+    case EVP_CTRL_GET_IVLEN:
+        *(int *)ptr = octx->ivlen;
+        return 1;
+
     case EVP_CTRL_AEAD_SET_IVLEN:
         /* IV len must be 1 to 15 */
         if (arg <= 0 || arg > 15)
diff --git a/crypto/evp/e_aria.c b/crypto/evp/e_aria.c
index f2588f141a..84b14826cb 100644
--- a/crypto/evp/e_aria.c
+++ b/crypto/evp/e_aria.c
@@ -252,13 +252,17 @@ static int aria_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
     case EVP_CTRL_INIT:
         gctx->key_set = 0;
         gctx->iv_set = 0;
-        gctx->ivlen = EVP_CIPHER_CTX_iv_length(c);
+        gctx->ivlen = EVP_CIPHER_iv_length(c->cipher);
         gctx->iv = EVP_CIPHER_CTX_iv_noconst(c);
         gctx->taglen = -1;
         gctx->iv_gen = 0;
         gctx->tls_aad_len = -1;
         return 1;
 
+    case EVP_CTRL_GET_IVLEN:
+        *(int *)ptr = gctx->ivlen;
+        return 1;
+
     case EVP_CTRL_AEAD_SET_IVLEN:
         if (arg <= 0)
             return 0;
@@ -539,6 +543,10 @@ static int aria_ccm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
         cctx->tls_aad_len = -1;
         return 1;
 
+    case EVP_CTRL_GET_IVLEN:
+        *(int *)ptr = 15 - cctx->L;
+        return 1;
+
     case EVP_CTRL_AEAD_TLS1_AAD:
         /* Save the AAD for later use */
         if (arg != EVP_AEAD_TLS1_AAD_LEN)
@@ -742,7 +750,8 @@ static int aria_ccm_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
 #define ARIA_AUTH_FLAGS  (EVP_CIPH_FLAG_DEFAULT_ASN1 \
                           | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER \
                           | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT \
-                          | EVP_CIPH_CUSTOM_COPY | EVP_CIPH_FLAG_AEAD_CIPHER)
+                          | EVP_CIPH_CUSTOM_COPY | EVP_CIPH_FLAG_AEAD_CIPHER \
+                          | EVP_CIPH_CUSTOM_IV_LENGTH)
 
 #define BLOCK_CIPHER_aead(nid,keylen,blocksize,ivlen,nmode,mode,MODE,flags) \
 static const EVP_CIPHER aria_##keylen##_##mode = { \
diff --git a/crypto/evp/e_chacha20_poly1305.c b/crypto/evp/e_chacha20_poly1305.c
index ccef031b89..570378b1af 100644
--- a/crypto/evp/e_chacha20_poly1305.c
+++ b/crypto/evp/e_chacha20_poly1305.c
@@ -534,6 +534,10 @@ static int chacha20_poly1305_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
         }
         return 1;
 
+    case EVP_CTRL_GET_IVLEN:
+        *(int *)ptr = actx->nonce_len;
+        return 1;
+
     case EVP_CTRL_AEAD_SET_IVLEN:
         if (arg <= 0 || arg > CHACHA20_POLY1305_MAX_IVLEN)
             return 0;
@@ -613,7 +617,8 @@ static EVP_CIPHER chacha20_poly1305 = {
     12,                 /* iv_len, 96-bit nonce in the context */
     EVP_CIPH_FLAG_AEAD_CIPHER | EVP_CIPH_CUSTOM_IV |
     EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT |
-    EVP_CIPH_CUSTOM_COPY | EVP_CIPH_FLAG_CUSTOM_CIPHER,
+    EVP_CIPH_CUSTOM_COPY | EVP_CIPH_FLAG_CUSTOM_CIPHER |
+    EVP_CIPH_CUSTOM_IV_LENGTH,
     chacha20_poly1305_init_key,
     chacha20_poly1305_cipher,
     chacha20_poly1305_cleanup,
diff --git a/crypto/evp/evp_lib.c b/crypto/evp/evp_lib.c
index d112eaf65a..0d6a7722a7 100644
--- a/crypto/evp/evp_lib.c
+++ b/crypto/evp/evp_lib.c
@@ -315,13 +315,22 @@ int EVP_CIPHER_iv_length(const EVP_CIPHER *cipher)
 
 int EVP_CIPHER_CTX_iv_length(const EVP_CIPHER_CTX *ctx)
 {
-    int ok, v = EVP_CIPHER_iv_length(ctx->cipher);
+    int len, rv, v = EVP_CIPHER_iv_length(ctx->cipher);
     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 
     params[0] = OSSL_PARAM_construct_int(OSSL_CIPHER_PARAM_IVLEN, &v);
-    ok = evp_do_ciph_ctx_getparams(ctx->cipher, ctx->provctx, params);
-
-    return ok != 0 ? v : -1;
+    rv = evp_do_ciph_ctx_getparams(ctx->cipher, ctx->provctx, params);
+    if (rv == EVP_CTRL_RET_UNSUPPORTED)
+        goto legacy;
+    return rv != 0 ? v : -1;
+    /* TODO (3.0) Remove legacy support */
+legacy:
+    if ((EVP_CIPHER_flags(ctx->cipher) & EVP_CIPH_CUSTOM_IV_LENGTH) != 0) {
+        rv = EVP_CIPHER_CTX_ctrl((EVP_CIPHER_CTX *)ctx, EVP_CTRL_GET_IVLEN,
+                                 0, &len);
+        return (rv == 1) ? len : -1;
+    }
+    return v;
 }
 
 const unsigned char *EVP_CIPHER_CTX_original_iv(const EVP_CIPHER_CTX *ctx)