Merge pull request #8740 from valeriosetti/issue8647

Move RSA basic key parsing/writing to rsa.c
diff --git a/ChangeLog.d/8647.txt b/ChangeLog.d/8647.txt
new file mode 100644
index 0000000..98326dc
--- /dev/null
+++ b/ChangeLog.d/8647.txt
@@ -0,0 +1,10 @@
+Default behavior changes
+   * psa_import_key() now only accepts RSA keys in the PSA standard formats.
+     The undocumented ability to import other formats (PKCS#8, SubjectPublicKey,
+     PEM) accepted by the pkparse module has been removed. Applications that
+     need these formats can call mbedtls_pk_parse_{public,}key() followed by
+     mbedtls_pk_import_into_psa().
+
+Changes
+   * RSA support in PSA no longer auto-enables the pkparse and pkwrite modules,
+     saving code size when those are not otherwise enabled.
diff --git a/include/mbedtls/config_adjust_legacy_crypto.h b/include/mbedtls/config_adjust_legacy_crypto.h
index 696266c..818a8c6 100644
--- a/include/mbedtls/config_adjust_legacy_crypto.h
+++ b/include/mbedtls/config_adjust_legacy_crypto.h
@@ -324,15 +324,6 @@
 #define MBEDTLS_PSA_CRYPTO_CLIENT
 #endif /* MBEDTLS_PSA_CRYPTO_C */
 
-/* The PK wrappers need pk_write/pk_parse functions to format RSA key objects
- * when they are dispatching to the PSA API. This happens under MBEDTLS_USE_PSA_CRYPTO,
- * and even under just MBEDTLS_PSA_CRYPTO_C in psa_crypto_rsa.c. */
-#if defined(MBEDTLS_PSA_CRYPTO_C) && defined(MBEDTLS_RSA_C)
-#define MBEDTLS_PK_C
-#define MBEDTLS_PK_WRITE_C
-#define MBEDTLS_PK_PARSE_C
-#endif
-
 /* Helpers to state that each key is supported either on the builtin or PSA side. */
 #if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED) || defined(PSA_WANT_ECC_SECP_R1_521)
 #define MBEDTLS_ECP_HAVE_SECP521R1
diff --git a/include/mbedtls/config_adjust_legacy_from_psa.h b/include/mbedtls/config_adjust_legacy_from_psa.h
index 56ec276..0091e24 100644
--- a/include/mbedtls/config_adjust_legacy_from_psa.h
+++ b/include/mbedtls/config_adjust_legacy_from_psa.h
@@ -685,9 +685,6 @@
 #define MBEDTLS_RSA_C
 #define MBEDTLS_BIGNUM_C
 #define MBEDTLS_OID_C
-#define MBEDTLS_PK_PARSE_C
-#define MBEDTLS_PK_WRITE_C
-#define MBEDTLS_PK_C
 #define MBEDTLS_ASN1_PARSE_C
 #define MBEDTLS_ASN1_WRITE_C
 #endif /* !MBEDTLS_PSA_ACCEL_KEY_TYPE_RSA_PUBLIC_KEY */
diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index c232650..f8ce099 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -32,6 +32,7 @@
 
 #if defined(MBEDTLS_RSA_C)
 #include "pkwrite.h"
+#include "rsa_internal.h"
 #endif
 
 #if defined(MBEDTLS_PK_CAN_ECDSA_SOME)
@@ -69,9 +70,9 @@
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     mbedtls_svc_key_id_t key_id = MBEDTLS_SVC_KEY_ID_INIT;
     psa_status_t status;
-    mbedtls_pk_context key;
     int key_len;
     unsigned char buf[MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES];
+    unsigned char *p = buf + sizeof(buf);
     psa_algorithm_t psa_alg_md =
         PSA_ALG_RSA_PKCS1V15_SIGN(mbedtls_md_psa_alg_from_type(md_alg));
     size_t rsa_len = mbedtls_rsa_get_len(rsa);
@@ -86,11 +87,7 @@
         return MBEDTLS_ERR_RSA_VERIFY_FAILED;
     }
 
-    /* mbedtls_pk_write_pubkey_der() expects a full PK context;
-     * re-construct one to make it happy */
-    key.pk_info = &mbedtls_rsa_info;
-    key.pk_ctx = rsa;
-    key_len = mbedtls_pk_write_pubkey_der(&key, buf, sizeof(buf));
+    key_len = mbedtls_rsa_write_pubkey(rsa, buf, &p);
     if (key_len <= 0) {
         return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
     }
@@ -172,14 +169,15 @@
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     mbedtls_svc_key_id_t key_id = MBEDTLS_SVC_KEY_ID_INIT;
     psa_status_t status;
-    mbedtls_pk_context key;
     int key_len;
     unsigned char *buf = NULL;
+    unsigned char *p;
+
     buf = mbedtls_calloc(1, MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES);
     if (buf == NULL) {
         return MBEDTLS_ERR_PK_ALLOC_FAILED;
     }
-    mbedtls_pk_info_t pk_info = mbedtls_rsa_info;
+    p = buf + MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES;
 
     *sig_len = mbedtls_rsa_get_len(rsa_ctx);
     if (sig_size < *sig_len) {
@@ -187,11 +185,7 @@
         return MBEDTLS_ERR_PK_BUFFER_TOO_SMALL;
     }
 
-    /* mbedtls_pk_write_key_der() expects a full PK context;
-     * re-construct one to make it happy */
-    key.pk_info = &pk_info;
-    key.pk_ctx = rsa_ctx;
-    key_len = mbedtls_pk_write_key_der(&key, buf, MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES);
+    key_len = mbedtls_rsa_write_key(rsa_ctx, buf, &p);
     if (key_len <= 0) {
         mbedtls_free(buf);
         return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
@@ -282,9 +276,9 @@
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     mbedtls_svc_key_id_t key_id = MBEDTLS_SVC_KEY_ID_INIT;
     psa_status_t status;
-    mbedtls_pk_context key;
     int key_len;
     unsigned char buf[MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES];
+    unsigned char *p = buf + sizeof(buf);
 
     ((void) f_rng);
     ((void) p_rng);
@@ -299,11 +293,7 @@
         return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
     }
 
-    /* mbedtls_pk_write_key_der() expects a full PK context;
-     * re-construct one to make it happy */
-    key.pk_info = &mbedtls_rsa_info;
-    key.pk_ctx = rsa;
-    key_len = mbedtls_pk_write_key_der(&key, buf, sizeof(buf));
+    key_len = mbedtls_rsa_write_key(rsa, buf, &p);
     if (key_len <= 0) {
         return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
     }
@@ -368,9 +358,9 @@
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     mbedtls_svc_key_id_t key_id = MBEDTLS_SVC_KEY_ID_INIT;
     psa_status_t status;
-    mbedtls_pk_context key;
     int key_len;
     unsigned char buf[MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES];
+    unsigned char *p = buf + sizeof(buf);
 
     ((void) f_rng);
     ((void) p_rng);
@@ -385,11 +375,7 @@
         return MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE;
     }
 
-    /* mbedtls_pk_write_pubkey_der() expects a full PK context;
-     * re-construct one to make it happy */
-    key.pk_info = &mbedtls_rsa_info;
-    key.pk_ctx = rsa;
-    key_len = mbedtls_pk_write_pubkey_der(&key, buf, sizeof(buf));
+    key_len = mbedtls_rsa_write_pubkey(rsa, buf, &p);
     if (key_len <= 0) {
         return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
     }
diff --git a/library/pkparse.c b/library/pkparse.c
index 5f95545..5a3d3b2 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -28,6 +28,7 @@
 /* Key types */
 #if defined(MBEDTLS_RSA_C)
 #include "mbedtls/rsa.h"
+#include "rsa_internal.h"
 #endif
 
 /* Extended formats */
@@ -757,68 +758,6 @@
 
 #endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
 
-#if defined(MBEDTLS_RSA_C)
-/*
- *  RSAPublicKey ::= SEQUENCE {
- *      modulus           INTEGER,  -- n
- *      publicExponent    INTEGER   -- e
- *  }
- */
-static int pk_get_rsapubkey(unsigned char **p,
-                            const unsigned char *end,
-                            mbedtls_rsa_context *rsa)
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t len;
-
-    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
-                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
-        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
-    }
-
-    if (*p + len != end) {
-        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY,
-                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
-    }
-
-    /* Import N */
-    if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
-        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
-    }
-
-    if ((ret = mbedtls_rsa_import_raw(rsa, *p, len, NULL, 0, NULL, 0,
-                                      NULL, 0, NULL, 0)) != 0) {
-        return MBEDTLS_ERR_PK_INVALID_PUBKEY;
-    }
-
-    *p += len;
-
-    /* Import E */
-    if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
-        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
-    }
-
-    if ((ret = mbedtls_rsa_import_raw(rsa, NULL, 0, NULL, 0, NULL, 0,
-                                      NULL, 0, *p, len)) != 0) {
-        return MBEDTLS_ERR_PK_INVALID_PUBKEY;
-    }
-
-    *p += len;
-
-    if (mbedtls_rsa_complete(rsa) != 0 ||
-        mbedtls_rsa_check_pubkey(rsa) != 0) {
-        return MBEDTLS_ERR_PK_INVALID_PUBKEY;
-    }
-
-    if (*p != end) {
-        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY,
-                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
-    }
-
-    return 0;
-}
-#endif /* MBEDTLS_RSA_C */
-
 /* Get a PK algorithm identifier
  *
  *  AlgorithmIdentifier  ::=  SEQUENCE  {
@@ -911,7 +850,17 @@
 
 #if defined(MBEDTLS_RSA_C)
     if (pk_alg == MBEDTLS_PK_RSA) {
-        ret = pk_get_rsapubkey(p, end, mbedtls_pk_rsa(*pk));
+        ret = mbedtls_rsa_parse_pubkey(mbedtls_pk_rsa(*pk), *p, (size_t) (end - *p));
+        if (ret == 0) {
+            /* On success all the input has been consumed by the parsing function. */
+            *p += end - *p;
+        } else if ((ret <= MBEDTLS_ERR_ASN1_OUT_OF_DATA) &&
+                   (ret >= MBEDTLS_ERR_ASN1_BUF_TOO_SMALL)) {
+            /* In case of ASN1 error codes add MBEDTLS_ERR_PK_INVALID_PUBKEY. */
+            ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
+        } else {
+            ret = MBEDTLS_ERR_PK_INVALID_PUBKEY;
+        }
     } else
 #endif /* MBEDTLS_RSA_C */
 #if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
@@ -944,195 +893,6 @@
     return ret;
 }
 
-#if defined(MBEDTLS_RSA_C)
-/*
- * Wrapper around mbedtls_asn1_get_mpi() that rejects zero.
- *
- * The value zero is:
- * - never a valid value for an RSA parameter
- * - interpreted as "omitted, please reconstruct" by mbedtls_rsa_complete().
- *
- * Since values can't be omitted in PKCS#1, passing a zero value to
- * rsa_complete() would be incorrect, so reject zero values early.
- */
-static int asn1_get_nonzero_mpi(unsigned char **p,
-                                const unsigned char *end,
-                                mbedtls_mpi *X)
-{
-    int ret;
-
-    ret = mbedtls_asn1_get_mpi(p, end, X);
-    if (ret != 0) {
-        return ret;
-    }
-
-    if (mbedtls_mpi_cmp_int(X, 0) == 0) {
-        return MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
-    }
-
-    return 0;
-}
-
-/*
- * Parse a PKCS#1 encoded private RSA key
- */
-static int pk_parse_key_pkcs1_der(mbedtls_rsa_context *rsa,
-                                  const unsigned char *key,
-                                  size_t keylen)
-{
-    int ret, version;
-    size_t len;
-    unsigned char *p, *end;
-
-    mbedtls_mpi T;
-    mbedtls_mpi_init(&T);
-
-    p = (unsigned char *) key;
-    end = p + keylen;
-
-    /*
-     * This function parses the RSAPrivateKey (PKCS#1)
-     *
-     *  RSAPrivateKey ::= SEQUENCE {
-     *      version           Version,
-     *      modulus           INTEGER,  -- n
-     *      publicExponent    INTEGER,  -- e
-     *      privateExponent   INTEGER,  -- d
-     *      prime1            INTEGER,  -- p
-     *      prime2            INTEGER,  -- q
-     *      exponent1         INTEGER,  -- d mod (p-1)
-     *      exponent2         INTEGER,  -- d mod (q-1)
-     *      coefficient       INTEGER,  -- (inverse of q) mod p
-     *      otherPrimeInfos   OtherPrimeInfos OPTIONAL
-     *  }
-     */
-    if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
-                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
-        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
-    }
-
-    end = p + len;
-
-    if ((ret = mbedtls_asn1_get_int(&p, end, &version)) != 0) {
-        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
-    }
-
-    if (version != 0) {
-        return MBEDTLS_ERR_PK_KEY_INVALID_VERSION;
-    }
-
-    /* Import N */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = mbedtls_rsa_import(rsa, &T, NULL, NULL,
-                                  NULL, NULL)) != 0) {
-        goto cleanup;
-    }
-
-    /* Import E */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
-                                  NULL, &T)) != 0) {
-        goto cleanup;
-    }
-
-    /* Import D */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
-                                  &T, NULL)) != 0) {
-        goto cleanup;
-    }
-
-    /* Import P */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = mbedtls_rsa_import(rsa, NULL, &T, NULL,
-                                  NULL, NULL)) != 0) {
-        goto cleanup;
-    }
-
-    /* Import Q */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = mbedtls_rsa_import(rsa, NULL, NULL, &T,
-                                  NULL, NULL)) != 0) {
-        goto cleanup;
-    }
-
-#if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT)
-    /*
-     * The RSA CRT parameters DP, DQ and QP are nominally redundant, in
-     * that they can be easily recomputed from D, P and Q. However by
-     * parsing them from the PKCS1 structure it is possible to avoid
-     * recalculating them which both reduces the overhead of loading
-     * RSA private keys into memory and also avoids side channels which
-     * can arise when computing those values, since all of D, P, and Q
-     * are secret. See https://eprint.iacr.org/2020/055 for a
-     * description of one such attack.
-     */
-
-    /* Import DP */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = mbedtls_mpi_copy(&rsa->DP, &T)) != 0) {
-        goto cleanup;
-    }
-
-    /* Import DQ */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = mbedtls_mpi_copy(&rsa->DQ, &T)) != 0) {
-        goto cleanup;
-    }
-
-    /* Import QP */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = mbedtls_mpi_copy(&rsa->QP, &T)) != 0) {
-        goto cleanup;
-    }
-
-#else
-    /* Verify existence of the CRT params */
-    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
-        (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0) {
-        goto cleanup;
-    }
-#endif
-
-    /* rsa_complete() doesn't complete anything with the default
-     * implementation but is still called:
-     * - for the benefit of alternative implementation that may want to
-     *   pre-compute stuff beyond what's provided (eg Montgomery factors)
-     * - as is also sanity-checks the key
-     *
-     * Furthermore, we also check the public part for consistency with
-     * mbedtls_pk_parse_pubkey(), as it includes size minima for example.
-     */
-    if ((ret = mbedtls_rsa_complete(rsa)) != 0 ||
-        (ret = mbedtls_rsa_check_pubkey(rsa)) != 0) {
-        goto cleanup;
-    }
-
-    if (p != end) {
-        ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
-                                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
-    }
-
-cleanup:
-
-    mbedtls_mpi_free(&T);
-
-    if (ret != 0) {
-        /* Wrap error code if it's coming from a lower level */
-        if ((ret & 0xff80) == 0) {
-            ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
-        } else {
-            ret = MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
-        }
-
-        mbedtls_rsa_free(rsa);
-    }
-
-    return ret;
-}
-#endif /* MBEDTLS_RSA_C */
-
 #if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
 /*
  * Parse a SEC1 encoded private EC key
@@ -1348,7 +1108,7 @@
 
 #if defined(MBEDTLS_RSA_C)
     if (pk_alg == MBEDTLS_PK_RSA) {
-        if ((ret = pk_parse_key_pkcs1_der(mbedtls_pk_rsa(*pk), p, len)) != 0) {
+        if ((ret = mbedtls_rsa_parse_key(mbedtls_pk_rsa(*pk), p, len)) != 0) {
             mbedtls_pk_free(pk);
             return ret;
         }
@@ -1538,8 +1298,8 @@
     if (ret == 0) {
         pk_info = mbedtls_pk_info_from_type(MBEDTLS_PK_RSA);
         if ((ret = mbedtls_pk_setup(pk, pk_info)) != 0 ||
-            (ret = pk_parse_key_pkcs1_der(mbedtls_pk_rsa(*pk),
-                                          pem.buf, pem.buflen)) != 0) {
+            (ret = mbedtls_rsa_parse_key(mbedtls_pk_rsa(*pk),
+                                         pem.buf, pem.buflen)) != 0) {
             mbedtls_pk_free(pk);
         }
 
@@ -1679,7 +1439,7 @@
 
     pk_info = mbedtls_pk_info_from_type(MBEDTLS_PK_RSA);
     if (mbedtls_pk_setup(pk, pk_info) == 0 &&
-        pk_parse_key_pkcs1_der(mbedtls_pk_rsa(*pk), key, keylen) == 0) {
+        mbedtls_rsa_parse_key(mbedtls_pk_rsa(*pk), key, keylen) == 0) {
         return 0;
     }
 
@@ -1754,7 +1514,7 @@
             return ret;
         }
 
-        if ((ret = pk_get_rsapubkey(&p, p + pem.buflen, mbedtls_pk_rsa(*ctx))) != 0) {
+        if ((ret = mbedtls_rsa_parse_pubkey(mbedtls_pk_rsa(*ctx), p, pem.buflen)) != 0) {
             mbedtls_pk_free(ctx);
         }
 
@@ -1801,13 +1561,12 @@
     }
 
     p = (unsigned char *) key;
-    ret = pk_get_rsapubkey(&p, p + keylen, mbedtls_pk_rsa(*ctx));
+    ret = mbedtls_rsa_parse_pubkey(mbedtls_pk_rsa(*ctx), p, keylen);
     if (ret == 0) {
         return ret;
     }
     mbedtls_pk_free(ctx);
-    if (ret != (MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY,
-                                  MBEDTLS_ERR_ASN1_UNEXPECTED_TAG))) {
+    if (ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
         return ret;
     }
 #endif /* MBEDTLS_RSA_C */
diff --git a/library/pkwrite.c b/library/pkwrite.c
index 1f0d399..b9ddcf1 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -32,6 +32,9 @@
 #if defined(MBEDTLS_PEM_WRITE_C)
 #include "mbedtls/pem.h"
 #endif
+#if defined(MBEDTLS_RSA_C)
+#include "rsa_internal.h"
+#endif
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
 #include "psa/crypto.h"
@@ -56,60 +59,13 @@
  * Internal functions for RSA keys.
  ******************************************************************************/
 #if defined(MBEDTLS_RSA_C)
-/*
- *  RSAPublicKey ::= SEQUENCE {
- *      modulus           INTEGER,  -- n
- *      publicExponent    INTEGER   -- e
- *  }
- */
-static int pk_write_rsa_pubkey(unsigned char **p, unsigned char *start,
-                               const mbedtls_pk_context *pk)
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t len = 0;
-    mbedtls_mpi T;
-    mbedtls_rsa_context *rsa = mbedtls_pk_rsa(*pk);
-
-    mbedtls_mpi_init(&T);
-
-    /* Export E */
-    if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
-        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
-        goto end_of_export;
-    }
-    len += ret;
-
-    /* Export N */
-    if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
-        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
-        goto end_of_export;
-    }
-    len += ret;
-
-end_of_export:
-
-    mbedtls_mpi_free(&T);
-    if (ret < 0) {
-        return ret;
-    }
-
-    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
-    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED |
-                                                     MBEDTLS_ASN1_SEQUENCE));
-
-    return (int) len;
-}
-
 static int pk_write_rsa_der(unsigned char **p, unsigned char *buf,
                             const mbedtls_pk_context *pk)
 {
-    size_t len = 0;
-    int ret;
-
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
         uint8_t tmp[PSA_EXPORT_KEY_PAIR_MAX_SIZE];
-        size_t tmp_len = 0;
+        size_t len = 0, tmp_len = 0;
 
         if (psa_export_key(pk->priv_id, tmp, sizeof(tmp), &tmp_len) != PSA_SUCCESS) {
             return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
@@ -118,94 +74,11 @@
         memcpy(*p, tmp, tmp_len);
         len += tmp_len;
         mbedtls_platform_zeroize(tmp, sizeof(tmp));
-    } else
-#endif /* MBEDTLS_USE_PSA_CRYPTO */
-    {
-        mbedtls_mpi T; /* Temporary holding the exported parameters */
-        mbedtls_rsa_context *rsa = mbedtls_pk_rsa(*pk);
 
-        /*
-         * Export the parameters one after another to avoid simultaneous copies.
-         */
-
-        mbedtls_mpi_init(&T);
-
-        /* Export QP */
-        if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
-            (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
-            goto end_of_export;
-        }
-        len += ret;
-
-        /* Export DQ */
-        if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
-            (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
-            goto end_of_export;
-        }
-        len += ret;
-
-        /* Export DP */
-        if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
-            (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
-            goto end_of_export;
-        }
-        len += ret;
-
-        /* Export Q */
-        if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
-                                      &T, NULL, NULL)) != 0 ||
-            (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
-            goto end_of_export;
-        }
-        len += ret;
-
-        /* Export P */
-        if ((ret = mbedtls_rsa_export(rsa, NULL, &T,
-                                      NULL, NULL, NULL)) != 0 ||
-            (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
-            goto end_of_export;
-        }
-        len += ret;
-
-        /* Export D */
-        if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
-                                      NULL, &T, NULL)) != 0 ||
-            (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
-            goto end_of_export;
-        }
-        len += ret;
-
-        /* Export E */
-        if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
-                                      NULL, NULL, &T)) != 0 ||
-            (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
-            goto end_of_export;
-        }
-        len += ret;
-
-        /* Export N */
-        if ((ret = mbedtls_rsa_export(rsa, &T, NULL,
-                                      NULL, NULL, NULL)) != 0 ||
-            (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
-            goto end_of_export;
-        }
-        len += ret;
-
-end_of_export:
-
-        mbedtls_mpi_free(&T);
-        if (ret < 0) {
-            return ret;
-        }
-
-        MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, buf, 0));
-        MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
-        MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p,
-                                                         buf, MBEDTLS_ASN1_CONSTRUCTED |
-                                                         MBEDTLS_ASN1_SEQUENCE));
+        return (int) len;
     }
-
-    return (int) len;
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+    return mbedtls_rsa_write_key(mbedtls_pk_rsa(*pk), buf, p);
 }
 #endif /* MBEDTLS_RSA_C */
 
@@ -543,7 +416,7 @@
 
 #if defined(MBEDTLS_RSA_C)
     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
-        MBEDTLS_ASN1_CHK_ADD(len, pk_write_rsa_pubkey(p, start, key));
+        MBEDTLS_ASN1_CHK_ADD(len, mbedtls_rsa_write_pubkey(mbedtls_pk_rsa(*key), start, p));
     } else
 #endif
 #if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
diff --git a/library/psa_crypto_rsa.c b/library/psa_crypto_rsa.c
index 7b58ea2..4a574d1 100644
--- a/library/psa_crypto_rsa.c
+++ b/library/psa_crypto_rsa.c
@@ -24,8 +24,7 @@
 
 #include <mbedtls/rsa.h>
 #include <mbedtls/error.h>
-#include <mbedtls/pk.h>
-#include "pk_wrap.h"
+#include "rsa_internal.h"
 
 #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \
     defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) || \
@@ -62,50 +61,38 @@
     mbedtls_rsa_context **p_rsa)
 {
     psa_status_t status;
-    mbedtls_pk_context ctx;
     size_t bits;
-    mbedtls_pk_init(&ctx);
+
+    *p_rsa = mbedtls_calloc(1, sizeof(mbedtls_rsa_context));
+    if (*p_rsa == NULL) {
+        return PSA_ERROR_INSUFFICIENT_MEMORY;
+    }
+    mbedtls_rsa_init(*p_rsa);
 
     /* Parse the data. */
     if (PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
-        status = mbedtls_to_psa_error(
-            mbedtls_pk_parse_key(&ctx, data, data_length, NULL, 0,
-                                 mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE));
+        status = mbedtls_to_psa_error(mbedtls_rsa_parse_key(*p_rsa, data, data_length));
     } else {
-        status = mbedtls_to_psa_error(
-            mbedtls_pk_parse_public_key(&ctx, data, data_length));
+        status = mbedtls_to_psa_error(mbedtls_rsa_parse_pubkey(*p_rsa, data, data_length));
     }
     if (status != PSA_SUCCESS) {
         goto exit;
     }
 
-    /* We have something that the pkparse module recognizes. If it is a
-     * valid RSA key, store it. */
-    if (mbedtls_pk_get_type(&ctx) != MBEDTLS_PK_RSA) {
-        status = PSA_ERROR_INVALID_ARGUMENT;
-        goto exit;
-    }
-
     /* The size of an RSA key doesn't have to be a multiple of 8. Mbed TLS
      * supports non-byte-aligned key sizes, but not well. For example,
      * mbedtls_rsa_get_len() returns the key size in bytes, not in bits. */
-    bits = PSA_BYTES_TO_BITS(mbedtls_rsa_get_len(mbedtls_pk_rsa(ctx)));
+    bits = PSA_BYTES_TO_BITS(mbedtls_rsa_get_len(*p_rsa));
     if (bits > PSA_VENDOR_RSA_MAX_KEY_BITS) {
         status = PSA_ERROR_NOT_SUPPORTED;
         goto exit;
     }
-    status = psa_check_rsa_key_byte_aligned(mbedtls_pk_rsa(ctx));
+    status = psa_check_rsa_key_byte_aligned(*p_rsa);
     if (status != PSA_SUCCESS) {
         goto exit;
     }
 
-    /* Copy out the pointer to the RSA context, and reset the PK context
-     * such that pk_free doesn't free the RSA context we just grabbed. */
-    *p_rsa = mbedtls_pk_rsa(ctx);
-    ctx.pk_info = NULL;
-
 exit:
-    mbedtls_pk_free(&ctx);
     return status;
 }
 #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) ||
@@ -168,20 +155,15 @@
                                         size_t *data_length)
 {
     int ret;
-    mbedtls_pk_context pk;
-    uint8_t *pos = data + data_size;
-
-    mbedtls_pk_init(&pk);
-    pk.pk_info = &mbedtls_rsa_info;
-    pk.pk_ctx = rsa;
+    uint8_t *end = data + data_size;
 
     /* PSA Crypto API defines the format of an RSA key as a DER-encoded
      * representation of the non-encrypted PKCS#1 RSAPrivateKey for a
      * private key and of the RFC3279 RSAPublicKey for a public key. */
     if (PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
-        ret = mbedtls_pk_write_key_der(&pk, data, data_size);
+        ret = mbedtls_rsa_write_key(rsa, data, &end);
     } else {
-        ret = mbedtls_pk_write_pubkey(&pos, data, &pk);
+        ret = mbedtls_rsa_write_pubkey(rsa, data, &end);
     }
 
     if (ret < 0) {
diff --git a/library/rsa.c b/library/rsa.c
index a90b83a..f4c0862 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -32,6 +32,7 @@
 #include "rsa_alt_helpers.h"
 #include "rsa_internal.h"
 #include "mbedtls/oid.h"
+#include "mbedtls/asn1write.h"
 #include "mbedtls/platform_util.h"
 #include "mbedtls/error.h"
 #include "constant_time_internal.h"
@@ -46,6 +47,367 @@
 
 #include "mbedtls/platform.h"
 
+/*
+ * Wrapper around mbedtls_asn1_get_mpi() that rejects zero.
+ *
+ * The value zero is:
+ * - never a valid value for an RSA parameter
+ * - interpreted as "omitted, please reconstruct" by mbedtls_rsa_complete().
+ *
+ * Since values can't be omitted in PKCS#1, passing a zero value to
+ * rsa_complete() would be incorrect, so reject zero values early.
+ */
+static int asn1_get_nonzero_mpi(unsigned char **p,
+                                const unsigned char *end,
+                                mbedtls_mpi *X)
+{
+    int ret;
+
+    ret = mbedtls_asn1_get_mpi(p, end, X);
+    if (ret != 0) {
+        return ret;
+    }
+
+    if (mbedtls_mpi_cmp_int(X, 0) == 0) {
+        return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+    }
+
+    return 0;
+}
+
+int mbedtls_rsa_parse_key(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen)
+{
+    int ret, version;
+    size_t len;
+    unsigned char *p, *end;
+
+    mbedtls_mpi T;
+    mbedtls_mpi_init(&T);
+
+    p = (unsigned char *) key;
+    end = p + keylen;
+
+    /*
+     * This function parses the RSAPrivateKey (PKCS#1)
+     *
+     *  RSAPrivateKey ::= SEQUENCE {
+     *      version           Version,
+     *      modulus           INTEGER,  -- n
+     *      publicExponent    INTEGER,  -- e
+     *      privateExponent   INTEGER,  -- d
+     *      prime1            INTEGER,  -- p
+     *      prime2            INTEGER,  -- q
+     *      exponent1         INTEGER,  -- d mod (p-1)
+     *      exponent2         INTEGER,  -- d mod (q-1)
+     *      coefficient       INTEGER,  -- (inverse of q) mod p
+     *      otherPrimeInfos   OtherPrimeInfos OPTIONAL
+     *  }
+     */
+    if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
+                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
+        return ret;
+    }
+
+    /* mbedtls_asn1_get_tag() already ensures that len is valid (i.e. p+len <= end)*/
+    end = p + len;
+
+    if ((ret = mbedtls_asn1_get_int(&p, end, &version)) != 0) {
+        return ret;
+    }
+
+    if (version != 0) {
+        return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+    }
+
+    /* Import N */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = mbedtls_rsa_import(rsa, &T, NULL, NULL,
+                                  NULL, NULL)) != 0) {
+        goto cleanup;
+    }
+
+    /* Import E */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
+                                  NULL, &T)) != 0) {
+        goto cleanup;
+    }
+
+    /* Import D */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
+                                  &T, NULL)) != 0) {
+        goto cleanup;
+    }
+
+    /* Import P */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = mbedtls_rsa_import(rsa, NULL, &T, NULL,
+                                  NULL, NULL)) != 0) {
+        goto cleanup;
+    }
+
+    /* Import Q */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = mbedtls_rsa_import(rsa, NULL, NULL, &T,
+                                  NULL, NULL)) != 0) {
+        goto cleanup;
+    }
+
+#if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT)
+    /*
+     * The RSA CRT parameters DP, DQ and QP are nominally redundant, in
+     * that they can be easily recomputed from D, P and Q. However by
+     * parsing them from the PKCS1 structure it is possible to avoid
+     * recalculating them which both reduces the overhead of loading
+     * RSA private keys into memory and also avoids side channels which
+     * can arise when computing those values, since all of D, P, and Q
+     * are secret. See https://eprint.iacr.org/2020/055 for a
+     * description of one such attack.
+     */
+
+    /* Import DP */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = mbedtls_mpi_copy(&rsa->DP, &T)) != 0) {
+        goto cleanup;
+    }
+
+    /* Import DQ */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = mbedtls_mpi_copy(&rsa->DQ, &T)) != 0) {
+        goto cleanup;
+    }
+
+    /* Import QP */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = mbedtls_mpi_copy(&rsa->QP, &T)) != 0) {
+        goto cleanup;
+    }
+
+#else
+    /* Verify existence of the CRT params */
+    if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
+        (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0) {
+        goto cleanup;
+    }
+#endif
+
+    /* rsa_complete() doesn't complete anything with the default
+     * implementation but is still called:
+     * - for the benefit of alternative implementation that may want to
+     *   pre-compute stuff beyond what's provided (eg Montgomery factors)
+     * - as is also sanity-checks the key
+     *
+     * Furthermore, we also check the public part for consistency with
+     * mbedtls_pk_parse_pubkey(), as it includes size minima for example.
+     */
+    if ((ret = mbedtls_rsa_complete(rsa)) != 0 ||
+        (ret = mbedtls_rsa_check_pubkey(rsa)) != 0) {
+        goto cleanup;
+    }
+
+    if (p != end) {
+        ret = MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
+    }
+
+cleanup:
+
+    mbedtls_mpi_free(&T);
+
+    if (ret != 0) {
+        mbedtls_rsa_free(rsa);
+    }
+
+    return ret;
+}
+
+int mbedtls_rsa_parse_pubkey(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen)
+{
+    unsigned char *p = (unsigned char *) key;
+    unsigned char *end = (unsigned char *) (key + keylen);
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len;
+
+    /*
+     *  RSAPublicKey ::= SEQUENCE {
+     *      modulus           INTEGER,  -- n
+     *      publicExponent    INTEGER   -- e
+     *  }
+     */
+
+    if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
+                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
+        return ret;
+    }
+
+    /* mbedtls_asn1_get_tag() already ensures that len is valid (i.e. p+len <= end)*/
+    end = p + len;
+
+    /* Import N */
+    if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
+        return ret;
+    }
+
+    if ((ret = mbedtls_rsa_import_raw(rsa, p, len, NULL, 0, NULL, 0,
+                                      NULL, 0, NULL, 0)) != 0) {
+        return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+    }
+
+    p += len;
+
+    /* Import E */
+    if ((ret = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
+        return ret;
+    }
+
+    if ((ret = mbedtls_rsa_import_raw(rsa, NULL, 0, NULL, 0, NULL, 0,
+                                      NULL, 0, p, len)) != 0) {
+        return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+    }
+
+    p += len;
+
+    if (mbedtls_rsa_complete(rsa) != 0 ||
+        mbedtls_rsa_check_pubkey(rsa) != 0) {
+        return MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
+    }
+
+    if (p != end) {
+        return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
+    }
+
+    return 0;
+}
+
+int mbedtls_rsa_write_key(const mbedtls_rsa_context *rsa, unsigned char *start,
+                          unsigned char **p)
+{
+    size_t len = 0;
+    int ret;
+
+    mbedtls_mpi T; /* Temporary holding the exported parameters */
+
+    /*
+     * Export the parameters one after another to avoid simultaneous copies.
+     */
+
+    mbedtls_mpi_init(&T);
+
+    /* Export QP */
+    if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+    /* Export DQ */
+    if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+    /* Export DP */
+    if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+    /* Export Q */
+    if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, &T, NULL, NULL)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+    /* Export P */
+    if ((ret = mbedtls_rsa_export(rsa, NULL, &T, NULL, NULL, NULL)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+    /* Export D */
+    if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, &T, NULL)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+    /* Export E */
+    if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+    /* Export N */
+    if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+end_of_export:
+
+    mbedtls_mpi_free(&T);
+    if (ret < 0) {
+        return ret;
+    }
+
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, start, 0));
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
+                                                     MBEDTLS_ASN1_CONSTRUCTED |
+                                                     MBEDTLS_ASN1_SEQUENCE));
+
+    return (int) len;
+}
+
+/*
+ *  RSAPublicKey ::= SEQUENCE {
+ *      modulus           INTEGER,  -- n
+ *      publicExponent    INTEGER   -- e
+ *  }
+ */
+int mbedtls_rsa_write_pubkey(const mbedtls_rsa_context *rsa, unsigned char *start,
+                             unsigned char **p)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len = 0;
+    mbedtls_mpi T;
+
+    mbedtls_mpi_init(&T);
+
+    /* Export E */
+    if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+    /* Export N */
+    if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
+        (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+        goto end_of_export;
+    }
+    len += ret;
+
+end_of_export:
+
+    mbedtls_mpi_free(&T);
+    if (ret < 0) {
+        return ret;
+    }
+
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
+    MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED |
+                                                     MBEDTLS_ASN1_SEQUENCE));
+
+    return (int) len;
+}
 
 #if defined(MBEDTLS_PKCS1_V15) && defined(MBEDTLS_RSA_C) && !defined(MBEDTLS_RSA_ALT)
 
@@ -660,7 +1022,6 @@
     return ctx->len;
 }
 
-
 #if defined(MBEDTLS_GENPRIME)
 
 /*
diff --git a/library/rsa_internal.h b/library/rsa_internal.h
index 4081ac6..f79c3b7 100644
--- a/library/rsa_internal.h
+++ b/library/rsa_internal.h
@@ -15,6 +15,85 @@
 #define MBEDTLS_RSA_INTERNAL_H
 
 #include "mbedtls/rsa.h"
+#include "mbedtls/asn1.h"
+
+/**
+ * \brief           Parse a PKCS#1 (ASN.1) encoded private RSA key.
+ *
+ * \param rsa       The RSA context where parsed data will be stored.
+ * \param key       The buffer that contains the key.
+ * \param keylen    The length of the key buffer in bytes.
+ *
+ * \return          0 on success.
+ * \return          MBEDTLS_ERR_ASN1_xxx in case of ASN.1 parsing errors.
+ * \return          MBEDTLS_ERR_RSA_xxx in case of RSA internal failures while
+ *                  parsing data.
+ * \return          MBEDTLS_ERR_RSA_KEY_CHECK_FAILED if validity checks on the
+ *                  provided key fail.
+ */
+int mbedtls_rsa_parse_key(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen);
+
+/**
+ * \brief           Parse a PKCS#1 (ASN.1) encoded public RSA key.
+ *
+ * \param rsa       The RSA context where parsed data will be stored.
+ * \param key       The buffer that contains the key.
+ * \param keylen    The length of the key buffer in bytes.
+ *
+ * \return          0 on success.
+ * \return          MBEDTLS_ERR_ASN1_xxx in case of ASN.1 parsing errors.
+ * \return          MBEDTLS_ERR_RSA_xxx in case of RSA internal failures while
+ *                  parsing data.
+ * \return          MBEDTLS_ERR_RSA_KEY_CHECK_FAILED if validity checks on the
+ *                  provided key fail.
+ */
+int mbedtls_rsa_parse_pubkey(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen);
+
+/**
+ * \brief           Write a PKCS#1 (ASN.1) encoded private RSA key.
+ *
+ * \param rsa       The RSA context which contains the data to be written.
+ * \param start     Beginning of the buffer that will be filled with the
+ *                  private key.
+ * \param p         End of the buffer that will be filled with the private key.
+ *                  On successful return, the referenced pointer will be
+ *                  updated in order to point to the beginning of written data.
+ *
+ * \return          On success, the number of bytes written to the output buffer
+ *                  (i.e. a value > 0).
+ * \return          MBEDTLS_ERR_RSA_BAD_INPUT_DATA if the RSA context does not
+ *                  contain a valid key pair.
+ * \return          MBEDTLS_ERR_ASN1_xxx in case of failure while writing to the
+ *                  output buffer.
+ *
+ * \note            The output buffer is filled backward, i.e. starting from its
+ *                  end and moving toward its start.
+ */
+int mbedtls_rsa_write_key(const mbedtls_rsa_context *rsa, unsigned char *start,
+                          unsigned char **p);
+
+/**
+ * \brief           Parse a PKCS#1 (ASN.1) encoded public RSA key.
+ *
+ * \param rsa       The RSA context which contains the data to be written.
+ * \param start     Beginning of the buffer that will be filled with the
+ *                  private key.
+ * \param p         End of the buffer that will be filled with the private key.
+ *                  On successful return, the referenced pointer will be
+ *                  updated in order to point to the beginning of written data.
+ *
+ * \return          On success, the number of bytes written to the output buffer
+ *                  (i.e. a value > 0).
+ * \return          MBEDTLS_ERR_RSA_BAD_INPUT_DATA if the RSA context does not
+ *                  contain a valid public key.
+ * \return          MBEDTLS_ERR_ASN1_xxx in case of failure while writing to the
+ *                  output buffer.
+ *
+ * \note            The output buffer is filled backward, i.e. starting from its
+ *                  end and moving toward its start.
+ */
+int mbedtls_rsa_write_pubkey(const mbedtls_rsa_context *rsa, unsigned char *start,
+                             unsigned char **p);
 
 #if defined(MBEDTLS_PKCS1_V21)
 /**
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index d73a028..a484f10 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -1089,9 +1089,6 @@
     echo "MBEDTLS_ECP_RESTARTABLE" >> $expected
     # No PSA equivalent - needed by some init tests
     echo "MBEDTLS_ENTROPY_NV_SEED" >> $expected
-    # Used by two tests that are about an extension to the PSA standard;
-    # as such, no PSA equivalent.
-    echo "MBEDTLS_PEM_PARSE_C" >> $expected
 
     # Compare reality with expectation.
     # We want an exact match, to ensure the above list remains up-to-date.
@@ -2795,12 +2792,6 @@
     scripts/config.py unset MBEDTLS_PK_C
     scripts/config.py unset MBEDTLS_PK_PARSE_C
     scripts/config.py unset MBEDTLS_PK_WRITE_C
-    # We need to disable RSA too or PK will be re-enabled.
-    scripts/config.py -f "$CRYPTO_CONFIG_H" unset-all "PSA_WANT_KEY_TYPE_RSA_[0-9A-Z_a-z]*"
-    scripts/config.py -f "$CRYPTO_CONFIG_H" unset-all "PSA_WANT_ALG_RSA_[0-9A-Z_a-z]*"
-    scripts/config.py unset MBEDTLS_RSA_C
-    scripts/config.py unset MBEDTLS_PKCS1_V15
-    scripts/config.py unset MBEDTLS_PKCS1_V21
 
     # Disable modules that are accelerated - some will be re-enabled
     scripts/config.py unset MBEDTLS_ECDSA_C
diff --git a/tests/scripts/test_psa_compliance.py b/tests/scripts/test_psa_compliance.py
index 0d56ddf..8d70cbc 100755
--- a/tests/scripts/test_psa_compliance.py
+++ b/tests/scripts/test_psa_compliance.py
@@ -27,22 +27,10 @@
 # The test numbers correspond to the numbers used by the console output of the test suite.
 # Test number 2xx corresponds to the files in the folder
 # psa-arch-tests/api-tests/dev_apis/crypto/test_c0xx
-EXPECTED_FAILURES = {
-    # psa_hash_suspend() and psa_hash_resume() are not supported.
-    # - Tracked in issue #3274
-    262, 263
-}
+EXPECTED_FAILURES = {} # type: dict
 
-# We currently use a fork of ARM-software/psa-arch-tests, with a couple of downstream patches
-# that allow it to build with Mbed TLS 3, and fixes a couple of issues in the compliance test suite.
-# These fixes allow the tests numbered 216, 248 and 249 to complete successfully.
-#
-# Once all the fixes are upstreamed, this fork should be replaced with an upstream commit/tag.
-# - Tracked in issue #5145
-#
-# Web URL: https://github.com/bensze01/psa-arch-tests/tree/fixes-for-mbedtls-3
-PSA_ARCH_TESTS_REPO = 'https://github.com/bensze01/psa-arch-tests.git'
-PSA_ARCH_TESTS_REF = 'fix-pr-5736'
+PSA_ARCH_TESTS_REPO = 'https://github.com/ARM-software/psa-arch-tests.git'
+PSA_ARCH_TESTS_REF = 'v23.06_API1.5_ADAC_EAC'
 
 #pylint: disable=too-many-branches,too-many-statements,too-many-locals
 def main(library_build_dir: str):
diff --git a/tests/suites/test_suite_pkparse.data b/tests/suites/test_suite_pkparse.data
index 6387735..762fd52 100644
--- a/tests/suites/test_suite_pkparse.data
+++ b/tests/suites/test_suite_pkparse.data
@@ -1120,78 +1120,6 @@
 Key ASN1 (First tag not Sequence)
 pk_parse_key:"020100":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
 
-Key ASN1 (RSAPrivateKey, incorrect version tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"300100":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, version tag missing)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3000":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, invalid version)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3003020101":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct version, incorrect tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"300402010000":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct format+values, minimal modulus size (128 bit))
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":0
-
-Key ASN1 (RSAPrivateKey, correct format, modulus too small (127 bit))
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"30630201000211007c8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct format, modulus even)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c857002030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct format, d == 0)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"30630201000211007c8ab070369ede72920e5a51523c8571020301000102110000000000000000000000000000000000020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct format, d == p == q == 0)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c8571020301000102110000000000000000000000000000000000020900000000000000000002090000000000000000000209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, trailing garbage)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3064020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c00":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, n wrong tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100FF1100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, e wrong tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c8571FF030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, d wrong tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c85710203010001FF11009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, p wrong tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201FF0900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, q wrong tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61FF0900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, dp wrong tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a211FF09009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, dq wrong tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401FF0813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
-Key ASN1 (RSAPrivateKey, correct values, qp wrong tag)
-depends_on:MBEDTLS_RSA_C
-pk_parse_key:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b7221FF08052b93d01747a87c":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
-
 Key ASN1 (ECPrivateKey, empty parameters)
 depends_on:MBEDTLS_PK_HAVE_ECC_KEYS
 pk_parse_key:"30070201010400a000":MBEDTLS_ERR_PK_KEY_INVALID_FORMAT
diff --git a/tests/suites/test_suite_psa_crypto.data b/tests/suites/test_suite_psa_crypto.data
index 122552d..34af94a 100644
--- a/tests/suites/test_suite_psa_crypto.data
+++ b/tests/suites/test_suite_psa_crypto.data
@@ -496,16 +496,6 @@
 depends_on:PSA_WANT_ALG_RSA_PKCS1V15_SIGN:PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_BASIC:PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_IMPORT:PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_EXPORT:PSA_CRYPTO_DRIVER_TEST
 import_export:"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":PSA_KEY_TYPE_RSA_KEY_PAIR:PSA_KEY_USAGE_SIGN_HASH | PSA_KEY_USAGE_VERIFY_HASH:PSA_ALG_RSA_PKCS1V15_SIGN_RAW:PSA_KEY_LIFETIME_FROM_PERSISTENCE_AND_LOCATION( PSA_KEY_PERSISTENCE_VOLATILE, TEST_DRIVER_LOCATION ):1024:0:PSA_ERROR_NOT_PERMITTED:1
 
-# Test PEM import. Note that this is not a PSA feature, it's an Mbed TLS
-# extension which we may drop in the future.
-PSA import/export RSA public key: import PEM
-depends_on:PSA_WANT_ALG_RSA_PKCS1V15_SIGN:PSA_WANT_KEY_TYPE_RSA_PUBLIC_KEY:MBEDTLS_PEM_PARSE_C
-import_export:"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":PSA_KEY_TYPE_RSA_PUBLIC_KEY:PSA_KEY_USAGE_EXPORT:PSA_ALG_RSA_PKCS1V15_SIGN_RAW:0:1024:0:PSA_SUCCESS:0
-
-PSA import/export RSA keypair: import PEM
-depends_on:PSA_WANT_ALG_RSA_PKCS1V15_SIGN:PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_BASIC:PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_IMPORT:PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_EXPORT:MBEDTLS_PEM_PARSE_C
-import_export:"3082025e02010002818100af057d396ee84fb75fdbb5c2b13c7fe5a654aa8aa2470b541ee1feb0b12d25c79711531249e1129628042dbbb6c120d1443524ef4c0e6e1d8956eeb2077af12349ddeee54483bc06c2c61948cd02b202e796aebd94d3a7cbf859c2c1819c324cb82b9cd34ede263a2abffe4733f077869e8660f7d6834da53d690ef7985f6bc3020301000102818100874bf0ffc2f2a71d14671ddd0171c954d7fdbf50281e4f6d99ea0e1ebcf82faa58e7b595ffb293d1abe17f110b37c48cc0f36c37e84d876621d327f64bbe08457d3ec4098ba2fa0a319fba411c2841ed7be83196a8cdf9daa5d00694bc335fc4c32217fe0488bce9cb7202e59468b1ead119000477db2ca797fac19eda3f58c1024100e2ab760841bb9d30a81d222de1eb7381d82214407f1b975cbbfe4e1a9467fd98adbd78f607836ca5be1928b9d160d97fd45c12d6b52e2c9871a174c66b488113024100c5ab27602159ae7d6f20c3c2ee851e46dc112e689e28d5fcbbf990a99ef8a90b8bb44fd36467e7fc1789ceb663abda338652c3c73f111774902e840565927091024100b6cdbd354f7df579a63b48b3643e353b84898777b48b15f94e0bfc0567a6ae5911d57ad6409cf7647bf96264e9bd87eb95e263b7110b9a1f9f94acced0fafa4d024071195eec37e8d257decfc672b07ae639f10cbb9b0c739d0c809968d644a94e3fd6ed9287077a14583f379058f76a8aecd43c62dc8c0f41766650d725275ac4a1024100bb32d133edc2e048d463388b7be9cb4be29f4b6250be603e70e3647501c97ddde20a4e71be95fd5e71784e25aca4baf25be5738aae59bbfe1c997781447a2b2400":PSA_KEY_TYPE_RSA_KEY_PAIR:PSA_KEY_USAGE_EXPORT:PSA_ALG_RSA_PKCS1V15_SIGN_RAW:0:1024:0:PSA_SUCCESS:0
-
 PSA import/export FFDH RFC7919 2048 key pair: good
 depends_on:PSA_WANT_ALG_FFDH:PSA_WANT_KEY_TYPE_DH_KEY_PAIR_BASIC:PSA_WANT_KEY_TYPE_DH_KEY_PAIR_IMPORT:PSA_WANT_KEY_TYPE_DH_KEY_PAIR_EXPORT:PSA_WANT_DH_RFC7919_2048
 import_export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
diff --git a/tests/suites/test_suite_rsa.data b/tests/suites/test_suite_rsa.data
index 0a60f31..b89d158 100644
--- a/tests/suites/test_suite_rsa.data
+++ b/tests/suites/test_suite_rsa.data
@@ -615,3 +615,120 @@
 RSA Selftest
 depends_on:MBEDTLS_SELF_TEST
 rsa_selftest:
+
+RSA parse/write PKCS#1 private key - 1024 bits
+rsa_parse_write_pkcs1_key:0:"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"
+
+RSA parse/write PKCS#1 public key - 1024 bits
+rsa_parse_write_pkcs1_key:1:"308189028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001"
+
+RSA parse/write PKCS#1 private key - 2048 bits
+rsa_parse_write_pkcs1_key:0:"308204a40201000282010100dcabfd25f3b7d67155e5c2520518570e95754ef883a973f94b2b0fb2d7ad733a3b0976c6314770eaf728304ee61e0dfe91811fc4a8219fbc3687cb3cfca54b58804d1ed4de985dc827374cb31b7b23225e130858d6b812dee6a356a8f8d211ba0930d0ec38193cee0a186f4a760cc3aa40e1d04fe4a14506ed279a9080aedd2676a4026bcb1ee24b2c00853bffcc04b5fb3e542626c2b2c54a62f3d6e01df95544fdf85c22cc0846275cb9cdfe73876e94e532ced0bca9876de74ff1edc9c8ac89aa8586aa34ca6f44c972d1e73aaddae168a5e67ec69cd14f206155e6e1161e7aa6754e947d5d26ee5f8789598a79ea4ff0263e2b8bf90641320771955007d102030100010282010100d25c964f769d3aad0210ac04da5c90a9136b27e41a47108a86d0beff6341330640bf4dddb39e82134b97a12da58ae3165988f94ad4687148cfc6f5c4e6a7804316d3eddf496f807f4c7b17ffe9e3a1e3a2408c857bf32ff2137584284242a7a96c1780229f7bd7aca82d10f2afc48d4620e1e35e35fa52be3e97b16dad6e84dbdfab4e7e21c7c2e5e5cd1c936f6c221e806bd14afa77b3eefc62e984aa2d391da408aaec0dbd2eade3023ebac77e3416cd67491d60053d317c6c8665be5c33961c379309d37d0a653d1859a6abfe195644d474739dbc44f62e623505f9460d9d8defafb12f4149d5baaf798f1345f565430cd7c096c24ca8d02d13fe90c20c5102818100f116cfdbfc0d5b3528cbfada1b21d4292ff188d41a4b22e658a9e29f610adf5fcb3329b0f567ba5029195fd648d06cc2174638f2f18ff0e0251e283e0a0b1f792751925efb617af3405083245c673dae77edc811fd668769d28ac1bee36261658a32f56a5e1b9b9e4f4fa7da55adeeb08c92f1de89f6186bd9c6d1e721638d2d02818100ea51e8798225e4ee77aa08e2f5ee0f8b847edd4c34d9bf7b8cf339b61d5bd22d504c5ab5f17572850f39018736474a449186e783dfda35da95902c8eaaec4bebb8ab6c057c678f37cd53fc1a12e5ace83d2a44d72195d565b3e8c12f89f2523fe37e52adbafde783be361fcd1f021aaaabf860febd8c5726c7089622ccca73b50281807d8248b7d76204a78a13970650b5adc3bb67dcb9beee7abebc4dc4e3001c2ee9a9d97accdb1523137431f78890e3a09af28ee63ae3b2f1cd5ec57261c9ccbc97cff651630d2f5458aa94bf910061e6e49b1eb8d754ba39a8c7a8e0f04564041c5e73e4fb78fe9a673216dfe57451563fa70f20c79fbef43bc166160463877609028180693b0fa44206b2a145ac5f014e60f32a3cfe9c73b4e8754e0f26cc2c35531f38aa6f1fedc5da70ebc0c261255003041f771b96ad6ac29c9ce5be31c4808e4e2a366d05be10f89121065d49428c6a0914e32330774ce5f5480f5be02671551a0b07279c09d9885d8894cbc9cc5cb89d3138b9fb156c1ab2a8ff89a3a34d453e6102818100aff57dd813fd064d8d1a5e8c7ea7e534dff6963a9b5b1c4da12219268c0500288901bbd36edb8071679bcd9d0d8deacfaa52e4b3659f4a69a5c5322f104524f83eb4b94bf6f02b5ad7c2ccd9bc5688f4e18ff2a70ae7638a83f2f87d8ecc9e0eebf2283f809670c8a0b79e1a576a6c9c04d4d71b75647c818a23873cdc0d77bf"
+
+RSA parse/write PKCS#1 public key - 2048 bits
+rsa_parse_write_pkcs1_key:1:"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"
+
+RSA parse private key - incorrect version tag
+rsa_parse_pkcs1_key:0:"300100":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - version tag missing
+rsa_parse_pkcs1_key:0:"3000":MBEDTLS_ERR_ASN1_OUT_OF_DATA
+
+RSA parse private key - invalid version
+rsa_parse_pkcs1_key:0:"3003020101":MBEDTLS_ERR_RSA_BAD_INPUT_DATA
+
+RSA parse private key - correct version, incorrect tag
+rsa_parse_pkcs1_key:0:"300402010000":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct format+values, minimal modulus size (128 bit)
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":0
+
+RSA parse private key - missing SEQUENCE
+rsa_parse_pkcs1_key:0:"020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct format, modulus too small (127 bit)
+rsa_parse_pkcs1_key:0:"30630201000211007c8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_RSA_KEY_CHECK_FAILED
+
+RSA parse private key - correct format, modulus even
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c857002030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_RSA_BAD_INPUT_DATA
+
+RSA parse private key - correct format, d == 0
+rsa_parse_pkcs1_key:0:"30630201000211007c8ab070369ede72920e5a51523c8571020301000102110000000000000000000000000000000000020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_RSA_BAD_INPUT_DATA
+
+RSA parse private key - correct format, d == p == q == 0
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c8571020301000102110000000000000000000000000000000000020900000000000000000002090000000000000000000209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_RSA_BAD_INPUT_DATA
+
+RSA parse private key - correct values, extra integer inside the SEQUENCE
+rsa_parse_pkcs1_key:0:"3066020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c020100":MBEDTLS_ERR_ASN1_LENGTH_MISMATCH
+
+RSA parse private key - correct values, extra integer outside the SEQUENCE
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c020100":0
+
+RSA parse private key - correct values, n wrong tag
+rsa_parse_pkcs1_key:0:"3063020100FF1100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct values, e wrong tag
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c8571FF030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct values, d wrong tag
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c85710203010001FF11009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct values, p wrong tag
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201FF0900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct values, q wrong tag
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61FF0900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct values, dp wrong tag
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a211FF09009471f14c26428401020813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct values, dq wrong tag
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401FF0813425f060c4b72210208052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse private key - correct values, qp wrong tag
+rsa_parse_pkcs1_key:0:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b7221FF08052b93d01747a87c":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse public key - missing SEQUENCE
+rsa_parse_pkcs1_key:1:"028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse public key - wrong initial tag
+rsa_parse_pkcs1_key:1:"318189028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse public key - wrong modulus tag
+rsa_parse_pkcs1_key:1:"308189038181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse public key - wrong public exponent tag
+rsa_parse_pkcs1_key:1:"308189028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70303010001":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse public key - modulus 0
+rsa_parse_pkcs1_key:1:"3081890281810000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000203010001":MBEDTLS_ERR_RSA_BAD_INPUT_DATA
+
+RSA parse public key - public exponent 0
+rsa_parse_pkcs1_key:1:"308189028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203000000":MBEDTLS_ERR_RSA_BAD_INPUT_DATA
+
+RSA parse public key - wrong sequence length
+rsa_parse_pkcs1_key:1:"308188028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001":MBEDTLS_ERR_ASN1_OUT_OF_DATA
+
+RSA parse public key - wrong modulus length
+rsa_parse_pkcs1_key:1:"308189028180009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001":MBEDTLS_ERR_ASN1_UNEXPECTED_TAG
+
+RSA parse public key - wrong public exponent length
+rsa_parse_pkcs1_key:1:"308189028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70202010001":MBEDTLS_ERR_RSA_BAD_INPUT_DATA
+
+RSA parse public key - missing modulus
+rsa_parse_pkcs1_key:1:"30050203010001":MBEDTLS_ERR_ASN1_OUT_OF_DATA
+
+RSA parse public key - missing public exponent
+rsa_parse_pkcs1_key:1:"308184028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb7":MBEDTLS_ERR_ASN1_OUT_OF_DATA
+
+RSA parse public key - correct values, extra integer inside the SEQUENCE
+rsa_parse_pkcs1_key:1:"30818c028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001020100":MBEDTLS_ERR_ASN1_LENGTH_MISMATCH
+
+RSA parse public key - correct values, extra integer outside the SEQUENCE
+rsa_parse_pkcs1_key:1:"308189028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001020100":0
+
+RSA priv key write - incremental output buffer size
+rsa_key_write_incremental:0:"3063020100021100cc8ab070369ede72920e5a51523c857102030100010211009a6318982a7231de1894c54aa4909201020900f3058fd8dc484d61020900d7770dbd8b78a2110209009471f14c26428401020813425f060c4b72210208052b93d01747a87c"
+
+RSA priv public key write - incremental output buffer size
+rsa_key_write_incremental:1:"308189028181009f091e6968b474f76f0e9c237c1d895996ae704b4f6d706acec8d2daac6209bf524aa3f658d0283adba1077f6cbe92e425dcde52290b239cade91be86c88425434986806e85734e159768f3dfea932baaa9409d25bace8ee9dce0cdde0903207299de575ae60feccf0daf82334ab83638539b0da74072f253acea8afc8e66bb70203010001"
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index 37bed6d..2f70028 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -1,6 +1,7 @@
 /* BEGIN_HEADER */
 #include "mbedtls/rsa.h"
 #include "rsa_alt_helpers.h"
+#include "rsa_internal.h"
 /* END_HEADER */
 
 /* BEGIN_DEPENDENCIES
@@ -1371,6 +1372,112 @@
 }
 /* END_CASE */
 
+/* BEGIN_CASE */
+void rsa_parse_pkcs1_key(int is_public, data_t *input, int exp_ret_val)
+{
+    mbedtls_rsa_context rsa_ctx;
+
+    mbedtls_rsa_init(&rsa_ctx);
+
+    if (is_public) {
+        TEST_EQUAL(mbedtls_rsa_parse_pubkey(&rsa_ctx, input->x, input->len), exp_ret_val);
+    } else {
+        TEST_EQUAL(mbedtls_rsa_parse_key(&rsa_ctx, input->x, input->len), exp_ret_val);
+    }
+
+exit:
+    mbedtls_rsa_free(&rsa_ctx);
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void rsa_parse_write_pkcs1_key(int is_public, data_t *input)
+{
+    mbedtls_rsa_context rsa_ctx;
+    unsigned char *output_buf = NULL;
+    unsigned char *output_end, *output_p;
+    size_t output_len;
+
+    mbedtls_rsa_init(&rsa_ctx);
+
+    TEST_CALLOC(output_buf, input->len);
+    output_end = output_buf + input->len;
+    output_p = output_end;
+
+    /* Parse the key and write it back to output_buf. */
+    if (is_public) {
+        TEST_EQUAL(mbedtls_rsa_parse_pubkey(&rsa_ctx, input->x, input->len), 0);
+        TEST_EQUAL(mbedtls_rsa_write_pubkey(&rsa_ctx, output_buf, &output_p), input->len);
+    } else {
+        TEST_EQUAL(mbedtls_rsa_parse_key(&rsa_ctx, input->x, input->len), 0);
+        TEST_EQUAL(mbedtls_rsa_write_key(&rsa_ctx, output_buf, &output_p), input->len);
+    }
+    output_len = output_end - output_p;
+
+    /* Check that the written key matches with the one provided in input. */
+    TEST_MEMORY_COMPARE(output_p, output_len, input->x, input->len);
+
+exit:
+    mbedtls_free(output_buf);
+    mbedtls_rsa_free(&rsa_ctx);
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void rsa_key_write_incremental(int is_public, data_t *input)
+{
+    mbedtls_rsa_context rsa_ctx;
+    unsigned char *buf = NULL, *end, *p;
+    size_t i, written_data;
+
+    mbedtls_rsa_init(&rsa_ctx);
+
+    /* This is supposed to succeed as the real target of this test are the
+     * write attempt below. */
+    if (is_public) {
+        TEST_EQUAL(mbedtls_rsa_parse_pubkey(&rsa_ctx, input->x, input->len), 0);
+    } else {
+        TEST_EQUAL(mbedtls_rsa_parse_key(&rsa_ctx, input->x, input->len), 0);
+    }
+
+    /* Test with an output buffer smaller than required. */
+    for (i = 1; i < input->len; i++) {
+        TEST_CALLOC(buf, i);
+        end = buf + i;
+        p = end;
+        /* We don't care much about the return value as long as it fails. */
+        if (is_public) {
+            TEST_ASSERT(mbedtls_rsa_write_pubkey(&rsa_ctx, buf, &p) != 0);
+        } else {
+            TEST_ASSERT(mbedtls_rsa_write_key(&rsa_ctx, buf, &p) != 0);
+        }
+        mbedtls_free(buf);
+        buf = NULL;
+    }
+
+    /* Test with an output buffer equal or larger than what it is strictly required. */
+    for (i = input->len; i < (2 * input->len); i++) {
+        TEST_CALLOC(buf, i);
+        end = buf + i;
+        p = end;
+        /* This time all write functions must succeed. */
+        if (is_public) {
+            TEST_ASSERT(mbedtls_rsa_write_pubkey(&rsa_ctx, buf, &p) > 0);
+        } else {
+            TEST_ASSERT(mbedtls_rsa_write_key(&rsa_ctx, buf, &p) > 0);
+        }
+        written_data = (end - p);
+        TEST_MEMORY_COMPARE(p, written_data, input->x, input->len);
+        mbedtls_free(buf);
+        buf = NULL;
+    }
+
+exit:
+    mbedtls_free(buf);
+    mbedtls_rsa_free(&rsa_ctx);
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */
 void rsa_selftest()
 {
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index 261c220..b9ae20c 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -1774,7 +1774,7 @@
 
 X509 CRT ASN1 (TBS, inv SubPubKeyInfo, inv internal bitstring length)
 depends_on:MBEDTLS_RSA_C:MBEDTLS_MD_CAN_SHA256
-x509parse_crt:"308180306ba0030201008204deadbeef300d06092a864886f70d01010b0500300c310a30080600130454657374301c170c303930313031303030303030170c303931323331323335393539300c310a300806001304546573743015300d06092A864886F70D0101010500030400300000300d06092a864886f70d01010b0500030200ff":"":MBEDTLS_ERR_PK_INVALID_PUBKEY + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH
+x509parse_crt:"308180306ba0030201008204deadbeef300d06092a864886f70d01010b0500300c310a30080600130454657374301c170c303930313031303030303030170c303931323331323335393539300c310a300806001304546573743015300d06092A864886F70D0101010500030400300000300d06092a864886f70d01010b0500030200ff":"":MBEDTLS_ERR_PK_INVALID_PUBKEY + MBEDTLS_ERR_ASN1_OUT_OF_DATA
 
 X509 CRT ASN1 (TBS, inv SubPubKeyInfo, inv internal bitstring tag)
 depends_on:MBEDTLS_RSA_C:MBEDTLS_MD_CAN_SHA256