/src/openssl/crypto/dsa/dsa_pmeth.c

Source
/*
 * Copyright 2006-2025 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

/*
 * DSA low level APIs are deprecated for public use, but still ok for
 * internal use.
 */
#include "internal/deprecated.h"

#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/asn1t.h>
#include <openssl/x509.h>
#include <openssl/evp.h>
#include <openssl/bn.h>
#include "crypto/evp.h"
#include "dsa_local.h"

/* DSA pkey context structure */

typedef struct {
    /* Parameter gen parameters */
    int nbits;                  /* size of p in bits (default: 2048) */
    int qbits;                  /* size of q in bits (default: 224) */
    const EVP_MD *pmd;          /* MD for parameter generation */
    /* Keygen callback info */
    int gentmp[2];
    /* message digest */
    const EVP_MD *md;           /* MD for the signature */
} DSA_PKEY_CTX;

static int pkey_dsa_init(EVP_PKEY_CTX *ctx)
{
    DSA_PKEY_CTX *dctx = OPENSSL_malloc(sizeof(*dctx));

    if (dctx == NULL)
        return 0;
    dctx->nbits = 2048;
    dctx->qbits = 224;
    dctx->pmd = NULL;
    dctx->md = NULL;

    ctx->data = dctx;
    ctx->keygen_info = dctx->gentmp;
    ctx->keygen_info_count = 2;

    return 1;
}

static int pkey_dsa_copy(EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src)
{
    DSA_PKEY_CTX *dctx, *sctx;

    if (!pkey_dsa_init(dst))
        return 0;
    sctx = src->data;
    dctx = dst->data;
    dctx->nbits = sctx->nbits;
    dctx->qbits = sctx->qbits;
    dctx->pmd = sctx->pmd;
    dctx->md = sctx->md;
    return 1;
}

static void pkey_dsa_cleanup(EVP_PKEY_CTX *ctx)
{
    DSA_PKEY_CTX *dctx = ctx->data;
    OPENSSL_free(dctx);
}

static int pkey_dsa_sign(EVP_PKEY_CTX *ctx, unsigned char *sig,
                         size_t *siglen, const unsigned char *tbs,
                         size_t tbslen)
{
    int ret, md_size;
    unsigned int sltmp;
    DSA_PKEY_CTX *dctx = ctx->data;
    /*
     * Discard const. Its marked as const because this may be a cached copy of
     * the "real" key. These calls don't make any modifications that need to
     * be reflected back in the "original" key.
     */
    DSA *dsa = (DSA *)EVP_PKEY_get0_DSA(ctx->pkey);

    if (dctx->md != NULL) {
        md_size = EVP_MD_get_size(dctx->md);
        if (md_size <= 0)
            return 0;
        if (tbslen != (size_t)md_size)
            return 0;
    }

    ret = DSA_sign(0, tbs, (int)tbslen, sig, &sltmp, dsa);

    if (ret <= 0)
        return ret;
    *siglen = sltmp;
    return 1;
}

static int pkey_dsa_verify(EVP_PKEY_CTX *ctx,
                           const unsigned char *sig, size_t siglen,
                           const unsigned char *tbs, size_t tbslen)
{
    int ret, md_size;
    DSA_PKEY_CTX *dctx = ctx->data;
    /*
     * Discard const. Its marked as const because this may be a cached copy of
     * the "real" key. These calls don't make any modifications that need to
     * be reflected back in the "original" key.
     */
    DSA *dsa = (DSA *)EVP_PKEY_get0_DSA(ctx->pkey);

    if (dctx->md != NULL) {
        md_size = EVP_MD_get_size(dctx->md);
        if (md_size <= 0)
            return 0;
        if (tbslen != (size_t)md_size)
            return 0;
    }

    ret = DSA_verify(0, tbs, (int)tbslen, sig, (int)siglen, dsa);

    return ret;
}

static int pkey_dsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
{
    DSA_PKEY_CTX *dctx = ctx->data;

    switch (type) {
    case EVP_PKEY_CTRL_DSA_PARAMGEN_BITS:
        if (p1 < 256)
            return -2;
        dctx->nbits = p1;
        return 1;

    case EVP_PKEY_CTRL_DSA_PARAMGEN_Q_BITS:
        if (p1 != 160 && p1 != 224 && p1 && p1 != 256)
            return -2;
        dctx->qbits = p1;
        return 1;

    case EVP_PKEY_CTRL_DSA_PARAMGEN_MD:
        if (EVP_MD_get_type((const EVP_MD *)p2) != NID_sha1 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha224 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha256) {
            ERR_raise(ERR_LIB_DSA, DSA_R_INVALID_DIGEST_TYPE);
            return 0;
        }
        dctx->pmd = p2;
        return 1;

    case EVP_PKEY_CTRL_MD:
        if (EVP_MD_get_type((const EVP_MD *)p2) != NID_sha1 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_dsa &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_dsaWithSHA &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha224 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha256 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha384 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha512 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_224 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_256 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_384 &&
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_512) {
            ERR_raise(ERR_LIB_DSA, DSA_R_INVALID_DIGEST_TYPE);
            return 0;
        }
        dctx->md = p2;
        return 1;

    case EVP_PKEY_CTRL_GET_MD:
        *(const EVP_MD **)p2 = dctx->md;
        return 1;

    case EVP_PKEY_CTRL_DIGESTINIT:
    case EVP_PKEY_CTRL_PKCS7_SIGN:
    case EVP_PKEY_CTRL_CMS_SIGN:
        return 1;

    case EVP_PKEY_CTRL_PEER_KEY:
        ERR_raise(ERR_LIB_DSA, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
        return -2;
    default:
        return -2;

    }
}

static int pkey_dsa_ctrl_str(EVP_PKEY_CTX *ctx,
                             const char *type, const char *value)
{
    if (strcmp(type, "dsa_paramgen_bits") == 0) {
        int nbits;
        nbits = atoi(value);
        return EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, nbits);
    }
    if (strcmp(type, "dsa_paramgen_q_bits") == 0) {
        int qbits = atoi(value);
        return EVP_PKEY_CTX_set_dsa_paramgen_q_bits(ctx, qbits);
    }
    if (strcmp(type, "dsa_paramgen_md") == 0) {
        const EVP_MD *md = EVP_get_digestbyname(value);

        if (md == NULL) {
            ERR_raise(ERR_LIB_DSA, DSA_R_INVALID_DIGEST_TYPE);
            return 0;
        }
        return EVP_PKEY_CTX_set_dsa_paramgen_md(ctx, md);
    }
    return -2;
}

static int pkey_dsa_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
{
    DSA *dsa = NULL;
    DSA_PKEY_CTX *dctx = ctx->data;
    BN_GENCB *pcb;
    int ret, res;

    if (ctx->pkey_gencb) {
        pcb = BN_GENCB_new();
        if (pcb == NULL)
            return 0;
        evp_pkey_set_cb_translate(pcb, ctx);
    } else
        pcb = NULL;
    dsa = DSA_new();
    if (dsa == NULL) {
        BN_GENCB_free(pcb);
        return 0;
    }
    if (dctx->md != NULL)
        ossl_ffc_set_digest(&dsa->params, EVP_MD_get0_name(dctx->md), NULL);

    ret = ossl_ffc_params_FIPS186_4_generate(NULL, &dsa->params,
                                             FFC_PARAM_TYPE_DSA, dctx->nbits,
                                             dctx->qbits, &res, pcb);
    BN_GENCB_free(pcb);
    if (ret > 0)
        EVP_PKEY_assign_DSA(pkey, dsa);
    else
        DSA_free(dsa);
    return ret;
}

static int pkey_dsa_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
{
    DSA *dsa = NULL;

    if (ctx->pkey == NULL) {
        ERR_raise(ERR_LIB_DSA, DSA_R_NO_PARAMETERS_SET);
        return 0;
    }
    dsa = DSA_new();
    if (dsa == NULL)
        return 0;
    EVP_PKEY_assign_DSA(pkey, dsa);
    /* Note: if error return, pkey is freed by parent routine */
    if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
        return 0;
    return DSA_generate_key((DSA *)EVP_PKEY_get0_DSA(pkey));
}

static const EVP_PKEY_METHOD dsa_pkey_meth = {
    EVP_PKEY_DSA,
    EVP_PKEY_FLAG_AUTOARGLEN,
    pkey_dsa_init,
    pkey_dsa_copy,
    pkey_dsa_cleanup,

    0,
    pkey_dsa_paramgen,

    0,
    pkey_dsa_keygen,

    0,
    pkey_dsa_sign,

    0,
    pkey_dsa_verify,

    0, 0,

    0, 0, 0, 0,

    0, 0,

    0, 0,

    0, 0,

    pkey_dsa_ctrl,
    pkey_dsa_ctrl_str
};

const EVP_PKEY_METHOD *ossl_dsa_pkey_method(void)
{
    return &dsa_pkey_meth;
}

Coverage Report

Created: 2025-10-28 06:56

Line	Count	Source
1		/*
2		* Copyright 2006-2025 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9
10		/*
11		* DSA low level APIs are deprecated for public use, but still ok for
12		* internal use.
13		*/
14		#include "internal/deprecated.h"
15
16		#include <stdio.h>
17		#include "internal/cryptlib.h"
18		#include <openssl/asn1t.h>
19		#include <openssl/x509.h>
20		#include <openssl/evp.h>
21		#include <openssl/bn.h>
22		#include "crypto/evp.h"
23		#include "dsa_local.h"
24
25		/* DSA pkey context structure */
26
27		typedef struct {
28		/* Parameter gen parameters */
29		int nbits; /* size of p in bits (default: 2048) */
30		int qbits; /* size of q in bits (default: 224) */
31		const EVP_MD pmd; / MD for parameter generation */
32		/* Keygen callback info */
33		int gentmp[2];
34		/* message digest */
35		const EVP_MD md; / MD for the signature */
36		} DSA_PKEY_CTX;
37
38		static int pkey_dsa_init(EVP_PKEY_CTX *ctx)
39	0	{
40	0	DSA_PKEY_CTX dctx = OPENSSL_malloc(sizeof(dctx));
41
42	0	if (dctx == NULL)
43	0	return 0;
44	0	dctx->nbits = 2048;
45	0	dctx->qbits = 224;
46	0	dctx->pmd = NULL;
47	0	dctx->md = NULL;
48
49	0	ctx->data = dctx;
50	0	ctx->keygen_info = dctx->gentmp;
51	0	ctx->keygen_info_count = 2;
52
53	0	return 1;
54	0	}
55
56		static int pkey_dsa_copy(EVP_PKEY_CTX dst, const EVP_PKEY_CTX src)
57	0	{
58	0	DSA_PKEY_CTX dctx, sctx;
59
60	0	if (!pkey_dsa_init(dst))
61	0	return 0;
62	0	sctx = src->data;
63	0	dctx = dst->data;
64	0	dctx->nbits = sctx->nbits;
65	0	dctx->qbits = sctx->qbits;
66	0	dctx->pmd = sctx->pmd;
67	0	dctx->md = sctx->md;
68	0	return 1;
69	0	}
70
71		static void pkey_dsa_cleanup(EVP_PKEY_CTX *ctx)
72	0	{
73	0	DSA_PKEY_CTX *dctx = ctx->data;
74	0	OPENSSL_free(dctx);
75	0	}
76
77		static int pkey_dsa_sign(EVP_PKEY_CTX ctx, unsigned char sig,
78		size_t siglen, const unsigned char tbs,
79		size_t tbslen)
80	0	{
81	0	int ret, md_size;
82	0	unsigned int sltmp;
83	0	DSA_PKEY_CTX *dctx = ctx->data;
84		/*
85		* Discard const. Its marked as const because this may be a cached copy of
86		* the "real" key. These calls don't make any modifications that need to
87		* be reflected back in the "original" key.
88		*/
89	0	DSA dsa = (DSA )EVP_PKEY_get0_DSA(ctx->pkey);
90
91	0	if (dctx->md != NULL) {
92	0	md_size = EVP_MD_get_size(dctx->md);
93	0	if (md_size <= 0)
94	0	return 0;
95	0	if (tbslen != (size_t)md_size)
96	0	return 0;
97	0	}
98
99	0	ret = DSA_sign(0, tbs, (int)tbslen, sig, &sltmp, dsa);
100
101	0	if (ret <= 0)
102	0	return ret;
103	0	*siglen = sltmp;
104	0	return 1;
105	0	}
106
107		static int pkey_dsa_verify(EVP_PKEY_CTX *ctx,
108		const unsigned char *sig, size_t siglen,
109		const unsigned char *tbs, size_t tbslen)
110	0	{
111	0	int ret, md_size;
112	0	DSA_PKEY_CTX *dctx = ctx->data;
113		/*
114		* Discard const. Its marked as const because this may be a cached copy of
115		* the "real" key. These calls don't make any modifications that need to
116		* be reflected back in the "original" key.
117		*/
118	0	DSA dsa = (DSA )EVP_PKEY_get0_DSA(ctx->pkey);
119
120	0	if (dctx->md != NULL) {
121	0	md_size = EVP_MD_get_size(dctx->md);
122	0	if (md_size <= 0)
123	0	return 0;
124	0	if (tbslen != (size_t)md_size)
125	0	return 0;
126	0	}
127
128	0	ret = DSA_verify(0, tbs, (int)tbslen, sig, (int)siglen, dsa);
129
130	0	return ret;
131	0	}
132
133		static int pkey_dsa_ctrl(EVP_PKEY_CTX ctx, int type, int p1, void p2)
134	0	{
135	0	DSA_PKEY_CTX *dctx = ctx->data;
136
137	0	switch (type) {
138	0	case EVP_PKEY_CTRL_DSA_PARAMGEN_BITS:
139	0	if (p1 < 256)
140	0	return -2;
141	0	dctx->nbits = p1;
142	0	return 1;
143
144	0	case EVP_PKEY_CTRL_DSA_PARAMGEN_Q_BITS:
145	0	if (p1 != 160 && p1 != 224 && p1 && p1 != 256)
146	0	return -2;
147	0	dctx->qbits = p1;
148	0	return 1;
149
150	0	case EVP_PKEY_CTRL_DSA_PARAMGEN_MD:
151	0	if (EVP_MD_get_type((const EVP_MD *)p2) != NID_sha1 &&
152	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha224 &&
153	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha256) {
154	0	ERR_raise(ERR_LIB_DSA, DSA_R_INVALID_DIGEST_TYPE);
155	0	return 0;
156	0	}
157	0	dctx->pmd = p2;
158	0	return 1;
159
160	0	case EVP_PKEY_CTRL_MD:
161	0	if (EVP_MD_get_type((const EVP_MD *)p2) != NID_sha1 &&
162	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_dsa &&
163	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_dsaWithSHA &&
164	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha224 &&
165	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha256 &&
166	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha384 &&
167	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha512 &&
168	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_224 &&
169	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_256 &&
170	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_384 &&
171	0	EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_512) {
172	0	ERR_raise(ERR_LIB_DSA, DSA_R_INVALID_DIGEST_TYPE);
173	0	return 0;
174	0	}
175	0	dctx->md = p2;
176	0	return 1;
177
178	0	case EVP_PKEY_CTRL_GET_MD:
179	0	(const EVP_MD *)p2 = dctx->md;
180	0	return 1;
181
182	0	case EVP_PKEY_CTRL_DIGESTINIT:
183	0	case EVP_PKEY_CTRL_PKCS7_SIGN:
184	0	case EVP_PKEY_CTRL_CMS_SIGN:
185	0	return 1;
186
187	0	case EVP_PKEY_CTRL_PEER_KEY:
188	0	ERR_raise(ERR_LIB_DSA, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
189	0	return -2;
190	0	default:
191	0	return -2;
192
193	0	}
194	0	}
195
196		static int pkey_dsa_ctrl_str(EVP_PKEY_CTX *ctx,
197		const char type, const char value)
198	0	{
199	0	if (strcmp(type, "dsa_paramgen_bits") == 0) {
200	0	int nbits;
201	0	nbits = atoi(value);
202	0	return EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, nbits);
203	0	}
204	0	if (strcmp(type, "dsa_paramgen_q_bits") == 0) {
205	0	int qbits = atoi(value);
206	0	return EVP_PKEY_CTX_set_dsa_paramgen_q_bits(ctx, qbits);
207	0	}
208	0	if (strcmp(type, "dsa_paramgen_md") == 0) {
209	0	const EVP_MD *md = EVP_get_digestbyname(value);
210
211	0	if (md == NULL) {
212	0	ERR_raise(ERR_LIB_DSA, DSA_R_INVALID_DIGEST_TYPE);
213	0	return 0;
214	0	}
215	0	return EVP_PKEY_CTX_set_dsa_paramgen_md(ctx, md);
216	0	}
217	0	return -2;
218	0	}
219
220		static int pkey_dsa_paramgen(EVP_PKEY_CTX ctx, EVP_PKEY pkey)
221	0	{
222	0	DSA *dsa = NULL;
223	0	DSA_PKEY_CTX *dctx = ctx->data;
224	0	BN_GENCB *pcb;
225	0	int ret, res;
226
227	0	if (ctx->pkey_gencb) {
228	0	pcb = BN_GENCB_new();
229	0	if (pcb == NULL)
230	0	return 0;
231	0	evp_pkey_set_cb_translate(pcb, ctx);
232	0	} else
233	0	pcb = NULL;
234	0	dsa = DSA_new();
235	0	if (dsa == NULL) {
236	0	BN_GENCB_free(pcb);
237	0	return 0;
238	0	}
239	0	if (dctx->md != NULL)
240	0	ossl_ffc_set_digest(&dsa->params, EVP_MD_get0_name(dctx->md), NULL);
241
242	0	ret = ossl_ffc_params_FIPS186_4_generate(NULL, &dsa->params,
243	0	FFC_PARAM_TYPE_DSA, dctx->nbits,
244	0	dctx->qbits, &res, pcb);
245	0	BN_GENCB_free(pcb);
246	0	if (ret > 0)
247	0	EVP_PKEY_assign_DSA(pkey, dsa);
248	0	else
249	0	DSA_free(dsa);
250	0	return ret;
251	0	}
252
253		static int pkey_dsa_keygen(EVP_PKEY_CTX ctx, EVP_PKEY pkey)
254	0	{
255	0	DSA *dsa = NULL;
256
257	0	if (ctx->pkey == NULL) {
258	0	ERR_raise(ERR_LIB_DSA, DSA_R_NO_PARAMETERS_SET);
259	0	return 0;
260	0	}
261	0	dsa = DSA_new();
262	0	if (dsa == NULL)
263	0	return 0;
264	0	EVP_PKEY_assign_DSA(pkey, dsa);
265		/* Note: if error return, pkey is freed by parent routine */
266	0	if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
267	0	return 0;
268	0	return DSA_generate_key((DSA *)EVP_PKEY_get0_DSA(pkey));
269	0	}
270
271		static const EVP_PKEY_METHOD dsa_pkey_meth = {
272		EVP_PKEY_DSA,
273		EVP_PKEY_FLAG_AUTOARGLEN,
274		pkey_dsa_init,
275		pkey_dsa_copy,
276		pkey_dsa_cleanup,
277
278		0,
279		pkey_dsa_paramgen,
280
281		0,
282		pkey_dsa_keygen,
283
284		0,
285		pkey_dsa_sign,
286
287		0,
288		pkey_dsa_verify,
289
290		0, 0,
291
292		0, 0, 0, 0,
293
294		0, 0,
295
296		0, 0,
297
298		0, 0,
299
300		pkey_dsa_ctrl,
301		pkey_dsa_ctrl_str
302		};
303
304		const EVP_PKEY_METHOD *ossl_dsa_pkey_method(void)
305	0	{
306	0	return &dsa_pkey_meth;
307	0	}