Squashed 'lib/mbedtls/external/mbedtls/' content from commit 2ca6c285a0dd

git-subtree-dir: lib/mbedtls/external/mbedtls
git-subtree-split: 2ca6c285a0dd3f33982dd57299012dacab1ff206

1 files changed, 712 insertions, 0 deletions

diff --git a/library/dhm.c b/library/dhm.c
new file mode 100644
index 00000000000..bcc07f54419
--- /dev/null
+++ b/library/dhm.c
@@ -0,0 +1,712 @@
+/*
+ *  Diffie-Hellman-Merkle key exchange
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+/*
+ *  The following sources were referenced in the design of this implementation
+ *  of the Diffie-Hellman-Merkle algorithm:
+ *
+ *  [1] Handbook of Applied Cryptography - 1997, Chapter 12
+ *      Menezes, van Oorschot and Vanstone
+ *
+ */
+
+#include "common.h"
+
+#if defined(MBEDTLS_DHM_C)
+
+#include "mbedtls/dhm.h"
+#include "mbedtls/platform_util.h"
+#include "mbedtls/error.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+#include "mbedtls/pem.h"
+#endif
+
+#if defined(MBEDTLS_ASN1_PARSE_C)
+#include "mbedtls/asn1.h"
+#endif
+
+#include "mbedtls/platform.h"
+
+#if !defined(MBEDTLS_DHM_ALT)
+
+/*
+ * helper to validate the mbedtls_mpi size and import it
+ */
+static int dhm_read_bignum(mbedtls_mpi *X,
+                           unsigned char **p,
+                           const unsigned char *end)
+{
+    int ret, n;
+
+    if (end - *p < 2) {
+        return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+
+    n = MBEDTLS_GET_UINT16_BE(*p, 0);
+    (*p) += 2;
+
+    if ((size_t) (end - *p) < (size_t) n) {
+        return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+
+    if ((ret = mbedtls_mpi_read_binary(X, *p, n)) != 0) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_READ_PARAMS_FAILED, ret);
+    }
+
+    (*p) += n;
+
+    return 0;
+}
+
+/*
+ * Verify sanity of parameter with regards to P
+ *
+ * Parameter should be: 2 <= public_param <= P - 2
+ *
+ * This means that we need to return an error if
+ *              public_param < 2 or public_param > P-2
+ *
+ * For more information on the attack, see:
+ *  http://www.cl.cam.ac.uk/~rja14/Papers/psandqs.pdf
+ *  http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2005-2643
+ */
+static int dhm_check_range(const mbedtls_mpi *param, const mbedtls_mpi *P)
+{
+    mbedtls_mpi U;
+    int ret = 0;
+
+    mbedtls_mpi_init(&U);
+
+    MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&U, P, 2));
+
+    if (mbedtls_mpi_cmp_int(param, 2) < 0 ||
+        mbedtls_mpi_cmp_mpi(param, &U) > 0) {
+        ret = MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+
+cleanup:
+    mbedtls_mpi_free(&U);
+    return ret;
+}
+
+void mbedtls_dhm_init(mbedtls_dhm_context *ctx)
+{
+    memset(ctx, 0, sizeof(mbedtls_dhm_context));
+}
+
+size_t mbedtls_dhm_get_bitlen(const mbedtls_dhm_context *ctx)
+{
+    return mbedtls_mpi_bitlen(&ctx->P);
+}
+
+size_t mbedtls_dhm_get_len(const mbedtls_dhm_context *ctx)
+{
+    return mbedtls_mpi_size(&ctx->P);
+}
+
+int mbedtls_dhm_get_value(const mbedtls_dhm_context *ctx,
+                          mbedtls_dhm_parameter param,
+                          mbedtls_mpi *dest)
+{
+    const mbedtls_mpi *src = NULL;
+    switch (param) {
+        case MBEDTLS_DHM_PARAM_P:
+            src = &ctx->P;
+            break;
+        case MBEDTLS_DHM_PARAM_G:
+            src = &ctx->G;
+            break;
+        case MBEDTLS_DHM_PARAM_X:
+            src = &ctx->X;
+            break;
+        case MBEDTLS_DHM_PARAM_GX:
+            src = &ctx->GX;
+            break;
+        case MBEDTLS_DHM_PARAM_GY:
+            src = &ctx->GY;
+            break;
+        case MBEDTLS_DHM_PARAM_K:
+            src = &ctx->K;
+            break;
+        default:
+            return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+    return mbedtls_mpi_copy(dest, src);
+}
+
+/*
+ * Parse the ServerKeyExchange parameters
+ */
+int mbedtls_dhm_read_params(mbedtls_dhm_context *ctx,
+                            unsigned char **p,
+                            const unsigned char *end)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+    if ((ret = dhm_read_bignum(&ctx->P,  p, end)) != 0 ||
+        (ret = dhm_read_bignum(&ctx->G,  p, end)) != 0 ||
+        (ret = dhm_read_bignum(&ctx->GY, p, end)) != 0) {
+        return ret;
+    }
+
+    if ((ret = dhm_check_range(&ctx->GY, &ctx->P)) != 0) {
+        return ret;
+    }
+
+    return 0;
+}
+
+/*
+ * Pick a random R in the range [2, M-2] for blinding or key generation.
+ */
+static int dhm_random_below(mbedtls_mpi *R, const mbedtls_mpi *M,
+                            int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
+{
+    int ret;
+
+    MBEDTLS_MPI_CHK(mbedtls_mpi_random(R, 3, M, f_rng, p_rng));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(R, R, 1));
+
+cleanup:
+    return ret;
+}
+
+static int dhm_make_common(mbedtls_dhm_context *ctx, int x_size,
+                           int (*f_rng)(void *, unsigned char *, size_t),
+                           void *p_rng)
+{
+    int ret = 0;
+
+    if (mbedtls_mpi_cmp_int(&ctx->P, 0) == 0) {
+        return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+    if (x_size < 0) {
+        return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+
+    if ((unsigned) x_size < mbedtls_mpi_size(&ctx->P)) {
+        MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&ctx->X, x_size, f_rng, p_rng));
+    } else {
+        /* Generate X as large as possible ( <= P - 2 ) */
+        ret = dhm_random_below(&ctx->X, &ctx->P, f_rng, p_rng);
+        if (ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE) {
+            return MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED;
+        }
+        if (ret != 0) {
+            return ret;
+        }
+    }
+
+    /*
+     * Calculate GX = G^X mod P
+     */
+    MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->GX, &ctx->G, &ctx->X,
+                                        &ctx->P, &ctx->RP));
+
+    if ((ret = dhm_check_range(&ctx->GX, &ctx->P)) != 0) {
+        return ret;
+    }
+
+cleanup:
+    return ret;
+}
+
+/*
+ * Setup and write the ServerKeyExchange parameters
+ */
+int mbedtls_dhm_make_params(mbedtls_dhm_context *ctx, int x_size,
+                            unsigned char *output, size_t *olen,
+                            int (*f_rng)(void *, unsigned char *, size_t),
+                            void *p_rng)
+{
+    int ret;
+    size_t n1, n2, n3;
+    unsigned char *p;
+
+    ret = dhm_make_common(ctx, x_size, f_rng, p_rng);
+    if (ret != 0) {
+        goto cleanup;
+    }
+
+    /*
+     * Export P, G, GX. RFC 5246 §4.4 states that "leading zero octets are
+     * not required". We omit leading zeros for compactness.
+     */
+#define DHM_MPI_EXPORT(X, n)                                          \
+    do {                                                                \
+        MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary((X),               \
+                                                 p + 2,               \
+                                                 (n)));           \
+        *p++ = MBEDTLS_BYTE_1(n);                                     \
+        *p++ = MBEDTLS_BYTE_0(n);                                     \
+        p += (n);                                                     \
+    } while (0)
+
+    n1 = mbedtls_mpi_size(&ctx->P);
+    n2 = mbedtls_mpi_size(&ctx->G);
+    n3 = mbedtls_mpi_size(&ctx->GX);
+
+    p = output;
+    DHM_MPI_EXPORT(&ctx->P, n1);
+    DHM_MPI_EXPORT(&ctx->G, n2);
+    DHM_MPI_EXPORT(&ctx->GX, n3);
+
+    *olen = (size_t) (p - output);
+
+cleanup:
+    if (ret != 0 && ret > -128) {
+        ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED, ret);
+    }
+    return ret;
+}
+
+/*
+ * Set prime modulus and generator
+ */
+int mbedtls_dhm_set_group(mbedtls_dhm_context *ctx,
+                          const mbedtls_mpi *P,
+                          const mbedtls_mpi *G)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+    if ((ret = mbedtls_mpi_copy(&ctx->P, P)) != 0 ||
+        (ret = mbedtls_mpi_copy(&ctx->G, G)) != 0) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_SET_GROUP_FAILED, ret);
+    }
+
+    return 0;
+}
+
+/*
+ * Import the peer's public value G^Y
+ */
+int mbedtls_dhm_read_public(mbedtls_dhm_context *ctx,
+                            const unsigned char *input, size_t ilen)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+    if (ilen < 1 || ilen > mbedtls_dhm_get_len(ctx)) {
+        return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+
+    if ((ret = mbedtls_mpi_read_binary(&ctx->GY, input, ilen)) != 0) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_READ_PUBLIC_FAILED, ret);
+    }
+
+    return 0;
+}
+
+/*
+ * Create own private value X and export G^X
+ */
+int mbedtls_dhm_make_public(mbedtls_dhm_context *ctx, int x_size,
+                            unsigned char *output, size_t olen,
+                            int (*f_rng)(void *, unsigned char *, size_t),
+                            void *p_rng)
+{
+    int ret;
+
+    if (olen < 1 || olen > mbedtls_dhm_get_len(ctx)) {
+        return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+
+    ret = dhm_make_common(ctx, x_size, f_rng, p_rng);
+    if (ret == MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED) {
+        return MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED;
+    }
+    if (ret != 0) {
+        goto cleanup;
+    }
+
+    MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->GX, output, olen));
+
+cleanup:
+    if (ret != 0 && ret > -128) {
+        ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED, ret);
+    }
+    return ret;
+}
+
+
+/*
+ * Use the blinding method and optimisation suggested in section 10 of:
+ *  KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
+ *  DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
+ *  Berlin Heidelberg, 1996. p. 104-113.
+ */
+static int dhm_update_blinding(mbedtls_dhm_context *ctx,
+                               int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
+{
+    int ret;
+    mbedtls_mpi R;
+
+    mbedtls_mpi_init(&R);
+
+    /*
+     * Don't use any blinding the first time a particular X is used,
+     * but remember it to use blinding next time.
+     */
+    if (mbedtls_mpi_cmp_mpi(&ctx->X, &ctx->pX) != 0) {
+        MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&ctx->pX, &ctx->X));
+        MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&ctx->Vi, 1));
+        MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&ctx->Vf, 1));
+
+        return 0;
+    }
+
+    /*
+     * Ok, we need blinding. Can we re-use existing values?
+     * If yes, just update them by squaring them.
+     */
+    if (mbedtls_mpi_cmp_int(&ctx->Vi, 1) != 0) {
+        MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vi, &ctx->Vi, &ctx->Vi));
+        MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vi, &ctx->Vi, &ctx->P));
+
+        MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vf, &ctx->Vf));
+        MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
+
+        return 0;
+    }
+
+    /*
+     * We need to generate blinding values from scratch
+     */
+
+    /* Vi = random( 2, P-2 ) */
+    MBEDTLS_MPI_CHK(dhm_random_below(&ctx->Vi, &ctx->P, f_rng, p_rng));
+
+    /* Vf = Vi^-X mod P
+     * First compute Vi^-1 = R * (R Vi)^-1, (avoiding leaks from inv_mod),
+     * then elevate to the Xth power. */
+    MBEDTLS_MPI_CHK(dhm_random_below(&R, &ctx->P, f_rng, p_rng));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vi, &R));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&ctx->Vf, &ctx->Vf, &ctx->P));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vf, &R));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
+
+    MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP));
+
+cleanup:
+    mbedtls_mpi_free(&R);
+
+    return ret;
+}
+
+/*
+ * Derive and export the shared secret (G^Y)^X mod P
+ */
+int mbedtls_dhm_calc_secret(mbedtls_dhm_context *ctx,
+                            unsigned char *output, size_t output_size, size_t *olen,
+                            int (*f_rng)(void *, unsigned char *, size_t),
+                            void *p_rng)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_mpi GYb;
+
+    if (f_rng == NULL) {
+        return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+
+    if (output_size < mbedtls_dhm_get_len(ctx)) {
+        return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
+    }
+
+    if ((ret = dhm_check_range(&ctx->GY, &ctx->P)) != 0) {
+        return ret;
+    }
+
+    mbedtls_mpi_init(&GYb);
+
+    /* Blind peer's value */
+    MBEDTLS_MPI_CHK(dhm_update_blinding(ctx, f_rng, p_rng));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&GYb, &ctx->GY, &ctx->Vi));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&GYb, &GYb, &ctx->P));
+
+    /* Do modular exponentiation */
+    MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->K, &GYb, &ctx->X,
+                                        &ctx->P, &ctx->RP));
+
+    /* Unblind secret value */
+    MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->K, &ctx->K, &ctx->Vf));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->K, &ctx->K, &ctx->P));
+
+    /* Output the secret without any leading zero byte. This is mandatory
+     * for TLS per RFC 5246 §8.1.2. */
+    *olen = mbedtls_mpi_size(&ctx->K);
+    MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->K, output, *olen));
+
+cleanup:
+    mbedtls_mpi_free(&GYb);
+
+    if (ret != 0) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_CALC_SECRET_FAILED, ret);
+    }
+
+    return 0;
+}
+
+/*
+ * Free the components of a DHM key
+ */
+void mbedtls_dhm_free(mbedtls_dhm_context *ctx)
+{
+    if (ctx == NULL) {
+        return;
+    }
+
+    mbedtls_mpi_free(&ctx->pX);
+    mbedtls_mpi_free(&ctx->Vf);
+    mbedtls_mpi_free(&ctx->Vi);
+    mbedtls_mpi_free(&ctx->RP);
+    mbedtls_mpi_free(&ctx->K);
+    mbedtls_mpi_free(&ctx->GY);
+    mbedtls_mpi_free(&ctx->GX);
+    mbedtls_mpi_free(&ctx->X);
+    mbedtls_mpi_free(&ctx->G);
+    mbedtls_mpi_free(&ctx->P);
+
+    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_dhm_context));
+}
+
+#if defined(MBEDTLS_ASN1_PARSE_C)
+/*
+ * Parse DHM parameters
+ */
+int mbedtls_dhm_parse_dhm(mbedtls_dhm_context *dhm, const unsigned char *dhmin,
+                          size_t dhminlen)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len;
+    unsigned char *p, *end;
+#if defined(MBEDTLS_PEM_PARSE_C)
+    mbedtls_pem_context pem;
+#endif /* MBEDTLS_PEM_PARSE_C */
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+    mbedtls_pem_init(&pem);
+
+    /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
+    if (dhminlen == 0 || dhmin[dhminlen - 1] != '\0') {
+        ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
+    } else {
+        ret = mbedtls_pem_read_buffer(&pem,
+                                      "-----BEGIN DH PARAMETERS-----",
+                                      "-----END DH PARAMETERS-----",
+                                      dhmin, NULL, 0, &dhminlen);
+    }
+
+    if (ret == 0) {
+        /*
+         * Was PEM encoded
+         */
+        dhminlen = pem.buflen;
+    } else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
+        goto exit;
+    }
+
+    p = (ret == 0) ? pem.buf : (unsigned char *) dhmin;
+#else
+    p = (unsigned char *) dhmin;
+#endif /* MBEDTLS_PEM_PARSE_C */
+    end = p + dhminlen;
+
+    /*
+     *  DHParams ::= SEQUENCE {
+     *      prime              INTEGER,  -- P
+     *      generator          INTEGER,  -- g
+     *      privateValueLength INTEGER OPTIONAL
+     *  }
+     */
+    if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
+                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
+        ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
+        goto exit;
+    }
+
+    end = p + len;
+
+    if ((ret = mbedtls_asn1_get_mpi(&p, end, &dhm->P)) != 0 ||
+        (ret = mbedtls_asn1_get_mpi(&p, end, &dhm->G)) != 0) {
+        ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
+        goto exit;
+    }
+
+    if (p != end) {
+        /* This might be the optional privateValueLength.
+         * If so, we can cleanly discard it */
+        mbedtls_mpi rec;
+        mbedtls_mpi_init(&rec);
+        ret = mbedtls_asn1_get_mpi(&p, end, &rec);
+        mbedtls_mpi_free(&rec);
+        if (ret != 0) {
+            ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
+            goto exit;
+        }
+        if (p != end) {
+            ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT,
+                                    MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
+            goto exit;
+        }
+    }
+
+    ret = 0;
+
+exit:
+#if defined(MBEDTLS_PEM_PARSE_C)
+    mbedtls_pem_free(&pem);
+#endif
+    if (ret != 0) {
+        mbedtls_dhm_free(dhm);
+    }
+
+    return ret;
+}
+
+#if defined(MBEDTLS_FS_IO)
+/*
+ * Load all data from a file into a given buffer.
+ *
+ * The file is expected to contain either PEM or DER encoded data.
+ * A terminating null byte is always appended. It is included in the announced
+ * length only if the data looks like it is PEM encoded.
+ */
+static int load_file(const char *path, unsigned char **buf, size_t *n)
+{
+    FILE *f;
+    long size;
+
+    if ((f = fopen(path, "rb")) == NULL) {
+        return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
+    }
+    /* The data loaded here is public, so don't bother disabling buffering. */
+
+    fseek(f, 0, SEEK_END);
+    if ((size = ftell(f)) == -1) {
+        fclose(f);
+        return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
+    }
+    fseek(f, 0, SEEK_SET);
+
+    *n = (size_t) size;
+
+    if (*n + 1 == 0 ||
+        (*buf = mbedtls_calloc(1, *n + 1)) == NULL) {
+        fclose(f);
+        return MBEDTLS_ERR_DHM_ALLOC_FAILED;
+    }
+
+    if (fread(*buf, 1, *n, f) != *n) {
+        fclose(f);
+
+        mbedtls_zeroize_and_free(*buf, *n + 1);
+
+        return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
+    }
+
+    fclose(f);
+
+    (*buf)[*n] = '\0';
+
+    if (strstr((const char *) *buf, "-----BEGIN ") != NULL) {
+        ++*n;
+    }
+
+    return 0;
+}
+
+/*
+ * Load and parse DHM parameters
+ */
+int mbedtls_dhm_parse_dhmfile(mbedtls_dhm_context *dhm, const char *path)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t n;
+    unsigned char *buf;
+
+    if ((ret = load_file(path, &buf, &n)) != 0) {
+        return ret;
+    }
+
+    ret = mbedtls_dhm_parse_dhm(dhm, buf, n);
+
+    mbedtls_zeroize_and_free(buf, n);
+
+    return ret;
+}
+#endif /* MBEDTLS_FS_IO */
+#endif /* MBEDTLS_ASN1_PARSE_C */
+#endif /* MBEDTLS_DHM_ALT */
+
+#if defined(MBEDTLS_SELF_TEST)
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+static const char mbedtls_test_dhm_params[] =
+    "-----BEGIN DH PARAMETERS-----\r\n"
+    "MIGHAoGBAJ419DBEOgmQTzo5qXl5fQcN9TN455wkOL7052HzxxRVMyhYmwQcgJvh\r\n"
+    "1sa18fyfR9OiVEMYglOpkqVoGLN7qd5aQNNi5W7/C+VBdHTBJcGZJyyP5B3qcz32\r\n"
+    "9mLJKudlVudV0Qxk5qUJaPZ/xupz0NyoVpviuiBOI1gNi8ovSXWzAgEC\r\n"
+    "-----END DH PARAMETERS-----\r\n";
+#else /* MBEDTLS_PEM_PARSE_C */
+static const char mbedtls_test_dhm_params[] = {
+    0x30, 0x81, 0x87, 0x02, 0x81, 0x81, 0x00, 0x9e, 0x35, 0xf4, 0x30, 0x44,
+    0x3a, 0x09, 0x90, 0x4f, 0x3a, 0x39, 0xa9, 0x79, 0x79, 0x7d, 0x07, 0x0d,
+    0xf5, 0x33, 0x78, 0xe7, 0x9c, 0x24, 0x38, 0xbe, 0xf4, 0xe7, 0x61, 0xf3,
+    0xc7, 0x14, 0x55, 0x33, 0x28, 0x58, 0x9b, 0x04, 0x1c, 0x80, 0x9b, 0xe1,
+    0xd6, 0xc6, 0xb5, 0xf1, 0xfc, 0x9f, 0x47, 0xd3, 0xa2, 0x54, 0x43, 0x18,
+    0x82, 0x53, 0xa9, 0x92, 0xa5, 0x68, 0x18, 0xb3, 0x7b, 0xa9, 0xde, 0x5a,
+    0x40, 0xd3, 0x62, 0xe5, 0x6e, 0xff, 0x0b, 0xe5, 0x41, 0x74, 0x74, 0xc1,
+    0x25, 0xc1, 0x99, 0x27, 0x2c, 0x8f, 0xe4, 0x1d, 0xea, 0x73, 0x3d, 0xf6,
+    0xf6, 0x62, 0xc9, 0x2a, 0xe7, 0x65, 0x56, 0xe7, 0x55, 0xd1, 0x0c, 0x64,
+    0xe6, 0xa5, 0x09, 0x68, 0xf6, 0x7f, 0xc6, 0xea, 0x73, 0xd0, 0xdc, 0xa8,
+    0x56, 0x9b, 0xe2, 0xba, 0x20, 0x4e, 0x23, 0x58, 0x0d, 0x8b, 0xca, 0x2f,
+    0x49, 0x75, 0xb3, 0x02, 0x01, 0x02
+};
+#endif /* MBEDTLS_PEM_PARSE_C */
+
+static const size_t mbedtls_test_dhm_params_len = sizeof(mbedtls_test_dhm_params);
+
+/*
+ * Checkup routine
+ */
+int mbedtls_dhm_self_test(int verbose)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_dhm_context dhm;
+
+    mbedtls_dhm_init(&dhm);
+
+    if (verbose != 0) {
+        mbedtls_printf("  DHM parameter load: ");
+    }
+
+    if ((ret = mbedtls_dhm_parse_dhm(&dhm,
+                                     (const unsigned char *) mbedtls_test_dhm_params,
+                                     mbedtls_test_dhm_params_len)) != 0) {
+        if (verbose != 0) {
+            mbedtls_printf("failed\n");
+        }
+
+        ret = 1;
+        goto exit;
+    }
+
+    if (verbose != 0) {
+        mbedtls_printf("passed\n\n");
+    }
+
+exit:
+    mbedtls_dhm_free(&dhm);
+
+    return ret;
+}
+
+#endif /* MBEDTLS_SELF_TEST */
+
+#endif /* MBEDTLS_DHM_C */